PaperMC/feature-patches/1059-Moonrise-optimisation-patches.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Fri, 14 Jun 2024 11:57:26 -0700
Subject: [PATCH] Moonrise optimisation patches

Currently includes:
 - Starlight + Chunk System
 - Entity tracker optimisations
 - Collision optimisations
 - Random block ticking optimisations
 - Chunk tick iteration optimisations
 - Bitstorage optimisations
 - Block/Biome Palette read optimisations
 - StateHolder (BlockState/FluidState) property access optimisations
 - Basic Fluid property read optimisations
 - Entity/Level random replacement

See https://github.com/Tuinity/Moonrise

diff --git a/src/main/java/ca/spottedleaf/moonrise/common/misc/NearbyPlayers.java b/src/main/java/ca/spottedleaf/moonrise/common/misc/NearbyPlayers.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/common/misc/NearbyPlayers.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.common.misc;
+
+import ca.spottedleaf.moonrise.common.list.ReferenceList;
+import ca.spottedleaf.moonrise.common.util.CoordinateUtils;
+import ca.spottedleaf.moonrise.common.util.MoonriseConstants;
+import ca.spottedleaf.moonrise.common.util.ChunkSystem;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkData;
+import ca.spottedleaf.moonrise.patches.chunk_tick_iteration.ChunkTickConstants;
+import ca.spottedleaf.moonrise.patches.chunk_tick_iteration.ChunkTickServerLevel;
+import it.unimi.dsi.fastutil.longs.Long2ReferenceOpenHashMap;
+import it.unimi.dsi.fastutil.objects.Reference2ReferenceOpenHashMap;
+import net.minecraft.core.BlockPos;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.level.ChunkPos;
+import java.util.ArrayList;
+
+public final class NearbyPlayers {
+
+    public static enum NearbyMapType {
+        GENERAL,
+        GENERAL_SMALL,
+        GENERAL_REALLY_SMALL,
+        TICK_VIEW_DISTANCE,
+        VIEW_DISTANCE,
+        // Moonrise start - chunk tick iteration
+        SPAWN_RANGE {
+            @Override
+            void addTo(final ServerPlayer player, final ServerLevel world, final int chunkX, final int chunkZ) {
+                ((ChunkTickServerLevel)world).moonrise$addPlayerTickingRequest(chunkX, chunkZ);
+            }
+
+            @Override
+            void removeFrom(final ServerPlayer player, final ServerLevel world, final int chunkX, final int chunkZ) {
+                ((ChunkTickServerLevel)world).moonrise$removePlayerTickingRequest(chunkX, chunkZ);
+            }
+        };
+        // Moonrise end - chunk tick iteration
+
+        void addTo(final ServerPlayer player, final ServerLevel world, final int chunkX, final int chunkZ) {
+
+        }
+
+        void removeFrom(final ServerPlayer player, final ServerLevel world, final int chunkX, final int chunkZ) {
+
+        }
+    }
+
+    private static final NearbyMapType[] MAP_TYPES = NearbyMapType.values();
+    public static final int TOTAL_MAP_TYPES = MAP_TYPES.length;
+
+    private static final int GENERAL_AREA_VIEW_DISTANCE = MoonriseConstants.MAX_VIEW_DISTANCE + 1;
+    private static final int GENERAL_SMALL_VIEW_DISTANCE = 10;
+    private static final int GENERAL_REALLY_SMALL_VIEW_DISTANCE = 3;
+
+    public static final int GENERAL_AREA_VIEW_DISTANCE_BLOCKS = (GENERAL_AREA_VIEW_DISTANCE << 4);
+    public static final int GENERAL_SMALL_AREA_VIEW_DISTANCE_BLOCKS = (GENERAL_SMALL_VIEW_DISTANCE << 4);
+    public static final int GENERAL_REALLY_SMALL_AREA_VIEW_DISTANCE_BLOCKS = (GENERAL_REALLY_SMALL_VIEW_DISTANCE << 4);
+
+    private final ServerLevel world;
+    private final Reference2ReferenceOpenHashMap<ServerPlayer, TrackedPlayer[]> players = new Reference2ReferenceOpenHashMap<>();
+    private final Long2ReferenceOpenHashMap<TrackedChunk> byChunk = new Long2ReferenceOpenHashMap<>();
+    private final Long2ReferenceOpenHashMap<ReferenceList<ServerPlayer>>[] directByChunk = new Long2ReferenceOpenHashMap[TOTAL_MAP_TYPES];
+    {
+        for (int i = 0; i < this.directByChunk.length; ++i) {
+            this.directByChunk[i] = new Long2ReferenceOpenHashMap<>();
+        }
+    }
+
+    public NearbyPlayers(final ServerLevel world) {
+        this.world = world;
+    }
+
+    public void addPlayer(final ServerPlayer player) {
+        final TrackedPlayer[] newTrackers = new TrackedPlayer[TOTAL_MAP_TYPES];
+        if (this.players.putIfAbsent(player, newTrackers) != null) {
+            throw new IllegalStateException("Already have player " + player);
+        }
+
+        final ChunkPos chunk = player.chunkPosition();
+
+        for (int i = 0; i < TOTAL_MAP_TYPES; ++i) {
+            // use 0 for default, will be updated by tickPlayer
+            (newTrackers[i] = new TrackedPlayer(player, MAP_TYPES[i])).add(chunk.x, chunk.z, 0);
+        }
+
+        // update view distances
+        this.tickPlayer(player);
+    }
+
+    public void removePlayer(final ServerPlayer player) {
+        final TrackedPlayer[] players = this.players.remove(player);
+        if (players == null) {
+            return; // May be called during teleportation before the player is actually placed
+        }
+
+        for (final TrackedPlayer tracker : players) {
+            tracker.remove();
+        }
+    }
+
+    public void clear() {
+        if (this.players.isEmpty()) {
+            return;
+        }
+
+        for (final ServerPlayer player : new ArrayList<>(this.players.keySet())) {
+            this.removePlayer(player);
+        }
+    }
+
+    public void tickPlayer(final ServerPlayer player) {
+        final TrackedPlayer[] players = this.players.get(player);
+        if (players == null) {
+            throw new IllegalStateException("Don't have player " + player);
+        }
+
+        final ChunkPos chunk = player.chunkPosition();
+
+        players[NearbyMapType.GENERAL.ordinal()].update(chunk.x, chunk.z, GENERAL_AREA_VIEW_DISTANCE);
+        players[NearbyMapType.GENERAL_SMALL.ordinal()].update(chunk.x, chunk.z, GENERAL_SMALL_VIEW_DISTANCE);
+        players[NearbyMapType.GENERAL_REALLY_SMALL.ordinal()].update(chunk.x, chunk.z, GENERAL_REALLY_SMALL_VIEW_DISTANCE);
+        players[NearbyMapType.TICK_VIEW_DISTANCE.ordinal()].update(chunk.x, chunk.z, ChunkSystem.getTickViewDistance(player));
+        players[NearbyMapType.VIEW_DISTANCE.ordinal()].update(chunk.x, chunk.z, ChunkSystem.getViewDistance(player));
+        players[NearbyMapType.SPAWN_RANGE.ordinal()].update(chunk.x, chunk.z, ChunkTickConstants.PLAYER_SPAWN_TRACK_RANGE); // Moonrise - chunk tick iteration
+    }
+
+    public TrackedChunk getChunk(final ChunkPos pos) {
+        return this.byChunk.get(CoordinateUtils.getChunkKey(pos));
+    }
+
+    public TrackedChunk getChunk(final BlockPos pos) {
+        return this.byChunk.get(CoordinateUtils.getChunkKey(pos));
+    }
+
+    public TrackedChunk getChunk(final int chunkX, final int chunkZ) {
+        return this.byChunk.get(CoordinateUtils.getChunkKey(chunkX, chunkZ));
+    }
+
+    public ReferenceList<ServerPlayer> getPlayers(final BlockPos pos, final NearbyMapType type) {
+        return this.directByChunk[type.ordinal()].get(CoordinateUtils.getChunkKey(pos));
+    }
+
+    public ReferenceList<ServerPlayer> getPlayers(final ChunkPos pos, final NearbyMapType type) {
+        return this.directByChunk[type.ordinal()].get(CoordinateUtils.getChunkKey(pos));
+    }
+
+    public ReferenceList<ServerPlayer> getPlayersByChunk(final int chunkX, final int chunkZ, final NearbyMapType type) {
+        return this.directByChunk[type.ordinal()].get(CoordinateUtils.getChunkKey(chunkX, chunkZ));
+    }
+
+    public ReferenceList<ServerPlayer> getPlayersByBlock(final int blockX, final int blockZ, final NearbyMapType type) {
+        return this.directByChunk[type.ordinal()].get(CoordinateUtils.getChunkKey(blockX >> 4, blockZ >> 4));
+    }
+
+    public static final class TrackedChunk {
+
+        private static final ServerPlayer[] EMPTY_PLAYERS_ARRAY = new ServerPlayer[0];
+
+        private final long chunkKey;
+        private final NearbyPlayers nearbyPlayers;
+        private final ReferenceList<ServerPlayer>[] players = new ReferenceList[TOTAL_MAP_TYPES];
+        private int nonEmptyLists;
+        private long updateCount;
+
+        public TrackedChunk(final long chunkKey, final NearbyPlayers nearbyPlayers) {
+            this.chunkKey = chunkKey;
+            this.nearbyPlayers = nearbyPlayers;
+        }
+
+        public boolean isEmpty() {
+            return this.nonEmptyLists == 0;
+        }
+
+        public long getUpdateCount() {
+            return this.updateCount;
+        }
+
+        public ReferenceList<ServerPlayer> getPlayers(final NearbyMapType type) {
+            return this.players[type.ordinal()];
+        }
+
+        public void addPlayer(final ServerPlayer player, final NearbyMapType type) {
+            ++this.updateCount;
+
+            final int idx = type.ordinal();
+            final ReferenceList<ServerPlayer> list = this.players[idx];
+            if (list == null) {
+                ++this.nonEmptyLists;
+                final ReferenceList<ServerPlayer> players = (this.players[idx] = new ReferenceList<>(EMPTY_PLAYERS_ARRAY));
+                this.nearbyPlayers.directByChunk[idx].put(this.chunkKey, players);
+                players.add(player);
+                return;
+            }
+
+            if (!list.add(player)) {
+                throw new IllegalStateException("Already contains player " + player);
+            }
+        }
+
+        public void removePlayer(final ServerPlayer player, final NearbyMapType type) {
+            ++this.updateCount;
+
+            final int idx = type.ordinal();
+            final ReferenceList<ServerPlayer> list = this.players[idx];
+            if (list == null) {
+                throw new IllegalStateException("Does not contain player " + player);
+            }
+
+            if (!list.remove(player)) {
+                throw new IllegalStateException("Does not contain player " + player);
+            }
+
+            if (list.size() == 0) {
+                this.players[idx] = null;
+                this.nearbyPlayers.directByChunk[idx].remove(this.chunkKey);
+                --this.nonEmptyLists;
+            }
+        }
+    }
+
+    private final class TrackedPlayer extends SingleUserAreaMap<ServerPlayer> {
+
+        private final NearbyMapType type;
+
+        public TrackedPlayer(final ServerPlayer player, final NearbyMapType type) {
+            super(player);
+            this.type = type;
+        }
+
+        @Override
+        protected void addCallback(final ServerPlayer parameter, final int chunkX, final int chunkZ) {
+            final long chunkKey = CoordinateUtils.getChunkKey(chunkX, chunkZ);
+
+            final TrackedChunk chunk = NearbyPlayers.this.byChunk.get(chunkKey);
+            final NearbyMapType type = this.type;
+            if (chunk != null) {
+                chunk.addPlayer(parameter, type);
+                type.addTo(parameter, NearbyPlayers.this.world, chunkX, chunkZ);
+            } else {
+                final TrackedChunk created = new TrackedChunk(chunkKey, NearbyPlayers.this);
+                NearbyPlayers.this.byChunk.put(chunkKey, created);
+                created.addPlayer(parameter, type);
+                type.addTo(parameter, NearbyPlayers.this.world, chunkX, chunkZ);
+
+                ((ChunkSystemLevel)NearbyPlayers.this.world).moonrise$requestChunkData(chunkKey).nearbyPlayers = created;
+            }
+        }
+
+        @Override
+        protected void removeCallback(final ServerPlayer parameter, final int chunkX, final int chunkZ) {
+            final long chunkKey = CoordinateUtils.getChunkKey(chunkX, chunkZ);
+
+            final TrackedChunk chunk = NearbyPlayers.this.byChunk.get(chunkKey);
+            if (chunk == null) {
+                throw new IllegalStateException("Chunk should exist at " + new ChunkPos(chunkKey));
+            }
+
+            final NearbyMapType type = this.type;
+            chunk.removePlayer(parameter, type);
+            type.removeFrom(parameter, NearbyPlayers.this.world, chunkX, chunkZ);
+
+            if (chunk.isEmpty()) {
+                NearbyPlayers.this.byChunk.remove(chunkKey);
+                final ChunkData chunkData = ((ChunkSystemLevel)NearbyPlayers.this.world).moonrise$releaseChunkData(chunkKey);
+                if (chunkData != null) {
+                    chunkData.nearbyPlayers = null;
+                }
+            }
+        }
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/common/util/ChunkSystem.java b/src/main/java/ca/spottedleaf/moonrise/common/util/ChunkSystem.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/ca/spottedleaf/moonrise/common/util/ChunkSystem.java
+++ b/src/main/java/ca/spottedleaf/moonrise/common/util/ChunkSystem.java
@@ -0,0 +0,0 @@ package ca.spottedleaf.moonrise.common.util;
 
 import ca.spottedleaf.concurrentutil.util.Priority;
 import ca.spottedleaf.moonrise.common.PlatformHooks;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemLevelChunk;
+import ca.spottedleaf.moonrise.patches.chunk_system.player.RegionizedPlayerChunkLoader;
+import ca.spottedleaf.moonrise.patches.chunk_system.world.ChunkSystemServerChunkCache;
+import ca.spottedleaf.moonrise.patches.chunk_tick_iteration.ChunkTickServerLevel;
 import com.mojang.logging.LogUtils;
 import net.minecraft.server.level.ChunkHolder;
 import net.minecraft.server.level.FullChunkStatus;
 import net.minecraft.server.level.ServerLevel;
 import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.server.level.progress.ChunkProgressListener;
 import net.minecraft.world.entity.Entity;
 import net.minecraft.world.level.chunk.ChunkAccess;
 import net.minecraft.world.level.chunk.LevelChunk;
@@ -0,0 +0,0 @@ import java.util.function.Consumer;
 public final class ChunkSystem {
 
     private static final Logger LOGGER = LogUtils.getLogger();
-    private static final net.minecraft.world.level.chunk.status.ChunkStep FULL_CHUNK_STEP = net.minecraft.world.level.chunk.status.ChunkPyramid.GENERATION_PYRAMID.getStepTo(ChunkStatus.FULL);
-
-    private static int getDistance(final ChunkStatus status) {
-        return FULL_CHUNK_STEP.getAccumulatedRadiusOf(status);
-    }
 
     public static void scheduleChunkTask(final ServerLevel level, final int chunkX, final int chunkZ, final Runnable run) {
         scheduleChunkTask(level, chunkX, chunkZ, run, Priority.NORMAL);
     }
 
     public static void scheduleChunkTask(final ServerLevel level, final int chunkX, final int chunkZ, final Runnable run, final Priority priority) {
-        level.chunkSource.mainThreadProcessor.execute(run);
+        ((ChunkSystemServerLevel)level).moonrise$getChunkTaskScheduler().scheduleChunkTask(chunkX, chunkZ, run, priority);
     }
 
     public static void scheduleChunkLoad(final ServerLevel level, final int chunkX, final int chunkZ, final boolean gen,
                                          final ChunkStatus toStatus, final boolean addTicket, final Priority priority,
                                          final Consumer<ChunkAccess> onComplete) {
-        if (gen) {
-            scheduleChunkLoad(level, chunkX, chunkZ, toStatus, addTicket, priority, onComplete);
-            return;
-        }
-        scheduleChunkLoad(level, chunkX, chunkZ, ChunkStatus.EMPTY, addTicket, priority, (final ChunkAccess chunk) -> {
-            if (chunk == null) {
-                if (onComplete != null) {
-                    onComplete.accept(null);
-                }
-            } else {
-                if (chunk.getPersistedStatus().isOrAfter(toStatus)) {
-                    scheduleChunkLoad(level, chunkX, chunkZ, toStatus, addTicket, priority, onComplete);
-                } else {
-                    if (onComplete != null) {
-                        onComplete.accept(null);
-                    }
-                }
-            }
-        });
+        ((ChunkSystemServerLevel)level).moonrise$getChunkTaskScheduler().scheduleChunkLoad(chunkX, chunkZ, gen, toStatus, addTicket, priority, onComplete);
     }
 
-    static final net.minecraft.server.level.TicketType<Long> CHUNK_LOAD = net.minecraft.server.level.TicketType.create("chunk_load", Long::compareTo);
-
-    private static long chunkLoadCounter = 0L;
     public static void scheduleChunkLoad(final ServerLevel level, final int chunkX, final int chunkZ, final ChunkStatus toStatus,
                                          final boolean addTicket, final Priority priority, final Consumer<ChunkAccess> onComplete) {
-        if (!org.bukkit.Bukkit.isOwnedByCurrentRegion(level.getWorld(), chunkX, chunkZ)) {
-            scheduleChunkTask(level, chunkX, chunkZ, () -> {
-                scheduleChunkLoad(level, chunkX, chunkZ, toStatus, addTicket, priority, onComplete);
-            }, priority);
-            return;
-        }
-
-        final int minLevel = 33 + getDistance(toStatus);
-        final Long chunkReference = addTicket ? Long.valueOf(++chunkLoadCounter) : null;
-        final net.minecraft.world.level.ChunkPos chunkPos = new net.minecraft.world.level.ChunkPos(chunkX, chunkZ);
-
-        if (addTicket) {
-            level.chunkSource.addTicketAtLevel(CHUNK_LOAD, chunkPos, minLevel, chunkReference);
-        }
-        level.chunkSource.runDistanceManagerUpdates();
-
-        final Consumer<ChunkAccess> loadCallback = (final ChunkAccess chunk) -> {
-            try {
-                if (onComplete != null) {
-                    onComplete.accept(chunk);
-                }
-            } catch (final Throwable thr) {
-                LOGGER.error("Exception handling chunk load callback", thr);
-                com.destroystokyo.paper.util.SneakyThrow.sneaky(thr);
-            } finally {
-                if (addTicket) {
-                    level.chunkSource.addTicketAtLevel(net.minecraft.server.level.TicketType.UNKNOWN, chunkPos, minLevel, chunkPos);
-                    level.chunkSource.removeTicketAtLevel(CHUNK_LOAD, chunkPos, minLevel, chunkReference);
-                }
-            }
-        };
-
-        final ChunkHolder holder = level.chunkSource.chunkMap.updatingChunkMap.get(CoordinateUtils.getChunkKey(chunkX, chunkZ));
-
-        if (holder == null || holder.getTicketLevel() > minLevel) {
-            loadCallback.accept(null);
-            return;
-        }
-
-        final java.util.concurrent.CompletableFuture<net.minecraft.server.level.ChunkResult<net.minecraft.world.level.chunk.ChunkAccess>> loadFuture = holder.scheduleChunkGenerationTask(toStatus, level.chunkSource.chunkMap);
-
-        if (loadFuture.isDone()) {
-            loadCallback.accept(loadFuture.join().orElse(null));
-            return;
-        }
-
-        loadFuture.whenCompleteAsync((final net.minecraft.server.level.ChunkResult<net.minecraft.world.level.chunk.ChunkAccess> result, final Throwable thr) -> {
-            if (thr != null) {
-                loadCallback.accept(null);
-                return;
-            }
-            loadCallback.accept(result.orElse(null));
-        }, (final Runnable r) -> {
-            scheduleChunkTask(level, chunkX, chunkZ, r, Priority.HIGHEST);
-        });
+        ((ChunkSystemServerLevel)level).moonrise$getChunkTaskScheduler().scheduleChunkLoad(chunkX, chunkZ, toStatus, addTicket, priority, onComplete);
     }
 
     public static void scheduleTickingState(final ServerLevel level, final int chunkX, final int chunkZ,
                                             final FullChunkStatus toStatus, final boolean addTicket,
                                             final Priority priority, final Consumer<LevelChunk> onComplete) {
-        // This method goes unused until the chunk system rewrite
-        if (toStatus == FullChunkStatus.INACCESSIBLE) {
-            throw new IllegalArgumentException("Cannot wait for INACCESSIBLE status");
-        }
-
-        if (!org.bukkit.Bukkit.isOwnedByCurrentRegion(level.getWorld(), chunkX, chunkZ)) {
-            scheduleChunkTask(level, chunkX, chunkZ, () -> {
-                scheduleTickingState(level, chunkX, chunkZ, toStatus, addTicket, priority, onComplete);
-            }, priority);
-            return;
-        }
-
-        final int minLevel = 33 - (toStatus.ordinal() - 1);
-        final int radius = toStatus.ordinal() - 1;
-        final Long chunkReference = addTicket ? Long.valueOf(++chunkLoadCounter) : null;
-        final net.minecraft.world.level.ChunkPos chunkPos = new net.minecraft.world.level.ChunkPos(chunkX, chunkZ);
-
-        if (addTicket) {
-            level.chunkSource.addTicketAtLevel(CHUNK_LOAD, chunkPos, minLevel, chunkReference);
-        }
-        level.chunkSource.runDistanceManagerUpdates();
-
-        final Consumer<LevelChunk> loadCallback = (final LevelChunk chunk) -> {
-            try {
-                if (onComplete != null) {
-                    onComplete.accept(chunk);
-                }
-            } catch (final Throwable thr) {
-                LOGGER.error("Exception handling chunk load callback", thr);
-                com.destroystokyo.paper.util.SneakyThrow.sneaky(thr);
-            } finally {
-                if (addTicket) {
-                    level.chunkSource.addTicketAtLevel(net.minecraft.server.level.TicketType.UNKNOWN, chunkPos, minLevel, chunkPos);
-                    level.chunkSource.removeTicketAtLevel(CHUNK_LOAD, chunkPos, minLevel, chunkReference);
-                }
-            }
-        };
-
-        final ChunkHolder holder = level.chunkSource.chunkMap.updatingChunkMap.get(CoordinateUtils.getChunkKey(chunkX, chunkZ));
-
-        if (holder == null || holder.getTicketLevel() > minLevel) {
-            loadCallback.accept(null);
-            return;
-        }
-
-        final java.util.concurrent.CompletableFuture<net.minecraft.server.level.ChunkResult<net.minecraft.world.level.chunk.LevelChunk>> tickingState;
-        switch (toStatus) {
-            case FULL: {
-                tickingState = holder.getFullChunkFuture();
-                break;
-            }
-            case BLOCK_TICKING: {
-                tickingState = holder.getTickingChunkFuture();
-                break;
-            }
-            case ENTITY_TICKING: {
-                tickingState = holder.getEntityTickingChunkFuture();
-                break;
-            }
-            default: {
-                throw new IllegalStateException("Cannot reach here");
-            }
-        }
-
-        if (tickingState.isDone()) {
-            loadCallback.accept(tickingState.join().orElse(null));
-            return;
-        }
-
-        tickingState.whenCompleteAsync((final net.minecraft.server.level.ChunkResult<net.minecraft.world.level.chunk.LevelChunk> result, final Throwable thr) -> {
-            if (thr != null) {
-                loadCallback.accept(null);
-                return;
-            }
-            loadCallback.accept(result.orElse(null));
-        }, (final Runnable r) -> {
-            scheduleChunkTask(level, chunkX, chunkZ, r, Priority.HIGHEST);
-        });
+        ((ChunkSystemServerLevel)level).moonrise$getChunkTaskScheduler().scheduleTickingState(chunkX, chunkZ, toStatus, addTicket, priority, onComplete);
     }
 
     public static List<ChunkHolder> getVisibleChunkHolders(final ServerLevel level) {
-        return new java.util.ArrayList<>(level.chunkSource.chunkMap.visibleChunkMap.values());
+        return ((ChunkSystemServerLevel)level).moonrise$getChunkTaskScheduler().chunkHolderManager.getOldChunkHolders();
     }
 
     public static List<ChunkHolder> getUpdatingChunkHolders(final ServerLevel level) {
-        return new java.util.ArrayList<>(level.chunkSource.chunkMap.updatingChunkMap.values());
+        return ((ChunkSystemServerLevel)level).moonrise$getChunkTaskScheduler().chunkHolderManager.getOldChunkHolders();
     }
 
     public static int getVisibleChunkHolderCount(final ServerLevel level) {
-        return level.chunkSource.chunkMap.visibleChunkMap.size();
+        return ((ChunkSystemServerLevel)level).moonrise$getChunkTaskScheduler().chunkHolderManager.size();
     }
 
     public static int getUpdatingChunkHolderCount(final ServerLevel level) {
-        return level.chunkSource.chunkMap.updatingChunkMap.size();
+        return ((ChunkSystemServerLevel)level).moonrise$getChunkTaskScheduler().chunkHolderManager.size();
     }
 
     public static boolean hasAnyChunkHolders(final ServerLevel level) {
@@ -0,0 +0,0 @@ public final class ChunkSystem {
     }
 
     public static void onChunkHolderDelete(final ServerLevel level, final ChunkHolder holder) {
+        // Update progress listener for LevelLoadingScreen
+        final ChunkProgressListener progressListener = level.getChunkSource().chunkMap.progressListener;
+        if (progressListener != null) {
+            ChunkSystem.scheduleChunkTask(level, holder.getPos().x, holder.getPos().z, () -> {
+                progressListener.onStatusChange(holder.getPos(), null);
+            });
+        }
+    }
 
+    public static void onChunkPreBorder(final LevelChunk chunk, final ChunkHolder holder) {
+        ((ChunkSystemServerChunkCache)((ServerLevel)chunk.getLevel()).getChunkSource())
+                .moonrise$setFullChunk(chunk.getPos().x, chunk.getPos().z, chunk);
     }
 
     public static void onChunkBorder(final LevelChunk chunk, final ChunkHolder holder) {
-
+        ((ChunkSystemServerLevel)((ServerLevel)chunk.getLevel())).moonrise$getLoadedChunks().add(
+                ((ChunkSystemLevelChunk)chunk).moonrise$getChunkAndHolder()
+        );
+        chunk.loadCallback();
     }
 
     public static void onChunkNotBorder(final LevelChunk chunk, final ChunkHolder holder) {
+        ((ChunkSystemServerLevel)((ServerLevel)chunk.getLevel())).moonrise$getLoadedChunks().remove(
+                ((ChunkSystemLevelChunk)chunk).moonrise$getChunkAndHolder()
+        );
+        chunk.unloadCallback();
+    }
 
+    public static void onChunkPostNotBorder(final LevelChunk chunk, final ChunkHolder holder) {
+        ((ChunkSystemServerChunkCache)((ServerLevel)chunk.getLevel()).getChunkSource())
+                .moonrise$setFullChunk(chunk.getPos().x, chunk.getPos().z, null);
     }
 
     public static void onChunkTicking(final LevelChunk chunk, final ChunkHolder holder) {
-
+        ((ChunkSystemServerLevel)((ServerLevel)chunk.getLevel())).moonrise$getTickingChunks().add(
+                ((ChunkSystemLevelChunk)chunk).moonrise$getChunkAndHolder()
+        );
+        if (!((ChunkSystemLevelChunk)chunk).moonrise$isPostProcessingDone()) {
+            chunk.postProcessGeneration((ServerLevel)chunk.getLevel());
+        }
+        ((ServerLevel)chunk.getLevel()).startTickingChunk(chunk);
+        ((ServerLevel)chunk.getLevel()).getChunkSource().chunkMap.tickingGenerated.incrementAndGet();
+        ((ChunkTickServerLevel)(ServerLevel)chunk.getLevel()).moonrise$markChunkForPlayerTicking(chunk); // Moonrise - chunk tick iteration
     }
 
     public static void onChunkNotTicking(final LevelChunk chunk, final ChunkHolder holder) {
-
+        ((ChunkSystemServerLevel)((ServerLevel)chunk.getLevel())).moonrise$getTickingChunks().remove(
+                ((ChunkSystemLevelChunk)chunk).moonrise$getChunkAndHolder()
+        );
+        ((ChunkTickServerLevel)(ServerLevel)chunk.getLevel()).moonrise$removeChunkForPlayerTicking(chunk); // Moonrise - chunk tick iteration
     }
 
     public static void onChunkEntityTicking(final LevelChunk chunk, final ChunkHolder holder) {
-
+        ((ChunkSystemServerLevel)((ServerLevel)chunk.getLevel())).moonrise$getEntityTickingChunks().add(
+                ((ChunkSystemLevelChunk)chunk).moonrise$getChunkAndHolder()
+        );
     }
 
     public static void onChunkNotEntityTicking(final LevelChunk chunk, final ChunkHolder holder) {
-
+        ((ChunkSystemServerLevel)((ServerLevel)chunk.getLevel())).moonrise$getEntityTickingChunks().remove(
+                ((ChunkSystemLevelChunk)chunk).moonrise$getChunkAndHolder()
+        );
     }
 
     public static ChunkHolder getUnloadingChunkHolder(final ServerLevel level, final int chunkX, final int chunkZ) {
-        return level.chunkSource.chunkMap.getUnloadingChunkHolder(chunkX, chunkZ);
+        return null;
     }
 
     public static int getSendViewDistance(final ServerPlayer player) {
-        return getViewDistance(player);
+        return RegionizedPlayerChunkLoader.getAPISendViewDistance(player);
     }
 
     public static int getViewDistance(final ServerPlayer player) {
-        final ServerLevel level = player.serverLevel();
-        if (level == null) {
-            return org.bukkit.Bukkit.getViewDistance();
-        }
-        return level.chunkSource.chunkMap.serverViewDistance;
+        return RegionizedPlayerChunkLoader.getAPIViewDistance(player);
     }
 
     public static int getTickViewDistance(final ServerPlayer player) {
-        final ServerLevel level = player.serverLevel();
-        if (level == null) {
-            return org.bukkit.Bukkit.getSimulationDistance();
-        }
-        return level.chunkSource.chunkMap.distanceManager.simulationDistance;
+        return RegionizedPlayerChunkLoader.getAPITickViewDistance(player);
+    }
+
+    public static void addPlayerToDistanceMaps(final ServerLevel world, final ServerPlayer player) {
+        ((ChunkSystemServerLevel)world).moonrise$getPlayerChunkLoader().addPlayer(player);
+    }
+
+    public static void removePlayerFromDistanceMaps(final ServerLevel world, final ServerPlayer player) {
+        ((ChunkSystemServerLevel)world).moonrise$getPlayerChunkLoader().removePlayer(player);
+    }
+
+    public static void updateMaps(final ServerLevel world, final ServerPlayer player) {
+        ((ChunkSystemServerLevel)world).moonrise$getPlayerChunkLoader().updatePlayer(player);
     }
 
     private ChunkSystem() {}
diff --git a/src/main/java/ca/spottedleaf/moonrise/common/util/ThreadUnsafeRandom.java b/src/main/java/ca/spottedleaf/moonrise/common/util/ThreadUnsafeRandom.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/ca/spottedleaf/moonrise/common/util/ThreadUnsafeRandom.java
+++ b/src/main/java/ca/spottedleaf/moonrise/common/util/ThreadUnsafeRandom.java
@@ -0,0 +0,0 @@ import net.minecraft.world.level.levelgen.PositionalRandomFactory;
 /**
  * Avoid costly CAS of superclass
  */
-public final class ThreadUnsafeRandom implements BitRandomSource {
+public class ThreadUnsafeRandom implements BitRandomSource { // Paper - replace random
 
     private static final long MULTIPLIER = 25214903917L;
     private static final long ADDEND = 11L;
diff --git a/src/main/java/ca/spottedleaf/moonrise/paper/PaperHooks.java b/src/main/java/ca/spottedleaf/moonrise/paper/PaperHooks.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/ca/spottedleaf/moonrise/paper/PaperHooks.java
+++ b/src/main/java/ca/spottedleaf/moonrise/paper/PaperHooks.java
@@ -0,0 +0,0 @@ public final class PaperHooks implements PlatformHooks {
 
     @Override
     public void postLoadProtoChunk(final ServerLevel world, final ProtoChunk chunk) {
-        net.minecraft.world.level.chunk.status.ChunkStatusTasks.postLoadProtoChunk(world, chunk.getEntities());
+        net.minecraft.world.level.chunk.status.ChunkStatusTasks.postLoadProtoChunk(world, chunk.getEntities(), chunk.getPos()); // Paper - rewrite chunk system - add ChunkPos param
     }
 
     @Override
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/block_counting/BlockCountingBitStorage.java b/src/main/java/ca/spottedleaf/moonrise/patches/block_counting/BlockCountingBitStorage.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/block_counting/BlockCountingBitStorage.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.block_counting;
+
+import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
+import it.unimi.dsi.fastutil.shorts.ShortArrayList;
+
+public interface BlockCountingBitStorage {
+
+    public Int2ObjectOpenHashMap<ShortArrayList> moonrise$countEntries();
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/block_counting/BlockCountingChunkSection.java b/src/main/java/ca/spottedleaf/moonrise/patches/block_counting/BlockCountingChunkSection.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/block_counting/BlockCountingChunkSection.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.block_counting;
+
+import ca.spottedleaf.moonrise.common.list.ShortList;
+
+public interface BlockCountingChunkSection {
+
+    public boolean moonrise$hasSpecialCollidingBlocks();
+
+    public ShortList moonrise$getTickingBlockList();
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/blockstate_propertyaccess/PropertyAccess.java b/src/main/java/ca/spottedleaf/moonrise/patches/blockstate_propertyaccess/PropertyAccess.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/blockstate_propertyaccess/PropertyAccess.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.blockstate_propertyaccess;
+
+public interface PropertyAccess<T> {
+
+    public int moonrise$getId();
+
+    public int moonrise$getIdFor(final T value);
+
+    public T moonrise$getById(final int id);
+
+    public void moonrise$setById(final T[] values);
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/blockstate_propertyaccess/PropertyAccessStateHolder.java b/src/main/java/ca/spottedleaf/moonrise/patches/blockstate_propertyaccess/PropertyAccessStateHolder.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/blockstate_propertyaccess/PropertyAccessStateHolder.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.blockstate_propertyaccess;
+
+public interface PropertyAccessStateHolder {
+
+    public long moonrise$getTableIndex();
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/blockstate_propertyaccess/util/ZeroCollidingReferenceStateTable.java b/src/main/java/ca/spottedleaf/moonrise/patches/blockstate_propertyaccess/util/ZeroCollidingReferenceStateTable.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/blockstate_propertyaccess/util/ZeroCollidingReferenceStateTable.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.blockstate_propertyaccess.util;
+
+import ca.spottedleaf.concurrentutil.util.IntegerUtil;
+import ca.spottedleaf.moonrise.patches.blockstate_propertyaccess.PropertyAccess;
+import ca.spottedleaf.moonrise.patches.blockstate_propertyaccess.PropertyAccessStateHolder;
+import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
+import it.unimi.dsi.fastutil.objects.AbstractObjectSet;
+import it.unimi.dsi.fastutil.objects.AbstractReference2ObjectMap;
+import it.unimi.dsi.fastutil.objects.ObjectIterator;
+import it.unimi.dsi.fastutil.objects.ObjectSet;
+import it.unimi.dsi.fastutil.objects.Reference2ObjectMap;
+import it.unimi.dsi.fastutil.objects.ReferenceArrayList;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import net.minecraft.world.level.block.state.StateHolder;
+import net.minecraft.world.level.block.state.properties.Property;
+
+public final class ZeroCollidingReferenceStateTable<O, S> {
+
+    private final Int2ObjectOpenHashMap<Indexer> propertyToIndexer;
+    private S[] lookup;
+    private final Collection<Property<?>> properties;
+
+    public ZeroCollidingReferenceStateTable(final Collection<Property<?>> properties) {
+        this.propertyToIndexer = new Int2ObjectOpenHashMap<>(properties.size());
+        this.properties = new ReferenceArrayList<>(properties);
+
+        final List<Property<?>> sortedProperties = new ArrayList<>(properties);
+
+        // important that each table sees the same property order given the same _set_ of properties,
+        // as each table will calculate the index for the block state
+        sortedProperties.sort((final Property<?> p1, final Property<?> p2) -> {
+            return Integer.compare(
+                ((PropertyAccess<?>)p1).moonrise$getId(),
+                ((PropertyAccess<?>)p2).moonrise$getId()
+            );
+        });
+
+        int currentMultiple = 1;
+        for (final Property<?> property : sortedProperties) {
+            final int totalValues = property.getPossibleValues().size();
+
+            this.propertyToIndexer.put(
+                ((PropertyAccess<?>)property).moonrise$getId(),
+                new Indexer(
+                    totalValues,
+                    currentMultiple,
+                    IntegerUtil.getUnsignedDivisorMagic((long)currentMultiple, 32),
+                    IntegerUtil.getUnsignedDivisorMagic((long)totalValues, 32)
+                )
+            );
+
+            currentMultiple *= totalValues;
+        }
+    }
+
+    public <T extends Comparable<T>> boolean hasProperty(final Property<T> property) {
+        return this.propertyToIndexer.containsKey(((PropertyAccess<T>)property).moonrise$getId());
+    }
+
+    public long getIndex(final StateHolder<O, S> stateHolder) {
+        long ret = 0L;
+
+        for (final Map.Entry<Property<?>, Comparable<?>> entry : stateHolder.getValues().entrySet()) {
+            final Property<?> property = entry.getKey();
+            final Comparable<?> value = entry.getValue();
+
+            final Indexer indexer = this.propertyToIndexer.get(((PropertyAccess<?>)property).moonrise$getId());
+
+            ret += (((PropertyAccess)property).moonrise$getIdFor(value)) * indexer.multiple;
+        }
+
+        return ret;
+    }
+
+    public boolean isLoaded() {
+        return this.lookup != null;
+    }
+
+    public void loadInTable(final Map<Map<Property<?>, Comparable<?>>, S> universe) {
+        if (this.lookup != null) {
+            throw new IllegalStateException();
+        }
+
+        this.lookup = (S[])new StateHolder[universe.size()];
+
+        for (final Map.Entry<Map<Property<?>, Comparable<?>>, S> entry : universe.entrySet()) {
+            final S value = entry.getValue();
+            if (value == null) {
+                continue;
+            }
+            this.lookup[(int)((PropertyAccessStateHolder)(StateHolder<O, S>)value).moonrise$getTableIndex()] = value;
+        }
+
+        for (final S value : this.lookup) {
+            if (value == null) {
+                throw new IllegalStateException();
+            }
+        }
+    }
+
+    public <T extends Comparable<T>> T get(final long index, final Property<T> property) {
+        final Indexer indexer = this.propertyToIndexer.get(((PropertyAccess<T>)property).moonrise$getId());
+        if (indexer == null) {
+            return null;
+        }
+
+        final long divided = (index * indexer.multipleDivMagic) >>> 32;
+        final long modded = (((divided * indexer.modMagic) & 0xFFFFFFFFL) * indexer.totalValues) >>> 32;
+        // equiv to: divided = index / multiple
+        //           modded = divided % totalValues
+
+        return ((PropertyAccess<T>)property).moonrise$getById((int)modded);
+    }
+
+    public <T extends Comparable<T>> S set(final long index, final Property<T> property, final T with) {
+        final int newValueId = ((PropertyAccess<T>)property).moonrise$getIdFor(with);
+        if (newValueId < 0) {
+            return null;
+        }
+
+        final Indexer indexer = this.propertyToIndexer.get(((PropertyAccess<T>)property).moonrise$getId());
+        if (indexer == null) {
+            return null;
+        }
+
+        final long divided = (index * indexer.multipleDivMagic) >>> 32;
+        final long modded = (((divided * indexer.modMagic) & 0xFFFFFFFFL) * indexer.totalValues) >>> 32;
+        // equiv to: divided = index / multiple
+        //           modded = divided % totalValues
+
+        // subtract out the old value, add in the new
+        final long newIndex = (((long)newValueId - modded) * indexer.multiple) + index;
+
+        return this.lookup[(int)newIndex];
+    }
+
+    public <T extends Comparable<T>> S trySet(final long index, final Property<T> property, final T with, final S dfl) {
+        final Indexer indexer = this.propertyToIndexer.get(((PropertyAccess<T>)property).moonrise$getId());
+        if (indexer == null) {
+            return dfl;
+        }
+
+        final int newValueId = ((PropertyAccess<T>)property).moonrise$getIdFor(with);
+        if (newValueId < 0) {
+            return null;
+        }
+
+        final long divided = (index * indexer.multipleDivMagic) >>> 32;
+        final long modded = (((divided * indexer.modMagic) & 0xFFFFFFFFL) * indexer.totalValues) >>> 32;
+        // equiv to: divided = index / multiple
+        //           modded = divided % totalValues
+
+        // subtract out the old value, add in the new
+        final long newIndex = (((long)newValueId - modded) * indexer.multiple) + index;
+
+        return this.lookup[(int)newIndex];
+    }
+
+    public Collection<Property<?>> getProperties() {
+        return Collections.unmodifiableCollection(this.properties);
+    }
+
+    public Map<Property<?>, Comparable<?>> getMapView(final long stateIndex) {
+        return new MapView(stateIndex);
+    }
+
+    private static final record Indexer(
+        int totalValues, int multiple, long multipleDivMagic, long modMagic
+    ) {}
+
+    private class MapView extends AbstractReference2ObjectMap<Property<?>, Comparable<?>> {
+        private final long stateIndex;
+        private EntrySet entrySet;
+
+        MapView(final long stateIndex) {
+            this.stateIndex = stateIndex;
+        }
+
+        @Override
+        public boolean containsKey(final Object key) {
+            return key instanceof Property<?> prop && ZeroCollidingReferenceStateTable.this.hasProperty(prop);
+        }
+
+        @Override
+        public int size() {
+            return ZeroCollidingReferenceStateTable.this.properties.size();
+        }
+
+        @Override
+        public ObjectSet<Entry<Property<?>, Comparable<?>>> reference2ObjectEntrySet() {
+            if (this.entrySet == null)
+                this.entrySet = new EntrySet();
+            return this.entrySet;
+        }
+
+        @Override
+        public Comparable<?> get(final Object key) {
+            return key instanceof Property<?> prop ? ZeroCollidingReferenceStateTable.this.get(this.stateIndex, prop) : null;
+        }
+
+        class EntrySet extends AbstractObjectSet<Entry<Property<?>, Comparable<?>>> {
+            @Override
+            public ObjectIterator<Reference2ObjectMap.Entry<Property<?>, Comparable<?>>> iterator() {
+                final Iterator<Property<?>> propIterator = ZeroCollidingReferenceStateTable.this.properties.iterator();
+                return new ObjectIterator<>() {
+                    @Override
+                    public boolean hasNext() {
+                        return propIterator.hasNext();
+                    }
+
+                    @Override
+                    public Entry<Property<?>, Comparable<?>> next() {
+                        Property<?> prop = propIterator.next();
+                        return new AbstractReference2ObjectMap.BasicEntry<>(prop, ZeroCollidingReferenceStateTable.this.get(MapView.this.stateIndex, prop));
+                    }
+                };
+            }
+
+            @Override
+            public int size() {
+                return ZeroCollidingReferenceStateTable.this.properties.size();
+            }
+        }
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/ChunkSystemConverters.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/ChunkSystemConverters.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/ChunkSystemConverters.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system;
+
+import ca.spottedleaf.moonrise.common.PlatformHooks;
+import net.minecraft.SharedConstants;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.Tag;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.util.datafix.fixes.References;
+
+public final class ChunkSystemConverters {
+
+    // See SectionStorage#getVersion
+    private static final int DEFAULT_POI_DATA_VERSION = 1945;
+
+    private static final int DEFAULT_ENTITY_CHUNK_DATA_VERSION = -1;
+
+    private static int getCurrentVersion() {
+        return SharedConstants.getCurrentVersion().getDataVersion().getVersion();
+    }
+
+    private static int getDataVersion(final CompoundTag data, final int dfl) {
+        return !data.contains(SharedConstants.DATA_VERSION_TAG, Tag.TAG_ANY_NUMERIC)
+            ? dfl : data.getInt(SharedConstants.DATA_VERSION_TAG);
+    }
+
+    public static CompoundTag convertPoiCompoundTag(final CompoundTag data, final ServerLevel world) {
+        final int dataVersion = getDataVersion(data, DEFAULT_POI_DATA_VERSION);
+
+        return PlatformHooks.get().convertNBT(References.POI_CHUNK, world.getServer().getFixerUpper(), data, dataVersion, getCurrentVersion());
+    }
+
+    public static CompoundTag convertEntityChunkCompoundTag(final CompoundTag data, final ServerLevel world) {
+        final int dataVersion = getDataVersion(data, DEFAULT_ENTITY_CHUNK_DATA_VERSION);
+
+        return PlatformHooks.get().convertNBT(References.ENTITY_CHUNK, world.getServer().getFixerUpper(), data, dataVersion, getCurrentVersion());
+    }
+
+    private ChunkSystemConverters() {}
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/entity/ChunkSystemEntity.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/entity/ChunkSystemEntity.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/entity/ChunkSystemEntity.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.entity;
+
+import ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkData;
+import net.minecraft.server.level.FullChunkStatus;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.entity.monster.Shulker;
+import net.minecraft.world.entity.vehicle.AbstractMinecart;
+import net.minecraft.world.entity.vehicle.Boat;
+
+public interface ChunkSystemEntity {
+
+    public boolean moonrise$isHardColliding();
+
+    // for mods to override
+    public default boolean moonrise$isHardCollidingUncached() {
+        return this instanceof Boat || this instanceof AbstractMinecart || this instanceof Shulker || ((Entity)this).canBeCollidedWith();
+    }
+
+    public FullChunkStatus moonrise$getChunkStatus();
+
+    public void moonrise$setChunkStatus(final FullChunkStatus status);
+
+    public ChunkData moonrise$getChunkData();
+
+    public void moonrise$setChunkData(final ChunkData chunkData);
+
+    public int moonrise$getSectionX();
+
+    public void moonrise$setSectionX(final int x);
+
+    public int moonrise$getSectionY();
+
+    public void moonrise$setSectionY(final int y);
+
+    public int moonrise$getSectionZ();
+
+    public void moonrise$setSectionZ(final int z);
+
+    public boolean moonrise$isUpdatingSectionStatus();
+
+    public void moonrise$setUpdatingSectionStatus(final boolean to);
+
+    public boolean moonrise$hasAnyPlayerPassengers();
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/io/ChunkSystemRegionFileStorage.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/io/ChunkSystemRegionFileStorage.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/io/ChunkSystemRegionFileStorage.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.io;
+
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.world.level.chunk.storage.RegionFile;
+import java.io.IOException;
+
+public interface ChunkSystemRegionFileStorage {
+
+    public boolean moonrise$doesRegionFileNotExistNoIO(final int chunkX, final int chunkZ);
+
+    public RegionFile moonrise$getRegionFileIfLoaded(final int chunkX, final int chunkZ);
+
+    public RegionFile moonrise$getRegionFileIfExists(final int chunkX, final int chunkZ) throws IOException;
+
+    public MoonriseRegionFileIO.RegionDataController.WriteData moonrise$startWrite(
+            final int chunkX, final int chunkZ, final CompoundTag compound
+    ) throws IOException;
+
+    public void moonrise$finishWrite(
+                    final int chunkX, final int chunkZ, final MoonriseRegionFileIO.RegionDataController.WriteData writeData
+    ) throws IOException;
+
+    public MoonriseRegionFileIO.RegionDataController.ReadData moonrise$readData(
+            final int chunkX, final int chunkZ
+    ) throws IOException;
+
+    // if the return value is null, then the caller needs to re-try with a new call to readData()
+    public CompoundTag moonrise$finishRead(
+            final int chunkX, final int chunkZ, final MoonriseRegionFileIO.RegionDataController.ReadData readData
+    ) throws IOException;
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/io/MoonriseRegionFileIO.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/io/MoonriseRegionFileIO.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/io/MoonriseRegionFileIO.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.io;
+
+import ca.spottedleaf.concurrentutil.collection.MultiThreadedQueue;
+import ca.spottedleaf.concurrentutil.completable.CallbackCompletable;
+import ca.spottedleaf.concurrentutil.completable.Completable;
+import ca.spottedleaf.concurrentutil.executor.Cancellable;
+import ca.spottedleaf.concurrentutil.executor.PrioritisedExecutor;
+import ca.spottedleaf.concurrentutil.executor.queue.PrioritisedTaskQueue;
+import ca.spottedleaf.concurrentutil.function.BiLong1Function;
+import ca.spottedleaf.concurrentutil.map.ConcurrentLong2ReferenceChainedHashTable;
+import ca.spottedleaf.concurrentutil.util.ConcurrentUtil;
+import ca.spottedleaf.concurrentutil.util.Priority;
+import ca.spottedleaf.moonrise.common.util.CoordinateUtils;
+import ca.spottedleaf.moonrise.common.util.TickThread;
+import ca.spottedleaf.moonrise.common.util.WorldUtil;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel;
+import it.unimi.dsi.fastutil.objects.ReferenceOpenHashSet;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.world.level.chunk.storage.RegionFile;
+import net.minecraft.world.level.chunk.storage.RegionFileStorage;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.lang.invoke.VarHandle;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionException;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.function.BiConsumer;
+import java.util.function.Consumer;
+
+public final class MoonriseRegionFileIO {
+
+    private static final int REGION_FILE_SHIFT = 5;
+    private static final Logger LOGGER = LoggerFactory.getLogger(MoonriseRegionFileIO.class);
+
+    /**
+     * The types of RegionFiles controlled by the I/O thread(s).
+     */
+    public static enum RegionFileType {
+        CHUNK_DATA,
+        POI_DATA,
+        ENTITY_DATA;
+    }
+
+    public static RegionDataController getControllerFor(final ServerLevel world, final RegionFileType type) {
+        switch (type) {
+            case CHUNK_DATA:
+                return ((ChunkSystemServerLevel)world).moonrise$getChunkDataController();
+            case POI_DATA:
+                return ((ChunkSystemServerLevel)world).moonrise$getPoiChunkDataController();
+            case ENTITY_DATA:
+                return ((ChunkSystemServerLevel)world).moonrise$getEntityChunkDataController();
+            default:
+                throw new IllegalStateException("Unknown controller type " + type);
+        }
+    }
+
+    private static final RegionFileType[] CACHED_REGIONFILE_TYPES = RegionFileType.values();
+
+    /**
+     * Collects RegionFile data for a certain chunk.
+     */
+    public static final class RegionFileData {
+
+        private final boolean[] hasResult = new boolean[CACHED_REGIONFILE_TYPES.length];
+        private final CompoundTag[] data = new CompoundTag[CACHED_REGIONFILE_TYPES.length];
+        private final Throwable[] throwables = new Throwable[CACHED_REGIONFILE_TYPES.length];
+
+        /**
+         * Sets the result associated with the specified RegionFile type. Note that
+         * results can only be set once per RegionFile type.
+         *
+         * @param type The RegionFile type.
+         * @param data The result to set.
+         */
+        public void setData(final MoonriseRegionFileIO.RegionFileType type, final CompoundTag data) {
+            final int index = type.ordinal();
+
+            if (this.hasResult[index]) {
+                throw new IllegalArgumentException("Result already exists for type " + type);
+            }
+            this.hasResult[index] = true;
+            this.data[index] = data;
+        }
+
+        /**
+         * Sets the result associated with the specified RegionFile type. Note that
+         * results can only be set once per RegionFile type.
+         *
+         * @param type The RegionFile type.
+         * @param throwable The result to set.
+         */
+        public void setThrowable(final MoonriseRegionFileIO.RegionFileType type, final Throwable throwable) {
+            final int index = type.ordinal();
+
+            if (this.hasResult[index]) {
+                throw new IllegalArgumentException("Result already exists for type " + type);
+            }
+            this.hasResult[index] = true;
+            this.throwables[index] = throwable;
+        }
+
+        /**
+         * Returns whether there is a result for the specified RegionFile type.
+         *
+         * @param type Specified RegionFile type.
+         *
+         * @return Whether a result exists for {@code type}.
+         */
+        public boolean hasResult(final MoonriseRegionFileIO.RegionFileType type) {
+            return this.hasResult[type.ordinal()];
+        }
+
+        /**
+         * Returns the data result for the RegionFile type.
+         *
+         * @param type Specified RegionFile type.
+         *
+         * @throws IllegalArgumentException If the result has not been set for {@code type}.
+         * @return The data result for the specified type. If the result is a {@code Throwable},
+         * then returns {@code null}.
+         */
+        public CompoundTag getData(final MoonriseRegionFileIO.RegionFileType type) {
+            final int index = type.ordinal();
+
+            if (!this.hasResult[index]) {
+                throw new IllegalArgumentException("Result does not exist for type " + type);
+            }
+
+            return this.data[index];
+        }
+
+        /**
+         * Returns the throwable result for the RegionFile type.
+         *
+         * @param type Specified RegionFile type.
+         *
+         * @throws IllegalArgumentException If the result has not been set for {@code type}.
+         * @return The throwable result for the specified type. If the result is an {@code CompoundTag},
+         * then returns {@code null}.
+         */
+        public Throwable getThrowable(final MoonriseRegionFileIO.RegionFileType type) {
+            final int index = type.ordinal();
+
+            if (!this.hasResult[index]) {
+                throw new IllegalArgumentException("Result does not exist for type " + type);
+            }
+
+            return this.throwables[index];
+        }
+    }
+
+    public static void flushRegionStorages(final ServerLevel world) throws IOException {
+        for (final RegionFileType type : CACHED_REGIONFILE_TYPES) {
+            flushRegionStorages(world, type);
+        }
+    }
+
+    public static void flushRegionStorages(final ServerLevel world, final RegionFileType type) throws IOException {
+        getControllerFor(world, type).getCache().flush();
+    }
+
+    public static void flush(final MinecraftServer server) {
+        for (final ServerLevel world : server.getAllLevels()) {
+            flush(world);
+        }
+    }
+
+    public static void flush(final ServerLevel world) {
+        for (final RegionFileType regionFileType : CACHED_REGIONFILE_TYPES) {
+            flush(world, regionFileType);
+        }
+    }
+
+    public static void flush(final ServerLevel world, final RegionFileType type) {
+        final RegionDataController taskController = getControllerFor(world, type);
+
+        long failures = 1L; // start at 0.13ms
+
+        while (taskController.hasTasks()) {
+            Thread.yield();
+            failures = ConcurrentUtil.linearLongBackoff(failures, 125_000L, 5_000_000L); // 125us, 5ms
+        }
+    }
+
+    public static void partialFlush(final ServerLevel world, final int tasksRemaining) {
+        for (long failures = 1L;;) { // start at 0.13ms
+            long totalTasks = 0L;
+            for (final RegionFileType regionFileType : CACHED_REGIONFILE_TYPES) {
+                totalTasks += getControllerFor(world, regionFileType).getTotalWorkingTasks();
+            }
+
+            if (totalTasks > (long)tasksRemaining) {
+                Thread.yield();
+                failures = ConcurrentUtil.linearLongBackoff(failures, 125_000L, 5_000_000L); // 125us, 5ms
+            } else {
+                return;
+            }
+        }
+    }
+
+    /**
+     * Returns the priority associated with blocking I/O based on the current thread. The goal is to avoid
+     * dumb plugins from taking away priority from threads we consider crucial.
+     * @return The priroity to use with blocking I/O on the current thread.
+     */
+    public static Priority getIOBlockingPriorityForCurrentThread() {
+        if (TickThread.isTickThread()) {
+            return Priority.BLOCKING;
+        }
+        return Priority.HIGHEST;
+    }
+
+    /**
+     * Returns the priority for the specified regionfile type for the specified chunk.
+     * @param world Specified world.
+     * @param chunkX Specified chunk x.
+     * @param chunkZ Specified chunk z.
+     * @param type Specified regionfile type.
+     * @return The priority for the chunk
+     */
+    public static Priority getPriority(final ServerLevel world, final int chunkX, final int chunkZ, final RegionFileType type) {
+        final RegionDataController taskController = getControllerFor(world, type);
+        final ChunkIOTask task = taskController.chunkTasks.get(CoordinateUtils.getChunkKey(chunkX, chunkZ));
+
+        if (task == null) {
+            return Priority.COMPLETING;
+        }
+
+        return task.getPriority();
+    }
+
+    /**
+     * Sets the priority for all regionfile types for the specified chunk. Note that great care should
+     * be taken using this method, as there can be multiple tasks tied to the same chunk that want different
+     * priorities.
+     *
+     * @param world Specified world.
+     * @param chunkX Specified chunk x.
+     * @param chunkZ Specified chunk z.
+     * @param priority New priority.
+     *
+     * @see #raisePriority(ServerLevel, int, int, Priority)
+     * @see #raisePriority(ServerLevel, int, int, RegionFileType, Priority)
+     * @see #lowerPriority(ServerLevel, int, int, Priority)
+     * @see #lowerPriority(ServerLevel, int, int, RegionFileType, Priority)
+     */
+    public static void setPriority(final ServerLevel world, final int chunkX, final int chunkZ,
+                                   final Priority priority) {
+        for (final RegionFileType type : CACHED_REGIONFILE_TYPES) {
+            MoonriseRegionFileIO.setPriority(world, chunkX, chunkZ, type, priority);
+        }
+    }
+
+    /**
+     * Sets the priority for the specified regionfile type for the specified chunk. Note that great care should
+     * be taken using this method, as there can be multiple tasks tied to the same chunk that want different
+     * priorities.
+     *
+     * @param world Specified world.
+     * @param chunkX Specified chunk x.
+     * @param chunkZ Specified chunk z.
+     * @param type Specified regionfile type.
+     * @param priority New priority.
+     *
+     * @see #raisePriority(ServerLevel, int, int, Priority)
+     * @see #raisePriority(ServerLevel, int, int, RegionFileType, Priority)
+     * @see #lowerPriority(ServerLevel, int, int, Priority)
+     * @see #lowerPriority(ServerLevel, int, int, RegionFileType, Priority)
+     */
+    public static void setPriority(final ServerLevel world, final int chunkX, final int chunkZ, final RegionFileType type,
+                                   final Priority priority) {
+        final RegionDataController taskController = getControllerFor(world, type);
+        final ChunkIOTask task = taskController.chunkTasks.get(CoordinateUtils.getChunkKey(chunkX, chunkZ));
+
+        if (task != null) {
+            task.setPriority(priority);
+        }
+    }
+
+    /**
+     * Raises the priority for all regionfile types for the specified chunk.
+     *
+     * @param world Specified world.
+     * @param chunkX Specified chunk x.
+     * @param chunkZ Specified chunk z.
+     * @param priority New priority.
+     *
+     * @see #setPriority(ServerLevel, int, int, Priority)
+     * @see #setPriority(ServerLevel, int, int, RegionFileType, Priority)
+     * @see #lowerPriority(ServerLevel, int, int, Priority)
+     * @see #lowerPriority(ServerLevel, int, int, RegionFileType, Priority)
+     */
+    public static void raisePriority(final ServerLevel world, final int chunkX, final int chunkZ,
+                                     final Priority priority) {
+        for (final RegionFileType type : CACHED_REGIONFILE_TYPES) {
+            MoonriseRegionFileIO.raisePriority(world, chunkX, chunkZ, type, priority);
+        }
+    }
+
+    /**
+     * Raises the priority for the specified regionfile type for the specified chunk.
+     *
+     * @param world Specified world.
+     * @param chunkX Specified chunk x.
+     * @param chunkZ Specified chunk z.
+     * @param type Specified regionfile type.
+     * @param priority New priority.
+     *
+     * @see #setPriority(ServerLevel, int, int, Priority)
+     * @see #setPriority(ServerLevel, int, int, RegionFileType, Priority)
+     * @see #lowerPriority(ServerLevel, int, int, Priority)
+     * @see #lowerPriority(ServerLevel, int, int, RegionFileType, Priority)
+     */
+    public static void raisePriority(final ServerLevel world, final int chunkX, final int chunkZ, final RegionFileType type,
+                                     final Priority priority) {
+        final RegionDataController taskController = getControllerFor(world, type);
+        final ChunkIOTask task = taskController.chunkTasks.get(CoordinateUtils.getChunkKey(chunkX, chunkZ));
+
+        if (task != null) {
+            task.raisePriority(priority);
+        }
+    }
+
+    /**
+     * Lowers the priority for all regionfile types for the specified chunk.
+     *
+     * @param world Specified world.
+     * @param chunkX Specified chunk x.
+     * @param chunkZ Specified chunk z.
+     * @param priority New priority.
+     *
+     * @see #raisePriority(ServerLevel, int, int, Priority)
+     * @see #raisePriority(ServerLevel, int, int, RegionFileType, Priority)
+     * @see #setPriority(ServerLevel, int, int, Priority)
+     * @see #setPriority(ServerLevel, int, int, RegionFileType, Priority)
+     */
+    public static void lowerPriority(final ServerLevel world, final int chunkX, final int chunkZ,
+                                     final Priority priority) {
+        for (final RegionFileType type : CACHED_REGIONFILE_TYPES) {
+            MoonriseRegionFileIO.lowerPriority(world, chunkX, chunkZ, type, priority);
+        }
+    }
+
+    /**
+     * Lowers the priority for the specified regionfile type for the specified chunk.
+     *
+     * @param world Specified world.
+     * @param chunkX Specified chunk x.
+     * @param chunkZ Specified chunk z.
+     * @param type Specified regionfile type.
+     * @param priority New priority.
+     *
+     * @see #raisePriority(ServerLevel, int, int, Priority)
+     * @see #raisePriority(ServerLevel, int, int, RegionFileType, Priority)
+     * @see #setPriority(ServerLevel, int, int, Priority)
+     * @see #setPriority(ServerLevel, int, int, RegionFileType, Priority)
+     */
+    public static void lowerPriority(final ServerLevel world, final int chunkX, final int chunkZ, final RegionFileType type,
+                                     final Priority priority) {
+        final RegionDataController taskController = getControllerFor(world, type);
+        final ChunkIOTask task = taskController.chunkTasks.get(CoordinateUtils.getChunkKey(chunkX, chunkZ));
+
+        if (task != null) {
+            task.lowerPriority(priority);
+        }
+    }
+
+    /**
+     * Schedules the chunk data to be written asynchronously.
+     * <p>
+     *     Impl notes:
+     * </p>
+     * <li>
+     *     This function presumes a chunk load for the coordinates is not called during this function (anytime after is OK). This means
+     *     saves must be scheduled before a chunk is unloaded.
+     * </li>
+     * <li>
+     *     Writes may be called concurrently, although only the "later" write will go through.
+     * </li>
+     *
+     * @param world Chunk's world
+     * @param chunkX Chunk's x coordinate
+     * @param chunkZ Chunk's z coordinate
+     * @param data Chunk's data
+     * @param type The regionfile type to write to.
+     *
+     * @throws IllegalStateException If the file io thread has shutdown.
+     */
+    public static void scheduleSave(final ServerLevel world, final int chunkX, final int chunkZ, final CompoundTag data,
+                                    final RegionFileType type) {
+        MoonriseRegionFileIO.scheduleSave(world, chunkX, chunkZ, data, type, Priority.NORMAL);
+    }
+
+    /**
+     * Schedules the chunk data to be written asynchronously.
+     * <p>
+     *     Impl notes:
+     * </p>
+     * <li>
+     *     This function presumes a chunk load for the coordinates is not called during this function (anytime after is OK). This means
+     *     saves must be scheduled before a chunk is unloaded.
+     * </li>
+     * <li>
+     *     Writes may be called concurrently, although only the "later" write will go through.
+     * </li>
+     *
+     * @param world Chunk's world
+     * @param chunkX Chunk's x coordinate
+     * @param chunkZ Chunk's z coordinate
+     * @param data Chunk's data
+     * @param type The regionfile type to write to.
+     * @param priority The minimum priority to schedule at.
+     *
+     * @throws IllegalStateException If the file io thread has shutdown.
+     */
+    public static void scheduleSave(final ServerLevel world, final int chunkX, final int chunkZ, final CompoundTag data,
+                                    final RegionFileType type, final Priority priority) {
+        scheduleSave(
+            world, chunkX, chunkZ,
+            (final BiConsumer<CompoundTag, Throwable> consumer) -> {
+                consumer.accept(data, null);
+            }, null, type, priority
+        );
+    }
+
+    /**
+     * Schedules the chunk data to be written asynchronously.
+     * <p>
+     *     Impl notes:
+     * </p>
+     * <li>
+     *     This function presumes a chunk load for the coordinates is not called during this function (anytime after is OK). This means
+     *     saves must be scheduled before a chunk is unloaded.
+     * </li>
+     * <li>
+     *     Writes may be called concurrently, although only the "later" write will go through.
+     * </li>
+     * <li>
+     *     The specified write task, if not null, will have its priority controlled by the scheduler.
+     * </li>
+     *
+     * @param world Chunk's world
+     * @param chunkX Chunk's x coordinate
+     * @param chunkZ Chunk's z coordinate
+     * @param completable Chunk's pending data
+     * @param writeTask The task responsible for completing the pending chunk data
+     * @param type The regionfile type to write to.
+     * @param priority The minimum priority to schedule at.
+     *
+     * @throws IllegalStateException If the file io thread has shutdown.
+     */
+    public static void scheduleSave(final ServerLevel world, final int chunkX, final int chunkZ, final CallbackCompletable<CompoundTag> completable,
+                                    final PrioritisedExecutor.PrioritisedTask writeTask, final RegionFileType type, final Priority priority) {
+        scheduleSave(world, chunkX, chunkZ, completable::addWaiter, writeTask, type, priority);
+    }
+
+    /**
+     * Schedules the chunk data to be written asynchronously.
+     * <p>
+     *     Impl notes:
+     * </p>
+     * <li>
+     *     This function presumes a chunk load for the coordinates is not called during this function (anytime after is OK). This means
+     *     saves must be scheduled before a chunk is unloaded.
+     * </li>
+     * <li>
+     *     Writes may be called concurrently, although only the "later" write will go through.
+     * </li>
+     * <li>
+     *     The specified write task, if not null, will have its priority controlled by the scheduler.
+     * </li>
+     *
+     * @param world Chunk's world
+     * @param chunkX Chunk's x coordinate
+     * @param chunkZ Chunk's z coordinate
+     * @param completable Chunk's pending data
+     * @param writeTask The task responsible for completing the pending chunk data
+     * @param type The regionfile type to write to.
+     * @param priority The minimum priority to schedule at.
+     *
+     * @throws IllegalStateException If the file io thread has shutdown.
+     */
+    public static void scheduleSave(final ServerLevel world, final int chunkX, final int chunkZ, final Completable<CompoundTag> completable,
+                                    final PrioritisedExecutor.PrioritisedTask writeTask, final RegionFileType type, final Priority priority) {
+        scheduleSave(world, chunkX, chunkZ, completable::whenComplete, writeTask, type, priority);
+    }
+
+    private static void scheduleSave(final ServerLevel world, final int chunkX, final int chunkZ, final Consumer<BiConsumer<CompoundTag, Throwable>> scheduler,
+                                     final PrioritisedExecutor.PrioritisedTask writeTask, final RegionFileType type, final Priority priority) {
+        final RegionDataController taskController = getControllerFor(world, type);
+
+        final boolean[] created = new boolean[1];
+        final ChunkIOTask.InProgressWrite write = new ChunkIOTask.InProgressWrite(writeTask);
+        final ChunkIOTask task = taskController.chunkTasks.compute(CoordinateUtils.getChunkKey(chunkX, chunkZ),
+            (final long keyInMap, final ChunkIOTask taskRunning) -> {
+                if (taskRunning == null || taskRunning.failedWrite) {
+                    // no task is scheduled or the previous write failed - meaning we need to overwrite it
+
+                    // create task
+                    final ChunkIOTask newTask = new ChunkIOTask(
+                        world, taskController, chunkX, chunkZ, priority, new ChunkIOTask.InProgressRead()
+                    );
+
+                    newTask.pushPendingWrite(write);
+
+                    created[0] = true;
+
+                    return newTask;
+                }
+
+                taskRunning.pushPendingWrite(write);
+
+                return taskRunning;
+            }
+        );
+
+        write.schedule(task, scheduler);
+
+        if (created[0]) {
+            taskController.startTask(task);
+            task.scheduleWriteCompress();
+        } else {
+            task.raisePriority(priority);
+        }
+    }
+
+    /**
+     * Schedules a load to be executed asynchronously. This task will load all regionfile types, and then call
+     * {@code onComplete}. This is a bulk load operation, see {@link #loadDataAsync(ServerLevel, int, int, RegionFileType, BiConsumer, boolean)}
+     * for single load.
+     * <p>
+     *     Impl notes:
+     * </p>
+     * <li>
+     *     The {@code onComplete} parameter may be completed during the execution of this function synchronously or it may
+     *     be completed asynchronously on this file io thread. Interacting with the file IO thread in the completion of
+     *     data is undefined behaviour, and can cause deadlock.
+     * </li>
+     *
+     * @param world Chunk's world
+     * @param chunkX Chunk's x coordinate
+     * @param chunkZ Chunk's z coordinate
+     * @param onComplete Consumer to execute once this task has completed
+     * @param intendingToBlock Whether the caller is intending to block on completion. This only affects the cost
+     *                         of this call.
+     *
+     * @return The {@link Cancellable} for this chunk load. Cancelling it will not affect other loads for the same chunk data.
+     *
+     * @see #loadDataAsync(ServerLevel, int, int, RegionFileType, BiConsumer, boolean)
+     * @see #loadDataAsync(ServerLevel, int, int, RegionFileType, BiConsumer, boolean, Priority)
+     * @see #loadChunkData(ServerLevel, int, int, Consumer, boolean, RegionFileType...)
+     * @see #loadChunkData(ServerLevel, int, int, Consumer, boolean, Priority, RegionFileType...)
+     */
+    public static Cancellable loadAllChunkData(final ServerLevel world, final int chunkX, final int chunkZ,
+                                               final Consumer<RegionFileData> onComplete, final boolean intendingToBlock) {
+        return MoonriseRegionFileIO.loadAllChunkData(world, chunkX, chunkZ, onComplete, intendingToBlock, Priority.NORMAL);
+    }
+
+    /**
+     * Schedules a load to be executed asynchronously. This task will load all regionfile types, and then call
+     * {@code onComplete}. This is a bulk load operation, see {@link #loadDataAsync(ServerLevel, int, int, RegionFileType, BiConsumer, boolean, Priority)}
+     * for single load.
+     * <p>
+     *     Impl notes:
+     * </p>
+     * <li>
+     *     The {@code onComplete} parameter may be completed during the execution of this function synchronously or it may
+     *     be completed asynchronously on this file io thread. Interacting with the file IO thread in the completion of
+     *     data is undefined behaviour, and can cause deadlock.
+     * </li>
+     *
+     * @param world Chunk's world
+     * @param chunkX Chunk's x coordinate
+     * @param chunkZ Chunk's z coordinate
+     * @param onComplete Consumer to execute once this task has completed
+     * @param intendingToBlock Whether the caller is intending to block on completion. This only affects the cost
+     *                         of this call.
+     * @param priority The minimum priority to load the data at.
+     *
+     * @return The {@link Cancellable} for this chunk load. Cancelling it will not affect other loads for the same chunk data.
+     *
+     * @see #loadDataAsync(ServerLevel, int, int, RegionFileType, BiConsumer, boolean)
+     * @see #loadDataAsync(ServerLevel, int, int, RegionFileType, BiConsumer, boolean, Priority)
+     * @see #loadChunkData(ServerLevel, int, int, Consumer, boolean, RegionFileType...)
+     * @see #loadChunkData(ServerLevel, int, int, Consumer, boolean, Priority, RegionFileType...)
+     */
+    public static Cancellable loadAllChunkData(final ServerLevel world, final int chunkX, final int chunkZ,
+                                               final Consumer<RegionFileData> onComplete, final boolean intendingToBlock,
+                                               final Priority priority) {
+        return MoonriseRegionFileIO.loadChunkData(world, chunkX, chunkZ, onComplete, intendingToBlock, priority, CACHED_REGIONFILE_TYPES);
+    }
+
+    /**
+     * Schedules a load to be executed asynchronously. This task will load data for the specified regionfile type(s), and
+     * then call {@code onComplete}. This is a bulk load operation, see {@link #loadDataAsync(ServerLevel, int, int, RegionFileType, BiConsumer, boolean)}
+     * for single load.
+     * <p>
+     *     Impl notes:
+     * </p>
+     * <li>
+     *     The {@code onComplete} parameter may be completed during the execution of this function synchronously or it may
+     *     be completed asynchronously on this file io thread. Interacting with the file IO thread in the completion of
+     *     data is undefined behaviour, and can cause deadlock.
+     * </li>
+     *
+     * @param world Chunk's world
+     * @param chunkX Chunk's x coordinate
+     * @param chunkZ Chunk's z coordinate
+     * @param onComplete Consumer to execute once this task has completed
+     * @param intendingToBlock Whether the caller is intending to block on completion. This only affects the cost
+     *                         of this call.
+     * @param types The regionfile type(s) to load.
+     *
+     * @return The {@link Cancellable} for this chunk load. Cancelling it will not affect other loads for the same chunk data.
+     *
+     * @see #loadDataAsync(ServerLevel, int, int, RegionFileType, BiConsumer, boolean)
+     * @see #loadDataAsync(ServerLevel, int, int, RegionFileType, BiConsumer, boolean, Priority)
+     * @see #loadAllChunkData(ServerLevel, int, int, Consumer, boolean)
+     * @see #loadAllChunkData(ServerLevel, int, int, Consumer, boolean, Priority)
+     */
+    public static Cancellable loadChunkData(final ServerLevel world, final int chunkX, final int chunkZ,
+                                            final Consumer<RegionFileData> onComplete, final boolean intendingToBlock,
+                                            final RegionFileType... types) {
+        return MoonriseRegionFileIO.loadChunkData(world, chunkX, chunkZ, onComplete, intendingToBlock, Priority.NORMAL, types);
+    }
+
+    /**
+     * Schedules a load to be executed asynchronously. This task will load data for the specified regionfile type(s), and
+     * then call {@code onComplete}. This is a bulk load operation, see {@link #loadDataAsync(ServerLevel, int, int, RegionFileType, BiConsumer, boolean, Priority)}
+     * for single load.
+     * <p>
+     *     Impl notes:
+     * </p>
+     * <li>
+     *     The {@code onComplete} parameter may be completed during the execution of this function synchronously or it may
+     *     be completed asynchronously on this file io thread. Interacting with the file IO thread in the completion of
+     *     data is undefined behaviour, and can cause deadlock.
+     * </li>
+     *
+     * @param world Chunk's world
+     * @param chunkX Chunk's x coordinate
+     * @param chunkZ Chunk's z coordinate
+     * @param onComplete Consumer to execute once this task has completed
+     * @param intendingToBlock Whether the caller is intending to block on completion. This only affects the cost
+     *                         of this call.
+     * @param types The regionfile type(s) to load.
+     * @param priority The minimum priority to load the data at.
+     *
+     * @return The {@link Cancellable} for this chunk load. Cancelling it will not affect other loads for the same chunk data.
+     *
+     * @see #loadDataAsync(ServerLevel, int, int, RegionFileType, BiConsumer, boolean)
+     * @see #loadDataAsync(ServerLevel, int, int, RegionFileType, BiConsumer, boolean, Priority)
+     * @see #loadAllChunkData(ServerLevel, int, int, Consumer, boolean)
+     * @see #loadAllChunkData(ServerLevel, int, int, Consumer, boolean, Priority)
+     */
+    public static Cancellable loadChunkData(final ServerLevel world, final int chunkX, final int chunkZ,
+                                            final Consumer<RegionFileData> onComplete, final boolean intendingToBlock,
+                                            final Priority priority, final RegionFileType... types) {
+        if (types == null) {
+            throw new NullPointerException("Types cannot be null");
+        }
+        if (types.length == 0) {
+            throw new IllegalArgumentException("Types cannot be empty");
+        }
+
+        final RegionFileData ret = new RegionFileData();
+
+        final Cancellable[] reads = new CancellableRead[types.length];
+        final AtomicInteger completions = new AtomicInteger();
+        final int expectedCompletions = types.length;
+
+        for (int i = 0; i < expectedCompletions; ++i) {
+            final RegionFileType type = types[i];
+            reads[i] = MoonriseRegionFileIO.loadDataAsync(world, chunkX, chunkZ, type,
+                (final CompoundTag data, final Throwable throwable) -> {
+                    if (throwable != null) {
+                        ret.setThrowable(type, throwable);
+                    } else {
+                        ret.setData(type, data);
+                    }
+
+                    if (completions.incrementAndGet() == expectedCompletions) {
+                        onComplete.accept(ret);
+                    }
+                }, intendingToBlock, priority);
+        }
+
+        return new CancellableReads(reads);
+    }
+
+    /**
+     * Schedules a load to be executed asynchronously. This task will load the specified regionfile type, and then call
+     * {@code onComplete}.
+     * <p>
+     *     Impl notes:
+     * </p>
+     * <li>
+     *     The {@code onComplete} parameter may be completed during the execution of this function synchronously or it may
+     *     be completed asynchronously on this file io thread. Interacting with the file IO thread in the completion of
+     *     data is undefined behaviour, and can cause deadlock.
+     * </li>
+     *
+     * @param world Chunk's world
+     * @param chunkX Chunk's x coordinate
+     * @param chunkZ Chunk's z coordinate
+     * @param onComplete Consumer to execute once this task has completed
+     * @param intendingToBlock Whether the caller is intending to block on completion. This only affects the cost
+     *                         of this call.
+     *
+     * @return The {@link Cancellable} for this chunk load. Cancelling it will not affect other loads for the same chunk data.
+     *
+     * @see #loadChunkData(ServerLevel, int, int, Consumer, boolean, RegionFileType...)
+     * @see #loadChunkData(ServerLevel, int, int, Consumer, boolean, Priority, RegionFileType...)
+     * @see #loadAllChunkData(ServerLevel, int, int, Consumer, boolean)
+     * @see #loadAllChunkData(ServerLevel, int, int, Consumer, boolean, Priority)
+     */
+    public static Cancellable loadDataAsync(final ServerLevel world, final int chunkX, final int chunkZ,
+                                            final RegionFileType type, final BiConsumer<CompoundTag, Throwable> onComplete,
+                                            final boolean intendingToBlock) {
+        return MoonriseRegionFileIO.loadDataAsync(world, chunkX, chunkZ, type, onComplete, intendingToBlock, Priority.NORMAL);
+    }
+
+    /**
+     * Schedules a load to be executed asynchronously. This task will load the specified regionfile type, and then call
+     * {@code onComplete}.
+     * <p>
+     *     Impl notes:
+     * </p>
+     * <li>
+     *     The {@code onComplete} parameter may be completed during the execution of this function synchronously or it may
+     *     be completed asynchronously on this file io thread. Interacting with the file IO thread in the completion of
+     *     data is undefined behaviour, and can cause deadlock.
+     * </li>
+     *
+     * @param world Chunk's world
+     * @param chunkX Chunk's x coordinate
+     * @param chunkZ Chunk's z coordinate
+     * @param onComplete Consumer to execute once this task has completed
+     * @param intendingToBlock Whether the caller is intending to block on completion. This only affects the cost
+     *                         of this call.
+     * @param priority Minimum priority to load the data at.
+     *
+     * @return The {@link Cancellable} for this chunk load. Cancelling it will not affect other loads for the same chunk data.
+     *
+     * @see #loadChunkData(ServerLevel, int, int, Consumer, boolean, RegionFileType...)
+     * @see #loadChunkData(ServerLevel, int, int, Consumer, boolean, Priority, RegionFileType...)
+     * @see #loadAllChunkData(ServerLevel, int, int, Consumer, boolean)
+     * @see #loadAllChunkData(ServerLevel, int, int, Consumer, boolean, Priority)
+     */
+    public static Cancellable loadDataAsync(final ServerLevel world, final int chunkX, final int chunkZ,
+                                            final RegionFileType type, final BiConsumer<CompoundTag, Throwable> onComplete,
+                                            final boolean intendingToBlock, final Priority priority) {
+        final RegionDataController taskController = getControllerFor(world, type);
+
+        final ImmediateCallbackCompletion callbackInfo = new ImmediateCallbackCompletion();
+
+        final long key = CoordinateUtils.getChunkKey(chunkX, chunkZ);
+        final BiLong1Function<ChunkIOTask, ChunkIOTask> compute = (final long keyInMap, final ChunkIOTask running) -> {
+            if (running == null) {
+                // not scheduled
+
+                // set up task
+                final ChunkIOTask newTask = new ChunkIOTask(
+                    world, taskController, chunkX, chunkZ, priority, new ChunkIOTask.InProgressRead()
+                );
+                newTask.inProgressRead.addToAsyncWaiters(onComplete);
+
+                callbackInfo.tasksNeedReadScheduling = true;
+                return newTask;
+            }
+
+            final ChunkIOTask.InProgressWrite pendingWrite = running.inProgressWrite;
+
+            if (pendingWrite == null) {
+                // need to add to waiters here, because the regionfile thread will use compute() to lock and check for cancellations
+                if (!running.inProgressRead.addToAsyncWaiters(onComplete)) {
+                    callbackInfo.data = running.inProgressRead.value;
+                    callbackInfo.throwable = running.inProgressRead.throwable;
+                    callbackInfo.completeNow = true;
+                    return running;
+                }
+
+                callbackInfo.read = running.inProgressRead;
+
+                return running;
+            }
+
+            // at this stage we have to use the in progress write's data to avoid an order issue
+
+            if (!pendingWrite.addToAsyncWaiters(onComplete)) {
+                // data is ready now
+                callbackInfo.data = pendingWrite.value;
+                callbackInfo.throwable = pendingWrite.throwable;
+                callbackInfo.completeNow = true;
+                return running;
+            }
+
+            callbackInfo.write = pendingWrite;
+
+            return running;
+        };
+
+        final ChunkIOTask ret = taskController.chunkTasks.compute(key, compute);
+
+        // needs to be scheduled
+        if (callbackInfo.tasksNeedReadScheduling) {
+            taskController.startTask(ret);
+            ret.scheduleReadIO();
+        } else if (callbackInfo.completeNow) {
+            try {
+                onComplete.accept(callbackInfo.data == null ? null : callbackInfo.data.copy(), callbackInfo.throwable);
+            } catch (final Throwable thr) {
+                LOGGER.error("Callback " + ConcurrentUtil.genericToString(onComplete) + " synchronously failed to handle chunk data for task " + ret.toString(), thr);
+            }
+        } else {
+            // we're waiting on a task we didn't schedule, so raise its priority to what we want
+            ret.raisePriority(priority);
+        }
+
+        return new CancellableRead(onComplete, callbackInfo.read, callbackInfo.write);
+    }
+
+    private static final class ImmediateCallbackCompletion {
+
+        private CompoundTag data;
+        private Throwable throwable;
+        private boolean completeNow;
+        private boolean tasksNeedReadScheduling;
+        private ChunkIOTask.InProgressRead read;
+        private ChunkIOTask.InProgressWrite write;
+
+    }
+
+    /**
+     * Schedules a load task to be executed asynchronously, and blocks on that task.
+     *
+     * @param world Chunk's world
+     * @param chunkX Chunk's x coordinate
+     * @param chunkZ Chunk's z coordinate
+     * @param type Regionfile type
+     * @param priority Minimum priority to load the data at.
+     *
+     * @return The chunk data for the chunk. Note that a {@code null} result means the chunk or regionfile does not exist on disk.
+     *
+     * @throws IOException If the load fails for any reason
+     */
+    public static CompoundTag loadData(final ServerLevel world, final int chunkX, final int chunkZ, final RegionFileType type,
+                                       final Priority priority) throws IOException {
+        final CompletableFuture<CompoundTag> ret = new CompletableFuture<>();
+
+        MoonriseRegionFileIO.loadDataAsync(world, chunkX, chunkZ, type, (final CompoundTag compound, final Throwable thr) -> {
+            if (thr != null) {
+                ret.completeExceptionally(thr);
+            } else {
+                ret.complete(compound);
+            }
+        }, true, priority);
+
+        try {
+            return ret.join();
+        } catch (final CompletionException ex) {
+            throw new IOException(ex);
+        }
+    }
+    
+    private static final class CancellableRead implements Cancellable {
+
+        private BiConsumer<CompoundTag, Throwable> callback;
+        private ChunkIOTask.InProgressRead read;
+        private ChunkIOTask.InProgressWrite write;
+
+        private CancellableRead(final BiConsumer<CompoundTag, Throwable> callback,
+                                final ChunkIOTask.InProgressRead read,
+                                final ChunkIOTask.InProgressWrite write) {
+            this.callback = callback;
+            this.read = read;
+            this.write = write;
+        }
+
+        @Override
+        public boolean cancel() {
+            final BiConsumer<CompoundTag, Throwable> callback = this.callback;
+            final ChunkIOTask.InProgressRead read = this.read;
+            final ChunkIOTask.InProgressWrite write = this.write;
+
+            if (callback == null || (read == null && write == null)) {
+                return false;
+            }
+
+            this.callback = null;
+            this.read = null;
+            this.write = null;
+
+            if (read != null) {
+                return read.cancel(callback);
+            }
+            if (write != null) {
+                return write.cancel(callback);
+            }
+
+            // unreachable
+            throw new InternalError();
+        }
+    }
+
+    private static final class CancellableReads implements Cancellable {
+
+        private Cancellable[] reads;
+        private static final VarHandle READS_HANDLE = ConcurrentUtil.getVarHandle(CancellableReads.class, "reads", Cancellable[].class);
+
+        private CancellableReads(final Cancellable[] reads) {
+            this.reads = reads;
+        }
+
+        @Override
+        public boolean cancel() {
+            final Cancellable[] reads = (Cancellable[])READS_HANDLE.getAndSet((CancellableReads)this, (Cancellable[])null);
+
+            if (reads == null) {
+                return false;
+            }
+
+            boolean ret = false;
+
+            for (final Cancellable read : reads) {
+                ret |= read.cancel();
+            }
+
+            return ret;
+        }
+    }
+
+    private static final class ChunkIOTask {
+
+        private final ServerLevel world;
+        private final RegionDataController regionDataController;
+        private final int chunkX;
+        private final int chunkZ;
+        private Priority priority;
+        private PrioritisedExecutor.PrioritisedTask currentTask;
+
+        private final InProgressRead inProgressRead;
+        private volatile InProgressWrite inProgressWrite;
+        private final ReferenceOpenHashSet<InProgressWrite> allPendingWrites = new ReferenceOpenHashSet<>();
+
+        private RegionDataController.ReadData readData;
+        private RegionDataController.WriteData writeData;
+        private boolean failedWrite;
+
+        public ChunkIOTask(final ServerLevel world, final RegionDataController regionDataController,
+                           final int chunkX, final int chunkZ, final Priority priority, final InProgressRead inProgressRead) {
+            this.world = world;
+            this.regionDataController = regionDataController;
+            this.chunkX = chunkX;
+            this.chunkZ = chunkZ;
+            this.priority = priority;
+            this.inProgressRead = inProgressRead;
+        }
+
+        public Priority getPriority() {
+            synchronized (this) {
+                return this.priority;
+            }
+        }
+
+        // must hold lock on this object
+        private void updatePriority(final Priority priority) {
+            this.priority = priority;
+            if (this.currentTask != null) {
+                this.currentTask.setPriority(priority);
+            }
+            for (final InProgressWrite write : this.allPendingWrites) {
+                if (write.writeTask != null) {
+                    write.writeTask.setPriority(priority);
+                }
+            }
+        }
+
+        public boolean setPriority(final Priority priority) {
+            synchronized (this) {
+                if (this.priority == priority) {
+                    return false;
+                }
+
+                this.updatePriority(priority);
+
+                return true;
+            }
+        }
+
+        public boolean raisePriority(final Priority priority) {
+            synchronized (this) {
+                if (this.priority.isHigherOrEqualPriority(priority)) {
+                    return false;
+                }
+
+                this.updatePriority(priority);
+
+                return true;
+            }
+        }
+
+        public boolean lowerPriority(final Priority priority) {
+            synchronized (this) {
+                if (this.priority.isLowerOrEqualPriority(priority)) {
+                    return false;
+                }
+
+                this.updatePriority(priority);
+
+                return true;
+            }
+        }
+
+        private void pushPendingWrite(final InProgressWrite write) {
+            this.inProgressWrite = write;
+            synchronized (this) {
+                this.allPendingWrites.add(write);
+                if (write.writeTask != null) {
+                    write.writeTask.setPriority(this.priority);
+                }
+            }
+        }
+
+        private void pendingWriteComplete(final InProgressWrite write) {
+            synchronized (this) {
+                this.allPendingWrites.remove(write);
+            }
+        }
+
+        public void scheduleReadIO() {
+            final PrioritisedExecutor.PrioritisedTask task;
+            synchronized (this) {
+                task = this.regionDataController.ioScheduler.createTask(this.chunkX, this.chunkZ, this::performReadIO, this.priority);
+                this.currentTask = task;
+            }
+            task.queue();
+        }
+
+        private void performReadIO() {
+            final InProgressRead read = this.inProgressRead;
+            final long chunkKey = CoordinateUtils.getChunkKey(this.chunkX, this.chunkZ);
+
+            final boolean[] canRead = new boolean[] { true };
+
+            if (read.hasNoWaiters()) {
+                // cancelled read? go to task controller to confirm
+                final ChunkIOTask inMap = this.regionDataController.chunkTasks.compute(chunkKey, (final long keyInMap, final ChunkIOTask valueInMap) -> {
+                    if (valueInMap == null) {
+                        throw new IllegalStateException("Write completed concurrently, expected this task: " + ChunkIOTask.this.toString() + ", report this!");
+                    }
+                    if (valueInMap != ChunkIOTask.this) {
+                        throw new IllegalStateException("Chunk task mismatch, expected this task: " + ChunkIOTask.this.toString() + ", got: " + valueInMap.toString() + ", report this!");
+                    }
+
+                    if (!read.hasNoWaiters()) {
+                        return valueInMap;
+                    } else {
+                        canRead[0] = false;
+                    }
+
+                    if (valueInMap.inProgressWrite != null) {
+                        return valueInMap;
+                    }
+
+                    return null;
+                });
+
+                if (inMap == null) {
+                    this.regionDataController.endTask(this);
+                    // read is cancelled - and no write pending, so we're done
+                    return;
+                }
+                // if there is a write in progress, we don't actually have to worry about waiters gaining new entries -
+                // the readers will just use the in progress write, so the value in canRead is good to use without
+                // further synchronisation.
+            }
+
+            if (canRead[0]) {
+                RegionDataController.ReadData readData = null;
+                Throwable throwable = null;
+
+                try {
+                    readData = this.regionDataController.readData(this.chunkX, this.chunkZ);
+                } catch (final Throwable thr) {
+                    throwable = thr;
+                    LOGGER.error("Failed to read chunk data for task: " + this.toString(), thr);
+                }
+
+                if (throwable != null) {
+                    this.finishRead(null, throwable);
+                } else {
+                    switch (readData.result()) {
+                        case NO_DATA:
+                        case SYNC_READ: {
+                            this.finishRead(readData.syncRead(), null);
+                            break;
+                        }
+                        case HAS_DATA: {
+                            this.readData = readData;
+                            this.scheduleReadDecompress();
+                            // read will handle write scheduling
+                            return;
+                        }
+                        default: {
+                            throw new IllegalStateException("Unknown state: " + readData.result());
+                        }
+                    }
+                }
+            }
+
+            if (!this.tryAbortWrite()) {
+                this.scheduleWriteCompress();
+            }
+        }
+
+        private void scheduleReadDecompress() {
+            final PrioritisedExecutor.PrioritisedTask task;
+            synchronized (this) {
+                task = this.regionDataController.compressionExecutor.createTask(this::performReadDecompress, this.priority);
+                this.currentTask = task;
+            }
+            task.queue();
+        }
+
+        private void performReadDecompress() {
+            final RegionDataController.ReadData readData = this.readData;
+            this.readData = null;
+
+            CompoundTag compoundTag = null;
+            Throwable throwable = null;
+
+            try {
+                compoundTag = this.regionDataController.finishRead(this.chunkX, this.chunkZ, readData);
+            } catch (final Throwable thr) {
+                throwable = thr;
+                LOGGER.error("Failed to decompress chunk data for task: " + this.toString(), thr);
+            }
+
+            if (compoundTag == null) {
+                // need to re-try from the start
+                this.scheduleReadIO();
+                return;
+            }
+
+            this.finishRead(compoundTag, throwable);
+            if (!this.tryAbortWrite()) {
+                this.scheduleWriteCompress();
+            }
+        }
+
+        private void finishRead(final CompoundTag compoundTag, final Throwable throwable) {
+            this.inProgressRead.complete(this, compoundTag, throwable);
+        }
+
+        public void scheduleWriteCompress() {
+            final InProgressWrite inProgressWrite = this.inProgressWrite;
+
+            final PrioritisedExecutor.PrioritisedTask task;
+            synchronized (this) {
+                task = this.regionDataController.compressionExecutor.createTask(() -> {
+                    ChunkIOTask.this.performWriteCompress(inProgressWrite);
+                }, this.priority);
+                this.currentTask = task;
+            }
+
+            inProgressWrite.addToWaiters(this, (final CompoundTag data, final Throwable throwable) -> {
+                task.queue();
+            });
+        }
+
+        private boolean tryAbortWrite() {
+            final long chunkKey = CoordinateUtils.getChunkKey(this.chunkX, this.chunkZ);
+            if (this.inProgressWrite == null) {
+                final ChunkIOTask inMap = this.regionDataController.chunkTasks.compute(chunkKey, (final long keyInMap, final ChunkIOTask valueInMap) -> {
+                    if (valueInMap == null) {
+                        throw new IllegalStateException("Write completed concurrently, expected this task: " + ChunkIOTask.this.toString() + ", report this!");
+                    }
+                    if (valueInMap != ChunkIOTask.this) {
+                        throw new IllegalStateException("Chunk task mismatch, expected this task: " + ChunkIOTask.this.toString() + ", got: " + valueInMap.toString() + ", report this!");
+                    }
+
+                    if (valueInMap.inProgressWrite != null) {
+                        return valueInMap;
+                    }
+
+                    return null;
+                });
+
+                if (inMap == null) {
+                    this.regionDataController.endTask(this);
+                    return true; // set the task value to null, indicating we're done
+                } // else: inProgressWrite changed, so now we have something to write
+            }
+
+            return false;
+        }
+
+        private void performWriteCompress(final InProgressWrite inProgressWrite) {
+            final CompoundTag write = inProgressWrite.value;
+            if (!inProgressWrite.isComplete()) {
+                throw new IllegalStateException("Should be writable");
+            }
+
+            RegionDataController.WriteData writeData = null;
+            boolean failedWrite = false;
+
+            try {
+                writeData = this.regionDataController.startWrite(this.chunkX, this.chunkZ, write);
+            } catch (final Throwable thr) {
+                failedWrite = thr instanceof IOException;
+                LOGGER.error("Failed to write chunk data for task: " + this.toString(), thr);
+            }
+
+            if (writeData == null) {
+                // null if a throwable was encountered
+
+                // we cannot continue to the I/O stage here, so try to complete
+
+                if (this.tryCompleteWrite(inProgressWrite, failedWrite)) {
+                    return;
+                } else {
+                    // fetch new data and try again
+                    this.scheduleWriteCompress();
+                    return;
+                }
+            } else {
+                // writeData != null && !failedWrite
+                // we can continue to I/O stage
+                this.writeData = writeData;
+                this.scheduleWriteIO(inProgressWrite);
+                return;
+            }
+        }
+
+        private void scheduleWriteIO(final InProgressWrite inProgressWrite) {
+            final PrioritisedExecutor.PrioritisedTask task;
+            synchronized (this) {
+                task = this.regionDataController.ioScheduler.createTask(this.chunkX, this.chunkZ, () -> {
+                    ChunkIOTask.this.runWriteIO(inProgressWrite);
+                }, this.priority);
+                this.currentTask = task;
+            }
+            task.queue();
+        }
+
+        private void runWriteIO(final InProgressWrite inProgressWrite) {
+            RegionDataController.WriteData writeData = this.writeData;
+            this.writeData = null;
+
+            boolean failedWrite = false;
+
+            try {
+                this.regionDataController.finishWrite(this.chunkX, this.chunkZ, writeData);
+            } catch (final Throwable thr) {
+                failedWrite = thr instanceof IOException;
+                LOGGER.error("Failed to write chunk data for task: " + this.toString(), thr);
+            }
+
+            if (!this.tryCompleteWrite(inProgressWrite, failedWrite)) {
+                // fetch new data and try again
+                this.scheduleWriteCompress();
+            }
+            return;
+        }
+
+        private boolean tryCompleteWrite(final InProgressWrite written, final boolean failedWrite) {
+            final long chunkKey = CoordinateUtils.getChunkKey(this.chunkX, this.chunkZ);
+
+            final boolean[] done = new boolean[] { false };
+
+            this.regionDataController.chunkTasks.compute(chunkKey, (final long keyInMap, final ChunkIOTask valueInMap) -> {
+                if (valueInMap == null) {
+                    throw new IllegalStateException("Write completed concurrently, expected this task: " + ChunkIOTask.this.toString() + ", report this!");
+                }
+                if (valueInMap != ChunkIOTask.this) {
+                    throw new IllegalStateException("Chunk task mismatch, expected this task: " + ChunkIOTask.this.toString() + ", got: " + valueInMap.toString() + ", report this!");
+                }
+                if (valueInMap.inProgressWrite == written) {
+                    valueInMap.failedWrite = failedWrite;
+                    done[0] = true;
+                    // keep the data in map if we failed the write so we can try to prevent data loss
+                    return failedWrite ? valueInMap : null;
+                }
+                // different data than expected, means we need to retry write
+                return valueInMap;
+            });
+
+            if (done[0]) {
+                this.regionDataController.endTask(this);
+                return true;
+            }
+            return false;
+        }
+
+        @Override
+        public String toString() {
+            return "Task for world: '" + WorldUtil.getWorldName(this.world) + "' at (" + this.chunkX + ","
+                    + this.chunkZ + ") type: " + this.regionDataController.type.name() + ", hash: " + this.hashCode();
+        }
+
+        private static final class InProgressRead {
+
+            private static final Logger LOGGER = LoggerFactory.getLogger(InProgressRead.class);
+
+            private CompoundTag value;
+            private Throwable throwable;
+            private final MultiThreadedQueue<BiConsumer<CompoundTag, Throwable>> callbacks = new MultiThreadedQueue<>();
+
+            public boolean hasNoWaiters() {
+                return this.callbacks.isEmpty();
+            }
+
+            public boolean addToAsyncWaiters(final BiConsumer<CompoundTag, Throwable> callback) {
+                return this.callbacks.add(callback);
+            }
+
+            public boolean cancel(final BiConsumer<CompoundTag, Throwable> callback) {
+                return this.callbacks.remove(callback);
+            }
+
+            public void complete(final ChunkIOTask task, final CompoundTag value, final Throwable throwable) {
+                this.value = value;
+                this.throwable = throwable;
+
+                BiConsumer<CompoundTag, Throwable> consumer;
+                while ((consumer = this.callbacks.pollOrBlockAdds()) != null) {
+                    try {
+                        consumer.accept(value == null ? null : value.copy(), throwable);
+                    } catch (final Throwable thr) {
+                        LOGGER.error("Callback " + ConcurrentUtil.genericToString(consumer) + " failed to handle chunk data (read) for task " + task.toString(), thr);
+                    }
+                }
+            }
+        }
+
+        private static final class InProgressWrite {
+
+            private static final Logger LOGGER = LoggerFactory.getLogger(InProgressWrite.class);
+
+            private CompoundTag value;
+            private Throwable throwable;
+            private volatile boolean complete;
+            private final MultiThreadedQueue<BiConsumer<CompoundTag, Throwable>> callbacks = new MultiThreadedQueue<>();
+
+            private final PrioritisedExecutor.PrioritisedTask writeTask;
+
+            public InProgressWrite(final PrioritisedExecutor.PrioritisedTask writeTask) {
+                this.writeTask = writeTask;
+            }
+
+            public boolean isComplete() {
+                return this.complete;
+            }
+
+            public void schedule(final ChunkIOTask task, final Consumer<BiConsumer<CompoundTag, Throwable>> scheduler) {
+                scheduler.accept((final CompoundTag data, final Throwable throwable) -> {
+                    InProgressWrite.this.complete(task, data, throwable);
+                });
+            }
+
+            public boolean addToAsyncWaiters(final BiConsumer<CompoundTag, Throwable> callback) {
+                return this.callbacks.add(callback);
+            }
+
+            public void addToWaiters(final ChunkIOTask task, final BiConsumer<CompoundTag, Throwable> consumer) {
+                if (!this.callbacks.add(consumer)) {
+                    this.syncAccept(task, consumer, this.value, this.throwable);
+                }
+            }
+
+            private void syncAccept(final ChunkIOTask task, final BiConsumer<CompoundTag, Throwable> consumer, final CompoundTag value, final Throwable throwable) {
+                try {
+                    consumer.accept(value == null ? null : value.copy(), throwable);
+                } catch (final Throwable thr) {
+                    LOGGER.error("Callback " + ConcurrentUtil.genericToString(consumer) + " failed to handle chunk data (write) for task " + task.toString(), thr);
+                }
+            }
+
+            public void complete(final ChunkIOTask task, final CompoundTag value, final Throwable throwable) {
+                this.value = value;
+                this.throwable = throwable;
+                this.complete = true;
+
+                task.pendingWriteComplete(this);
+
+                BiConsumer<CompoundTag, Throwable> consumer;
+                while ((consumer = this.callbacks.pollOrBlockAdds()) != null) {
+                    this.syncAccept(task, consumer, value, throwable);
+                }
+            }
+
+            public boolean cancel(final BiConsumer<CompoundTag, Throwable> callback) {
+                return this.callbacks.remove(callback);
+            }
+        }
+    }
+
+    public static abstract class RegionDataController {
+
+        public final RegionFileType type;
+        private final PrioritisedExecutor compressionExecutor;
+        private final IOScheduler ioScheduler;
+        private final ConcurrentLong2ReferenceChainedHashTable<ChunkIOTask> chunkTasks = new ConcurrentLong2ReferenceChainedHashTable<>();
+
+        private final AtomicLong inProgressTasks = new AtomicLong();
+
+        public RegionDataController(final RegionFileType type, final PrioritisedExecutor ioExecutor,
+                                    final PrioritisedExecutor compressionExecutor) {
+            this.type = type;
+            this.compressionExecutor = compressionExecutor;
+            this.ioScheduler = new IOScheduler(ioExecutor);
+        }
+
+        final void startTask(final ChunkIOTask task) {
+            this.inProgressTasks.getAndIncrement();
+        }
+
+        final void endTask(final ChunkIOTask task) {
+            this.inProgressTasks.getAndDecrement();
+        }
+
+        public boolean hasTasks() {
+            return this.inProgressTasks.get() != 0L;
+        }
+
+        public long getTotalWorkingTasks() {
+            return this.inProgressTasks.get();
+        }
+
+        public abstract RegionFileStorage getCache();
+
+        public static record WriteData(CompoundTag input, WriteResult result, DataOutputStream output, IORunnable write) {
+            public static enum WriteResult {
+                WRITE,
+                DELETE;
+            }
+        }
+
+        public abstract WriteData startWrite(final int chunkX, final int chunkZ, final CompoundTag compound) throws IOException;
+
+        public abstract void finishWrite(final int chunkX, final int chunkZ, final WriteData writeData) throws IOException;
+
+        public static record ReadData(ReadResult result, DataInputStream input, CompoundTag syncRead) {
+            public static enum ReadResult {
+                NO_DATA,
+                HAS_DATA,
+                SYNC_READ;
+            }
+        }
+
+        public abstract ReadData readData(final int chunkX, final int chunkZ) throws IOException;
+
+        // if the return value is null, then the caller needs to re-try with a new call to readData()
+        public abstract CompoundTag finishRead(final int chunkX, final int chunkZ, final ReadData readData) throws IOException;
+
+        public static interface IORunnable {
+
+            public void run(final RegionFile regionFile) throws IOException;
+
+        }
+    }
+
+    private static final class IOScheduler {
+
+        private final ConcurrentLong2ReferenceChainedHashTable<RegionIOTasks> regionTasks = new ConcurrentLong2ReferenceChainedHashTable<>();
+        private final PrioritisedExecutor executor;
+
+        public IOScheduler(final PrioritisedExecutor executor) {
+            this.executor = executor;
+        }
+
+        public PrioritisedExecutor.PrioritisedTask createTask(final int chunkX, final int chunkZ,
+                                                              final Runnable run, final Priority priority) {
+            final PrioritisedExecutor.PrioritisedTask[] ret = new PrioritisedExecutor.PrioritisedTask[1];
+            final long subOrder = this.executor.generateNextSubOrder();
+            this.regionTasks.compute(CoordinateUtils.getChunkKey(chunkX >> REGION_FILE_SHIFT, chunkZ >> REGION_FILE_SHIFT),
+                    (final long regionKey, final RegionIOTasks existing) -> {
+                final RegionIOTasks res;
+                if (existing != null) {
+                    res = existing;
+                } else {
+                    res = new RegionIOTasks(regionKey, IOScheduler.this);
+                }
+
+                ret[0] = res.createTask(run, priority, subOrder);
+
+                return res;
+            });
+
+            return ret[0];
+        }
+    }
+
+    private static final class RegionIOTasks implements Runnable {
+
+        private static final Logger LOGGER = LoggerFactory.getLogger(RegionIOTasks.class);
+
+        private final PrioritisedTaskQueue queue = new PrioritisedTaskQueue();
+        private final long regionKey;
+        private final IOScheduler ioScheduler;
+        private long createdTasks;
+        private long executedTasks;
+
+        private PrioritisedExecutor.PrioritisedTask task;
+
+        public RegionIOTasks(final long regionKey, final IOScheduler ioScheduler) {
+            this.regionKey = regionKey;
+            this.ioScheduler = ioScheduler;
+        }
+
+        public PrioritisedExecutor.PrioritisedTask createTask(final Runnable run, final Priority priority,
+                                                              final long subOrder) {
+            ++this.createdTasks;
+            return new WrappedTask(this.queue.createTask(run, priority, subOrder));
+        }
+
+        private void adjustTaskPriority() {
+            final PrioritisedTaskQueue.PrioritySubOrderPair priority = this.queue.getHighestPrioritySubOrder();
+            if (this.task == null) {
+                if (priority == null) {
+                    return;
+                }
+                this.task = this.ioScheduler.executor.createTask(this, priority.priority(), priority.subOrder());
+                this.task.queue();
+            } else {
+                if (priority == null) {
+                    throw new IllegalStateException();
+                } else {
+                    this.task.setPriorityAndSubOrder(priority.priority(), priority.subOrder());
+                }
+            }
+        }
+
+        @Override
+        public void run() {
+            final Runnable run;
+            synchronized (this) {
+                run = this.queue.pollTask();
+            }
+
+            try {
+                run.run();
+            } finally {
+                synchronized (this) {
+                    this.task = null;
+                    this.adjustTaskPriority();
+                }
+                this.ioScheduler.regionTasks.compute(this.regionKey, (final long keyInMap, final RegionIOTasks tasks) -> {
+                    if (tasks != RegionIOTasks.this) {
+                        throw new IllegalStateException("Region task mismatch");
+                    }
+                    ++tasks.executedTasks;
+                    if (tasks.createdTasks != tasks.executedTasks) {
+                        return tasks;
+                    }
+
+                    if (tasks.task != null) {
+                        throw new IllegalStateException("Task may not be null when created==executed");
+                    }
+
+                    return null;
+                });
+            }
+        }
+
+        private final class WrappedTask implements PrioritisedExecutor.PrioritisedTask {
+
+            private final PrioritisedExecutor.PrioritisedTask wrapped;
+
+            public WrappedTask(final PrioritisedExecutor.PrioritisedTask wrap) {
+                this.wrapped = wrap;
+            }
+
+            @Override
+            public PrioritisedExecutor getExecutor() {
+                return RegionIOTasks.this.ioScheduler.executor;
+            }
+
+            @Override
+            public boolean queue() {
+                synchronized (RegionIOTasks.this) {
+                    if (this.wrapped.queue()) {
+                        RegionIOTasks.this.adjustTaskPriority();
+                        return true;
+                    }
+                    return false;
+                }
+            }
+
+            @Override
+            public boolean isQueued() {
+                return this.wrapped.isQueued();
+            }
+
+            @Override
+            public boolean cancel() {
+                throw new UnsupportedOperationException();
+            }
+
+            @Override
+            public boolean execute() {
+                throw new UnsupportedOperationException();
+            }
+
+            @Override
+            public Priority getPriority() {
+                return this.wrapped.getPriority();
+            }
+
+            @Override
+            public boolean setPriority(final Priority priority) {
+                synchronized (RegionIOTasks.this) {
+                    if (this.wrapped.setPriority(priority) && this.wrapped.isQueued()) {
+                        RegionIOTasks.this.adjustTaskPriority();
+                        return true;
+                    }
+                    return false;
+                }
+            }
+
+            @Override
+            public boolean raisePriority(final Priority priority) {
+                synchronized (RegionIOTasks.this) {
+                    if (this.wrapped.raisePriority(priority) && this.wrapped.isQueued()) {
+                        RegionIOTasks.this.adjustTaskPriority();
+                        return true;
+                    }
+                    return false;
+                }
+            }
+
+            @Override
+            public boolean lowerPriority(final Priority priority) {
+                synchronized (RegionIOTasks.this) {
+                    if (this.wrapped.lowerPriority(priority) && this.wrapped.isQueued()) {
+                        RegionIOTasks.this.adjustTaskPriority();
+                        return true;
+                    }
+                    return false;
+                }
+            }
+
+            @Override
+            public long getSubOrder() {
+                return this.wrapped.getSubOrder();
+            }
+
+            @Override
+            public boolean setSubOrder(final long subOrder) {
+                synchronized (RegionIOTasks.this) {
+                    if (this.wrapped.setSubOrder(subOrder) && this.wrapped.isQueued()) {
+                        RegionIOTasks.this.adjustTaskPriority();
+                        return true;
+                    }
+                    return false;
+                }
+            }
+
+            @Override
+            public boolean raiseSubOrder(final long subOrder) {
+                synchronized (RegionIOTasks.this) {
+                    if (this.wrapped.raiseSubOrder(subOrder) && this.wrapped.isQueued()) {
+                        RegionIOTasks.this.adjustTaskPriority();
+                        return true;
+                    }
+                    return false;
+                }
+            }
+
+            @Override
+            public boolean lowerSubOrder(final long subOrder) {
+                synchronized (RegionIOTasks.this) {
+                    if (this.wrapped.lowerSubOrder(subOrder) && this.wrapped.isQueued()) {
+                        RegionIOTasks.this.adjustTaskPriority();
+                        return true;
+                    }
+                    return false;
+                }
+            }
+
+            @Override
+            public boolean setPriorityAndSubOrder(final Priority priority, final long subOrder) {
+                synchronized (RegionIOTasks.this) {
+                    if (this.wrapped.setPriorityAndSubOrder(priority, subOrder) && this.wrapped.isQueued()) {
+                        RegionIOTasks.this.adjustTaskPriority();
+                        return true;
+                    }
+                    return false;
+                }
+            }
+        }
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/io/datacontroller/ChunkDataController.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/io/datacontroller/ChunkDataController.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/io/datacontroller/ChunkDataController.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.io.datacontroller;
+
+import ca.spottedleaf.moonrise.patches.chunk_system.io.ChunkSystemRegionFileStorage;
+import ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemChunkMap;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler;
+import ca.spottedleaf.moonrise.patches.chunk_system.storage.ChunkSystemChunkStorage;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.chunk.storage.RegionFileStorage;
+import java.io.IOException;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionException;
+
+public final class ChunkDataController extends MoonriseRegionFileIO.RegionDataController {
+
+    private final ServerLevel world;
+
+    public ChunkDataController(final ServerLevel world, final ChunkTaskScheduler taskScheduler) {
+        super(MoonriseRegionFileIO.RegionFileType.CHUNK_DATA, taskScheduler.ioExecutor, taskScheduler.compressionExecutor);
+        this.world = world;
+    }
+
+    @Override
+    public RegionFileStorage getCache() {
+        return ((ChunkSystemChunkStorage)this.world.getChunkSource().chunkMap).moonrise$getRegionStorage();
+    }
+
+    @Override
+    public WriteData startWrite(final int chunkX, final int chunkZ, final CompoundTag compound) throws IOException {
+        return ((ChunkSystemRegionFileStorage)this.getCache()).moonrise$startWrite(chunkX, chunkZ, compound);
+    }
+
+    @Override
+    public void finishWrite(final int chunkX, final int chunkZ, final WriteData writeData) throws IOException {
+        ((ChunkSystemChunkMap)this.world.getChunkSource().chunkMap).moonrise$writeFinishCallback(new ChunkPos(chunkX, chunkZ));
+        ((ChunkSystemRegionFileStorage)this.getCache()).moonrise$finishWrite(chunkX, chunkZ, writeData);
+    }
+
+    @Override
+    public ReadData readData(final int chunkX, final int chunkZ) throws IOException {
+        return ((ChunkSystemRegionFileStorage)this.getCache()).moonrise$readData(chunkX, chunkZ);
+    }
+
+    @Override
+    public CompoundTag finishRead(final int chunkX, final int chunkZ, final ReadData readData) throws IOException {
+        return ((ChunkSystemRegionFileStorage)this.getCache()).moonrise$finishRead(chunkX, chunkZ, readData);
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/io/datacontroller/EntityDataController.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/io/datacontroller/EntityDataController.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/io/datacontroller/EntityDataController.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.io.datacontroller;
+
+import ca.spottedleaf.moonrise.patches.chunk_system.io.ChunkSystemRegionFileStorage;
+import ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.chunk.storage.EntityStorage;
+import net.minecraft.world.level.chunk.storage.RegionFileStorage;
+import net.minecraft.world.level.chunk.storage.RegionStorageInfo;
+import java.io.IOException;
+import java.nio.file.Path;
+
+public final class EntityDataController extends MoonriseRegionFileIO.RegionDataController {
+
+    private final EntityRegionFileStorage storage;
+
+    public EntityDataController(final EntityRegionFileStorage storage, final ChunkTaskScheduler taskScheduler) {
+        super(MoonriseRegionFileIO.RegionFileType.ENTITY_DATA, taskScheduler.ioExecutor, taskScheduler.compressionExecutor);
+        this.storage = storage;
+    }
+
+    @Override
+    public RegionFileStorage getCache() {
+        return this.storage;
+    }
+
+    @Override
+    public WriteData startWrite(final int chunkX, final int chunkZ, final CompoundTag compound) throws IOException {
+        checkPosition(new ChunkPos(chunkX, chunkZ), compound);
+
+        return ((ChunkSystemRegionFileStorage)this.getCache()).moonrise$startWrite(chunkX, chunkZ, compound);
+    }
+
+    @Override
+    public void finishWrite(final int chunkX, final int chunkZ, final WriteData writeData) throws IOException {
+        ((ChunkSystemRegionFileStorage)this.getCache()).moonrise$finishWrite(chunkX, chunkZ, writeData);
+    }
+
+    @Override
+    public ReadData readData(final int chunkX, final int chunkZ) throws IOException {
+        return ((ChunkSystemRegionFileStorage)this.getCache()).moonrise$readData(chunkX, chunkZ);
+    }
+
+    @Override
+    public CompoundTag finishRead(final int chunkX, final int chunkZ, final ReadData readData) throws IOException {
+        return ((ChunkSystemRegionFileStorage)this.getCache()).moonrise$finishRead(chunkX, chunkZ, readData);
+    }
+
+    private static void checkPosition(final ChunkPos pos, final CompoundTag nbt) {
+        final ChunkPos nbtPos = nbt == null ? null : EntityStorage.readChunkPos(nbt);
+        if (nbtPos != null && !pos.equals(nbtPos)) {
+            throw new IllegalArgumentException(
+                    "Entity chunk coordinate and serialized data do not have matching coordinates, trying to serialize coordinate " + pos.toString()
+                            + " but compound says coordinate is " + nbtPos
+            );
+        }
+    }
+
+    public static final class EntityRegionFileStorage extends RegionFileStorage {
+
+        public EntityRegionFileStorage(final RegionStorageInfo regionStorageInfo, final Path directory,
+                                       final boolean dsync) {
+            super(regionStorageInfo, directory, dsync);
+        }
+
+        @Override
+        public void write(final ChunkPos pos, final CompoundTag nbt) throws IOException {
+            checkPosition(pos, nbt);
+            super.write(pos, nbt);
+        }
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/io/datacontroller/PoiDataController.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/io/datacontroller/PoiDataController.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/io/datacontroller/PoiDataController.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.io.datacontroller;
+
+import ca.spottedleaf.moonrise.patches.chunk_system.io.ChunkSystemRegionFileStorage;
+import ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.storage.ChunkSystemSectionStorage;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.world.level.chunk.storage.RegionFileStorage;
+import java.io.IOException;
+
+public final class PoiDataController extends MoonriseRegionFileIO.RegionDataController {
+
+    private final ServerLevel world;
+
+    public PoiDataController(final ServerLevel world, final ChunkTaskScheduler taskScheduler) {
+        super(MoonriseRegionFileIO.RegionFileType.POI_DATA, taskScheduler.ioExecutor, taskScheduler.compressionExecutor);
+        this.world = world;
+    }
+
+    @Override
+    public RegionFileStorage getCache() {
+        return ((ChunkSystemSectionStorage)this.world.getPoiManager()).moonrise$getRegionStorage();
+    }
+
+    @Override
+    public WriteData startWrite(final int chunkX, final int chunkZ, final CompoundTag compound) throws IOException {
+        return ((ChunkSystemRegionFileStorage)this.getCache()).moonrise$startWrite(chunkX, chunkZ, compound);
+    }
+
+    @Override
+    public void finishWrite(final int chunkX, final int chunkZ, final WriteData writeData) throws IOException {
+        ((ChunkSystemRegionFileStorage)this.getCache()).moonrise$finishWrite(chunkX, chunkZ, writeData);
+    }
+
+    @Override
+    public ReadData readData(final int chunkX, final int chunkZ) throws IOException {
+        return ((ChunkSystemRegionFileStorage)this.getCache()).moonrise$readData(chunkX, chunkZ);
+    }
+
+    @Override
+    public CompoundTag finishRead(final int chunkX, final int chunkZ, final ReadData readData) throws IOException {
+        return ((ChunkSystemRegionFileStorage)this.getCache()).moonrise$finishRead(chunkX, chunkZ, readData);
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/ChunkSystemChunkMap.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/ChunkSystemChunkMap.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/ChunkSystemChunkMap.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.level;
+
+import net.minecraft.world.level.ChunkPos;
+import java.io.IOException;
+
+public interface ChunkSystemChunkMap {
+
+    public void moonrise$writeFinishCallback(final ChunkPos pos) throws IOException;
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/ChunkSystemLevel.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/ChunkSystemLevel.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/ChunkSystemLevel.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.level;
+
+import ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkData;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.entity.EntityLookup;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.LevelChunk;
+import net.minecraft.world.level.chunk.status.ChunkStatus;
+
+public interface ChunkSystemLevel {
+
+    public EntityLookup moonrise$getEntityLookup();
+
+    public void moonrise$setEntityLookup(final EntityLookup entityLookup);
+
+    public LevelChunk moonrise$getFullChunkIfLoaded(final int chunkX, final int chunkZ);
+
+    public ChunkAccess moonrise$getAnyChunkIfLoaded(final int chunkX, final int chunkZ);
+
+    public ChunkAccess moonrise$getSpecificChunkIfLoaded(final int chunkX, final int chunkZ, final ChunkStatus leastStatus);
+
+    public void moonrise$midTickTasks();
+
+    public ChunkData moonrise$getChunkData(final long chunkKey);
+
+    public ChunkData moonrise$getChunkData(final int chunkX, final int chunkZ);
+
+    public ChunkData moonrise$requestChunkData(final long chunkKey);
+
+    public ChunkData moonrise$releaseChunkData(final long chunkKey);
+
+    public boolean moonrise$areChunksLoaded(final int fromX, final int fromZ, final int toX, final int toZ);
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/ChunkSystemLevelReader.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/ChunkSystemLevelReader.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/ChunkSystemLevelReader.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.level;
+
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.status.ChunkStatus;
+
+public interface ChunkSystemLevelReader {
+
+    public ChunkAccess moonrise$syncLoadNonFull(final int chunkX, final int chunkZ, final ChunkStatus status);
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/ChunkSystemServerLevel.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/ChunkSystemServerLevel.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/ChunkSystemServerLevel.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.level;
+
+import ca.spottedleaf.concurrentutil.util.Priority;
+import ca.spottedleaf.moonrise.common.list.ReferenceList;
+import ca.spottedleaf.moonrise.common.misc.NearbyPlayers;
+import ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO;
+import ca.spottedleaf.moonrise.patches.chunk_system.player.RegionizedPlayerChunkLoader;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler;
+import net.minecraft.core.BlockPos;
+import net.minecraft.server.level.ChunkHolder;
+import net.minecraft.server.level.ServerChunkCache;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.status.ChunkStatus;
+import java.util.List;
+import java.util.function.Consumer;
+
+public interface ChunkSystemServerLevel extends ChunkSystemLevel {
+
+    public ChunkTaskScheduler moonrise$getChunkTaskScheduler();
+
+    public MoonriseRegionFileIO.RegionDataController moonrise$getChunkDataController();
+
+    public MoonriseRegionFileIO.RegionDataController moonrise$getPoiChunkDataController();
+
+    public MoonriseRegionFileIO.RegionDataController moonrise$getEntityChunkDataController();
+
+    public int moonrise$getRegionChunkShift();
+
+    // Paper
+
+    public RegionizedPlayerChunkLoader moonrise$getPlayerChunkLoader();
+
+    public void moonrise$loadChunksAsync(final BlockPos pos, final int radiusBlocks,
+                                         final Priority priority,
+                                         final Consumer<List<ChunkAccess>> onLoad);
+
+    public void moonrise$loadChunksAsync(final BlockPos pos, final int radiusBlocks,
+                                         final ChunkStatus chunkStatus, final Priority priority,
+                                         final Consumer<List<ChunkAccess>> onLoad);
+
+    public void moonrise$loadChunksAsync(final int minChunkX, final int maxChunkX, final int minChunkZ, final int maxChunkZ,
+                                         final Priority priority,
+                                         final Consumer<List<ChunkAccess>> onLoad);
+
+    public void moonrise$loadChunksAsync(final int minChunkX, final int maxChunkX, final int minChunkZ, final int maxChunkZ,
+                                         final ChunkStatus chunkStatus, final Priority priority,
+                                         final Consumer<List<ChunkAccess>> onLoad);
+
+    public RegionizedPlayerChunkLoader.ViewDistanceHolder moonrise$getViewDistanceHolder();
+
+    public long moonrise$getLastMidTickFailure();
+
+    public void moonrise$setLastMidTickFailure(final long time);
+
+    public NearbyPlayers moonrise$getNearbyPlayers();
+
+    public ReferenceList<ServerChunkCache.ChunkAndHolder> moonrise$getLoadedChunks();
+
+    public ReferenceList<ServerChunkCache.ChunkAndHolder> moonrise$getTickingChunks();
+
+    public ReferenceList<ServerChunkCache.ChunkAndHolder> moonrise$getEntityTickingChunks();
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/chunk/ChunkData.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/chunk/ChunkData.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/chunk/ChunkData.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.level.chunk;
+
+import ca.spottedleaf.moonrise.common.misc.NearbyPlayers;
+
+public final class ChunkData {
+
+    private int referenceCount = 0;
+    public NearbyPlayers.TrackedChunk nearbyPlayers; // Moonrise - nearby players
+
+    public ChunkData() {
+
+    }
+
+    public int increaseRef() {
+        return ++this.referenceCount;
+    }
+
+    public int decreaseRef() {
+        return --this.referenceCount;
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/chunk/ChunkSystemChunkHolder.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/chunk/ChunkSystemChunkHolder.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/chunk/ChunkSystemChunkHolder.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.level.chunk;
+
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.level.chunk.LevelChunk;
+import java.util.List;
+
+public interface ChunkSystemChunkHolder {
+
+    public NewChunkHolder moonrise$getRealChunkHolder();
+
+    public void moonrise$setRealChunkHolder(final NewChunkHolder newChunkHolder);
+
+    public void moonrise$addReceivedChunk(final ServerPlayer player);
+
+    public void moonrise$removeReceivedChunk(final ServerPlayer player);
+
+    public boolean moonrise$hasChunkBeenSent();
+
+    public boolean moonrise$hasChunkBeenSent(final ServerPlayer to);
+
+    public List<ServerPlayer> moonrise$getPlayers(final boolean onlyOnWatchDistanceEdge);
+
+    public LevelChunk moonrise$getFullChunk();
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/chunk/ChunkSystemChunkStatus.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/chunk/ChunkSystemChunkStatus.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/chunk/ChunkSystemChunkStatus.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.level.chunk;
+
+import net.minecraft.world.level.chunk.status.ChunkStatus;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+public interface ChunkSystemChunkStatus {
+
+    public boolean moonrise$isParallelCapable();
+
+    public void moonrise$setParallelCapable(final boolean value);
+
+    public int moonrise$getWriteRadius();
+
+    public void moonrise$setWriteRadius(final int value);
+
+    public ChunkStatus moonrise$getNextStatus();
+
+    public boolean moonrise$isEmptyLoadStatus();
+
+    public void moonrise$setEmptyLoadStatus(final boolean value);
+
+    public boolean moonrise$isEmptyGenStatus();
+
+    public AtomicBoolean moonrise$getWarnedAboutNoImmediateComplete();
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/chunk/ChunkSystemDistanceManager.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/chunk/ChunkSystemDistanceManager.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/chunk/ChunkSystemDistanceManager.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.level.chunk;
+
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkHolderManager;
+import net.minecraft.server.level.ChunkMap;
+
+public interface ChunkSystemDistanceManager {
+
+    public ChunkMap moonrise$getChunkMap();
+
+    public ChunkHolderManager moonrise$getChunkHolderManager();
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/chunk/ChunkSystemLevelChunk.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/chunk/ChunkSystemLevelChunk.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/chunk/ChunkSystemLevelChunk.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.level.chunk;
+
+import net.minecraft.server.level.ServerChunkCache;
+
+public interface ChunkSystemLevelChunk {
+
+    public boolean moonrise$isPostProcessingDone();
+
+    public ServerChunkCache.ChunkAndHolder moonrise$getChunkAndHolder();
+
+    public void moonrise$setChunkAndHolder(final ServerChunkCache.ChunkAndHolder holder);
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/entity/ChunkEntitySlices.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/entity/ChunkEntitySlices.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/entity/ChunkEntitySlices.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.level.entity;
+
+import ca.spottedleaf.moonrise.common.PlatformHooks;
+import ca.spottedleaf.moonrise.common.list.EntityList;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkData;
+import ca.spottedleaf.moonrise.patches.chunk_system.entity.ChunkSystemEntity;
+import com.google.common.collect.ImmutableList;
+import it.unimi.dsi.fastutil.objects.Reference2ObjectMap;
+import it.unimi.dsi.fastutil.objects.Reference2ObjectOpenHashMap;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.ListTag;
+import net.minecraft.nbt.NbtUtils;
+import net.minecraft.nbt.Tag;
+import net.minecraft.server.level.FullChunkStatus;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.util.Mth;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.entity.EntitySpawnReason;
+import net.minecraft.world.entity.EntityType;
+import net.minecraft.world.entity.boss.EnderDragonPart;
+import net.minecraft.world.entity.boss.enderdragon.EnderDragon;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.chunk.storage.EntityStorage;
+import net.minecraft.world.level.entity.Visibility;
+import net.minecraft.world.phys.AABB;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+import java.util.function.Predicate;
+
+public final class ChunkEntitySlices {
+
+    public final int minSection;
+    public final int maxSection;
+    public final int chunkX;
+    public final int chunkZ;
+    public final Level world;
+
+    private final EntityCollectionBySection allEntities;
+    private final EntityCollectionBySection hardCollidingEntities;
+    private final Reference2ObjectOpenHashMap<Class<? extends Entity>, EntityCollectionBySection> entitiesByClass;
+    private final Reference2ObjectOpenHashMap<EntityType<?>, EntityCollectionBySection> entitiesByType;
+    private final EntityList entities = new EntityList();
+
+    public FullChunkStatus status;
+    public final ChunkData chunkData;
+
+    private boolean isTransient;
+
+    public boolean isTransient() {
+        return this.isTransient;
+    }
+
+    public void setTransient(final boolean value) {
+        this.isTransient = value;
+    }
+
+    public ChunkEntitySlices(final Level world, final int chunkX, final int chunkZ, final FullChunkStatus status,
+                             final ChunkData chunkData, final int minSection, final int maxSection) { // inclusive, inclusive
+        this.minSection = minSection;
+        this.maxSection = maxSection;
+        this.chunkX = chunkX;
+        this.chunkZ = chunkZ;
+        this.world = world;
+
+        this.allEntities = new EntityCollectionBySection(this);
+        this.hardCollidingEntities = new EntityCollectionBySection(this);
+        this.entitiesByClass = new Reference2ObjectOpenHashMap<>();
+        this.entitiesByType = new Reference2ObjectOpenHashMap<>();
+
+        this.status = status;
+        this.chunkData = chunkData;
+    }
+
+    public static List<Entity> readEntities(final ServerLevel world, final CompoundTag compoundTag) {
+        // TODO check this and below on update for format changes
+        return EntityType.loadEntitiesRecursive(compoundTag.getList("Entities", 10), world, EntitySpawnReason.LOAD).collect(ImmutableList.toImmutableList());
+    }
+
+    // Paper start - rewrite chunk system
+    public static void copyEntities(final CompoundTag from, final CompoundTag into) {
+        if (from == null) {
+            return;
+        }
+        final ListTag entitiesFrom = from.getList("Entities", Tag.TAG_COMPOUND);
+        if (entitiesFrom == null || entitiesFrom.isEmpty()) {
+            return;
+        }
+
+        final ListTag entitiesInto = into.getList("Entities", Tag.TAG_COMPOUND);
+        into.put("Entities", entitiesInto); // this is in case into doesn't have any entities
+        entitiesInto.addAll(0, entitiesFrom);
+    }
+
+    public static CompoundTag saveEntityChunk(final List<Entity> entities, final ChunkPos chunkPos, final ServerLevel world) {
+        return saveEntityChunk0(entities, chunkPos, world, false);
+    }
+
+    public static CompoundTag saveEntityChunk0(final List<Entity> entities, final ChunkPos chunkPos, final ServerLevel world, final boolean force) {
+        if (!force && entities.isEmpty()) {
+            return null;
+        }
+
+        final ListTag entitiesTag = new ListTag();
+        for (final Entity entity : PlatformHooks.get().modifySavedEntities(world, chunkPos.x, chunkPos.z, entities)) {
+            CompoundTag compoundTag = new CompoundTag();
+            if (entity.save(compoundTag)) {
+                entitiesTag.add(compoundTag);
+            }
+        }
+        final CompoundTag ret = NbtUtils.addCurrentDataVersion(new CompoundTag());
+        ret.put("Entities", entitiesTag);
+        EntityStorage.writeChunkPos(ret, chunkPos);
+
+        return !force && entitiesTag.isEmpty() ? null : ret;
+    }
+
+    public CompoundTag save() {
+        final int len = this.entities.size();
+        if (len == 0) {
+            return null;
+        }
+
+        final Entity[] rawData = this.entities.getRawData();
+        final List<Entity> collectedEntities = new ArrayList<>(len);
+        for (int i = 0; i < len; ++i) {
+            final Entity entity = rawData[i];
+            if (entity.shouldBeSaved()) {
+                collectedEntities.add(entity);
+            }
+        }
+
+        if (collectedEntities.isEmpty()) {
+            return null;
+        }
+
+        return saveEntityChunk(collectedEntities, new ChunkPos(this.chunkX, this.chunkZ), (ServerLevel)this.world);
+    }
+
+    // returns true if this chunk has transient entities remaining
+    public boolean unload() {
+        final int len = this.entities.size();
+        final Entity[] collectedEntities = Arrays.copyOf(this.entities.getRawData(), len);
+
+        for (int i = 0; i < len; ++i) {
+            final Entity entity = collectedEntities[i];
+            if (entity.isRemoved()) {
+                // removed by us below
+                continue;
+            }
+            if (entity.shouldBeSaved()) {
+                PlatformHooks.get().unloadEntity(entity);
+                if (entity.isVehicle()) {
+                    // we cannot assume that these entities are contained within this chunk, because entities can
+                    // desync - so we need to remove them all
+                    for (final Entity passenger : entity.getIndirectPassengers()) {
+                        PlatformHooks.get().unloadEntity(passenger);
+                    }
+                }
+            }
+        }
+
+        return this.entities.size() != 0;
+    }
+
+    public List<Entity> getAllEntities() {
+        final int len = this.entities.size();
+        if (len == 0) {
+            return new ArrayList<>();
+        }
+
+        final Entity[] rawData = this.entities.getRawData();
+        final List<Entity> collectedEntities = new ArrayList<>(len);
+        for (int i = 0; i < len; ++i) {
+            collectedEntities.add(rawData[i]);
+        }
+
+        return collectedEntities;
+    }
+
+    public boolean isEmpty() {
+        return this.entities.size() == 0;
+    }
+
+    public void mergeInto(final ChunkEntitySlices slices) {
+        final Entity[] entities = this.entities.getRawData();
+        for (int i = 0, size = Math.min(entities.length, this.entities.size()); i < size; ++i) {
+            final Entity entity = entities[i];
+            slices.addEntity(entity, ((ChunkSystemEntity)entity).moonrise$getSectionY());
+        }
+    }
+
+    private boolean preventStatusUpdates;
+    public boolean startPreventingStatusUpdates() {
+        final boolean ret = this.preventStatusUpdates;
+        this.preventStatusUpdates = true;
+        return ret;
+    }
+
+    public boolean isPreventingStatusUpdates() {
+        return this.preventStatusUpdates;
+    }
+
+    public void stopPreventingStatusUpdates(final boolean prev) {
+        this.preventStatusUpdates = prev;
+    }
+
+    public void updateStatus(final FullChunkStatus status, final EntityLookup lookup) {
+        this.status = status;
+
+        final Entity[] entities = this.entities.getRawData();
+
+        for (int i = 0, size = this.entities.size(); i < size; ++i) {
+            final Entity entity = entities[i];
+
+            final Visibility oldVisibility = EntityLookup.getEntityStatus(entity);
+            ((ChunkSystemEntity)entity).moonrise$setChunkStatus(status);
+            final Visibility newVisibility = EntityLookup.getEntityStatus(entity);
+
+            lookup.entityStatusChange(entity, this, oldVisibility, newVisibility, false, false, false);
+        }
+    }
+
+    public boolean addEntity(final Entity entity, final int chunkSection) {
+        if (!this.entities.add(entity)) {
+            return false;
+        }
+        ((ChunkSystemEntity)entity).moonrise$setChunkStatus(this.status);
+        ((ChunkSystemEntity)entity).moonrise$setChunkData(this.chunkData);
+        final int sectionIndex = chunkSection - this.minSection;
+
+        this.allEntities.addEntity(entity, sectionIndex);
+
+        if (((ChunkSystemEntity)entity).moonrise$isHardColliding()) {
+            this.hardCollidingEntities.addEntity(entity, sectionIndex);
+        }
+
+        for (final Iterator<Reference2ObjectMap.Entry<Class<? extends Entity>, EntityCollectionBySection>> iterator =
+             this.entitiesByClass.reference2ObjectEntrySet().fastIterator(); iterator.hasNext();) {
+            final Reference2ObjectMap.Entry<Class<? extends Entity>, EntityCollectionBySection> entry = iterator.next();
+
+            if (entry.getKey().isInstance(entity)) {
+                entry.getValue().addEntity(entity, sectionIndex);
+            }
+        }
+
+        EntityCollectionBySection byType = this.entitiesByType.get(entity.getType());
+        if (byType != null) {
+            byType.addEntity(entity, sectionIndex);
+        } else {
+            this.entitiesByType.put(entity.getType(), byType = new EntityCollectionBySection(this));
+            byType.addEntity(entity, sectionIndex);
+        }
+
+        return true;
+    }
+
+    public boolean removeEntity(final Entity entity, final int chunkSection) {
+        if (!this.entities.remove(entity)) {
+            return false;
+        }
+        ((ChunkSystemEntity)entity).moonrise$setChunkStatus(null);
+        ((ChunkSystemEntity)entity).moonrise$setChunkData(null);
+        final int sectionIndex = chunkSection - this.minSection;
+
+        this.allEntities.removeEntity(entity, sectionIndex);
+
+        if (((ChunkSystemEntity)entity).moonrise$isHardColliding()) {
+            this.hardCollidingEntities.removeEntity(entity, sectionIndex);
+        }
+
+        for (final Iterator<Reference2ObjectMap.Entry<Class<? extends Entity>, EntityCollectionBySection>> iterator =
+             this.entitiesByClass.reference2ObjectEntrySet().fastIterator(); iterator.hasNext();) {
+            final Reference2ObjectMap.Entry<Class<? extends Entity>, EntityCollectionBySection> entry = iterator.next();
+
+            if (entry.getKey().isInstance(entity)) {
+                entry.getValue().removeEntity(entity, sectionIndex);
+            }
+        }
+
+        final EntityCollectionBySection byType = this.entitiesByType.get(entity.getType());
+        byType.removeEntity(entity, sectionIndex);
+
+        return true;
+    }
+
+    public void getHardCollidingEntities(final Entity except, final AABB box, final List<Entity> into, final Predicate<? super Entity> predicate) {
+        this.hardCollidingEntities.getEntities(except, box, into, predicate);
+    }
+
+    public void getEntities(final Entity except, final AABB box, final List<Entity> into, final Predicate<? super Entity> predicate) {
+        this.allEntities.getEntities(except, box, into, predicate);
+    }
+
+
+    public boolean getEntities(final Entity except, final AABB box, final List<Entity> into, final Predicate<? super Entity> predicate,
+                               final int maxCount) {
+        return this.allEntities.getEntitiesLimited(except, box, into, predicate, maxCount);
+    }
+
+    public <T extends Entity> void getEntities(final EntityType<?> type, final AABB box, final List<? super T> into,
+                                               final Predicate<? super T> predicate) {
+        final EntityCollectionBySection byType = this.entitiesByType.get(type);
+
+        if (byType != null) {
+            byType.getEntities((Entity)null, box, (List)into, (Predicate) predicate);
+        }
+    }
+
+    public <T extends Entity> boolean getEntities(final EntityType<?> type, final AABB box, final List<? super T> into,
+                                                  final Predicate<? super T> predicate, final int maxCount) {
+        final EntityCollectionBySection byType = this.entitiesByType.get(type);
+
+        if (byType != null) {
+            return byType.getEntitiesLimited((Entity)null, box, (List)into, (Predicate)predicate, maxCount);
+        }
+
+        return false;
+    }
+
+    protected EntityCollectionBySection initClass(final Class<? extends Entity> clazz) {
+        final EntityCollectionBySection ret = new EntityCollectionBySection(this);
+
+        for (int sectionIndex = 0; sectionIndex < this.allEntities.entitiesBySection.length; ++sectionIndex) {
+            final BasicEntityList<Entity> sectionEntities = this.allEntities.entitiesBySection[sectionIndex];
+            if (sectionEntities == null) {
+                continue;
+            }
+
+            final Entity[] storage = sectionEntities.storage;
+
+            for (int i = 0, len = Math.min(storage.length, sectionEntities.size()); i < len; ++i) {
+                final Entity entity = storage[i];
+
+                if (clazz.isInstance(entity)) {
+                    ret.addEntity(entity, sectionIndex);
+                }
+            }
+        }
+
+        return ret;
+    }
+
+    public <T extends Entity> void getEntities(final Class<? extends T> clazz, final Entity except, final AABB box, final List<? super T> into,
+                                               final Predicate<? super T> predicate) {
+        EntityCollectionBySection collection = this.entitiesByClass.get(clazz);
+        if (collection != null) {
+            collection.getEntities(except, box, (List)into, (Predicate)predicate);
+        } else {
+            this.entitiesByClass.put(clazz, collection = this.initClass(clazz));
+            collection.getEntities(except, box, (List)into, (Predicate)predicate);
+        }
+    }
+
+    public <T extends Entity> boolean getEntities(final Class<? extends T> clazz, final Entity except, final AABB box, final List<? super T> into,
+                                                  final Predicate<? super T> predicate, final int maxCount) {
+        EntityCollectionBySection collection = this.entitiesByClass.get(clazz);
+        if (collection != null) {
+            return collection.getEntitiesLimited(except, box, (List)into, (Predicate)predicate, maxCount);
+        } else {
+            this.entitiesByClass.put(clazz, collection = this.initClass(clazz));
+            return collection.getEntitiesLimited(except, box, (List)into, (Predicate)predicate, maxCount);
+        }
+    }
+
+    private static final class BasicEntityList<E extends Entity> {
+
+        private static final Entity[] EMPTY = new Entity[0];
+        private static final int DEFAULT_CAPACITY = 4;
+
+        private E[] storage;
+        private int size;
+
+        public BasicEntityList() {
+            this(0);
+        }
+
+        public BasicEntityList(final int cap) {
+            this.storage = (E[])(cap <= 0 ? EMPTY : new Entity[cap]);
+        }
+
+        public boolean isEmpty() {
+            return this.size == 0;
+        }
+
+        public int size() {
+            return this.size;
+        }
+
+        private void resize() {
+            if (this.storage == EMPTY) {
+                this.storage = (E[])new Entity[DEFAULT_CAPACITY];
+            } else {
+                this.storage = Arrays.copyOf(this.storage, this.storage.length * 2);
+            }
+        }
+
+        public void add(final E entity) {
+            final int idx = this.size++;
+            if (idx >= this.storage.length) {
+                this.resize();
+                this.storage[idx] = entity;
+            } else {
+                this.storage[idx] = entity;
+            }
+        }
+
+        public int indexOf(final E entity) {
+            final E[] storage = this.storage;
+
+            for (int i = 0, len = Math.min(this.storage.length, this.size); i < len; ++i) {
+                if (storage[i] == entity) {
+                    return i;
+                }
+            }
+
+            return -1;
+        }
+
+        public boolean remove(final E entity) {
+            final int idx = this.indexOf(entity);
+            if (idx == -1) {
+                return false;
+            }
+
+            final int size = --this.size;
+            final E[] storage = this.storage;
+            if (idx != size) {
+                System.arraycopy(storage, idx + 1, storage, idx, size - idx);
+            }
+
+            storage[size] = null;
+
+            return true;
+        }
+
+        public boolean has(final E entity) {
+            return this.indexOf(entity) != -1;
+        }
+    }
+
+    private static final class EntityCollectionBySection {
+
+        private final ChunkEntitySlices slices;
+        private final BasicEntityList<Entity>[] entitiesBySection;
+        private int count;
+
+        public EntityCollectionBySection(final ChunkEntitySlices slices) {
+            this.slices = slices;
+
+            final int sectionCount = slices.maxSection - slices.minSection + 1;
+
+            this.entitiesBySection = new BasicEntityList[sectionCount];
+        }
+
+        public void addEntity(final Entity entity, final int sectionIndex) {
+            BasicEntityList<Entity> list = this.entitiesBySection[sectionIndex];
+
+            if (list != null && list.has(entity)) {
+                return;
+            }
+
+            if (list == null) {
+                this.entitiesBySection[sectionIndex] = list = new BasicEntityList<>();
+            }
+
+            list.add(entity);
+            ++this.count;
+        }
+
+        public void removeEntity(final Entity entity, final int sectionIndex) {
+            final BasicEntityList<Entity> list = this.entitiesBySection[sectionIndex];
+
+            if (list == null || !list.remove(entity)) {
+                return;
+            }
+
+            --this.count;
+
+            if (list.isEmpty()) {
+                this.entitiesBySection[sectionIndex] = null;
+            }
+        }
+
+        public void getEntities(final Entity except, final AABB box, final List<Entity> into, final Predicate<? super Entity> predicate) {
+            if (this.count == 0) {
+                return;
+            }
+
+            final int minSection = this.slices.minSection;
+            final int maxSection = this.slices.maxSection;
+
+            final int min = Mth.clamp(Mth.floor(box.minY - 2.0) >> 4, minSection, maxSection);
+            final int max = Mth.clamp(Mth.floor(box.maxY + 2.0) >> 4, minSection, maxSection);
+
+            final BasicEntityList<Entity>[] entitiesBySection = this.entitiesBySection;
+
+            for (int section = min; section <= max; ++section) {
+                final BasicEntityList<Entity> list = entitiesBySection[section - minSection];
+
+                if (list == null) {
+                    continue;
+                }
+
+                final Entity[] storage = list.storage;
+
+                for (int i = 0, len = Math.min(storage.length, list.size()); i < len; ++i) {
+                    final Entity entity = storage[i];
+
+                    if (entity == null || entity == except || !entity.getBoundingBox().intersects(box)) {
+                        continue;
+                    }
+
+                    if (predicate != null && !predicate.test(entity)) {
+                        continue;
+                    }
+
+                    into.add(entity);
+                }
+            }
+        }
+
+        public boolean getEntitiesLimited(final Entity except, final AABB box, final List<Entity> into, final Predicate<? super Entity> predicate,
+                                          final int maxCount) {
+            if (this.count == 0) {
+                return false;
+            }
+
+            final int minSection = this.slices.minSection;
+            final int maxSection = this.slices.maxSection;
+
+            final int min = Mth.clamp(Mth.floor(box.minY - 2.0) >> 4, minSection, maxSection);
+            final int max = Mth.clamp(Mth.floor(box.maxY + 2.0) >> 4, minSection, maxSection);
+
+            final BasicEntityList<Entity>[] entitiesBySection = this.entitiesBySection;
+
+            for (int section = min; section <= max; ++section) {
+                final BasicEntityList<Entity> list = entitiesBySection[section - minSection];
+
+                if (list == null) {
+                    continue;
+                }
+
+                final Entity[] storage = list.storage;
+
+                for (int i = 0, len = Math.min(storage.length, list.size()); i < len; ++i) {
+                    final Entity entity = storage[i];
+
+                    if (entity == null || entity == except || !entity.getBoundingBox().intersects(box)) {
+                        continue;
+                    }
+
+                    if (predicate != null && !predicate.test(entity)) {
+                        continue;
+                    }
+
+                    into.add(entity);
+                    if (into.size() >= maxCount) {
+                        return true;
+                    }
+                }
+            }
+
+            return false;
+        }
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/entity/EntityLookup.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/entity/EntityLookup.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/entity/EntityLookup.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.level.entity;
+
+import ca.spottedleaf.concurrentutil.map.ConcurrentLong2ReferenceChainedHashTable;
+import ca.spottedleaf.concurrentutil.map.SWMRLong2ObjectHashTable;
+import ca.spottedleaf.moonrise.common.list.EntityList;
+import ca.spottedleaf.moonrise.common.util.CoordinateUtils;
+import ca.spottedleaf.moonrise.common.util.WorldUtil;
+import ca.spottedleaf.moonrise.patches.chunk_system.entity.ChunkSystemEntity;
+import net.minecraft.core.BlockPos;
+import net.minecraft.server.level.FullChunkStatus;
+import net.minecraft.util.AbortableIterationConsumer;
+import net.minecraft.util.Mth;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.entity.EntityType;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.entity.EntityInLevelCallback;
+import net.minecraft.world.level.entity.EntityTypeTest;
+import net.minecraft.world.level.entity.LevelCallback;
+import net.minecraft.world.level.entity.LevelEntityGetter;
+import net.minecraft.world.level.entity.Visibility;
+import net.minecraft.world.phys.AABB;
+import net.minecraft.world.phys.Vec3;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+import java.util.NoSuchElementException;
+import java.util.Objects;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.Consumer;
+import java.util.function.Predicate;
+
+public abstract class EntityLookup implements LevelEntityGetter<Entity> {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(EntityLookup.class);
+
+    protected static final int REGION_SHIFT = 5;
+    protected static final int REGION_MASK = (1 << REGION_SHIFT) - 1;
+    protected static final int REGION_SIZE = 1 << REGION_SHIFT;
+
+    public final Level world;
+
+    protected final SWMRLong2ObjectHashTable<ChunkSlicesRegion> regions = new SWMRLong2ObjectHashTable<>(128, 0.5f);
+
+    protected final LevelCallback<Entity> worldCallback;
+
+    protected final ConcurrentLong2ReferenceChainedHashTable<Entity> entityById = new ConcurrentLong2ReferenceChainedHashTable<>();
+    protected final ConcurrentHashMap<UUID, Entity> entityByUUID = new ConcurrentHashMap<>();
+    protected final EntityList accessibleEntities = new EntityList();
+
+    public EntityLookup(final Level world, final LevelCallback<Entity> worldCallback) {
+        this.world = world;
+        this.worldCallback = worldCallback;
+    }
+
+    protected abstract Boolean blockTicketUpdates();
+
+    protected abstract void setBlockTicketUpdates(final Boolean value);
+
+    protected abstract void checkThread(final int chunkX, final int chunkZ, final String reason);
+
+    protected abstract void checkThread(final Entity entity, final String reason);
+
+    protected abstract ChunkEntitySlices createEntityChunk(final int chunkX, final int chunkZ, final boolean transientChunk);
+
+    protected abstract void onEmptySlices(final int chunkX, final int chunkZ);
+
+    protected abstract void entitySectionChangeCallback(
+        final Entity entity,
+        final int oldSectionX, final int oldSectionY, final int oldSectionZ,
+        final int newSectionX, final int newSectionY, final int newSectionZ
+    );
+
+    protected abstract void addEntityCallback(final Entity entity);
+
+    protected abstract void removeEntityCallback(final Entity entity);
+
+    protected abstract void entityStartLoaded(final Entity entity);
+
+    protected abstract void entityEndLoaded(final Entity entity);
+
+    protected abstract void entityStartTicking(final Entity entity);
+
+    protected abstract void entityEndTicking(final Entity entity);
+
+    protected abstract boolean screenEntity(final Entity entity, final boolean fromDisk, final boolean event);
+
+    private static Entity maskNonAccessible(final Entity entity) {
+        if (entity == null) {
+            return null;
+        }
+        final Visibility visibility = EntityLookup.getEntityStatus(entity);
+        return visibility.isAccessible() ? entity : null;
+    }
+
+    @Override
+    public Entity get(final int id) {
+        return maskNonAccessible(this.entityById.get((long)id));
+    }
+
+    @Override
+    public Entity get(final UUID id) {
+        return maskNonAccessible(id == null ? null : this.entityByUUID.get(id));
+    }
+
+    public boolean hasEntity(final UUID uuid) {
+        return this.get(uuid) != null;
+    }
+
+    public String getDebugInfo() {
+        return "count_id:" + this.entityById.size() + ",count_uuid:" + this.entityByUUID.size() + ",count_accessible:" + this.getEntityCount() + ",region_count:" + this.regions.size();
+    }
+
+    protected static final class ArrayIterable<T> implements Iterable<T> {
+
+        private final T[] array;
+        private final int off;
+        private final int length;
+
+        public ArrayIterable(final T[] array, final int off, final int length) {
+            this.array = array;
+            this.off = off;
+            this.length = length;
+            if (length > array.length) {
+                throw new IllegalArgumentException("Length must be no greater-than the array length");
+            }
+        }
+
+        @Override
+        public Iterator<T> iterator() {
+            return new ArrayIterator<>(this.array, this.off, this.length);
+        }
+
+        protected static final class ArrayIterator<T> implements Iterator<T> {
+
+            private final T[] array;
+            private int off;
+            private final int length;
+
+            public ArrayIterator(final T[] array, final int off, final int length) {
+                this.array = array;
+                this.off = off;
+                this.length = length;
+            }
+
+            @Override
+            public boolean hasNext() {
+                return this.off < this.length;
+            }
+
+            @Override
+            public T next() {
+                if (this.off >= this.length) {
+                    throw new NoSuchElementException();
+                }
+                return this.array[this.off++];
+            }
+
+            @Override
+            public void remove() {
+                throw new UnsupportedOperationException();
+            }
+        }
+    }
+
+    @Override
+    public Iterable<Entity> getAll() {
+        synchronized (this.accessibleEntities) {
+            final int len = this.accessibleEntities.size();
+            final Entity[] cpy = Arrays.copyOf(this.accessibleEntities.getRawData(), len, Entity[].class);
+
+            Objects.checkFromToIndex(0, len, cpy.length);
+
+            return new ArrayIterable<>(cpy, 0, len);
+        }
+    }
+
+    public int getEntityCount() {
+        synchronized (this.accessibleEntities) {
+            return this.accessibleEntities.size();
+        }
+    }
+
+    public Entity[] getAllCopy() {
+        synchronized (this.accessibleEntities) {
+            return Arrays.copyOf(this.accessibleEntities.getRawData(), this.accessibleEntities.size(), Entity[].class);
+        }
+    }
+
+    @Override
+    public <U extends Entity> void get(final EntityTypeTest<Entity, U> filter, final AbortableIterationConsumer<U> action) {
+        for (final Iterator<Entity> iterator = this.entityById.valueIterator(); iterator.hasNext();) {
+            final Entity entity = iterator.next();
+            final Visibility visibility = EntityLookup.getEntityStatus(entity);
+            if (!visibility.isAccessible()) {
+                continue;
+            }
+            final U casted = filter.tryCast(entity);
+            if (casted != null && action.accept(casted).shouldAbort()) {
+                break;
+            }
+        }
+    }
+
+    @Override
+    public void get(final AABB box, final Consumer<Entity> action) {
+        List<Entity> entities = new ArrayList<>();
+        this.getEntities((Entity)null, box, entities, null);
+        for (int i = 0, len = entities.size(); i < len; ++i) {
+            action.accept(entities.get(i));
+        }
+    }
+
+    @Override
+    public <U extends Entity> void get(final EntityTypeTest<Entity, U> filter, final AABB box, final AbortableIterationConsumer<U> action) {
+        List<Entity> entities = new ArrayList<>();
+        this.getEntities((Entity)null, box, entities, null);
+        for (int i = 0, len = entities.size(); i < len; ++i) {
+            final U casted = filter.tryCast(entities.get(i));
+            if (casted != null && action.accept(casted).shouldAbort()) {
+                break;
+            }
+        }
+    }
+
+    public void entityStatusChange(final Entity entity, final ChunkEntitySlices slices, final Visibility oldVisibility, final Visibility newVisibility, final boolean moved,
+                                   final boolean created, final boolean destroyed) {
+        this.checkThread(entity, "Entity status change must only happen on the main thread");
+
+        if (((ChunkSystemEntity)entity).moonrise$isUpdatingSectionStatus()) {
+            // recursive status update
+            LOGGER.error("Cannot recursively update entity chunk status for entity " + entity, new Throwable());
+            return;
+        }
+
+        final boolean entityStatusUpdateBefore = slices == null ? false : slices.startPreventingStatusUpdates();
+
+        if (entityStatusUpdateBefore) {
+            LOGGER.error("Cannot update chunk status for entity " + entity + " since entity chunk (" + slices.chunkX + "," + slices.chunkZ + ") is receiving update", new Throwable());
+            return;
+        }
+
+        try {
+            final Boolean ticketBlockBefore = this.blockTicketUpdates();
+            try {
+                ((ChunkSystemEntity)entity).moonrise$setUpdatingSectionStatus(true);
+                try {
+                    if (created) {
+                        if (EntityLookup.this.worldCallback != null) {
+                            EntityLookup.this.worldCallback.onCreated(entity);
+                        }
+                    }
+
+                    if (oldVisibility == newVisibility) {
+                        if (moved && newVisibility.isAccessible()) {
+                            if (EntityLookup.this.worldCallback != null) {
+                                EntityLookup.this.worldCallback.onSectionChange(entity);
+                            }
+                        }
+                        return;
+                    }
+
+                    if (newVisibility.ordinal() > oldVisibility.ordinal()) {
+                        // status upgrade
+                        if (!oldVisibility.isAccessible() && newVisibility.isAccessible()) {
+                            EntityLookup.this.entityStartLoaded(entity);
+                            synchronized (this.accessibleEntities) {
+                                this.accessibleEntities.add(entity);
+                            }
+                            if (EntityLookup.this.worldCallback != null) {
+                                EntityLookup.this.worldCallback.onTrackingStart(entity);
+                            }
+                        }
+
+                        if (!oldVisibility.isTicking() && newVisibility.isTicking()) {
+                            EntityLookup.this.entityStartTicking(entity);
+                            if (EntityLookup.this.worldCallback != null) {
+                                EntityLookup.this.worldCallback.onTickingStart(entity);
+                            }
+                        }
+                    } else {
+                        // status downgrade
+                        if (oldVisibility.isTicking() && !newVisibility.isTicking()) {
+                            EntityLookup.this.entityEndTicking(entity);
+                            if (EntityLookup.this.worldCallback != null) {
+                                EntityLookup.this.worldCallback.onTickingEnd(entity);
+                            }
+                        }
+
+                        if (oldVisibility.isAccessible() && !newVisibility.isAccessible()) {
+                            EntityLookup.this.entityEndLoaded(entity);
+                            synchronized (this.accessibleEntities) {
+                                this.accessibleEntities.remove(entity);
+                            }
+                            if (EntityLookup.this.worldCallback != null) {
+                                EntityLookup.this.worldCallback.onTrackingEnd(entity);
+                            }
+                        }
+                    }
+
+                    if (moved && newVisibility.isAccessible()) {
+                        if (EntityLookup.this.worldCallback != null) {
+                            EntityLookup.this.worldCallback.onSectionChange(entity);
+                        }
+                    }
+
+                    if (destroyed) {
+                        if (EntityLookup.this.worldCallback != null) {
+                            EntityLookup.this.worldCallback.onDestroyed(entity);
+                        }
+                    }
+                } finally {
+                    ((ChunkSystemEntity)entity).moonrise$setUpdatingSectionStatus(false);
+                }
+            } finally {
+                this.setBlockTicketUpdates(ticketBlockBefore);
+            }
+        } finally {
+            if (slices != null) {
+                slices.stopPreventingStatusUpdates(false);
+            }
+        }
+    }
+
+    public void chunkStatusChange(final int x, final int z, final FullChunkStatus newStatus) {
+        this.getChunk(x, z).updateStatus(newStatus, this);
+    }
+
+    public void addLegacyChunkEntities(final List<Entity> entities, final ChunkPos forChunk) {
+        this.addEntityChunk(entities, forChunk, true);
+    }
+
+    public void addEntityChunkEntities(final List<Entity> entities, final ChunkPos forChunk) {
+        this.addEntityChunk(entities, forChunk, true);
+    }
+
+    public void addWorldGenChunkEntities(final List<Entity> entities, final ChunkPos forChunk) {
+        this.addEntityChunk(entities, forChunk, false);
+    }
+
+    protected void addRecursivelySafe(final Entity root, final boolean fromDisk) {
+        if (!this.addEntity(root, fromDisk, true)) {
+            // possible we are a passenger, and so should dismount from any valid entity in the world
+            root.stopRiding();
+            return;
+        }
+        for (final Entity passenger : root.getPassengers()) {
+            this.addRecursivelySafe(passenger, fromDisk);
+        }
+    }
+
+    protected void addEntityChunk(final List<Entity> entities, final ChunkPos forChunk, final boolean fromDisk) {
+        for (int i = 0, len = entities.size(); i < len; ++i) {
+            final Entity entity = entities.get(i);
+            if (entity.isPassenger()) {
+                continue;
+            }
+
+            if (forChunk != null && !entity.chunkPosition().equals(forChunk)) {
+                LOGGER.warn("Root entity " + entity + " is outside of serialized chunk " + forChunk);
+                // can't set removed here, as we may not own the chunk position
+                // skip the entity
+                continue;
+            }
+
+            final Vec3 rootPosition = entity.position();
+
+            // always adjust positions before adding passengers in case plugins access the entity, and so that
+            // they are added to the right entity chunk
+            for (final Entity passenger : entity.getIndirectPassengers()) {
+                if (forChunk != null && !passenger.chunkPosition().equals(forChunk)) {
+                    passenger.setPosRaw(rootPosition.x, rootPosition.y, rootPosition.z);
+                }
+            }
+
+            this.addRecursivelySafe(entity, fromDisk);
+        }
+    }
+
+    public boolean addNewEntity(final Entity entity) {
+        return this.addNewEntity(entity, true);
+    }
+
+    public boolean addNewEntity(final Entity entity, final boolean event) {
+        return this.addEntity(entity, false, event);
+    }
+
+    public static Visibility getEntityStatus(final Entity entity) {
+        if (entity.isAlwaysTicking()) {
+            return Visibility.TICKING;
+        }
+        final FullChunkStatus entityStatus = ((ChunkSystemEntity)entity).moonrise$getChunkStatus();
+        return Visibility.fromFullChunkStatus(entityStatus == null ? FullChunkStatus.INACCESSIBLE : entityStatus);
+    }
+
+    protected boolean addEntity(final Entity entity, final boolean fromDisk, final boolean event) {
+        final BlockPos pos = entity.blockPosition();
+        final int sectionX = pos.getX() >> 4;
+        final int sectionY = Mth.clamp(pos.getY() >> 4, WorldUtil.getMinSection(this.world), WorldUtil.getMaxSection(this.world));
+        final int sectionZ = pos.getZ() >> 4;
+        this.checkThread(sectionX, sectionZ, "Cannot add entity off-main thread");
+
+        if (entity.isRemoved()) {
+            LOGGER.warn("Refusing to add removed entity: " + entity);
+            return false;
+        }
+
+        if (((ChunkSystemEntity)entity).moonrise$isUpdatingSectionStatus()) {
+            LOGGER.warn("Entity " + entity + " is currently prevented from being added/removed to world since it is processing section status updates", new Throwable());
+            return false;
+        }
+
+        if (!this.screenEntity(entity, fromDisk, event)) {
+            return false;
+        }
+
+        Entity currentlyMapped = this.entityById.putIfAbsent((long)entity.getId(), entity);
+        if (currentlyMapped != null) {
+            LOGGER.warn("Entity id already exists: " + entity.getId() + ", mapped to " + currentlyMapped + ", can't add " + entity);
+            return false;
+        }
+
+        currentlyMapped = this.entityByUUID.putIfAbsent(entity.getUUID(), entity);
+        if (currentlyMapped != null) {
+            // need to remove mapping for id
+            this.entityById.remove((long)entity.getId(), entity);
+            LOGGER.warn("Entity uuid already exists: " + entity.getUUID() + ", mapped to " + currentlyMapped + ", can't add " + entity);
+            return false;
+        }
+
+        ((ChunkSystemEntity)entity).moonrise$setSectionX(sectionX);
+        ((ChunkSystemEntity)entity).moonrise$setSectionY(sectionY);
+        ((ChunkSystemEntity)entity).moonrise$setSectionZ(sectionZ);
+        final ChunkEntitySlices slices = this.getOrCreateChunk(sectionX, sectionZ);
+        if (!slices.addEntity(entity, sectionY)) {
+            LOGGER.warn("Entity " + entity + " added to world '" + WorldUtil.getWorldName(this.world) + "', but was already contained in entity chunk (" + sectionX + "," + sectionZ + ")");
+        }
+
+        entity.setLevelCallback(new EntityCallback(entity));
+
+        this.addEntityCallback(entity);
+
+        this.entityStatusChange(entity, slices, Visibility.HIDDEN, getEntityStatus(entity), false, !fromDisk, false);
+
+        return true;
+    }
+
+    public boolean canRemoveEntity(final Entity entity) {
+        if (((ChunkSystemEntity)entity).moonrise$isUpdatingSectionStatus()) {
+            return false;
+        }
+
+        final int sectionX = ((ChunkSystemEntity)entity).moonrise$getSectionX();
+        final int sectionZ = ((ChunkSystemEntity)entity).moonrise$getSectionZ();
+        final ChunkEntitySlices slices = this.getChunk(sectionX, sectionZ);
+        return slices == null || !slices.isPreventingStatusUpdates();
+    }
+
+    protected void removeEntity(final Entity entity) {
+        final int sectionX = ((ChunkSystemEntity)entity).moonrise$getSectionX();
+        final int sectionY = ((ChunkSystemEntity)entity).moonrise$getSectionY();
+        final int sectionZ = ((ChunkSystemEntity)entity).moonrise$getSectionZ();
+        this.checkThread(sectionX, sectionZ, "Cannot remove entity off-main");
+        if (!entity.isRemoved()) {
+            throw new IllegalStateException("Only call Entity#setRemoved to remove an entity");
+        }
+        final ChunkEntitySlices slices = this.getChunk(sectionX, sectionZ);
+        // all entities should be in a chunk
+        if (slices == null) {
+            LOGGER.warn("Cannot remove entity " + entity + " from null entity slices (" + sectionX + "," + sectionZ + ")");
+        } else {
+            if (slices.isPreventingStatusUpdates()) {
+                throw new IllegalStateException("Attempting to remove entity " + entity + " from entity slices (" + sectionX + "," + sectionZ + ") that is receiving status updates");
+            }
+            if (!slices.removeEntity(entity, sectionY)) {
+                LOGGER.warn("Failed to remove entity " + entity + " from entity slices (" + sectionX + "," + sectionZ + ")");
+            }
+        }
+        ((ChunkSystemEntity)entity).moonrise$setSectionX(Integer.MIN_VALUE);
+        ((ChunkSystemEntity)entity).moonrise$setSectionY(Integer.MIN_VALUE);
+        ((ChunkSystemEntity)entity).moonrise$setSectionZ(Integer.MIN_VALUE);
+
+
+        Entity currentlyMapped;
+        if ((currentlyMapped = this.entityById.remove(entity.getId(), entity)) != entity) {
+            LOGGER.warn("Failed to remove entity " + entity + " by id, current entity mapped: " + currentlyMapped);
+        }
+
+        Entity[] currentlyMappedArr = new Entity[1];
+
+        // need reference equality
+        this.entityByUUID.compute(entity.getUUID(), (final UUID keyInMap, final Entity valueInMap) -> {
+            currentlyMappedArr[0] = valueInMap;
+            if (valueInMap != entity) {
+                return valueInMap;
+            }
+            return null;
+        });
+
+        if (currentlyMappedArr[0] != entity) {
+            LOGGER.warn("Failed to remove entity " + entity + " by uuid, current entity mapped: " + currentlyMappedArr[0]);
+        }
+
+        if (slices != null && slices.isEmpty()) {
+            this.onEmptySlices(sectionX, sectionZ);
+        }
+    }
+
+    protected ChunkEntitySlices moveEntity(final Entity entity) {
+        // ensure we own the entity
+        this.checkThread(entity, "Cannot move entity off-main");
+
+        final int sectionX = ((ChunkSystemEntity)entity).moonrise$getSectionX();
+        final int sectionY = ((ChunkSystemEntity)entity).moonrise$getSectionY();
+        final int sectionZ = ((ChunkSystemEntity)entity).moonrise$getSectionZ();
+        final BlockPos newPos = entity.blockPosition();
+        final int newSectionX = newPos.getX() >> 4;
+        final int newSectionY = Mth.clamp(newPos.getY() >> 4, WorldUtil.getMinSection(this.world), WorldUtil.getMaxSection(this.world));
+        final int newSectionZ = newPos.getZ() >> 4;
+
+        if (newSectionX == sectionX && newSectionY == sectionY && newSectionZ == sectionZ) {
+            return null;
+        }
+
+        // ensure the new section is owned by this tick thread
+        this.checkThread(newSectionX, newSectionZ, "Cannot move entity off-main");
+
+        // ensure the old section is owned by this tick thread
+        this.checkThread(sectionX, sectionZ, "Cannot move entity off-main");
+
+        final ChunkEntitySlices old = this.getChunk(sectionX, sectionZ);
+        final ChunkEntitySlices slices = this.getOrCreateChunk(newSectionX, newSectionZ);
+
+        if (!old.removeEntity(entity, sectionY)) {
+            LOGGER.warn("Could not remove entity " + entity + " from its old chunk section (" + sectionX + "," + sectionY + "," + sectionZ + ") since it was not contained in the section");
+        }
+
+        if (!slices.addEntity(entity, newSectionY)) {
+            LOGGER.warn("Could not add entity " + entity + " to its new chunk section (" + newSectionX + "," + newSectionY + "," + newSectionZ + ") as it is already contained in the section");
+        }
+
+        ((ChunkSystemEntity)entity).moonrise$setSectionX(newSectionX);
+        ((ChunkSystemEntity)entity).moonrise$setSectionY(newSectionY);
+        ((ChunkSystemEntity)entity).moonrise$setSectionZ(newSectionZ);
+
+        if (old.isEmpty()) {
+            this.onEmptySlices(sectionX, sectionZ);
+        }
+
+        this.entitySectionChangeCallback(
+            entity,
+            sectionX, sectionY, sectionZ,
+            newSectionX, newSectionY, newSectionZ
+        );
+
+        return slices;
+    }
+
+    public void getEntities(final Entity except, final AABB box, final List<Entity> into, final Predicate<? super Entity> predicate) {
+        final int minChunkX = (Mth.floor(box.minX) - 2) >> 4;
+        final int minChunkZ = (Mth.floor(box.minZ) - 2) >> 4;
+        final int maxChunkX = (Mth.floor(box.maxX) + 2) >> 4;
+        final int maxChunkZ = (Mth.floor(box.maxZ) + 2) >> 4;
+
+        final int minRegionX = minChunkX >> REGION_SHIFT;
+        final int minRegionZ = minChunkZ >> REGION_SHIFT;
+        final int maxRegionX = maxChunkX >> REGION_SHIFT;
+        final int maxRegionZ = maxChunkZ >> REGION_SHIFT;
+
+        for (int currRegionZ = minRegionZ; currRegionZ <= maxRegionZ; ++currRegionZ) {
+            final int minZ = currRegionZ == minRegionZ ? minChunkZ & REGION_MASK : 0;
+            final int maxZ = currRegionZ == maxRegionZ ? maxChunkZ & REGION_MASK : REGION_MASK;
+
+            for (int currRegionX = minRegionX; currRegionX <= maxRegionX; ++currRegionX) {
+                final ChunkSlicesRegion region = this.getRegion(currRegionX, currRegionZ);
+
+                if (region == null) {
+                    continue;
+                }
+
+                final int minX = currRegionX == minRegionX ? minChunkX & REGION_MASK : 0;
+                final int maxX = currRegionX == maxRegionX ? maxChunkX & REGION_MASK : REGION_MASK;
+
+                for (int currZ = minZ; currZ <= maxZ; ++currZ) {
+                    for (int currX = minX; currX <= maxX; ++currX) {
+                        final ChunkEntitySlices chunk = region.get(currX | (currZ << REGION_SHIFT));
+                        if (chunk == null || !chunk.status.isOrAfter(FullChunkStatus.FULL)) {
+                            continue;
+                        }
+
+                        chunk.getEntities(except, box, into, predicate);
+                    }
+                }
+            }
+        }
+    }
+
+    public void getHardCollidingEntities(final Entity except, final AABB box, final List<Entity> into, final Predicate<? super Entity> predicate) {
+        final int minChunkX = (Mth.floor(box.minX) - 2) >> 4;
+        final int minChunkZ = (Mth.floor(box.minZ) - 2) >> 4;
+        final int maxChunkX = (Mth.floor(box.maxX) + 2) >> 4;
+        final int maxChunkZ = (Mth.floor(box.maxZ) + 2) >> 4;
+
+        final int minRegionX = minChunkX >> REGION_SHIFT;
+        final int minRegionZ = minChunkZ >> REGION_SHIFT;
+        final int maxRegionX = maxChunkX >> REGION_SHIFT;
+        final int maxRegionZ = maxChunkZ >> REGION_SHIFT;
+
+        for (int currRegionZ = minRegionZ; currRegionZ <= maxRegionZ; ++currRegionZ) {
+            final int minZ = currRegionZ == minRegionZ ? minChunkZ & REGION_MASK : 0;
+            final int maxZ = currRegionZ == maxRegionZ ? maxChunkZ & REGION_MASK : REGION_MASK;
+
+            for (int currRegionX = minRegionX; currRegionX <= maxRegionX; ++currRegionX) {
+                final ChunkSlicesRegion region = this.getRegion(currRegionX, currRegionZ);
+
+                if (region == null) {
+                    continue;
+                }
+
+                final int minX = currRegionX == minRegionX ? minChunkX & REGION_MASK : 0;
+                final int maxX = currRegionX == maxRegionX ? maxChunkX & REGION_MASK : REGION_MASK;
+
+                for (int currZ = minZ; currZ <= maxZ; ++currZ) {
+                    for (int currX = minX; currX <= maxX; ++currX) {
+                        final ChunkEntitySlices chunk = region.get(currX | (currZ << REGION_SHIFT));
+                        if (chunk == null || !chunk.status.isOrAfter(FullChunkStatus.FULL)) {
+                            continue;
+                        }
+
+                        chunk.getHardCollidingEntities(except, box, into, predicate);
+                    }
+                }
+            }
+        }
+    }
+
+    public <T extends Entity> void getEntities(final EntityType<?> type, final AABB box, final List<? super T> into,
+                                               final Predicate<? super T> predicate) {
+        final int minChunkX = (Mth.floor(box.minX) - 2) >> 4;
+        final int minChunkZ = (Mth.floor(box.minZ) - 2) >> 4;
+        final int maxChunkX = (Mth.floor(box.maxX) + 2) >> 4;
+        final int maxChunkZ = (Mth.floor(box.maxZ) + 2) >> 4;
+
+        final int minRegionX = minChunkX >> REGION_SHIFT;
+        final int minRegionZ = minChunkZ >> REGION_SHIFT;
+        final int maxRegionX = maxChunkX >> REGION_SHIFT;
+        final int maxRegionZ = maxChunkZ >> REGION_SHIFT;
+
+        for (int currRegionZ = minRegionZ; currRegionZ <= maxRegionZ; ++currRegionZ) {
+            final int minZ = currRegionZ == minRegionZ ? minChunkZ & REGION_MASK : 0;
+            final int maxZ = currRegionZ == maxRegionZ ? maxChunkZ & REGION_MASK : REGION_MASK;
+
+            for (int currRegionX = minRegionX; currRegionX <= maxRegionX; ++currRegionX) {
+                final ChunkSlicesRegion region = this.getRegion(currRegionX, currRegionZ);
+
+                if (region == null) {
+                    continue;
+                }
+
+                final int minX = currRegionX == minRegionX ? minChunkX & REGION_MASK : 0;
+                final int maxX = currRegionX == maxRegionX ? maxChunkX & REGION_MASK : REGION_MASK;
+
+                for (int currZ = minZ; currZ <= maxZ; ++currZ) {
+                    for (int currX = minX; currX <= maxX; ++currX) {
+                        final ChunkEntitySlices chunk = region.get(currX | (currZ << REGION_SHIFT));
+                        if (chunk == null || !chunk.status.isOrAfter(FullChunkStatus.FULL)) {
+                            continue;
+                        }
+
+                        chunk.getEntities(type, box, (List)into, (Predicate)predicate);
+                    }
+                }
+            }
+        }
+    }
+
+    public <T extends Entity> void getEntities(final Class<? extends T> clazz, final Entity except, final AABB box, final List<? super T> into,
+                                               final Predicate<? super T> predicate) {
+        final int minChunkX = (Mth.floor(box.minX) - 2) >> 4;
+        final int minChunkZ = (Mth.floor(box.minZ) - 2) >> 4;
+        final int maxChunkX = (Mth.floor(box.maxX) + 2) >> 4;
+        final int maxChunkZ = (Mth.floor(box.maxZ) + 2) >> 4;
+
+        final int minRegionX = minChunkX >> REGION_SHIFT;
+        final int minRegionZ = minChunkZ >> REGION_SHIFT;
+        final int maxRegionX = maxChunkX >> REGION_SHIFT;
+        final int maxRegionZ = maxChunkZ >> REGION_SHIFT;
+
+        for (int currRegionZ = minRegionZ; currRegionZ <= maxRegionZ; ++currRegionZ) {
+            final int minZ = currRegionZ == minRegionZ ? minChunkZ & REGION_MASK : 0;
+            final int maxZ = currRegionZ == maxRegionZ ? maxChunkZ & REGION_MASK : REGION_MASK;
+
+            for (int currRegionX = minRegionX; currRegionX <= maxRegionX; ++currRegionX) {
+                final ChunkSlicesRegion region = this.getRegion(currRegionX, currRegionZ);
+
+                if (region == null) {
+                    continue;
+                }
+
+                final int minX = currRegionX == minRegionX ? minChunkX & REGION_MASK : 0;
+                final int maxX = currRegionX == maxRegionX ? maxChunkX & REGION_MASK : REGION_MASK;
+
+                for (int currZ = minZ; currZ <= maxZ; ++currZ) {
+                    for (int currX = minX; currX <= maxX; ++currX) {
+                        final ChunkEntitySlices chunk = region.get(currX | (currZ << REGION_SHIFT));
+                        if (chunk == null || !chunk.status.isOrAfter(FullChunkStatus.FULL)) {
+                            continue;
+                        }
+
+                        chunk.getEntities(clazz, except, box, into, predicate);
+                    }
+                }
+            }
+        }
+    }
+
+    //////// Limited ////////
+
+    public void getEntities(final Entity except, final AABB box, final List<Entity> into, final Predicate<? super Entity> predicate,
+                            final int maxCount) {
+        final int minChunkX = (Mth.floor(box.minX) - 2) >> 4;
+        final int minChunkZ = (Mth.floor(box.minZ) - 2) >> 4;
+        final int maxChunkX = (Mth.floor(box.maxX) + 2) >> 4;
+        final int maxChunkZ = (Mth.floor(box.maxZ) + 2) >> 4;
+
+        final int minRegionX = minChunkX >> REGION_SHIFT;
+        final int minRegionZ = minChunkZ >> REGION_SHIFT;
+        final int maxRegionX = maxChunkX >> REGION_SHIFT;
+        final int maxRegionZ = maxChunkZ >> REGION_SHIFT;
+
+        for (int currRegionZ = minRegionZ; currRegionZ <= maxRegionZ; ++currRegionZ) {
+            final int minZ = currRegionZ == minRegionZ ? minChunkZ & REGION_MASK : 0;
+            final int maxZ = currRegionZ == maxRegionZ ? maxChunkZ & REGION_MASK : REGION_MASK;
+
+            for (int currRegionX = minRegionX; currRegionX <= maxRegionX; ++currRegionX) {
+                final ChunkSlicesRegion region = this.getRegion(currRegionX, currRegionZ);
+
+                if (region == null) {
+                    continue;
+                }
+
+                final int minX = currRegionX == minRegionX ? minChunkX & REGION_MASK : 0;
+                final int maxX = currRegionX == maxRegionX ? maxChunkX & REGION_MASK : REGION_MASK;
+
+                for (int currZ = minZ; currZ <= maxZ; ++currZ) {
+                    for (int currX = minX; currX <= maxX; ++currX) {
+                        final ChunkEntitySlices chunk = region.get(currX | (currZ << REGION_SHIFT));
+                        if (chunk == null || !chunk.status.isOrAfter(FullChunkStatus.FULL)) {
+                            continue;
+                        }
+
+                        if (chunk.getEntities(except, box, into, predicate, maxCount)) {
+                            return;
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    public <T extends Entity> void getEntities(final EntityType<?> type, final AABB box, final List<? super T> into,
+                                               final Predicate<? super T> predicate, final int maxCount) {
+        final int minChunkX = (Mth.floor(box.minX) - 2) >> 4;
+        final int minChunkZ = (Mth.floor(box.minZ) - 2) >> 4;
+        final int maxChunkX = (Mth.floor(box.maxX) + 2) >> 4;
+        final int maxChunkZ = (Mth.floor(box.maxZ) + 2) >> 4;
+
+        final int minRegionX = minChunkX >> REGION_SHIFT;
+        final int minRegionZ = minChunkZ >> REGION_SHIFT;
+        final int maxRegionX = maxChunkX >> REGION_SHIFT;
+        final int maxRegionZ = maxChunkZ >> REGION_SHIFT;
+
+        for (int currRegionZ = minRegionZ; currRegionZ <= maxRegionZ; ++currRegionZ) {
+            final int minZ = currRegionZ == minRegionZ ? minChunkZ & REGION_MASK : 0;
+            final int maxZ = currRegionZ == maxRegionZ ? maxChunkZ & REGION_MASK : REGION_MASK;
+
+            for (int currRegionX = minRegionX; currRegionX <= maxRegionX; ++currRegionX) {
+                final ChunkSlicesRegion region = this.getRegion(currRegionX, currRegionZ);
+
+                if (region == null) {
+                    continue;
+                }
+
+                final int minX = currRegionX == minRegionX ? minChunkX & REGION_MASK : 0;
+                final int maxX = currRegionX == maxRegionX ? maxChunkX & REGION_MASK : REGION_MASK;
+
+                for (int currZ = minZ; currZ <= maxZ; ++currZ) {
+                    for (int currX = minX; currX <= maxX; ++currX) {
+                        final ChunkEntitySlices chunk = region.get(currX | (currZ << REGION_SHIFT));
+                        if (chunk == null || !chunk.status.isOrAfter(FullChunkStatus.FULL)) {
+                            continue;
+                        }
+
+                        if (chunk.getEntities(type, box, (List)into, (Predicate)predicate, maxCount)) {
+                            return;
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    public <T extends Entity> void getEntities(final Class<? extends T> clazz, final Entity except, final AABB box, final List<? super T> into,
+                                               final Predicate<? super T> predicate, final int maxCount) {
+        final int minChunkX = (Mth.floor(box.minX) - 2) >> 4;
+        final int minChunkZ = (Mth.floor(box.minZ) - 2) >> 4;
+        final int maxChunkX = (Mth.floor(box.maxX) + 2) >> 4;
+        final int maxChunkZ = (Mth.floor(box.maxZ) + 2) >> 4;
+
+        final int minRegionX = minChunkX >> REGION_SHIFT;
+        final int minRegionZ = minChunkZ >> REGION_SHIFT;
+        final int maxRegionX = maxChunkX >> REGION_SHIFT;
+        final int maxRegionZ = maxChunkZ >> REGION_SHIFT;
+
+        for (int currRegionZ = minRegionZ; currRegionZ <= maxRegionZ; ++currRegionZ) {
+            final int minZ = currRegionZ == minRegionZ ? minChunkZ & REGION_MASK : 0;
+            final int maxZ = currRegionZ == maxRegionZ ? maxChunkZ & REGION_MASK : REGION_MASK;
+
+            for (int currRegionX = minRegionX; currRegionX <= maxRegionX; ++currRegionX) {
+                final ChunkSlicesRegion region = this.getRegion(currRegionX, currRegionZ);
+
+                if (region == null) {
+                    continue;
+                }
+
+                final int minX = currRegionX == minRegionX ? minChunkX & REGION_MASK : 0;
+                final int maxX = currRegionX == maxRegionX ? maxChunkX & REGION_MASK : REGION_MASK;
+
+                for (int currZ = minZ; currZ <= maxZ; ++currZ) {
+                    for (int currX = minX; currX <= maxX; ++currX) {
+                        final ChunkEntitySlices chunk = region.get(currX | (currZ << REGION_SHIFT));
+                        if (chunk == null || !chunk.status.isOrAfter(FullChunkStatus.FULL)) {
+                            continue;
+                        }
+
+                        if (chunk.getEntities(clazz, except, box, into, predicate, maxCount)) {
+                            return;
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    public void entitySectionLoad(final int chunkX, final int chunkZ, final ChunkEntitySlices slices) {
+        this.checkThread(chunkX, chunkZ, "Cannot load in entity section off-main");
+        synchronized (this) {
+            final ChunkEntitySlices curr = this.getChunk(chunkX, chunkZ);
+            if (curr != null) {
+                this.removeChunk(chunkX, chunkZ);
+
+                curr.mergeInto(slices);
+
+                this.addChunk(chunkX, chunkZ, slices);
+            } else {
+                this.addChunk(chunkX, chunkZ, slices);
+            }
+        }
+    }
+
+    public void entitySectionUnload(final int chunkX, final int chunkZ) {
+        this.checkThread(chunkX, chunkZ, "Cannot unload entity section off-main");
+        this.removeChunk(chunkX, chunkZ);
+    }
+
+    public ChunkEntitySlices getChunk(final int chunkX, final int chunkZ) {
+        final ChunkSlicesRegion region = this.getRegion(chunkX >> REGION_SHIFT, chunkZ >> REGION_SHIFT);
+        if (region == null) {
+            return null;
+        }
+
+        return region.get((chunkX & REGION_MASK) | ((chunkZ & REGION_MASK) << REGION_SHIFT));
+    }
+
+    public ChunkEntitySlices getOrCreateChunk(final int chunkX, final int chunkZ) {
+        final ChunkSlicesRegion region = this.getRegion(chunkX >> REGION_SHIFT, chunkZ >> REGION_SHIFT);
+        final ChunkEntitySlices ret;
+        if (region == null || (ret = region.get((chunkX & REGION_MASK) | ((chunkZ & REGION_MASK) << REGION_SHIFT))) == null) {
+            return this.createEntityChunk(chunkX, chunkZ, true);
+        }
+
+        return ret;
+    }
+
+    public ChunkSlicesRegion getRegion(final int regionX, final int regionZ) {
+        final long key = CoordinateUtils.getChunkKey(regionX, regionZ);
+
+        return this.regions.get(key);
+    }
+
+    protected synchronized void removeChunk(final int chunkX, final int chunkZ) {
+        final long key = CoordinateUtils.getChunkKey(chunkX >> REGION_SHIFT, chunkZ >> REGION_SHIFT);
+        final int relIndex = (chunkX & REGION_MASK) | ((chunkZ & REGION_MASK) << REGION_SHIFT);
+
+        final ChunkSlicesRegion region = this.regions.get(key);
+        final int remaining = region.remove(relIndex);
+
+        if (remaining == 0) {
+            this.regions.remove(key);
+        }
+    }
+
+    public synchronized void addChunk(final int chunkX, final int chunkZ, final ChunkEntitySlices slices) {
+        final long key = CoordinateUtils.getChunkKey(chunkX >> REGION_SHIFT, chunkZ >> REGION_SHIFT);
+        final int relIndex = (chunkX & REGION_MASK) | ((chunkZ & REGION_MASK) << REGION_SHIFT);
+
+        ChunkSlicesRegion region = this.regions.get(key);
+        if (region != null) {
+            region.add(relIndex, slices);
+        } else {
+            region = new ChunkSlicesRegion();
+            region.add(relIndex, slices);
+            this.regions.put(key, region);
+        }
+    }
+
+    public static final class ChunkSlicesRegion {
+
+        private final ChunkEntitySlices[] slices = new ChunkEntitySlices[REGION_SIZE * REGION_SIZE];
+        private int sliceCount;
+
+        public ChunkEntitySlices get(final int index) {
+            return this.slices[index];
+        }
+
+        public int remove(final int index) {
+            final ChunkEntitySlices slices = this.slices[index];
+            if (slices == null) {
+                throw new IllegalStateException();
+            }
+
+            this.slices[index] = null;
+
+            return --this.sliceCount;
+        }
+
+        public void add(final int index, final ChunkEntitySlices slices) {
+            final ChunkEntitySlices curr = this.slices[index];
+            if (curr != null) {
+                throw new IllegalStateException();
+            }
+
+            this.slices[index] = slices;
+
+            ++this.sliceCount;
+        }
+    }
+
+    protected final class EntityCallback implements EntityInLevelCallback {
+
+        public final Entity entity;
+
+        public EntityCallback(final Entity entity) {
+            this.entity = entity;
+        }
+
+        @Override
+        public void onMove() {
+            final Entity entity = this.entity;
+            final Visibility oldVisibility = getEntityStatus(entity);
+            final ChunkEntitySlices newSlices = EntityLookup.this.moveEntity(this.entity);
+            if (newSlices == null) {
+                // no new section, so didn't change sections
+                return;
+            }
+
+            final Visibility newVisibility = getEntityStatus(entity);
+
+            EntityLookup.this.entityStatusChange(entity, newSlices, oldVisibility, newVisibility, true, false, false);
+        }
+
+        @Override
+        public void onRemove(final Entity.RemovalReason reason) {
+            final Entity entity = this.entity;
+            EntityLookup.this.checkThread(entity, "Cannot remove entity off-main");
+            final Visibility tickingState = EntityLookup.getEntityStatus(entity);
+
+            EntityLookup.this.removeEntity(entity);
+
+            EntityLookup.this.entityStatusChange(entity, null, tickingState, Visibility.HIDDEN, false, false, reason.shouldDestroy());
+
+            EntityLookup.this.removeEntityCallback(entity);
+
+            this.entity.setLevelCallback(NoOpCallback.INSTANCE);
+        }
+    }
+
+    protected static final class NoOpCallback implements EntityInLevelCallback {
+
+        public static final NoOpCallback INSTANCE = new NoOpCallback();
+
+        @Override
+        public void onMove() {}
+
+        @Override
+        public void onRemove(final Entity.RemovalReason reason) {}
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/entity/client/ClientEntityLookup.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/entity/client/ClientEntityLookup.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/entity/client/ClientEntityLookup.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.level.entity.client;
+
+import ca.spottedleaf.moonrise.common.PlatformHooks;
+import ca.spottedleaf.moonrise.common.util.CoordinateUtils;
+import ca.spottedleaf.moonrise.common.util.WorldUtil;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.entity.ChunkEntitySlices;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.entity.EntityLookup;
+import it.unimi.dsi.fastutil.longs.LongOpenHashSet;
+import net.minecraft.server.level.FullChunkStatus;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.entity.LevelCallback;
+
+public final class ClientEntityLookup extends EntityLookup {
+
+    private final LongOpenHashSet tickingChunks = new LongOpenHashSet();
+
+    public ClientEntityLookup(final Level world, final LevelCallback<Entity> worldCallback) {
+        super(world, worldCallback);
+    }
+
+    @Override
+    protected Boolean blockTicketUpdates() {
+        // not present on client
+        return null;
+    }
+
+    @Override
+    protected void setBlockTicketUpdates(Boolean value) {
+        // not present on client
+    }
+
+    @Override
+    protected void checkThread(final int chunkX, final int chunkZ, final String reason) {
+        // TODO implement?
+    }
+
+    @Override
+    protected void checkThread(final Entity entity, final String reason) {
+        // TODO implement?
+    }
+
+    @Override
+    protected ChunkEntitySlices createEntityChunk(final int chunkX, final int chunkZ, final boolean transientChunk) {
+        final boolean ticking = this.tickingChunks.contains(CoordinateUtils.getChunkKey(chunkX, chunkZ));
+
+        final ChunkEntitySlices ret = new ChunkEntitySlices(
+                this.world, chunkX, chunkZ,
+                ticking ? FullChunkStatus.ENTITY_TICKING : FullChunkStatus.FULL, null,
+            WorldUtil.getMinSection(this.world), WorldUtil.getMaxSection(this.world)
+        );
+
+        // note: not handled by superclass
+        this.addChunk(chunkX, chunkZ, ret);
+
+        return ret;
+    }
+
+    @Override
+    protected void onEmptySlices(final int chunkX, final int chunkZ) {
+        this.removeChunk(chunkX, chunkZ);
+    }
+
+    @Override
+    protected void entitySectionChangeCallback(final Entity entity,
+                                               final int oldSectionX, final int oldSectionY, final int oldSectionZ,
+                                               final int newSectionX, final int newSectionY, final int newSectionZ) {
+        PlatformHooks.get().entityMove(
+            entity,
+            CoordinateUtils.getChunkSectionKey(oldSectionX, oldSectionY, oldSectionZ),
+            CoordinateUtils.getChunkSectionKey(newSectionX, newSectionY, newSectionZ)
+        );
+    }
+
+    @Override
+    protected void addEntityCallback(final Entity entity) {
+
+    }
+
+    @Override
+    protected void removeEntityCallback(final Entity entity) {
+
+    }
+
+    @Override
+    protected void entityStartLoaded(final Entity entity) {
+
+    }
+
+    @Override
+    protected void entityEndLoaded(final Entity entity) {
+
+    }
+
+    @Override
+    protected void entityStartTicking(final Entity entity) {
+
+    }
+
+    @Override
+    protected void entityEndTicking(final Entity entity) {
+
+    }
+
+    @Override
+    protected boolean screenEntity(final Entity entity, final boolean fromDisk, final boolean event) {
+        return true;
+    }
+
+    public void markTicking(final long pos) {
+        if (this.tickingChunks.add(pos)) {
+            final int chunkX = CoordinateUtils.getChunkX(pos);
+            final int chunkZ = CoordinateUtils.getChunkZ(pos);
+            if (this.getChunk(chunkX, chunkZ) != null) {
+                this.chunkStatusChange(chunkX, chunkZ, FullChunkStatus.ENTITY_TICKING);
+            }
+        }
+    }
+
+    public void markNonTicking(final long pos) {
+        if (this.tickingChunks.remove(pos)) {
+            final int chunkX = CoordinateUtils.getChunkX(pos);
+            final int chunkZ = CoordinateUtils.getChunkZ(pos);
+            if (this.getChunk(chunkX, chunkZ) != null) {
+                this.chunkStatusChange(chunkX, chunkZ, FullChunkStatus.FULL);
+            }
+        }
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/entity/dfl/DefaultEntityLookup.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/entity/dfl/DefaultEntityLookup.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/entity/dfl/DefaultEntityLookup.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.level.entity.dfl;
+
+import ca.spottedleaf.moonrise.common.util.CoordinateUtils;
+import ca.spottedleaf.moonrise.common.util.WorldUtil;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.entity.ChunkEntitySlices;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.entity.EntityLookup;
+import net.minecraft.server.level.FullChunkStatus;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.entity.LevelCallback;
+
+public final class DefaultEntityLookup extends EntityLookup {
+    public DefaultEntityLookup(final Level world) {
+        super(world, new DefaultLevelCallback());
+    }
+
+    @Override
+    protected Boolean blockTicketUpdates() {
+        return null;
+    }
+
+    @Override
+    protected void setBlockTicketUpdates(final Boolean value) {}
+
+    @Override
+    protected void checkThread(final int chunkX, final int chunkZ, final String reason) {}
+
+    @Override
+    protected void checkThread(final Entity entity, final String reason) {}
+
+    @Override
+    protected ChunkEntitySlices createEntityChunk(final int chunkX, final int chunkZ, final boolean transientChunk) {
+        final ChunkEntitySlices ret = new ChunkEntitySlices(
+                this.world, chunkX, chunkZ, FullChunkStatus.FULL,
+                null, WorldUtil.getMinSection(this.world), WorldUtil.getMaxSection(this.world)
+        );
+
+        // note: not handled by superclass
+        this.addChunk(chunkX, chunkZ, ret);
+
+        return ret;
+    }
+
+    @Override
+    protected void onEmptySlices(final int chunkX, final int chunkZ) {
+        this.removeChunk(chunkX, chunkZ);
+    }
+
+    @Override
+    protected void entitySectionChangeCallback(final Entity entity,
+                                               final int oldSectionX, final int oldSectionY, final int oldSectionZ,
+                                               final int newSectionX, final int newSectionY, final int newSectionZ) {
+
+    }
+
+    @Override
+    protected void addEntityCallback(final Entity entity) {
+
+    }
+
+    @Override
+    protected void removeEntityCallback(final Entity entity) {
+
+    }
+
+    @Override
+    protected void entityStartLoaded(final Entity entity) {
+
+    }
+
+    @Override
+    protected void entityEndLoaded(final Entity entity) {
+
+    }
+
+    @Override
+    protected void entityStartTicking(final Entity entity) {
+
+    }
+
+    @Override
+    protected void entityEndTicking(final Entity entity) {
+
+    }
+
+    @Override
+    protected boolean screenEntity(final Entity entity, final boolean fromDisk, final boolean event) {
+        return true;
+    }
+
+    protected static final class DefaultLevelCallback implements LevelCallback<Entity> {
+
+        @Override
+        public void onCreated(final Entity entity) {}
+
+        @Override
+        public void onDestroyed(final Entity entity) {}
+
+        @Override
+        public void onTickingStart(final Entity entity) {}
+
+        @Override
+        public void onTickingEnd(final Entity entity) {}
+
+        @Override
+        public void onTrackingStart(final Entity entity) {}
+
+        @Override
+        public void onTrackingEnd(final Entity entity) {}
+
+        @Override
+        public void onSectionChange(final Entity entity) {}
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/entity/server/ServerEntityLookup.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/entity/server/ServerEntityLookup.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/entity/server/ServerEntityLookup.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.level.entity.server;
+
+import ca.spottedleaf.moonrise.common.PlatformHooks;
+import ca.spottedleaf.moonrise.common.list.ReferenceList;
+import ca.spottedleaf.moonrise.common.util.CoordinateUtils;
+import ca.spottedleaf.moonrise.common.util.TickThread;
+import ca.spottedleaf.moonrise.common.util.ChunkSystem;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.entity.ChunkEntitySlices;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.entity.EntityLookup;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.level.entity.LevelCallback;
+
+public final class ServerEntityLookup extends EntityLookup {
+
+    private static final Entity[] EMPTY_ENTITY_ARRAY = new Entity[0];
+
+    private final ServerLevel serverWorld;
+    public final ReferenceList<Entity> trackerEntities = new ReferenceList<>(EMPTY_ENTITY_ARRAY); // Moonrise - entity tracker
+
+    public ServerEntityLookup(final ServerLevel world, final LevelCallback<Entity> worldCallback) {
+        super(world, worldCallback);
+        this.serverWorld = world;
+    }
+
+    @Override
+    protected Boolean blockTicketUpdates() {
+        return ((ChunkSystemServerLevel)this.serverWorld).moonrise$getChunkTaskScheduler().chunkHolderManager.blockTicketUpdates();
+    }
+
+    @Override
+    protected void setBlockTicketUpdates(final Boolean value) {
+        ((ChunkSystemServerLevel)this.serverWorld).moonrise$getChunkTaskScheduler().chunkHolderManager.unblockTicketUpdates(value);
+    }
+
+    @Override
+    protected void checkThread(final int chunkX, final int chunkZ, final String reason) {
+        TickThread.ensureTickThread(this.serverWorld, chunkX, chunkZ, reason);
+    }
+
+    @Override
+    protected void checkThread(final Entity entity, final String reason) {
+        TickThread.ensureTickThread(entity, reason);
+    }
+
+    @Override
+    protected ChunkEntitySlices createEntityChunk(final int chunkX, final int chunkZ, final boolean transientChunk) {
+        // loadInEntityChunk will call addChunk for us
+        return ((ChunkSystemServerLevel)this.serverWorld).moonrise$getChunkTaskScheduler().chunkHolderManager
+                .getOrCreateEntityChunk(chunkX, chunkZ, transientChunk);
+    }
+
+    @Override
+    protected void onEmptySlices(final int chunkX, final int chunkZ) {
+        // entity slices unloading is managed by ticket levels in chunk system
+    }
+
+    @Override
+    protected void entitySectionChangeCallback(final Entity entity,
+                                               final int oldSectionX, final int oldSectionY, final int oldSectionZ,
+                                               final int newSectionX, final int newSectionY, final int newSectionZ) {
+        if (entity instanceof ServerPlayer player) {
+            ((ChunkSystemServerLevel)this.serverWorld).moonrise$getNearbyPlayers().tickPlayer(player);
+        }
+        PlatformHooks.get().entityMove(
+            entity,
+            CoordinateUtils.getChunkSectionKey(oldSectionX, oldSectionY, oldSectionZ),
+            CoordinateUtils.getChunkSectionKey(newSectionX, newSectionY, newSectionZ)
+        );
+    }
+
+    @Override
+    protected void addEntityCallback(final Entity entity) {
+        if (entity instanceof ServerPlayer player) {
+            ((ChunkSystemServerLevel)this.serverWorld).moonrise$getNearbyPlayers().addPlayer(player);
+        }
+    }
+
+    @Override
+    protected void removeEntityCallback(final Entity entity) {
+        if (entity instanceof ServerPlayer player) {
+            ((ChunkSystemServerLevel)this.serverWorld).moonrise$getNearbyPlayers().removePlayer(player);
+        }
+    }
+
+    @Override
+    protected void entityStartLoaded(final Entity entity) {
+        // Moonrise start - entity tracker
+        this.trackerEntities.add(entity);
+        // Moonrise end - entity tracker
+    }
+
+    @Override
+    protected void entityEndLoaded(final Entity entity) {
+        // Moonrise start - entity tracker
+        this.trackerEntities.remove(entity);
+        // Moonrise end - entity tracker
+    }
+
+    @Override
+    protected void entityStartTicking(final Entity entity) {
+
+    }
+
+    @Override
+    protected void entityEndTicking(final Entity entity) {
+
+    }
+
+    @Override
+    protected boolean screenEntity(final Entity entity, final boolean fromDisk, final boolean event) {
+        return ChunkSystem.screenEntity(this.serverWorld, entity, fromDisk, event);
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/poi/ChunkSystemPoiManager.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/poi/ChunkSystemPoiManager.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/poi/ChunkSystemPoiManager.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.level.poi;
+
+import ca.spottedleaf.moonrise.patches.chunk_system.level.storage.ChunkSystemSectionStorage;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.world.level.chunk.ChunkAccess;
+
+public interface ChunkSystemPoiManager extends ChunkSystemSectionStorage {
+
+    public ServerLevel moonrise$getWorld();
+
+    public void moonrise$onUnload(final long coordinate);
+
+    public void moonrise$loadInPoiChunk(final PoiChunk poiChunk);
+
+    public void moonrise$checkConsistency(final ChunkAccess chunk);
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/poi/ChunkSystemPoiSection.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/poi/ChunkSystemPoiSection.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/poi/ChunkSystemPoiSection.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.level.poi;
+
+import net.minecraft.world.entity.ai.village.poi.PoiSection;
+import java.util.Optional;
+
+public interface ChunkSystemPoiSection {
+
+    public boolean moonrise$isEmpty();
+
+    public Optional<PoiSection> moonrise$asOptional();
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/poi/PoiChunk.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/poi/PoiChunk.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/poi/PoiChunk.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.level.poi;
+
+import ca.spottedleaf.moonrise.common.util.CoordinateUtils;
+import ca.spottedleaf.moonrise.common.util.TickThread;
+import ca.spottedleaf.moonrise.common.util.WorldUtil;
+import com.mojang.serialization.DataResult;
+import net.minecraft.SharedConstants;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.NbtOps;
+import net.minecraft.nbt.Tag;
+import net.minecraft.resources.RegistryOps;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.world.entity.ai.village.poi.PoiManager;
+import net.minecraft.world.entity.ai.village.poi.PoiSection;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import java.util.Optional;
+
+public final class PoiChunk {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(PoiChunk.class);
+
+    public final ServerLevel world;
+    public final int chunkX;
+    public final int chunkZ;
+    public final int minSection;
+    public final int maxSection;
+
+    private final PoiSection[] sections;
+
+    private boolean isDirty;
+    private boolean loaded;
+
+    public PoiChunk(final ServerLevel world, final int chunkX, final int chunkZ, final int minSection, final int maxSection) {
+        this(world, chunkX, chunkZ, minSection, maxSection, new PoiSection[maxSection - minSection + 1]);
+    }
+
+    public PoiChunk(final ServerLevel world, final int chunkX, final int chunkZ, final int minSection, final int maxSection, final PoiSection[] sections) {
+        this.world = world;
+        this.chunkX = chunkX;
+        this.chunkZ = chunkZ;
+        this.minSection = minSection;
+        this.maxSection = maxSection;
+        this.sections = sections;
+        if (this.sections.length != (maxSection - minSection + 1)) {
+            throw new IllegalStateException("Incorrect length used, expected " + (maxSection - minSection + 1) + ", got " + this.sections.length);
+        }
+    }
+
+    public void load() {
+        TickThread.ensureTickThread(this.world, this.chunkX, this.chunkZ, "Loading in poi chunk off-main");
+        if (this.loaded) {
+            return;
+        }
+        this.loaded = true;
+        ((ChunkSystemPoiManager)this.world.getChunkSource().getPoiManager()).moonrise$loadInPoiChunk(this);
+    }
+
+    public boolean isLoaded() {
+        return this.loaded;
+    }
+
+    public boolean isEmpty() {
+        for (final PoiSection section : this.sections) {
+            if (section != null && !((ChunkSystemPoiSection)section).moonrise$isEmpty()) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    public PoiSection getOrCreateSection(final int chunkY) {
+        if (chunkY >= this.minSection && chunkY <= this.maxSection) {
+            final int idx = chunkY - this.minSection;
+            final PoiSection ret = this.sections[idx];
+            if (ret != null) {
+                return ret;
+            }
+
+            final PoiManager poiManager = this.world.getPoiManager();
+            final long key = CoordinateUtils.getChunkSectionKey(this.chunkX, chunkY, this.chunkZ);
+
+            return this.sections[idx] = new PoiSection(() -> {
+                poiManager.setDirty(key);
+            });
+        }
+        throw new IllegalArgumentException("chunkY is out of bounds, chunkY: " + chunkY + " outside [" + this.minSection + "," + this.maxSection + "]");
+    }
+
+    public PoiSection getSection(final int chunkY) {
+        if (chunkY >= this.minSection && chunkY <= this.maxSection) {
+            return this.sections[chunkY - this.minSection];
+        }
+        return null;
+    }
+
+    public Optional<PoiSection> getSectionForVanilla(final int chunkY) {
+        if (chunkY >= this.minSection && chunkY <= this.maxSection) {
+            final PoiSection ret = this.sections[chunkY - this.minSection];
+            return ret == null ? Optional.empty() : ((ChunkSystemPoiSection)ret).moonrise$asOptional();
+        }
+        return Optional.empty();
+    }
+
+    public boolean isDirty() {
+        return this.isDirty;
+    }
+
+    public void setDirty(final boolean dirty) {
+        this.isDirty = dirty;
+    }
+
+    // returns null if empty
+    public CompoundTag save() {
+        final RegistryOps<Tag> registryOps = RegistryOps.create(NbtOps.INSTANCE, this.world.registryAccess());
+
+        final CompoundTag ret = new CompoundTag();
+        final CompoundTag sections = new CompoundTag();
+        ret.put("Sections", sections);
+
+        ret.putInt("DataVersion", SharedConstants.getCurrentVersion().getDataVersion().getVersion());
+
+        final ServerLevel world = this.world;
+        final int chunkX = this.chunkX;
+        final int chunkZ = this.chunkZ;
+
+        for (int sectionY = this.minSection; sectionY <= this.maxSection; ++sectionY) {
+            final PoiSection section = this.sections[sectionY - this.minSection];
+            if (section == null || ((ChunkSystemPoiSection)section).moonrise$isEmpty()) {
+                continue;
+            }
+
+            // I do not believe asynchronously converting to CompoundTag is worth the scheduling.
+            final DataResult<Tag> serializedResult = PoiSection.Packed.CODEC.encodeStart(registryOps, section.pack());
+            final int finalSectionY = sectionY;
+            final Tag serialized = serializedResult.resultOrPartial((final String description) -> {
+                LOGGER.error("Failed to serialize poi chunk for world: " + WorldUtil.getWorldName(world) + ", chunk: (" + chunkX + "," + finalSectionY + "," + chunkZ + "); description: " + description);
+            }).orElse(null);
+            if (serialized == null) {
+                // failed, should be logged from the resultOrPartial
+                continue;
+            }
+
+            sections.put(Integer.toString(sectionY), serialized);
+        }
+
+        return sections.isEmpty() ? null : ret;
+    }
+
+    public static PoiChunk empty(final ServerLevel world, final int chunkX, final int chunkZ) {
+        final PoiChunk ret = new PoiChunk(world, chunkX, chunkZ, WorldUtil.getMinSection(world), WorldUtil.getMaxSection(world));
+        ret.loaded = true;
+        return ret;
+    }
+
+    public static PoiChunk parse(final ServerLevel world, final int chunkX, final int chunkZ, final CompoundTag data) {
+        final PoiChunk ret = empty(world, chunkX, chunkZ);
+
+        final RegistryOps<Tag> registryOps = RegistryOps.create(NbtOps.INSTANCE, world.registryAccess());
+
+        final CompoundTag sections = data.getCompound("Sections");
+
+        if (sections.isEmpty()) {
+            // nothing to parse
+            return ret;
+        }
+
+        final PoiManager poiManager = world.getPoiManager();
+
+        boolean readAnything = false;
+
+        for (int sectionY = ret.minSection; sectionY <= ret.maxSection; ++sectionY) {
+            final String key = Integer.toString(sectionY);
+            if (!sections.contains(key)) {
+                continue;
+            }
+
+            final CompoundTag section = sections.getCompound(key);
+            final DataResult<PoiSection.Packed> deserializeResult = PoiSection.Packed.CODEC.parse(registryOps, section);
+            final int finalSectionY = sectionY;
+            final PoiSection.Packed packed = deserializeResult.resultOrPartial((final String description) -> {
+                LOGGER.error("Failed to deserialize poi chunk for world: " + WorldUtil.getWorldName(world) + ", chunk: (" + chunkX + "," + finalSectionY + "," + chunkZ + "); description: " + description);
+            }).orElse(null);
+
+            final long coordinateKey = CoordinateUtils.getChunkSectionKey(chunkX, sectionY, chunkZ);
+            final PoiSection deserialized = packed == null ? null : packed.unpack(() -> {
+                poiManager.setDirty(coordinateKey);
+            });
+
+            if (deserialized == null || ((ChunkSystemPoiSection)deserialized).moonrise$isEmpty()) {
+                // completely empty, no point in storing this
+                continue;
+            }
+
+            readAnything = true;
+            ret.sections[sectionY - ret.minSection] = deserialized;
+        }
+
+        ret.loaded = !readAnything; // Set loaded to false if we read anything to ensure proper callbacks to PoiManager are made on #load
+
+        return ret;
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/storage/ChunkSystemSectionStorage.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/storage/ChunkSystemSectionStorage.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/storage/ChunkSystemSectionStorage.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.level.storage;
+
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.world.level.chunk.storage.RegionFileStorage;
+import java.io.IOException;
+
+public interface ChunkSystemSectionStorage {
+
+    public RegionFileStorage moonrise$getRegionStorage();
+
+    public void moonrise$close() throws IOException;
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/player/ChunkSystemServerPlayer.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/player/ChunkSystemServerPlayer.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/player/ChunkSystemServerPlayer.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.player;
+
+public interface ChunkSystemServerPlayer {
+
+    public boolean moonrise$isRealPlayer();
+
+    public void moonrise$setRealPlayer(final boolean real);
+
+    public RegionizedPlayerChunkLoader.PlayerChunkLoaderData moonrise$getChunkLoader();
+
+    public void moonrise$setChunkLoader(final RegionizedPlayerChunkLoader.PlayerChunkLoaderData loader);
+
+    public RegionizedPlayerChunkLoader.ViewDistanceHolder moonrise$getViewDistanceHolder();
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/player/RegionizedPlayerChunkLoader.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/player/RegionizedPlayerChunkLoader.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/player/RegionizedPlayerChunkLoader.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.player;
+
+import ca.spottedleaf.concurrentutil.util.ConcurrentUtil;
+import ca.spottedleaf.concurrentutil.util.Priority;
+import ca.spottedleaf.moonrise.common.PlatformHooks;
+import ca.spottedleaf.moonrise.common.misc.AllocatingRateLimiter;
+import ca.spottedleaf.moonrise.common.misc.SingleUserAreaMap;
+import ca.spottedleaf.moonrise.common.util.CoordinateUtils;
+import ca.spottedleaf.moonrise.common.util.MoonriseConstants;
+import ca.spottedleaf.moonrise.common.util.TickThread;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemChunkHolder;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemLevelChunk;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkHolderManager;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler;
+import ca.spottedleaf.moonrise.patches.chunk_system.util.ParallelSearchRadiusIteration;
+import com.google.gson.JsonObject;
+import it.unimi.dsi.fastutil.longs.Long2ByteOpenHashMap;
+import it.unimi.dsi.fastutil.longs.LongArrayList;
+import it.unimi.dsi.fastutil.longs.LongComparator;
+import it.unimi.dsi.fastutil.longs.LongHeapPriorityQueue;
+import it.unimi.dsi.fastutil.longs.LongOpenHashSet;
+import net.minecraft.network.protocol.Packet;
+import net.minecraft.network.protocol.game.ClientboundForgetLevelChunkPacket;
+import net.minecraft.network.protocol.game.ClientboundSetChunkCacheCenterPacket;
+import net.minecraft.network.protocol.game.ClientboundSetChunkCacheRadiusPacket;
+import net.minecraft.network.protocol.game.ClientboundSetSimulationDistancePacket;
+import net.minecraft.server.level.ChunkTrackingView;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.server.level.TicketType;
+import net.minecraft.server.network.PlayerChunkSender;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.GameRules;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.LevelChunk;
+import net.minecraft.world.level.chunk.status.ChunkStatus;
+import net.minecraft.world.level.levelgen.BelowZeroRetrogen;
+import java.lang.invoke.VarHandle;
+import java.util.ArrayDeque;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.function.Function;
+
+public final class RegionizedPlayerChunkLoader {
+
+    public static final TicketType<Long> PLAYER_TICKET         = TicketType.create("chunk_system:player_ticket", Long::compareTo);
+    public static final TicketType<Long> PLAYER_TICKET_DELAYED = TicketType.create("chunk_system:player_ticket_delayed", Long::compareTo, 5 * 20);
+
+    public static final int MIN_VIEW_DISTANCE = 2;
+    public static final int MAX_VIEW_DISTANCE = 32;
+
+    public static final int GENERATED_TICKET_LEVEL = ChunkHolderManager.FULL_LOADED_TICKET_LEVEL;
+    public static final int LOADED_TICKET_LEVEL = ChunkTaskScheduler.getTicketLevel(ChunkStatus.EMPTY);
+    public static final int TICK_TICKET_LEVEL = ChunkHolderManager.ENTITY_TICKING_TICKET_LEVEL;
+
+    public static final class ViewDistanceHolder {
+
+        private volatile ViewDistances viewDistances;
+        private static final VarHandle VIEW_DISTANCES_HANDLE = ConcurrentUtil.getVarHandle(ViewDistanceHolder.class, "viewDistances", ViewDistances.class);
+
+        public ViewDistanceHolder() {
+            VIEW_DISTANCES_HANDLE.setVolatile(this, new ViewDistances(-1, -1, -1));
+        }
+
+        public ViewDistances getViewDistances() {
+            return (ViewDistances)VIEW_DISTANCES_HANDLE.getVolatile(this);
+        }
+
+        public ViewDistances compareAndExchangeViewDistance(final ViewDistances expect, final ViewDistances update) {
+            return (ViewDistances)VIEW_DISTANCES_HANDLE.compareAndExchange(this, expect, update);
+        }
+
+        public void updateViewDistance(final Function<ViewDistances, ViewDistances> update) {
+            int failures = 0;
+            for (ViewDistances curr = this.getViewDistances();;) {
+                for (int i = 0; i < failures; ++i) {
+                    ConcurrentUtil.backoff();
+                }
+
+                if (curr == (curr = this.compareAndExchangeViewDistance(curr, update.apply(curr)))) {
+                    return;
+                }
+                ++failures;
+            }
+        }
+
+        public void setTickViewDistance(final int distance) {
+            this.updateViewDistance((final ViewDistances param) -> {
+                return param.setTickViewDistance(distance);
+            });
+        }
+
+        public void setLoadViewDistance(final int distance) {
+            this.updateViewDistance((final ViewDistances param) -> {
+                return param.setLoadViewDistance(distance);
+            });
+        }
+
+        public void setSendViewDistance(final int distance) {
+            this.updateViewDistance((final ViewDistances param) -> {
+                return param.setSendViewDistance(distance);
+            });
+        }
+
+        public JsonObject toJson() {
+            return this.getViewDistances().toJson();
+        }
+    }
+
+    public static final record ViewDistances(
+        int tickViewDistance,
+        int loadViewDistance,
+        int sendViewDistance
+    ) {
+        public ViewDistances setTickViewDistance(final int distance) {
+            if (distance != -1 && (distance < (0) || distance > (MoonriseConstants.MAX_VIEW_DISTANCE))) {
+                throw new IllegalArgumentException(Integer.toString(distance));
+            }
+            return new ViewDistances(distance, this.loadViewDistance, this.sendViewDistance);
+        }
+
+        public ViewDistances setLoadViewDistance(final int distance) {
+            // note: load view distance = api view distance + 1
+            if (distance != -1 && (distance < (2 + 1) || distance > (MoonriseConstants.MAX_VIEW_DISTANCE + 1))) {
+                throw new IllegalArgumentException(Integer.toString(distance));
+            }
+            return new ViewDistances(this.tickViewDistance, distance, this.sendViewDistance);
+        }
+
+        public ViewDistances setSendViewDistance(final int distance) {
+            // note: send view distance <= load view distance - 1
+            if (distance != -1 && (distance < (0) || distance > (MoonriseConstants.MAX_VIEW_DISTANCE))) {
+                throw new IllegalArgumentException(Integer.toString(distance));
+            }
+            return new ViewDistances(this.tickViewDistance, this.loadViewDistance, distance);
+        }
+
+        public JsonObject toJson() {
+            final JsonObject ret = new JsonObject();
+
+            ret.addProperty("tick-view-distance", this.tickViewDistance);
+            ret.addProperty("load-view-distance", this.loadViewDistance);
+            ret.addProperty("send-view-distance", this.sendViewDistance);
+
+            return ret;
+        }
+    }
+
+    public static int getAPITickViewDistance(final ServerPlayer player) {
+        final ServerLevel level = player.serverLevel();
+        final PlayerChunkLoaderData data = ((ChunkSystemServerPlayer)player).moonrise$getChunkLoader();
+        if (data == null) {
+            return ((ChunkSystemServerLevel)level).moonrise$getPlayerChunkLoader().getAPITickDistance();
+        }
+        return data.lastTickDistance;
+    }
+
+    public static int getAPIViewDistance(final ServerPlayer player) {
+        final ServerLevel level = player.serverLevel();
+        final PlayerChunkLoaderData data = ((ChunkSystemServerPlayer)player).moonrise$getChunkLoader();
+        if (data == null) {
+            return ((ChunkSystemServerLevel)level).moonrise$getPlayerChunkLoader().getAPIViewDistance();
+        }
+        // view distance = load distance + 1
+        return data.lastLoadDistance - 1;
+    }
+
+    public static int getAPISendViewDistance(final ServerPlayer player) {
+        final ServerLevel level = player.serverLevel();
+        final PlayerChunkLoaderData data = ((ChunkSystemServerPlayer)player).moonrise$getChunkLoader();
+        if (data == null) {
+            return ((ChunkSystemServerLevel)level).moonrise$getPlayerChunkLoader().getAPISendViewDistance();
+        }
+        return data.lastSendDistance;
+    }
+
+    private final ServerLevel world;
+
+    public RegionizedPlayerChunkLoader(final ServerLevel world) {
+        this.world = world;
+    }
+
+    public void addPlayer(final ServerPlayer player) {
+        TickThread.ensureTickThread(player, "Cannot add player to player chunk loader async");
+        if (!((ChunkSystemServerPlayer)player).moonrise$isRealPlayer()) {
+            return;
+        }
+
+        if (((ChunkSystemServerPlayer)player).moonrise$getChunkLoader() != null) {
+            throw new IllegalStateException("Player is already added to player chunk loader");
+        }
+
+        final PlayerChunkLoaderData loader = new PlayerChunkLoaderData(this.world, player);
+
+        ((ChunkSystemServerPlayer)player).moonrise$setChunkLoader(loader);
+        loader.add();
+    }
+
+    public void updatePlayer(final ServerPlayer player) {
+        final PlayerChunkLoaderData loader = ((ChunkSystemServerPlayer)player).moonrise$getChunkLoader();
+        if (loader != null) {
+            loader.update();
+            // update view distances for nearby players
+            ((ChunkSystemServerLevel)loader.world).moonrise$getNearbyPlayers().tickPlayer(player);
+        }
+    }
+
+    public void removePlayer(final ServerPlayer player) {
+        TickThread.ensureTickThread(player, "Cannot remove player from player chunk loader async");
+        if (!((ChunkSystemServerPlayer)player).moonrise$isRealPlayer()) {
+            return;
+        }
+
+        final PlayerChunkLoaderData loader = ((ChunkSystemServerPlayer)player).moonrise$getChunkLoader();
+
+        if (loader == null) {
+            return;
+        }
+
+        loader.remove();
+        ((ChunkSystemServerPlayer)player).moonrise$setChunkLoader(null);
+    }
+
+    public void setSendDistance(final int distance) {
+        ((ChunkSystemServerLevel)this.world).moonrise$getViewDistanceHolder().setSendViewDistance(distance);
+    }
+
+    public void setLoadDistance(final int distance) {
+        ((ChunkSystemServerLevel)this.world).moonrise$getViewDistanceHolder().setLoadViewDistance(distance);
+    }
+
+    public void setTickDistance(final int distance) {
+        ((ChunkSystemServerLevel)this.world).moonrise$getViewDistanceHolder().setTickViewDistance(distance);
+    }
+
+    // Note: follow the player chunk loader so everything stays consistent...
+    public int getAPITickDistance() {
+        final ViewDistances distances = ((ChunkSystemServerLevel)this.world).moonrise$getViewDistanceHolder().getViewDistances();
+        final int tickViewDistance = PlayerChunkLoaderData.getTickDistance(
+                -1, distances.tickViewDistance,
+                -1, distances.loadViewDistance
+        );
+        return tickViewDistance;
+    }
+
+    public int getAPIViewDistance() {
+        final ViewDistances distances = ((ChunkSystemServerLevel)this.world).moonrise$getViewDistanceHolder().getViewDistances();
+        final int tickViewDistance = PlayerChunkLoaderData.getTickDistance(
+                -1, distances.tickViewDistance,
+                -1, distances.loadViewDistance
+        );
+        final int loadDistance = PlayerChunkLoaderData.getLoadViewDistance(tickViewDistance, -1, distances.loadViewDistance);
+
+        // loadDistance = api view distance + 1
+        return loadDistance - 1;
+    }
+
+    public int getAPISendViewDistance() {
+        final ViewDistances distances = ((ChunkSystemServerLevel)this.world).moonrise$getViewDistanceHolder().getViewDistances();
+        final int tickViewDistance = PlayerChunkLoaderData.getTickDistance(
+                -1, distances.tickViewDistance,
+                -1, distances.loadViewDistance
+        );
+        final int loadDistance = PlayerChunkLoaderData.getLoadViewDistance(tickViewDistance, -1, distances.loadViewDistance);
+        final int sendViewDistance = PlayerChunkLoaderData.getSendViewDistance(
+                loadDistance, -1, -1, distances.sendViewDistance
+        );
+
+        return sendViewDistance;
+    }
+
+    public boolean isChunkSent(final ServerPlayer player, final int chunkX, final int chunkZ, final boolean borderOnly) {
+        return borderOnly ? this.isChunkSentBorderOnly(player, chunkX, chunkZ) : this.isChunkSent(player, chunkX, chunkZ);
+    }
+
+    public boolean isChunkSent(final ServerPlayer player, final int chunkX, final int chunkZ) {
+        final PlayerChunkLoaderData loader = ((ChunkSystemServerPlayer)player).moonrise$getChunkLoader();
+        if (loader == null) {
+            return false;
+        }
+
+        return loader.sentChunks.contains(CoordinateUtils.getChunkKey(chunkX, chunkZ));
+    }
+
+    public boolean isChunkSentBorderOnly(final ServerPlayer player, final int chunkX, final int chunkZ) {
+        final PlayerChunkLoaderData loader = ((ChunkSystemServerPlayer)player).moonrise$getChunkLoader();
+        if (loader == null) {
+            return false;
+        }
+
+        for (int dz = -1; dz <= 1; ++dz) {
+            for (int dx = -1; dx <= 1; ++dx) {
+                if (!loader.sentChunks.contains(CoordinateUtils.getChunkKey(dx + chunkX, dz + chunkZ))) {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+
+    public void tick() {
+        TickThread.ensureTickThread("Cannot tick player chunk loader async");
+        long currTime = System.nanoTime();
+        for (final ServerPlayer player : new java.util.ArrayList<>(this.world.players())) {
+            final PlayerChunkLoaderData loader = ((ChunkSystemServerPlayer)player).moonrise$getChunkLoader();
+            if (loader == null || loader.removed || loader.world != this.world) {
+                // not our problem anymore
+                continue;
+            }
+            loader.update(); // can't invoke plugin logic
+            loader.updateQueues(currTime);
+        }
+    }
+
+    public static final class PlayerChunkLoaderData {
+
+        private static final AtomicLong ID_GENERATOR = new AtomicLong();
+        private final long id = ID_GENERATOR.incrementAndGet();
+        private final Long idBoxed = Long.valueOf(this.id);
+
+        private static final long MAX_RATE = 10_000L;
+
+        private final ServerPlayer player;
+        private final ServerLevel world;
+
+        private int lastChunkX = Integer.MIN_VALUE;
+        private int lastChunkZ = Integer.MIN_VALUE;
+
+        private int lastSendDistance = Integer.MIN_VALUE;
+        private int lastLoadDistance = Integer.MIN_VALUE;
+        private int lastTickDistance = Integer.MIN_VALUE;
+
+        private int lastSentChunkCenterX = Integer.MIN_VALUE;
+        private int lastSentChunkCenterZ = Integer.MIN_VALUE;
+
+        private int lastSentChunkRadius = Integer.MIN_VALUE;
+        private int lastSentSimulationDistance = Integer.MIN_VALUE;
+
+        private boolean canGenerateChunks = true;
+
+        private final ArrayDeque<ChunkHolderManager.TicketOperation<?, ?>> delayedTicketOps = new ArrayDeque<>();
+        private final LongOpenHashSet sentChunks = new LongOpenHashSet();
+
+        private static final byte CHUNK_TICKET_STAGE_NONE           = 0;
+        private static final byte CHUNK_TICKET_STAGE_LOADING        = 1;
+        private static final byte CHUNK_TICKET_STAGE_LOADED         = 2;
+        private static final byte CHUNK_TICKET_STAGE_GENERATING     = 3;
+        private static final byte CHUNK_TICKET_STAGE_GENERATED      = 4;
+        private static final byte CHUNK_TICKET_STAGE_TICK           = 5;
+        private static final int[] TICKET_STAGE_TO_LEVEL = new int[] {
+            ChunkHolderManager.MAX_TICKET_LEVEL + 1,
+            LOADED_TICKET_LEVEL,
+            LOADED_TICKET_LEVEL,
+            GENERATED_TICKET_LEVEL,
+            GENERATED_TICKET_LEVEL,
+            TICK_TICKET_LEVEL
+        };
+        private final Long2ByteOpenHashMap chunkTicketStage = new Long2ByteOpenHashMap();
+        {
+            this.chunkTicketStage.defaultReturnValue(CHUNK_TICKET_STAGE_NONE);
+        }
+
+        // rate limiting
+        private static final long ALLOCATION_GRANULARITY = TimeUnit.SECONDS.toNanos(1L);
+        private final AllocatingRateLimiter chunkSendLimiter = new AllocatingRateLimiter(ALLOCATION_GRANULARITY);
+        private final AllocatingRateLimiter chunkLoadTicketLimiter = new AllocatingRateLimiter(ALLOCATION_GRANULARITY);
+        private final AllocatingRateLimiter chunkGenerateTicketLimiter = new AllocatingRateLimiter(ALLOCATION_GRANULARITY);
+
+        // queues
+        private final LongComparator CLOSEST_MANHATTAN_DIST = (final long c1, final long c2) -> {
+            final int c1x = CoordinateUtils.getChunkX(c1);
+            final int c1z = CoordinateUtils.getChunkZ(c1);
+
+            final int c2x = CoordinateUtils.getChunkX(c2);
+            final int c2z = CoordinateUtils.getChunkZ(c2);
+
+            final int centerX = PlayerChunkLoaderData.this.lastChunkX;
+            final int centerZ = PlayerChunkLoaderData.this.lastChunkZ;
+
+            return Integer.compare(
+                Math.abs(c1x - centerX) + Math.abs(c1z - centerZ),
+                Math.abs(c2x - centerX) + Math.abs(c2z - centerZ)
+            );
+        };
+        private final LongHeapPriorityQueue sendQueue = new LongHeapPriorityQueue(CLOSEST_MANHATTAN_DIST);
+        private final LongHeapPriorityQueue tickingQueue = new LongHeapPriorityQueue(CLOSEST_MANHATTAN_DIST);
+        private final LongHeapPriorityQueue generatingQueue = new LongHeapPriorityQueue(CLOSEST_MANHATTAN_DIST);
+        private final LongHeapPriorityQueue genQueue = new LongHeapPriorityQueue(CLOSEST_MANHATTAN_DIST);
+        private final LongHeapPriorityQueue loadingQueue = new LongHeapPriorityQueue(CLOSEST_MANHATTAN_DIST);
+        private final LongHeapPriorityQueue loadQueue = new LongHeapPriorityQueue(CLOSEST_MANHATTAN_DIST);
+
+        private volatile boolean removed;
+
+        public PlayerChunkLoaderData(final ServerLevel world, final ServerPlayer player) {
+            this.world = world;
+            this.player = player;
+        }
+
+        private void flushDelayedTicketOps() {
+            if (this.delayedTicketOps.isEmpty()) {
+                return;
+            }
+            ((ChunkSystemServerLevel)this.world).moonrise$getChunkTaskScheduler().chunkHolderManager.performTicketUpdates(this.delayedTicketOps);
+            this.delayedTicketOps.clear();
+        }
+
+        private void pushDelayedTicketOp(final ChunkHolderManager.TicketOperation<?, ?> op) {
+            this.delayedTicketOps.addLast(op);
+        }
+
+        private void sendChunk(final int chunkX, final int chunkZ) {
+            if (this.sentChunks.add(CoordinateUtils.getChunkKey(chunkX, chunkZ))) {
+                ((ChunkSystemChunkHolder)((ChunkSystemServerLevel)this.world).moonrise$getChunkTaskScheduler().chunkHolderManager
+                        .getChunkHolder(chunkX, chunkZ).vanillaChunkHolder).moonrise$addReceivedChunk(this.player);
+
+                final LevelChunk chunk = ((ChunkSystemLevel)this.world).moonrise$getFullChunkIfLoaded(chunkX, chunkZ);
+
+                PlatformHooks.get().onChunkWatch(this.world, chunk, this.player);
+                PlayerChunkSender.sendChunk(this.player.connection, this.world, chunk);
+                return;
+            }
+            throw new IllegalStateException();
+        }
+
+        private void sendUnloadChunk(final int chunkX, final int chunkZ) {
+            if (!this.sentChunks.remove(CoordinateUtils.getChunkKey(chunkX, chunkZ))) {
+                return;
+            }
+            this.sendUnloadChunkRaw(chunkX, chunkZ);
+        }
+
+        private void sendUnloadChunkRaw(final int chunkX, final int chunkZ) {
+            PlatformHooks.get().onChunkUnWatch(this.world, new ChunkPos(chunkX, chunkZ), this.player);
+            // Note: Check PlayerChunkSender#dropChunk for other logic
+            // Note: drop isAlive() check so that chunks properly unload client-side when the player dies
+            ((ChunkSystemChunkHolder)((ChunkSystemServerLevel)this.world).moonrise$getChunkTaskScheduler().chunkHolderManager
+                .getChunkHolder(chunkX, chunkZ).vanillaChunkHolder).moonrise$removeReceivedChunk(this.player);
+            this.player.connection.send(new ClientboundForgetLevelChunkPacket(new ChunkPos(chunkX, chunkZ)));
+            // Paper start - PlayerChunkUnloadEvent
+            if (io.papermc.paper.event.packet.PlayerChunkUnloadEvent.getHandlerList().getRegisteredListeners().length > 0) {
+                new io.papermc.paper.event.packet.PlayerChunkUnloadEvent(player.getBukkitEntity().getWorld().getChunkAt(new ChunkPos(chunkX, chunkZ).longKey), player.getBukkitEntity()).callEvent();
+            }
+            // Paper end - PlayerChunkUnloadEvent
+        }
+
+        private final SingleUserAreaMap<PlayerChunkLoaderData> broadcastMap = new SingleUserAreaMap<>(this) {
+            @Override
+            protected void addCallback(final PlayerChunkLoaderData parameter, final int chunkX, final int chunkZ) {
+                // do nothing, we only care about remove
+            }
+
+            @Override
+            protected void removeCallback(final PlayerChunkLoaderData parameter, final int chunkX, final int chunkZ) {
+                parameter.sendUnloadChunk(chunkX, chunkZ);
+            }
+        };
+        private final SingleUserAreaMap<PlayerChunkLoaderData> loadTicketCleanup = new SingleUserAreaMap<>(this) {
+            @Override
+            protected void addCallback(final PlayerChunkLoaderData parameter, final int chunkX, final int chunkZ) {
+                // do nothing, we only care about remove
+            }
+
+            @Override
+            protected void removeCallback(final PlayerChunkLoaderData parameter, final int chunkX, final int chunkZ) {
+                final long chunk = CoordinateUtils.getChunkKey(chunkX, chunkZ);
+                final byte ticketStage = parameter.chunkTicketStage.remove(chunk);
+                final int level = TICKET_STAGE_TO_LEVEL[ticketStage];
+                if (level > ChunkHolderManager.MAX_TICKET_LEVEL) {
+                    return;
+                }
+
+                parameter.pushDelayedTicketOp(ChunkHolderManager.TicketOperation.addAndRemove(
+                        chunk,
+                        PLAYER_TICKET_DELAYED, level, parameter.idBoxed,
+                        PLAYER_TICKET, level, parameter.idBoxed
+                ));
+            }
+        };
+        private final SingleUserAreaMap<PlayerChunkLoaderData> tickMap = new SingleUserAreaMap<>(this) {
+            @Override
+            protected void addCallback(final PlayerChunkLoaderData parameter, final int chunkX, final int chunkZ) {
+                // do nothing, we will detect ticking chunks when we try to load them
+            }
+
+            @Override
+            protected void removeCallback(final PlayerChunkLoaderData parameter, final int chunkX, final int chunkZ) {
+                final long chunk = CoordinateUtils.getChunkKey(chunkX, chunkZ);
+                // note: by the time this is called, the tick cleanup should have ran - so, if the chunk is at
+                // the tick stage it was deemed in range for loading. Thus, we need to move it to generated
+                if (!parameter.chunkTicketStage.replace(chunk, CHUNK_TICKET_STAGE_TICK, CHUNK_TICKET_STAGE_GENERATED)) {
+                    return;
+                }
+
+                // Since we are possibly downgrading the ticket level, we add the delayed unload ticket so that
+                // the level is kept for a short period of time
+                parameter.pushDelayedTicketOp(ChunkHolderManager.TicketOperation.addAndRemove(
+                        chunk,
+                        PLAYER_TICKET_DELAYED, TICK_TICKET_LEVEL, parameter.idBoxed,
+                        PLAYER_TICKET, TICK_TICKET_LEVEL, parameter.idBoxed
+                ));
+                // keep chunk at new generated level
+                parameter.pushDelayedTicketOp(ChunkHolderManager.TicketOperation.addOp(
+                        chunk, PLAYER_TICKET, GENERATED_TICKET_LEVEL, parameter.idBoxed
+                ));
+            }
+        };
+
+        private static boolean wantChunkLoaded(final int centerX, final int centerZ, final int chunkX, final int chunkZ,
+                                               final int sendRadius) {
+            // expect sendRadius to be = 1 + target viewable radius
+            return ChunkTrackingView.isWithinDistance(centerX, centerZ, sendRadius, chunkX, chunkZ, true);
+        }
+
+        private static int getClientViewDistance(final ServerPlayer player) {
+            final Integer vd = player.requestedViewDistance();
+            return vd == null ? -1 : Math.max(0, vd.intValue());
+        }
+
+        private static int getTickDistance(final int playerTickViewDistance, final int worldTickViewDistance,
+                                           final int playerLoadViewDistance, final int worldLoadViewDistance) {
+            return Math.min(
+                    playerTickViewDistance < 0 ? worldTickViewDistance : playerTickViewDistance,
+                    playerLoadViewDistance < 0 ? (worldLoadViewDistance - 1) : (playerLoadViewDistance - 1)
+            );
+        }
+
+        private static int getLoadViewDistance(final int tickViewDistance, final int playerLoadViewDistance,
+                                               final int worldLoadViewDistance) {
+            return Math.max(tickViewDistance + 1, playerLoadViewDistance < 0 ? worldLoadViewDistance : playerLoadViewDistance);
+        }
+
+        private static int getSendViewDistance(final int loadViewDistance, final int clientViewDistance,
+                                               final int playerSendViewDistance, final int worldSendViewDistance) {
+            return Math.min(
+                loadViewDistance - 1,
+                playerSendViewDistance < 0 ? (!PlatformHooks.get().configAutoConfigSendDistance() || clientViewDistance < 0 ? (worldSendViewDistance < 0 ? (loadViewDistance - 1) : worldSendViewDistance) : clientViewDistance + 1) : playerSendViewDistance
+            );
+        }
+
+        private Packet<?> updateClientChunkRadius(final int radius) {
+            this.lastSentChunkRadius = radius;
+            return new ClientboundSetChunkCacheRadiusPacket(radius);
+        }
+
+        private Packet<?> updateClientSimulationDistance(final int distance) {
+            this.lastSentSimulationDistance = distance;
+            return new ClientboundSetSimulationDistancePacket(distance);
+        }
+
+        private Packet<?> updateClientChunkCenter(final int chunkX, final int chunkZ) {
+            this.lastSentChunkCenterX = chunkX;
+            this.lastSentChunkCenterZ = chunkZ;
+            return new ClientboundSetChunkCacheCenterPacket(chunkX, chunkZ);
+        }
+
+        private boolean canPlayerGenerateChunks() {
+            return !this.player.isSpectator() || this.world.getGameRules().getBoolean(GameRules.RULE_SPECTATORSGENERATECHUNKS);
+        }
+
+        private double getMaxChunkLoadRate() {
+            final double configRate = PlatformHooks.get().configPlayerMaxLoadRate();
+
+            return configRate <= 0.0 || configRate > (double)MAX_RATE ? (double)MAX_RATE : Math.max(1.0, configRate);
+        }
+
+        private double getMaxChunkGenRate() {
+            final double configRate = PlatformHooks.get().configPlayerMaxGenRate();
+
+            return configRate <= 0.0 || configRate > (double)MAX_RATE ? (double)MAX_RATE : Math.max(1.0, configRate);
+        }
+
+        private double getMaxChunkSendRate() {
+            final double configRate = PlatformHooks.get().configPlayerMaxSendRate();
+
+            return configRate <= 0.0 || configRate > (double)MAX_RATE ? (double)MAX_RATE : Math.max(1.0, configRate);
+        }
+
+        private long getMaxChunkLoads() {
+            final long radiusChunks = (2L * this.lastLoadDistance + 1L) * (2L * this.lastLoadDistance + 1L);
+            long configLimit = (long)PlatformHooks.get().configPlayerMaxConcurrentLoads();
+            if (configLimit == 0L) {
+                // by default, only allow 1/5th of the chunks in the view distance to be concurrently active
+                configLimit = Math.max(5L, radiusChunks / 5L);
+            } else if (configLimit < 0L) {
+                configLimit = Integer.MAX_VALUE;
+            } // else: use the value configured
+            configLimit = configLimit - this.loadingQueue.size();
+
+            return configLimit;
+        }
+
+        private long getMaxChunkGenerates() {
+            final long radiusChunks = (2L * this.lastLoadDistance + 1L) * (2L * this.lastLoadDistance + 1L);
+            long configLimit = (long)PlatformHooks.get().configPlayerMaxConcurrentGens();
+            if (configLimit == 0L) {
+                // by default, only allow 1/5th of the chunks in the view distance to be concurrently active
+                configLimit = Math.max(5L, radiusChunks / 5L);
+            } else if (configLimit < 0L) {
+                configLimit = Integer.MAX_VALUE;
+            } // else: use the value configured
+            configLimit = configLimit - this.generatingQueue.size();
+
+            return configLimit;
+        }
+
+        private boolean wantChunkSent(final int chunkX, final int chunkZ) {
+            final int dx = this.lastChunkX - chunkX;
+            final int dz = this.lastChunkZ - chunkZ;
+            return (Math.max(Math.abs(dx), Math.abs(dz)) <= (this.lastSendDistance + 1)) && wantChunkLoaded(
+                this.lastChunkX, this.lastChunkZ, chunkX, chunkZ, this.lastSendDistance
+            );
+        }
+
+        private boolean wantChunkTicked(final int chunkX, final int chunkZ) {
+            final int dx = this.lastChunkX - chunkX;
+            final int dz = this.lastChunkZ - chunkZ;
+            return Math.max(Math.abs(dx), Math.abs(dz)) <= this.lastTickDistance;
+        }
+
+        private boolean areNeighboursGenerated(final int chunkX, final int chunkZ, final int radius) {
+            for (int dz = -radius; dz <= radius; ++dz) {
+                for (int dx = -radius; dx <= radius; ++dx) {
+                    if ((dx | dz) == 0) {
+                        continue;
+                    }
+
+                    final long neighbour = CoordinateUtils.getChunkKey(dx + chunkX, dz + chunkZ);
+                    final byte stage = this.chunkTicketStage.get(neighbour);
+
+                    if (stage != CHUNK_TICKET_STAGE_GENERATED && stage != CHUNK_TICKET_STAGE_TICK) {
+                        return false;
+                    }
+                }
+            }
+
+            return true;
+        }
+
+        void updateQueues(final long time) {
+            TickThread.ensureTickThread(this.player, "Cannot tick player chunk loader async");
+            if (this.removed) {
+                throw new IllegalStateException("Ticking removed player chunk loader");
+            }
+            // update rate limits
+            final double loadRate = this.getMaxChunkLoadRate();
+            final double genRate = this.getMaxChunkGenRate();
+            final double sendRate = this.getMaxChunkSendRate();
+
+            this.chunkLoadTicketLimiter.tickAllocation(time, loadRate, loadRate);
+            this.chunkGenerateTicketLimiter.tickAllocation(time, genRate, genRate);
+            this.chunkSendLimiter.tickAllocation(time, sendRate, sendRate);
+
+            // try to progress chunk loads
+            while (!this.loadingQueue.isEmpty()) {
+                final long pendingLoadChunk = this.loadingQueue.firstLong();
+                final int pendingChunkX = CoordinateUtils.getChunkX(pendingLoadChunk);
+                final int pendingChunkZ = CoordinateUtils.getChunkZ(pendingLoadChunk);
+                final ChunkAccess pending = ((ChunkSystemLevel)this.world).moonrise$getAnyChunkIfLoaded(pendingChunkX, pendingChunkZ);
+                if (pending == null) {
+                    // nothing to do here
+                    break;
+                }
+                // chunk has loaded, so we can take it out of the queue
+                this.loadingQueue.dequeueLong();
+
+                // try to move to generate queue
+                final byte prev = this.chunkTicketStage.put(pendingLoadChunk, CHUNK_TICKET_STAGE_LOADED);
+                if (prev != CHUNK_TICKET_STAGE_LOADING) {
+                    throw new IllegalStateException("Previous state should be " + CHUNK_TICKET_STAGE_LOADING + ", not " + prev);
+                }
+
+                if (this.canGenerateChunks || this.isLoadedChunkGeneratable(pending)) {
+                    this.genQueue.enqueue(pendingLoadChunk);
+                } // else: don't want to generate, so just leave it loaded
+            }
+
+            // try to push more chunk loads
+            final long maxLoads = Math.max(0L, Math.min(MAX_RATE, Math.min(this.loadQueue.size(), this.getMaxChunkLoads())));
+            final int maxLoadsThisTick = (int)this.chunkLoadTicketLimiter.takeAllocation(time, loadRate, maxLoads);
+            if (maxLoadsThisTick > 0) {
+                final LongArrayList chunks = new LongArrayList(maxLoadsThisTick);
+                for (int i = 0; i < maxLoadsThisTick; ++i) {
+                    final long chunk = this.loadQueue.dequeueLong();
+                    final byte prev = this.chunkTicketStage.put(chunk, CHUNK_TICKET_STAGE_LOADING);
+                    if (prev != CHUNK_TICKET_STAGE_NONE) {
+                        throw new IllegalStateException("Previous state should be " + CHUNK_TICKET_STAGE_NONE + ", not " + prev);
+                    }
+                    this.pushDelayedTicketOp(
+                        ChunkHolderManager.TicketOperation.addOp(
+                            chunk,
+                            PLAYER_TICKET, LOADED_TICKET_LEVEL, this.idBoxed
+                        )
+                    );
+                    chunks.add(chunk);
+                    this.loadingQueue.enqueue(chunk);
+                }
+
+                // here we need to flush tickets, as scheduleChunkLoad requires tickets to be propagated with addTicket = false
+                this.flushDelayedTicketOps();
+                // we only need to call scheduleChunkLoad because the loaded ticket level is not enough to start the chunk
+                // load - only generate ticket levels start anything, but they start generation...
+                // propagate levels
+                // Note: this CAN call plugin logic, so it is VITAL that our bookkeeping logic is completely done by the time this is invoked
+                ((ChunkSystemServerLevel)this.world).moonrise$getChunkTaskScheduler().chunkHolderManager.processTicketUpdates();
+
+                if (this.removed) {
+                    // process ticket updates may invoke plugin logic, which may remove this player
+                    return;
+                }
+
+                for (int i = 0; i < maxLoadsThisTick; ++i) {
+                    final long queuedLoadChunk = chunks.getLong(i);
+                    final int queuedChunkX = CoordinateUtils.getChunkX(queuedLoadChunk);
+                    final int queuedChunkZ = CoordinateUtils.getChunkZ(queuedLoadChunk);
+                    ((ChunkSystemServerLevel)this.world).moonrise$getChunkTaskScheduler().scheduleChunkLoad(
+                        queuedChunkX, queuedChunkZ, ChunkStatus.EMPTY, false, Priority.NORMAL, null
+                    );
+                    if (this.removed) {
+                        return;
+                    }
+                }
+            }
+
+            // try to progress chunk generations
+            while (!this.generatingQueue.isEmpty()) {
+                final long pendingGenChunk = this.generatingQueue.firstLong();
+                final int pendingChunkX = CoordinateUtils.getChunkX(pendingGenChunk);
+                final int pendingChunkZ = CoordinateUtils.getChunkZ(pendingGenChunk);
+                final LevelChunk pending = ((ChunkSystemLevel)this.world).moonrise$getFullChunkIfLoaded(pendingChunkX, pendingChunkZ);
+                if (pending == null) {
+                    // nothing to do here
+                    break;
+                }
+
+                // chunk has generated, so we can take it out of queue
+                this.generatingQueue.dequeueLong();
+
+                final byte prev = this.chunkTicketStage.put(pendingGenChunk, CHUNK_TICKET_STAGE_GENERATED);
+                if (prev != CHUNK_TICKET_STAGE_GENERATING) {
+                    throw new IllegalStateException("Previous state should be " + CHUNK_TICKET_STAGE_GENERATING + ", not " + prev);
+                }
+
+                // try to move to send queue
+                if (this.wantChunkSent(pendingChunkX, pendingChunkZ)) {
+                    this.sendQueue.enqueue(pendingGenChunk);
+                }
+                // try to move to tick queue
+                if (this.wantChunkTicked(pendingChunkX, pendingChunkZ)) {
+                    this.tickingQueue.enqueue(pendingGenChunk);
+                }
+            }
+
+            // try to push more chunk generations
+            final long maxGens = Math.max(0L, Math.min(MAX_RATE, Math.min(this.genQueue.size(), this.getMaxChunkGenerates())));
+            // preview the allocations, as we may not actually utilise all of them
+            final long maxGensThisTick = this.chunkGenerateTicketLimiter.previewAllocation(time, genRate, maxGens);
+            long ratedGensThisTick = 0L;
+            while (!this.genQueue.isEmpty()) {
+                final long chunkKey = this.genQueue.firstLong();
+                final int chunkX = CoordinateUtils.getChunkX(chunkKey);
+                final int chunkZ = CoordinateUtils.getChunkZ(chunkKey);
+                final ChunkAccess chunk = ((ChunkSystemLevel)this.world).moonrise$getAnyChunkIfLoaded(chunkX, chunkZ);
+                if (chunk.getPersistedStatus() != ChunkStatus.FULL) {
+                    // only rate limit actual generations
+                    if ((ratedGensThisTick + 1L) > maxGensThisTick) {
+                        break;
+                    }
+                    ++ratedGensThisTick;
+                }
+
+                this.genQueue.dequeueLong();
+
+                final byte prev = this.chunkTicketStage.put(chunkKey, CHUNK_TICKET_STAGE_GENERATING);
+                if (prev != CHUNK_TICKET_STAGE_LOADED) {
+                    throw new IllegalStateException("Previous state should be " + CHUNK_TICKET_STAGE_LOADED + ", not " + prev);
+                }
+                this.pushDelayedTicketOp(
+                    ChunkHolderManager.TicketOperation.addAndRemove(
+                            chunkKey,
+                            PLAYER_TICKET, GENERATED_TICKET_LEVEL, this.idBoxed,
+                            PLAYER_TICKET, LOADED_TICKET_LEVEL, this.idBoxed
+                    )
+                );
+                this.generatingQueue.enqueue(chunkKey);
+            }
+            // take the allocations we actually used
+            this.chunkGenerateTicketLimiter.takeAllocation(time, genRate, ratedGensThisTick);
+
+            // try to pull ticking chunks
+            while (!this.tickingQueue.isEmpty()) {
+                final long pendingTicking = this.tickingQueue.firstLong();
+                final int pendingChunkX = CoordinateUtils.getChunkX(pendingTicking);
+                final int pendingChunkZ = CoordinateUtils.getChunkZ(pendingTicking);
+
+                if (!this.areNeighboursGenerated(pendingChunkX, pendingChunkZ,
+                    ChunkHolderManager.FULL_LOADED_TICKET_LEVEL - ChunkHolderManager.ENTITY_TICKING_TICKET_LEVEL)) {
+                    break;
+                }
+
+                // only gets here if all neighbours were marked as generated or ticking themselves
+                this.tickingQueue.dequeueLong();
+                this.pushDelayedTicketOp(
+                    ChunkHolderManager.TicketOperation.addAndRemove(
+                            pendingTicking,
+                            PLAYER_TICKET, TICK_TICKET_LEVEL, this.idBoxed,
+                            PLAYER_TICKET, GENERATED_TICKET_LEVEL, this.idBoxed
+                    )
+                );
+                // note: there is no queue to add after ticking
+                final byte prev = this.chunkTicketStage.put(pendingTicking, CHUNK_TICKET_STAGE_TICK);
+                if (prev != CHUNK_TICKET_STAGE_GENERATED) {
+                    throw new IllegalStateException("Previous state should be " + CHUNK_TICKET_STAGE_GENERATED + ", not " + prev);
+                }
+            }
+
+            // try to pull sending chunks
+            final long maxSends = Math.max(0L, Math.min(MAX_RATE, Integer.MAX_VALUE)); // note: no logic to track concurrent sends
+            final int maxSendsThisTick = Math.min((int)this.chunkSendLimiter.takeAllocation(time, sendRate, maxSends), this.sendQueue.size());
+            // we do not return sends that we took from the allocation back because we want to limit the max send rate, not target it
+            for (int i = 0; i < maxSendsThisTick; ++i) {
+                final long pendingSend = this.sendQueue.firstLong();
+                final int pendingSendX = CoordinateUtils.getChunkX(pendingSend);
+                final int pendingSendZ = CoordinateUtils.getChunkZ(pendingSend);
+                final LevelChunk chunk = ((ChunkSystemLevel)this.world).moonrise$getFullChunkIfLoaded(pendingSendX, pendingSendZ);
+                if (!this.areNeighboursGenerated(pendingSendX, pendingSendZ, 1) || !TickThread.isTickThreadFor(this.world, pendingSendX, pendingSendZ)) {
+                    // nothing to do
+                    // the target chunk may not be owned by this region, but this should be resolved in the future
+                    break;
+                }
+                if (!((ChunkSystemLevelChunk)chunk).moonrise$isPostProcessingDone()) {
+                    // not yet post-processed, need to do this so that tile entities can properly be sent to clients
+                    chunk.postProcessGeneration(this.world);
+                    // check if there was any recursive action
+                    if (this.removed || this.sendQueue.isEmpty() || this.sendQueue.firstLong() != pendingSend) {
+                        return;
+                    } // else: good to dequeue and send, fall through
+                }
+                this.sendQueue.dequeueLong();
+
+                this.sendChunk(pendingSendX, pendingSendZ);
+
+                if (this.removed) {
+                    // sendChunk may invoke plugin logic
+                    return;
+                }
+            }
+
+            this.flushDelayedTicketOps();
+        }
+
+        void add() {
+            TickThread.ensureTickThread(this.player, "Cannot add player asynchronously");
+            if (this.removed) {
+                throw new IllegalStateException("Adding removed player chunk loader");
+            }
+            final ViewDistances playerDistances = ((ChunkSystemServerPlayer)this.player).moonrise$getViewDistanceHolder().getViewDistances();
+            final ViewDistances worldDistances = ((ChunkSystemServerLevel)this.world).moonrise$getViewDistanceHolder().getViewDistances();
+            final int chunkX = this.player.chunkPosition().x;
+            final int chunkZ = this.player.chunkPosition().z;
+
+            final int tickViewDistance = getTickDistance(
+                    playerDistances.tickViewDistance, worldDistances.tickViewDistance,
+                    playerDistances.loadViewDistance, worldDistances.loadViewDistance
+            );
+            // load view cannot be less-than tick view + 1
+            final int loadViewDistance = getLoadViewDistance(tickViewDistance, playerDistances.loadViewDistance, worldDistances.loadViewDistance);
+            // send view cannot be greater-than load view
+            final int clientViewDistance = getClientViewDistance(this.player);
+            final int sendViewDistance = getSendViewDistance(loadViewDistance, clientViewDistance, playerDistances.sendViewDistance, worldDistances.sendViewDistance);
+
+            // send view distances
+            this.player.connection.send(this.updateClientChunkRadius(sendViewDistance));
+            this.player.connection.send(this.updateClientSimulationDistance(tickViewDistance));
+
+            // add to distance maps
+            this.broadcastMap.add(chunkX, chunkZ, sendViewDistance + 1);
+            this.loadTicketCleanup.add(chunkX, chunkZ, loadViewDistance + 1);
+            this.tickMap.add(chunkX, chunkZ, tickViewDistance);
+
+            // update chunk center
+            this.player.connection.send(this.updateClientChunkCenter(chunkX, chunkZ));
+
+            // reset limiters, they will start at a zero allocation
+            final long time = System.nanoTime();
+            this.chunkLoadTicketLimiter.reset(time);
+            this.chunkGenerateTicketLimiter.reset(time);
+            this.chunkSendLimiter.reset(time);
+
+            // now we can update
+            this.update();
+        }
+
+        private boolean isLoadedChunkGeneratable(final int chunkX, final int chunkZ) {
+            return this.isLoadedChunkGeneratable(((ChunkSystemLevel)this.world).moonrise$getAnyChunkIfLoaded(chunkX, chunkZ));
+        }
+
+        private boolean isLoadedChunkGeneratable(final ChunkAccess chunkAccess) {
+            final BelowZeroRetrogen belowZeroRetrogen;
+            // see PortalForcer#findPortalAround
+            return chunkAccess != null && (
+                chunkAccess.getPersistedStatus() == ChunkStatus.FULL ||
+                    ((belowZeroRetrogen = chunkAccess.getBelowZeroRetrogen()) != null && belowZeroRetrogen.targetStatus().isOrAfter(ChunkStatus.SPAWN))
+            );
+        }
+
+        void update() {
+            TickThread.ensureTickThread(this.player, "Cannot update player asynchronously");
+            if (this.removed) {
+                throw new IllegalStateException("Updating removed player chunk loader");
+            }
+            final ViewDistances playerDistances = ((ChunkSystemServerPlayer)this.player).moonrise$getViewDistanceHolder().getViewDistances();
+            final ViewDistances worldDistances = ((ChunkSystemServerLevel)this.world).moonrise$getViewDistanceHolder().getViewDistances();
+
+            final int tickViewDistance = getTickDistance(
+                    playerDistances.tickViewDistance, worldDistances.tickViewDistance,
+                    playerDistances.loadViewDistance, worldDistances.loadViewDistance
+            );
+            // load view cannot be less-than tick view + 1
+            final int loadViewDistance = getLoadViewDistance(tickViewDistance, playerDistances.loadViewDistance, worldDistances.loadViewDistance);
+            // send view cannot be greater-than load view
+            final int clientViewDistance = getClientViewDistance(this.player);
+            final int sendViewDistance = getSendViewDistance(loadViewDistance, clientViewDistance, playerDistances.sendViewDistance, worldDistances.sendViewDistance);
+
+            final ChunkPos playerPos = this.player.chunkPosition();
+            final boolean canGenerateChunks = this.canPlayerGenerateChunks();
+            final int currentChunkX = playerPos.x;
+            final int currentChunkZ = playerPos.z;
+
+            final int prevChunkX = this.lastChunkX;
+            final int prevChunkZ = this.lastChunkZ;
+
+            if (
+                // has view distance stayed the same?
+                sendViewDistance == this.lastSendDistance
+                    && loadViewDistance == this.lastLoadDistance
+                    && tickViewDistance == this.lastTickDistance
+
+                    // has our chunk stayed the same?
+                    && prevChunkX == currentChunkX
+                    && prevChunkZ == currentChunkZ
+
+                    // can we still generate chunks?
+                    && this.canGenerateChunks == canGenerateChunks
+            ) {
+                // nothing we care about changed, so we're not re-calculating
+                return;
+            }
+
+            // update distance maps
+            this.broadcastMap.update(currentChunkX, currentChunkZ, sendViewDistance + 1);
+            this.loadTicketCleanup.update(currentChunkX, currentChunkZ, loadViewDistance + 1);
+            this.tickMap.update(currentChunkX, currentChunkZ, tickViewDistance);
+            if (sendViewDistance > loadViewDistance || tickViewDistance > loadViewDistance) {
+                throw new IllegalStateException();
+            }
+
+            // update VDs for client
+            // this should be after the distance map updates, as they will send unload packets
+            if (this.lastSentChunkRadius != sendViewDistance) {
+                this.player.connection.send(this.updateClientChunkRadius(sendViewDistance));
+            }
+            if (this.lastSentSimulationDistance != tickViewDistance) {
+                this.player.connection.send(this.updateClientSimulationDistance(tickViewDistance));
+            }
+
+            this.sendQueue.clear();
+            this.tickingQueue.clear();
+            this.generatingQueue.clear();
+            this.genQueue.clear();
+            this.loadingQueue.clear();
+            this.loadQueue.clear();
+
+            this.lastChunkX = currentChunkX;
+            this.lastChunkZ = currentChunkZ;
+            this.lastSendDistance = sendViewDistance;
+            this.lastLoadDistance = loadViewDistance;
+            this.lastTickDistance = tickViewDistance;
+            this.canGenerateChunks = canGenerateChunks;
+
+            // +1 since we need to load chunks +1 around the load view distance...
+            final long[] toIterate = ParallelSearchRadiusIteration.getSearchIteration(loadViewDistance + 1);
+            // the iteration order is by increasing manhattan distance - so, we do NOT need to
+            // sort anything in the queue!
+            for (final long deltaChunk : toIterate) {
+                final int dx = CoordinateUtils.getChunkX(deltaChunk);
+                final int dz = CoordinateUtils.getChunkZ(deltaChunk);
+                final int chunkX = dx + currentChunkX;
+                final int chunkZ = dz + currentChunkZ;
+                final long chunk = CoordinateUtils.getChunkKey(chunkX, chunkZ);
+                final int squareDistance = Math.max(Math.abs(dx), Math.abs(dz));
+                final int manhattanDistance = Math.abs(dx) + Math.abs(dz);
+
+                // since chunk sending is not by radius alone, we need an extra check here to account for
+                // everything <= sendDistance
+                // Note: Vanilla may want to send chunks outside the send view distance, so we do need
+                // the dist <= view check
+                final boolean sendChunk = (squareDistance <= (sendViewDistance + 1))
+                    && wantChunkLoaded(currentChunkX, currentChunkZ, chunkX, chunkZ, sendViewDistance);
+                final boolean sentChunk = sendChunk ? this.sentChunks.contains(chunk) : this.sentChunks.remove(chunk);
+
+                if (!sendChunk && sentChunk) {
+                    // have sent the chunk, but don't want it anymore
+                    // unload it now
+                    this.sendUnloadChunkRaw(chunkX, chunkZ);
+                }
+
+                final byte stage = this.chunkTicketStage.get(chunk);
+                switch (stage) {
+                    case CHUNK_TICKET_STAGE_NONE: {
+                        // we want the chunk to be at least loaded
+                        this.loadQueue.enqueue(chunk);
+                        break;
+                    }
+                    case CHUNK_TICKET_STAGE_LOADING: {
+                        this.loadingQueue.enqueue(chunk);
+                        break;
+                    }
+                    case CHUNK_TICKET_STAGE_LOADED: {
+                        if (canGenerateChunks || this.isLoadedChunkGeneratable(chunkX, chunkZ)) {
+                            this.genQueue.enqueue(chunk);
+                        }
+                        break;
+                    }
+                    case CHUNK_TICKET_STAGE_GENERATING: {
+                        this.generatingQueue.enqueue(chunk);
+                        break;
+                    }
+                    case CHUNK_TICKET_STAGE_GENERATED: {
+                        if (sendChunk && !sentChunk) {
+                            this.sendQueue.enqueue(chunk);
+                        }
+                        if (squareDistance <= tickViewDistance) {
+                            this.tickingQueue.enqueue(chunk);
+                        }
+                        break;
+                    }
+                    case CHUNK_TICKET_STAGE_TICK: {
+                        if (sendChunk && !sentChunk) {
+                            this.sendQueue.enqueue(chunk);
+                        }
+                        break;
+                    }
+                    default: {
+                        throw new IllegalStateException("Unknown stage: " + stage);
+                    }
+                }
+            }
+
+            // update the chunk center
+            // this must be done last so that the client does not ignore any of our unload chunk packets above
+            if (this.lastSentChunkCenterX != currentChunkX || this.lastSentChunkCenterZ != currentChunkZ) {
+                this.player.connection.send(this.updateClientChunkCenter(currentChunkX, currentChunkZ));
+            }
+
+            this.flushDelayedTicketOps();
+        }
+
+        void remove() {
+            TickThread.ensureTickThread(this.player, "Cannot add player asynchronously");
+            if (this.removed) {
+                throw new IllegalStateException("Removing removed player chunk loader");
+            }
+            this.removed = true;
+            // sends the chunk unload packets
+            this.broadcastMap.remove();
+            // cleans up loading/generating tickets
+            this.loadTicketCleanup.remove();
+            // cleans up ticking tickets
+            this.tickMap.remove();
+
+            // purge queues
+            this.sendQueue.clear();
+            this.tickingQueue.clear();
+            this.generatingQueue.clear();
+            this.genQueue.clear();
+            this.loadingQueue.clear();
+            this.loadQueue.clear();
+
+            // flush ticket changes
+            this.flushDelayedTicketOps();
+
+            // now all tickets should be removed, which is all of our external state
+        }
+
+        public LongOpenHashSet getSentChunksRaw() {
+            return this.sentChunks;
+        }
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/queue/ChunkUnloadQueue.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/queue/ChunkUnloadQueue.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/queue/ChunkUnloadQueue.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.queue;
+
+import ca.spottedleaf.concurrentutil.map.ConcurrentLong2ReferenceChainedHashTable;
+import ca.spottedleaf.moonrise.common.util.CoordinateUtils;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import it.unimi.dsi.fastutil.longs.LongIterator;
+import it.unimi.dsi.fastutil.longs.LongLinkedOpenHashSet;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicLong;
+
+public final class ChunkUnloadQueue {
+
+    public final int coordinateShift;
+    private final AtomicLong orderGenerator = new AtomicLong();
+    private final ConcurrentLong2ReferenceChainedHashTable<UnloadSection> unloadSections = new ConcurrentLong2ReferenceChainedHashTable<>();
+
+    /*
+     * Note: write operations do not occur in parallel for any given section.
+     * Note: coordinateShift <= region shift in order for retrieveForCurrentRegion() to function correctly
+     */
+
+    public ChunkUnloadQueue(final int coordinateShift) {
+        this.coordinateShift = coordinateShift;
+    }
+
+    public static record SectionToUnload(int sectionX, int sectionZ, long order, int count) {}
+
+    public List<SectionToUnload> retrieveForAllRegions() {
+        final List<SectionToUnload> ret = new ArrayList<>();
+
+        for (final Iterator<ConcurrentLong2ReferenceChainedHashTable.TableEntry<UnloadSection>> iterator = this.unloadSections.entryIterator(); iterator.hasNext();) {
+            final ConcurrentLong2ReferenceChainedHashTable.TableEntry<UnloadSection> entry = iterator.next();
+            final long key = entry.getKey();
+            final UnloadSection section = entry.getValue();
+            final int sectionX = CoordinateUtils.getChunkX(key);
+            final int sectionZ = CoordinateUtils.getChunkZ(key);
+
+            ret.add(new SectionToUnload(sectionX, sectionZ, section.order, section.chunks.size()));
+        }
+
+        ret.sort((final SectionToUnload s1, final SectionToUnload s2) -> {
+            return Long.compare(s1.order, s2.order);
+        });
+
+        return ret;
+    }
+
+    public UnloadSection getSectionUnsynchronized(final int sectionX, final int sectionZ) {
+        return this.unloadSections.get(CoordinateUtils.getChunkKey(sectionX, sectionZ));
+    }
+
+    public UnloadSection removeSection(final int sectionX, final int sectionZ) {
+        return this.unloadSections.remove(CoordinateUtils.getChunkKey(sectionX, sectionZ));
+    }
+
+    // write operation
+    public boolean addChunk(final int chunkX, final int chunkZ) {
+        // write operations do not occur in parallel for a given section
+        final int shift = this.coordinateShift;
+        final int sectionX = chunkX >> shift;
+        final int sectionZ = chunkZ >> shift;
+        final long sectionKey = CoordinateUtils.getChunkKey(sectionX, sectionZ);
+        final long chunkKey = CoordinateUtils.getChunkKey(chunkX, chunkZ);
+
+        UnloadSection section = this.unloadSections.get(sectionKey);
+        if (section == null) {
+            section = new UnloadSection(this.orderGenerator.getAndIncrement());
+            this.unloadSections.put(sectionKey, section);
+        }
+
+        return section.chunks.add(chunkKey);
+    }
+
+    // write operation
+    public boolean removeChunk(final int chunkX, final int chunkZ) {
+        // write operations do not occur in parallel for a given section
+        final int shift = this.coordinateShift;
+        final int sectionX = chunkX >> shift;
+        final int sectionZ = chunkZ >> shift;
+        final long sectionKey = CoordinateUtils.getChunkKey(sectionX, sectionZ);
+        final long chunkKey = CoordinateUtils.getChunkKey(chunkX, chunkZ);
+
+        final UnloadSection section = this.unloadSections.get(sectionKey);
+
+        if (section == null) {
+            return false;
+        }
+
+        if (!section.chunks.remove(chunkKey)) {
+            return false;
+        }
+
+        if (section.chunks.isEmpty()) {
+            this.unloadSections.remove(sectionKey);
+        }
+
+        return true;
+    }
+
+    public JsonElement toDebugJson() {
+        final JsonArray ret = new JsonArray();
+
+        for (final SectionToUnload section : this.retrieveForAllRegions()) {
+            final JsonObject sectionJson = new JsonObject();
+            ret.add(sectionJson);
+
+            sectionJson.addProperty("sectionX", section.sectionX());
+            sectionJson.addProperty("sectionZ", section.sectionX());
+            sectionJson.addProperty("order", section.order());
+
+            final JsonArray coordinates = new JsonArray();
+            sectionJson.add("coordinates", coordinates);
+
+            final UnloadSection actualSection = this.getSectionUnsynchronized(section.sectionX(), section.sectionZ());
+            if (actualSection != null) {
+                for (final LongIterator iterator = actualSection.chunks.clone().iterator(); iterator.hasNext(); ) {
+                    final long coordinate = iterator.nextLong();
+
+                    final JsonObject coordinateJson = new JsonObject();
+                    coordinates.add(coordinateJson);
+
+                    coordinateJson.addProperty("chunkX", Integer.valueOf(CoordinateUtils.getChunkX(coordinate)));
+                    coordinateJson.addProperty("chunkZ", Integer.valueOf(CoordinateUtils.getChunkZ(coordinate)));
+                }
+            }
+        }
+
+        return ret;
+    }
+
+    public static final class UnloadSection {
+
+        public final long order;
+        public final LongLinkedOpenHashSet chunks = new LongLinkedOpenHashSet();
+
+        public UnloadSection(final long order) {
+            this.order = order;
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/ChunkHolderManager.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/ChunkHolderManager.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/ChunkHolderManager.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.scheduling;
+
+import ca.spottedleaf.concurrentutil.lock.ReentrantAreaLock;
+import ca.spottedleaf.concurrentutil.map.ConcurrentLong2ReferenceChainedHashTable;
+import ca.spottedleaf.concurrentutil.util.Priority;
+import ca.spottedleaf.moonrise.common.PlatformHooks;
+import ca.spottedleaf.moonrise.common.util.CoordinateUtils;
+import ca.spottedleaf.moonrise.common.util.TickThread;
+import ca.spottedleaf.moonrise.common.util.WorldUtil;
+import ca.spottedleaf.moonrise.common.util.ChunkSystem;
+import ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.entity.ChunkEntitySlices;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.poi.PoiChunk;
+import ca.spottedleaf.moonrise.patches.chunk_system.queue.ChunkUnloadQueue;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkLoadTask;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkProgressionTask;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.GenericDataLoadTask;
+import ca.spottedleaf.moonrise.patches.chunk_system.ticket.ChunkSystemTicket;
+import ca.spottedleaf.moonrise.patches.chunk_system.util.ChunkSystemSortedArraySet;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonObject;
+import com.mojang.logging.LogUtils;
+import it.unimi.dsi.fastutil.longs.Long2ByteLinkedOpenHashMap;
+import it.unimi.dsi.fastutil.longs.Long2ByteMap;
+import it.unimi.dsi.fastutil.longs.Long2IntMap;
+import it.unimi.dsi.fastutil.longs.Long2IntOpenHashMap;
+import it.unimi.dsi.fastutil.longs.Long2ObjectMap;
+import it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap;
+import it.unimi.dsi.fastutil.longs.LongArrayList;
+import it.unimi.dsi.fastutil.longs.LongIterator;
+import it.unimi.dsi.fastutil.objects.ObjectRBTreeSet;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.server.level.ChunkHolder;
+import net.minecraft.server.level.ChunkLevel;
+import net.minecraft.server.level.FullChunkStatus;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.Ticket;
+import net.minecraft.server.level.TicketType;
+import net.minecraft.util.SortedArraySet;
+import net.minecraft.util.Unit;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.chunk.LevelChunk;
+import org.slf4j.Logger;
+import java.io.IOException;
+import java.text.DecimalFormat;
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Objects;
+import java.util.PrimitiveIterator;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.concurrent.locks.LockSupport;
+import java.util.function.Predicate;
+
+public final class ChunkHolderManager {
+
+    private static final Logger LOGGER = LogUtils.getClassLogger();
+
+    public static final int FULL_LOADED_TICKET_LEVEL    = ChunkLevel.FULL_CHUNK_LEVEL;
+    public static final int BLOCK_TICKING_TICKET_LEVEL  = ChunkLevel.BLOCK_TICKING_LEVEL;
+    public static final int ENTITY_TICKING_TICKET_LEVEL = ChunkLevel.ENTITY_TICKING_LEVEL;
+    public static final int MAX_TICKET_LEVEL = ChunkLevel.MAX_LEVEL; // inclusive
+
+    public static final TicketType<Unit> UNLOAD_COOLDOWN = TicketType.create("unload_cooldown", (u1, u2) -> 0, 5 * 20);
+
+    private static final long NO_TIMEOUT_MARKER = Long.MIN_VALUE;
+    private static final long PROBE_MARKER = Long.MIN_VALUE + 1;
+    public final ReentrantAreaLock ticketLockArea;
+
+    private final ConcurrentLong2ReferenceChainedHashTable<SortedArraySet<Ticket<?>>> tickets = new ConcurrentLong2ReferenceChainedHashTable<>();
+    private final ConcurrentLong2ReferenceChainedHashTable<Long2IntOpenHashMap> sectionToChunkToExpireCount = new ConcurrentLong2ReferenceChainedHashTable<>();
+    final ChunkUnloadQueue unloadQueue;
+
+    private final ConcurrentLong2ReferenceChainedHashTable<NewChunkHolder> chunkHolders = ConcurrentLong2ReferenceChainedHashTable.createWithCapacity(16384, 0.25f);
+    private final ServerLevel world;
+    private final ChunkTaskScheduler taskScheduler;
+    private long currentTick;
+
+    private final ArrayDeque<NewChunkHolder> pendingFullLoadUpdate = new ArrayDeque<>();
+    private final ObjectRBTreeSet<NewChunkHolder> autoSaveQueue = new ObjectRBTreeSet<>((final NewChunkHolder c1, final NewChunkHolder c2) -> {
+        if (c1 == c2) {
+            return 0;
+        }
+
+        final int saveTickCompare = Long.compare(c1.lastAutoSave, c2.lastAutoSave);
+
+        if (saveTickCompare != 0) {
+            return saveTickCompare;
+        }
+
+        final long coord1 = CoordinateUtils.getChunkKey(c1.chunkX, c1.chunkZ);
+        final long coord2 = CoordinateUtils.getChunkKey(c2.chunkX, c2.chunkZ);
+
+        if (coord1 == coord2) {
+            throw new IllegalStateException("Duplicate chunkholder in auto save queue");
+        }
+
+        return Long.compare(coord1, coord2);
+    });
+
+    public ChunkHolderManager(final ServerLevel world, final ChunkTaskScheduler taskScheduler) {
+        this.world = world;
+        this.taskScheduler = taskScheduler;
+        this.ticketLockArea = new ReentrantAreaLock(taskScheduler.getChunkSystemLockShift());
+        this.unloadQueue = new ChunkUnloadQueue(((ChunkSystemServerLevel)world).moonrise$getRegionChunkShift());
+    }
+
+    public boolean processTicketUpdates(final int posX, final int posZ) {
+        final int ticketShift = ThreadedTicketLevelPropagator.SECTION_SHIFT;
+        final int ticketMask = (1 << ticketShift) - 1;
+        final List<ChunkProgressionTask> scheduledTasks = new ArrayList<>();
+        final List<NewChunkHolder> changedFullStatus = new ArrayList<>();
+        final boolean ret;
+        final ReentrantAreaLock.Node ticketLock = this.ticketLockArea.lock(
+                            ((posX >> ticketShift) - 1) << ticketShift,
+                            ((posZ >> ticketShift) - 1) << ticketShift,
+                            (((posX >> ticketShift) + 1) << ticketShift) | ticketMask,
+                            (((posZ >> ticketShift) + 1) << ticketShift) | ticketMask
+        );
+        try {
+            ret = this.processTicketUpdatesNoLock(posX >> ticketShift, posZ >> ticketShift, scheduledTasks, changedFullStatus);
+        } finally {
+            this.ticketLockArea.unlock(ticketLock);
+        }
+
+        this.addChangedStatuses(changedFullStatus);
+
+        for (int i = 0, len = scheduledTasks.size(); i < len; ++i) {
+            scheduledTasks.get(i).schedule();
+        }
+
+        return ret;
+    }
+
+    private boolean processTicketUpdatesNoLock(final int sectionX, final int sectionZ, final List<ChunkProgressionTask> scheduledTasks,
+                                               final List<NewChunkHolder> changedFullStatus) {
+        return this.ticketLevelPropagator.performUpdate(
+                sectionX, sectionZ, this.taskScheduler.schedulingLockArea, scheduledTasks, changedFullStatus
+        );
+    }
+
+    public List<ChunkHolder> getOldChunkHolders() {
+        final List<ChunkHolder> ret = new ArrayList<>(this.chunkHolders.size() + 1);
+        for (final Iterator<NewChunkHolder> iterator = this.chunkHolders.valueIterator(); iterator.hasNext();) {
+            ret.add(iterator.next().vanillaChunkHolder);
+        }
+        return ret;
+    }
+
+    public List<NewChunkHolder> getChunkHolders() {
+        final List<NewChunkHolder> ret = new ArrayList<>(this.chunkHolders.size() + 1);
+        for (final Iterator<NewChunkHolder> iterator = this.chunkHolders.valueIterator(); iterator.hasNext();) {
+            ret.add(iterator.next());
+        }
+        return ret;
+    }
+
+    public int size() {
+        return this.chunkHolders.size();
+    }
+
+    // TODO replace the need for this, specifically: optimise ServerChunkCache#tickChunks
+    public Iterable<ChunkHolder> getOldChunkHoldersIterable() {
+        return new Iterable<ChunkHolder>() {
+            @Override
+            public Iterator<ChunkHolder> iterator() {
+                final Iterator<NewChunkHolder> iterator = ChunkHolderManager.this.chunkHolders.valueIterator();
+                return new Iterator<ChunkHolder>() {
+                    @Override
+                    public boolean hasNext() {
+                        return iterator.hasNext();
+                    }
+
+                    @Override
+                    public ChunkHolder next() {
+                        return iterator.next().vanillaChunkHolder;
+                    }
+                };
+            }
+        };
+    }
+
+    public void close(final boolean save, final boolean halt) {
+        TickThread.ensureTickThread("Closing world off-main");
+        if (halt) {
+            LOGGER.info("Waiting 60s for chunk system to halt for world '" + WorldUtil.getWorldName(this.world) + "'");
+            if (!this.taskScheduler.halt(true, TimeUnit.SECONDS.toNanos(60L))) {
+                LOGGER.warn("Failed to halt generation/loading tasks for world '" + WorldUtil.getWorldName(this.world) + "'");
+            } else {
+                LOGGER.info("Halted chunk system for world '" + WorldUtil.getWorldName(this.world) + "'");
+            }
+        }
+
+        if (save) {
+            this.saveAllChunks(true, true, true);
+        }
+
+        MoonriseRegionFileIO.flush(this.world);
+
+        if (halt) {
+            LOGGER.info("Waiting 60s for chunk I/O to halt for world '" + WorldUtil.getWorldName(this.world) + "'");
+            if (!this.taskScheduler.haltIO(true, TimeUnit.SECONDS.toNanos(60L))) {
+                LOGGER.warn("Failed to halt I/O tasks for world '" + WorldUtil.getWorldName(this.world) + "'");
+            } else {
+                LOGGER.info("Halted I/O scheduler for world '" + WorldUtil.getWorldName(this.world) + "'");
+            }
+        }
+
+        // kill regionfile cache
+        for (final MoonriseRegionFileIO.RegionFileType type : MoonriseRegionFileIO.RegionFileType.values()) {
+            try {
+                MoonriseRegionFileIO.getControllerFor(this.world, type).getCache().close();
+            } catch (final IOException ex) {
+                LOGGER.error("Failed to close '" + type.name() + "' regionfile cache for world '" + WorldUtil.getWorldName(this.world) + "'", ex);
+            }
+        }
+
+        this.taskScheduler.setShutdown(true);
+    }
+
+    void ensureInAutosave(final NewChunkHolder holder) {
+        if (!this.autoSaveQueue.contains(holder)) {
+            holder.lastAutoSave = this.currentTick;
+            this.autoSaveQueue.add(holder);
+        }
+    }
+
+    public void autoSave() {
+        final List<NewChunkHolder> reschedule = new ArrayList<>();
+        final long currentTick = this.currentTick;
+        final long maxSaveTime = currentTick - Math.max(1L, PlatformHooks.get().configAutoSaveInterval(this.world));
+        final int maxToSave = PlatformHooks.get().configMaxAutoSavePerTick(this.world);
+        for (int autoSaved = 0; autoSaved < maxToSave && !this.autoSaveQueue.isEmpty();) {
+            final NewChunkHolder holder = this.autoSaveQueue.first();
+
+            if (holder.lastAutoSave > maxSaveTime) {
+                break;
+            }
+
+            this.autoSaveQueue.remove(holder);
+
+            holder.lastAutoSave = currentTick;
+            if (holder.save(false) != null) {
+                ++autoSaved;
+            }
+
+            if (holder.getChunkStatus().isOrAfter(FullChunkStatus.FULL)) {
+                reschedule.add(holder);
+            }
+        }
+
+        for (final NewChunkHolder holder : reschedule) {
+            if (holder.getChunkStatus().isOrAfter(FullChunkStatus.FULL)) {
+                this.autoSaveQueue.add(holder);
+            }
+        }
+    }
+
+    public void saveAllChunks(final boolean flush, final boolean shutdown, final boolean logProgress) {
+        final List<NewChunkHolder> holders = this.getChunkHolders();
+
+        if (logProgress) {
+            LOGGER.info("Saving all chunkholders for world '" + WorldUtil.getWorldName(this.world) + "'");
+        }
+
+        final DecimalFormat format = new DecimalFormat("#0.00");
+
+        int saved = 0;
+
+        long start = System.nanoTime();
+        long lastLog = start;
+        final int flushInterval = 200;
+        int lastFlush = 0;
+
+        int savedChunk = 0;
+        int savedEntity = 0;
+        int savedPoi = 0;
+
+        if (shutdown) {
+            // Normal unload process does not occur during shutdown: fire event manually
+            // for mods that expect ChunkEvent.Unload to fire on shutdown (before LevelEvent.Unload)
+            for (int i = 0, len = holders.size(); i < len; ++i) {
+                final NewChunkHolder holder = holders.get(i);
+                if (holder.getCurrentChunk() instanceof LevelChunk levelChunk) {
+                    PlatformHooks.get().chunkUnloadFromWorld(levelChunk);
+                }
+            }
+        }
+        for (int i = 0, len = holders.size(); i < len; ++i) {
+            final NewChunkHolder holder = holders.get(i);
+            try {
+                final NewChunkHolder.SaveStat saveStat = holder.save(shutdown);
+                if (saveStat != null) {
+                    if (saveStat.savedChunk()) {
+                        ++savedChunk;
+                        ++saved;
+                    }
+                    if (saveStat.savedEntityChunk()) {
+                        ++savedEntity;
+                        ++saved;
+                    }
+                    if (saveStat.savedPoiChunk()) {
+                        ++savedPoi;
+                        ++saved;
+                    }
+                }
+            } catch (final Throwable thr) {
+                LOGGER.error("Failed to save chunk (" + holder.chunkX + "," + holder.chunkZ + ") in world '" + WorldUtil.getWorldName(this.world) + "'", thr);
+            }
+            if (flush && (saved - lastFlush) > (flushInterval / 2)) {
+                lastFlush = saved;
+                MoonriseRegionFileIO.partialFlush(this.world, flushInterval / 2);
+            }
+            if (logProgress) {
+                final long currTime = System.nanoTime();
+                if ((currTime - lastLog) > TimeUnit.SECONDS.toNanos(10L)) {
+                    lastLog = currTime;
+                    LOGGER.info(
+                            "Saved " + savedChunk + " block chunks, " + savedEntity + " entity chunks, " + savedPoi
+                                    + " poi chunks in world '" + WorldUtil.getWorldName(this.world) + "', progress: "
+                                    + format.format((double)(i+1)/(double)len * 100.0)
+                    );
+                }
+            }
+        }
+        if (flush) {
+            MoonriseRegionFileIO.flush(this.world);
+            try {
+                MoonriseRegionFileIO.flushRegionStorages(this.world);
+            } catch (final IOException ex) {
+                LOGGER.error("Exception when flushing regions in world '" + WorldUtil.getWorldName(this.world) + "'", ex);
+            }
+        }
+        if (logProgress) {
+            LOGGER.info(
+                    "Saved " + savedChunk + " block chunks, " + savedEntity + " entity chunks, " + savedPoi
+                            + " poi chunks in world '" + WorldUtil.getWorldName(this.world) + "' in "
+                            + format.format(1.0E-9 * (System.nanoTime() - start)) + "s"
+            );
+        }
+    }
+
+    private final ThreadedTicketLevelPropagator ticketLevelPropagator = new ThreadedTicketLevelPropagator() {
+        @Override
+        protected void processLevelUpdates(final Long2ByteLinkedOpenHashMap updates) {
+            // first the necessary chunkholders must be created, so just update the ticket levels
+            for (final Iterator<Long2ByteMap.Entry> iterator = updates.long2ByteEntrySet().fastIterator(); iterator.hasNext();) {
+                final Long2ByteMap.Entry entry = iterator.next();
+                final long key = entry.getLongKey();
+                final int newLevel = convertBetweenTicketLevels((int)entry.getByteValue());
+
+                NewChunkHolder current = ChunkHolderManager.this.chunkHolders.get(key);
+                if (current == null && newLevel > MAX_TICKET_LEVEL) {
+                    // not loaded and it shouldn't be loaded!
+                    iterator.remove();
+                    continue;
+                }
+
+                final int currentLevel = current == null ? MAX_TICKET_LEVEL + 1 : current.getCurrentTicketLevel();
+                if (currentLevel == newLevel) {
+                    // nothing to do
+                    iterator.remove();
+                    continue;
+                }
+
+                if (current == null) {
+                    // must create
+                    current = ChunkHolderManager.this.createChunkHolder(key);
+                    ChunkHolderManager.this.chunkHolders.put(key, current);
+                    current.updateTicketLevel(newLevel);
+                } else {
+                    current.updateTicketLevel(newLevel);
+                }
+            }
+        }
+
+        @Override
+        protected void processSchedulingUpdates(final Long2ByteLinkedOpenHashMap updates, final List<ChunkProgressionTask> scheduledTasks,
+                                                final List<NewChunkHolder> changedFullStatus) {
+            final List<ChunkProgressionTask> prev = CURRENT_TICKET_UPDATE_SCHEDULING.get();
+            CURRENT_TICKET_UPDATE_SCHEDULING.set(scheduledTasks);
+            try {
+                for (final LongIterator iterator = updates.keySet().iterator(); iterator.hasNext();) {
+                    final long key = iterator.nextLong();
+                    final NewChunkHolder current = ChunkHolderManager.this.chunkHolders.get(key);
+
+                    if (current == null) {
+                        throw new IllegalStateException("Expected chunk holder to be created");
+                    }
+
+                    current.processTicketLevelUpdate(scheduledTasks, changedFullStatus);
+                }
+            } finally {
+                CURRENT_TICKET_UPDATE_SCHEDULING.set(prev);
+            }
+        }
+    };
+    // function for converting between ticket levels and propagator levels and vice versa
+    // the problem is the ticket level propagator will propagate from a set source down to zero, whereas mojang expects
+    // levels to propagate from a set value up to a maximum value. so we need to convert the levels we put into the propagator
+    // and the levels we get out of the propagator
+
+    public static int convertBetweenTicketLevels(final int level) {
+        return ChunkLevel.MAX_LEVEL - level + 1;
+    }
+
+    public String getTicketDebugString(final long coordinate) {
+        final ReentrantAreaLock.Node ticketLock = this.ticketLockArea.lock(CoordinateUtils.getChunkX(coordinate), CoordinateUtils.getChunkZ(coordinate));
+        try {
+            final SortedArraySet<Ticket<?>> tickets = this.tickets.get(coordinate);
+
+            return tickets != null ? tickets.first().toString() : "no_ticket";
+        } finally {
+            if (ticketLock != null) {
+                this.ticketLockArea.unlock(ticketLock);
+            }
+        }
+    }
+
+    public Long2ObjectOpenHashMap<SortedArraySet<Ticket<?>>> getTicketsCopy() {
+        final Long2ObjectOpenHashMap<SortedArraySet<Ticket<?>>> ret = new Long2ObjectOpenHashMap<>();
+        final Long2ObjectOpenHashMap<LongArrayList> sections = new Long2ObjectOpenHashMap<>();
+        final int sectionShift = this.taskScheduler.getChunkSystemLockShift();
+        for (final PrimitiveIterator.OfLong iterator = this.tickets.keyIterator(); iterator.hasNext();) {
+            final long coord = iterator.nextLong();
+            sections.computeIfAbsent(
+                CoordinateUtils.getChunkKey(
+                    CoordinateUtils.getChunkX(coord) >> sectionShift,
+                    CoordinateUtils.getChunkZ(coord) >> sectionShift
+                ),
+                (final long keyInMap) -> {
+                    return new LongArrayList();
+                }
+            ).add(coord);
+        }
+
+        for (final Iterator<Long2ObjectMap.Entry<LongArrayList>> iterator = sections.long2ObjectEntrySet().fastIterator();
+             iterator.hasNext();) {
+            final Long2ObjectMap.Entry<LongArrayList> entry = iterator.next();
+            final long sectionKey = entry.getLongKey();
+            final LongArrayList coordinates = entry.getValue();
+
+            final ReentrantAreaLock.Node ticketLock = this.ticketLockArea.lock(
+                CoordinateUtils.getChunkX(sectionKey) << sectionShift,
+                CoordinateUtils.getChunkZ(sectionKey) << sectionShift
+            );
+            try {
+                for (final LongIterator iterator2 = coordinates.iterator(); iterator2.hasNext();) {
+                    final long coord = iterator2.nextLong();
+                    final SortedArraySet<Ticket<?>> tickets = this.tickets.get(coord);
+                    if (tickets == null) {
+                        // removed before we acquired lock
+                        continue;
+                    }
+                    ret.put(coord, ((ChunkSystemSortedArraySet<Ticket<?>>)tickets).moonrise$copy());
+                }
+            } finally {
+                this.ticketLockArea.unlock(ticketLock);
+            }
+        }
+
+        return ret;
+    }
+
+    // Paper start
+    public Collection<org.bukkit.plugin.Plugin> getPluginChunkTickets(int x, int z) {
+        com.google.common.collect.ImmutableList.Builder<org.bukkit.plugin.Plugin> ret;
+        final ReentrantAreaLock.Node ticketLock = this.ticketLockArea.lock(x, z);
+        try {
+            final long coordinate = CoordinateUtils.getChunkKey(x, z);
+            final SortedArraySet<Ticket<?>> tickets = this.tickets.get(coordinate);
+
+            if (tickets == null) {
+                return java.util.Collections.emptyList();
+            }
+
+            ret = com.google.common.collect.ImmutableList.builder();
+            for (Ticket<?> ticket : tickets) {
+                if (ticket.getType() == TicketType.PLUGIN_TICKET) {
+                    ret.add((org.bukkit.plugin.Plugin)ticket.key);
+                }
+            }
+        } finally {
+            this.ticketLockArea.unlock(ticketLock);
+        }
+
+        return ret.build();
+    }
+    // Paper end
+
+    protected final void updateTicketLevel(final long coordinate, final int ticketLevel) {
+        if (ticketLevel > ChunkLevel.MAX_LEVEL) {
+            this.ticketLevelPropagator.removeSource(CoordinateUtils.getChunkX(coordinate), CoordinateUtils.getChunkZ(coordinate));
+        } else {
+            this.ticketLevelPropagator.setSource(CoordinateUtils.getChunkX(coordinate), CoordinateUtils.getChunkZ(coordinate), convertBetweenTicketLevels(ticketLevel));
+        }
+    }
+
+    private static int getTicketLevelAt(SortedArraySet<Ticket<?>> tickets) {
+        return !tickets.isEmpty() ? tickets.first().getTicketLevel() : MAX_TICKET_LEVEL + 1;
+    }
+
+    public <T> boolean addTicketAtLevel(final TicketType<T> type, final ChunkPos chunkPos, final int level,
+                                        final T identifier) {
+        return this.addTicketAtLevel(type, CoordinateUtils.getChunkKey(chunkPos), level, identifier);
+    }
+
+    public <T> boolean addTicketAtLevel(final TicketType<T> type, final int chunkX, final int chunkZ, final int level,
+                                        final T identifier) {
+        return this.addTicketAtLevel(type, CoordinateUtils.getChunkKey(chunkX, chunkZ), level, identifier);
+    }
+
+    private void addExpireCount(final int chunkX, final int chunkZ) {
+        final long chunkKey = CoordinateUtils.getChunkKey(chunkX, chunkZ);
+
+        final int sectionShift = ((ChunkSystemServerLevel)this.world).moonrise$getRegionChunkShift();
+        final long sectionKey = CoordinateUtils.getChunkKey(
+            chunkX >> sectionShift,
+            chunkZ >> sectionShift
+        );
+
+        this.sectionToChunkToExpireCount.computeIfAbsent(sectionKey, (final long keyInMap) -> {
+            return new Long2IntOpenHashMap();
+        }).addTo(chunkKey, 1);
+    }
+
+    private void removeExpireCount(final int chunkX, final int chunkZ) {
+        final long chunkKey = CoordinateUtils.getChunkKey(chunkX, chunkZ);
+
+        final int sectionShift = ((ChunkSystemServerLevel)this.world).moonrise$getRegionChunkShift();
+        final long sectionKey = CoordinateUtils.getChunkKey(
+            chunkX >> sectionShift,
+            chunkZ >> sectionShift
+        );
+
+        final Long2IntOpenHashMap removeCounts = this.sectionToChunkToExpireCount.get(sectionKey);
+        final int prevCount = removeCounts.addTo(chunkKey, -1);
+
+        if (prevCount == 1) {
+            removeCounts.remove(chunkKey);
+            if (removeCounts.isEmpty()) {
+                this.sectionToChunkToExpireCount.remove(sectionKey);
+            }
+        }
+    }
+
+    // supposed to return true if the ticket was added and did not replace another
+    // but, we always return false if the ticket cannot be added
+    public <T> boolean addTicketAtLevel(final TicketType<T> type, final long chunk, final int level, final T identifier) {
+        return this.addTicketAtLevel(type, chunk, level, identifier, true);
+    }
+
+    <T> boolean addTicketAtLevel(final TicketType<T> type, final long chunk, final int level, final T identifier, final boolean lock) {
+        final long removeDelay = type.timeout <= 0 ? NO_TIMEOUT_MARKER : type.timeout;
+        if (level > MAX_TICKET_LEVEL) {
+            return false;
+        }
+
+        final int chunkX = CoordinateUtils.getChunkX(chunk);
+        final int chunkZ = CoordinateUtils.getChunkZ(chunk);
+        final Ticket<T> ticket = new Ticket<>(type, level, identifier);
+        ((ChunkSystemTicket<T>)(Object)ticket).moonrise$setRemoveDelay(removeDelay);
+
+        final ReentrantAreaLock.Node ticketLock = lock ? this.ticketLockArea.lock(chunkX, chunkZ) : null;
+        try {
+            final SortedArraySet<Ticket<?>> ticketsAtChunk = this.tickets.computeIfAbsent(chunk, (final long keyInMap) -> {
+                return SortedArraySet.create(4);
+            });
+
+            final int levelBefore = getTicketLevelAt(ticketsAtChunk);
+            final Ticket<T> current = (Ticket<T>)((ChunkSystemSortedArraySet<Ticket<?>>)ticketsAtChunk).moonrise$replace(ticket);
+            final int levelAfter = getTicketLevelAt(ticketsAtChunk);
+
+            if (current != ticket) {
+                final long oldRemoveDelay = ((ChunkSystemTicket<T>)(Object)current).moonrise$getRemoveDelay();
+                if (removeDelay != oldRemoveDelay) {
+                    if (oldRemoveDelay != NO_TIMEOUT_MARKER && removeDelay == NO_TIMEOUT_MARKER) {
+                        this.removeExpireCount(chunkX, chunkZ);
+                    } else if (oldRemoveDelay == NO_TIMEOUT_MARKER) {
+                        // since old != new, we have that NO_TIMEOUT_MARKER != new
+                        this.addExpireCount(chunkX, chunkZ);
+                    }
+                }
+            } else {
+                if (removeDelay != NO_TIMEOUT_MARKER) {
+                    this.addExpireCount(chunkX, chunkZ);
+                }
+            }
+
+            if (levelBefore != levelAfter) {
+                this.updateTicketLevel(chunk, levelAfter);
+            }
+
+            return current == ticket;
+        } finally {
+            if (ticketLock != null) {
+                this.ticketLockArea.unlock(ticketLock);
+            }
+        }
+    }
+
+    public <T> boolean removeTicketAtLevel(final TicketType<T> type, final ChunkPos chunkPos, final int level, final T identifier) {
+        return this.removeTicketAtLevel(type, CoordinateUtils.getChunkKey(chunkPos), level, identifier);
+    }
+
+    public <T> boolean removeTicketAtLevel(final TicketType<T> type, final int chunkX, final int chunkZ, final int level, final T identifier) {
+        return this.removeTicketAtLevel(type, CoordinateUtils.getChunkKey(chunkX, chunkZ), level, identifier);
+    }
+
+    public <T> boolean removeTicketAtLevel(final TicketType<T> type, final long chunk, final int level, final T identifier) {
+        return this.removeTicketAtLevel(type, chunk, level, identifier, true);
+    }
+
+    <T> boolean removeTicketAtLevel(final TicketType<T> type, final long chunk, final int level, final T identifier, final boolean lock) {
+        if (level > MAX_TICKET_LEVEL) {
+            return false;
+        }
+
+        final int chunkX = CoordinateUtils.getChunkX(chunk);
+        final int chunkZ = CoordinateUtils.getChunkZ(chunk);
+        final Ticket<T> probe = new Ticket<>(type, level, identifier);
+
+        final ReentrantAreaLock.Node ticketLock = lock ? this.ticketLockArea.lock(chunkX, chunkZ) : null;
+        try {
+            final SortedArraySet<Ticket<?>> ticketsAtChunk = this.tickets.get(chunk);
+            if (ticketsAtChunk == null) {
+                return false;
+            }
+
+            final int oldLevel = getTicketLevelAt(ticketsAtChunk);
+            final Ticket<T> ticket = (Ticket<T>)((ChunkSystemSortedArraySet<Ticket<?>>)ticketsAtChunk).moonrise$removeAndGet(probe);
+
+            if (ticket == null) {
+                return false;
+            }
+
+            final int newLevel = getTicketLevelAt(ticketsAtChunk);
+            // we should not change the ticket levels while the target region may be ticking
+            if (oldLevel != newLevel) {
+                final Ticket<ChunkPos> unknownTicket = new Ticket<>(TicketType.UNKNOWN, level, new ChunkPos(chunk));
+                ((ChunkSystemTicket<ChunkPos>)(Object)unknownTicket).moonrise$setRemoveDelay(Math.max(1, TicketType.UNKNOWN.timeout));
+                if (ticketsAtChunk.add(unknownTicket)) {
+                    this.addExpireCount(chunkX, chunkZ);
+                } else {
+                    throw new IllegalStateException("Should have been able to add " + unknownTicket + " to " + ticketsAtChunk);
+                }
+            }
+
+            final long removeDelay = ((ChunkSystemTicket<T>)(Object)ticket).moonrise$getRemoveDelay();
+            if (removeDelay != NO_TIMEOUT_MARKER) {
+                this.removeExpireCount(chunkX, chunkZ);
+            }
+
+            return true;
+        } finally {
+            if (ticketLock != null) {
+                this.ticketLockArea.unlock(ticketLock);
+            }
+        }
+    }
+
+    // atomic with respect to all add/remove/addandremove ticket calls for the given chunk
+    public <T, V> void addAndRemoveTickets(final long chunk, final TicketType<T> addType, final int addLevel, final T addIdentifier,
+                                           final TicketType<V> removeType, final int removeLevel, final V removeIdentifier) {
+        final ReentrantAreaLock.Node ticketLock = this.ticketLockArea.lock(CoordinateUtils.getChunkX(chunk), CoordinateUtils.getChunkZ(chunk));
+        try {
+            this.addTicketAtLevel(addType, chunk, addLevel, addIdentifier, false);
+            this.removeTicketAtLevel(removeType, chunk, removeLevel, removeIdentifier, false);
+        } finally {
+            this.ticketLockArea.unlock(ticketLock);
+        }
+    }
+
+    // atomic with respect to all add/remove/addandremove ticket calls for the given chunk
+    public <T, V> boolean addIfRemovedTicket(final long chunk, final TicketType<T> addType, final int addLevel, final T addIdentifier,
+                                             final TicketType<V> removeType, final int removeLevel, final V removeIdentifier) {
+        final ReentrantAreaLock.Node ticketLock = this.ticketLockArea.lock(CoordinateUtils.getChunkX(chunk), CoordinateUtils.getChunkZ(chunk));
+        try {
+            if (this.removeTicketAtLevel(removeType, chunk, removeLevel, removeIdentifier, false)) {
+                this.addTicketAtLevel(addType, chunk, addLevel, addIdentifier, false);
+                return true;
+            }
+            return false;
+        } finally {
+            this.ticketLockArea.unlock(ticketLock);
+        }
+    }
+
+    public <T> void removeAllTicketsFor(final TicketType<T> ticketType, final int ticketLevel, final T ticketIdentifier) {
+        if (ticketLevel > MAX_TICKET_LEVEL) {
+            return;
+        }
+
+        final Long2ObjectOpenHashMap<LongArrayList> sections = new Long2ObjectOpenHashMap<>();
+        final int sectionShift = this.taskScheduler.getChunkSystemLockShift();
+        for (final PrimitiveIterator.OfLong iterator = this.tickets.keyIterator(); iterator.hasNext();) {
+            final long coord = iterator.nextLong();
+            sections.computeIfAbsent(
+                    CoordinateUtils.getChunkKey(
+                            CoordinateUtils.getChunkX(coord) >> sectionShift,
+                            CoordinateUtils.getChunkZ(coord) >> sectionShift
+                    ),
+                    (final long keyInMap) -> {
+                        return new LongArrayList();
+                    }
+            ).add(coord);
+        }
+
+        for (final Iterator<Long2ObjectMap.Entry<LongArrayList>> iterator = sections.long2ObjectEntrySet().fastIterator();
+             iterator.hasNext();) {
+            final Long2ObjectMap.Entry<LongArrayList> entry = iterator.next();
+            final long sectionKey = entry.getLongKey();
+            final LongArrayList coordinates = entry.getValue();
+
+            final ReentrantAreaLock.Node ticketLock = this.ticketLockArea.lock(
+                CoordinateUtils.getChunkX(sectionKey) << sectionShift,
+                CoordinateUtils.getChunkZ(sectionKey) << sectionShift
+            );
+            try {
+                for (final LongIterator iterator2 = coordinates.iterator(); iterator2.hasNext();) {
+                    final long coord = iterator2.nextLong();
+                    this.removeTicketAtLevel(ticketType, coord, ticketLevel, ticketIdentifier, false);
+                }
+            } finally {
+                this.ticketLockArea.unlock(ticketLock);
+            }
+        }
+    }
+
+    public void tick() {
+        ++this.currentTick;
+
+        final int sectionShift = ((ChunkSystemServerLevel)this.world).moonrise$getRegionChunkShift();
+
+        final Predicate<Ticket<?>> expireNow = (final Ticket<?> ticket) -> {
+            long removeDelay = ((ChunkSystemTicket<?>)(Object)ticket).moonrise$getRemoveDelay();
+            if (removeDelay == NO_TIMEOUT_MARKER) {
+                return false;
+            }
+            --removeDelay;
+            ((ChunkSystemTicket<?>)(Object)ticket).moonrise$setRemoveDelay(removeDelay);
+            return removeDelay <= 0L;
+        };
+
+        for (final PrimitiveIterator.OfLong iterator = this.sectionToChunkToExpireCount.keyIterator(); iterator.hasNext();) {
+            final long sectionKey = iterator.nextLong();
+
+            if (!this.sectionToChunkToExpireCount.containsKey(sectionKey)) {
+                // removed concurrently
+                continue;
+            }
+
+            final ReentrantAreaLock.Node ticketLock = this.ticketLockArea.lock(
+                CoordinateUtils.getChunkX(sectionKey) << sectionShift,
+                CoordinateUtils.getChunkZ(sectionKey) << sectionShift
+            );
+
+            try {
+                final Long2IntOpenHashMap chunkToExpireCount = this.sectionToChunkToExpireCount.get(sectionKey);
+                if (chunkToExpireCount == null) {
+                    // lost to some race
+                    continue;
+                }
+
+                for (final Iterator<Long2IntMap.Entry> iterator1 = chunkToExpireCount.long2IntEntrySet().fastIterator(); iterator1.hasNext();) {
+                    final Long2IntMap.Entry entry = iterator1.next();
+
+                    final long chunkKey = entry.getLongKey();
+                    final int expireCount = entry.getIntValue();
+
+                    final SortedArraySet<Ticket<?>> tickets = this.tickets.get(chunkKey);
+                    final int levelBefore = getTicketLevelAt(tickets);
+
+                    final int sizeBefore = tickets.size();
+                    tickets.removeIf(expireNow);
+                    final int sizeAfter = tickets.size();
+                    final int levelAfter = getTicketLevelAt(tickets);
+
+                    if (tickets.isEmpty()) {
+                        this.tickets.remove(chunkKey);
+                    }
+                    if (levelBefore != levelAfter) {
+                        this.updateTicketLevel(chunkKey, levelAfter);
+                    }
+
+                    final int newExpireCount = expireCount - (sizeBefore - sizeAfter);
+
+                    if (newExpireCount == expireCount) {
+                        continue;
+                    }
+
+                    if (newExpireCount != 0) {
+                        entry.setValue(newExpireCount);
+                    } else {
+                        iterator1.remove();
+                    }
+                }
+
+                if (chunkToExpireCount.isEmpty()) {
+                    this.sectionToChunkToExpireCount.remove(sectionKey);
+                }
+            } finally {
+                this.ticketLockArea.unlock(ticketLock);
+            }
+        }
+
+        this.processTicketUpdates();
+    }
+
+    public NewChunkHolder getChunkHolder(final int chunkX, final int chunkZ) {
+        return this.chunkHolders.get(CoordinateUtils.getChunkKey(chunkX, chunkZ));
+    }
+
+    public NewChunkHolder getChunkHolder(final long position) {
+        return this.chunkHolders.get(position);
+    }
+
+    public void raisePriority(final int x, final int z, final Priority priority) {
+        final NewChunkHolder chunkHolder = this.getChunkHolder(x, z);
+        if (chunkHolder != null) {
+            chunkHolder.raisePriority(priority);
+        }
+    }
+
+    public void setPriority(final int x, final int z, final Priority priority) {
+        final NewChunkHolder chunkHolder = this.getChunkHolder(x, z);
+        if (chunkHolder != null) {
+            chunkHolder.setPriority(priority);
+        }
+    }
+
+    public void lowerPriority(final int x, final int z, final Priority priority) {
+        final NewChunkHolder chunkHolder = this.getChunkHolder(x, z);
+        if (chunkHolder != null) {
+            chunkHolder.lowerPriority(priority);
+        }
+    }
+
+    private NewChunkHolder createChunkHolder(final long position) {
+        final NewChunkHolder ret = new NewChunkHolder(this.world, CoordinateUtils.getChunkX(position), CoordinateUtils.getChunkZ(position), this.taskScheduler);
+
+        ChunkSystem.onChunkHolderCreate(this.world, ret.vanillaChunkHolder);
+
+        return ret;
+    }
+
+    // because this function creates the chunk holder without a ticket, it is the caller's responsibility to ensure
+    // the chunk holder eventually unloads. this should only be used to avoid using processTicketUpdates to create chunkholders,
+    // as processTicketUpdates may call plugin logic; in every other case a ticket is appropriate
+    private NewChunkHolder getOrCreateChunkHolder(final int chunkX, final int chunkZ) {
+        return this.getOrCreateChunkHolder(CoordinateUtils.getChunkKey(chunkX, chunkZ));
+    }
+
+    private NewChunkHolder getOrCreateChunkHolder(final long position) {
+        final int chunkX = CoordinateUtils.getChunkX(position);
+        final int chunkZ = CoordinateUtils.getChunkZ(position);
+
+        if (!this.ticketLockArea.isHeldByCurrentThread(chunkX, chunkZ)) {
+            throw new IllegalStateException("Must hold ticket level update lock!");
+        }
+        if (!this.taskScheduler.schedulingLockArea.isHeldByCurrentThread(chunkX, chunkZ)) {
+            throw new IllegalStateException("Must hold scheduler lock!!");
+        }
+
+        // we could just acquire these locks, but...
+        // must own the locks because the caller needs to ensure that no unload can occur AFTER this function returns
+
+        NewChunkHolder current = this.chunkHolders.get(position);
+        if (current != null) {
+            return current;
+        }
+
+        current = this.createChunkHolder(position);
+        this.chunkHolders.put(position, current);
+
+
+        return current;
+    }
+
+    public ChunkEntitySlices getOrCreateEntityChunk(final int chunkX, final int chunkZ, final boolean transientChunk) {
+        TickThread.ensureTickThread(this.world, chunkX, chunkZ, "Cannot create entity chunk off-main");
+        ChunkEntitySlices ret;
+
+        NewChunkHolder current = this.getChunkHolder(chunkX, chunkZ);
+        if (current != null && (ret = current.getEntityChunk()) != null && (transientChunk || !ret.isTransient())) {
+            return ret;
+        }
+
+        final AtomicBoolean isCompleted = new AtomicBoolean();
+        final Thread waiter = Thread.currentThread();
+        final Long entityLoadId = ChunkTaskScheduler.getNextEntityLoadId();
+        NewChunkHolder.GenericDataLoadTaskCallback loadTask = null;
+        final ReentrantAreaLock.Node ticketLock = this.ticketLockArea.lock(chunkX, chunkZ);
+        try {
+            this.addTicketAtLevel(ChunkTaskScheduler.ENTITY_LOAD, chunkX, chunkZ, MAX_TICKET_LEVEL, entityLoadId);
+            final ReentrantAreaLock.Node schedulingLock = this.taskScheduler.schedulingLockArea.lock(chunkX, chunkZ);
+            try {
+                current = this.getOrCreateChunkHolder(chunkX, chunkZ);
+                if ((ret = current.getEntityChunk()) != null && (transientChunk || !ret.isTransient())) {
+                    this.removeTicketAtLevel(ChunkTaskScheduler.ENTITY_LOAD, chunkX, chunkZ, MAX_TICKET_LEVEL, entityLoadId);
+                    return ret;
+                }
+
+                if (!transientChunk) {
+                    if (current.isEntityChunkNBTLoaded()) {
+                        isCompleted.setPlain(true);
+                    } else {
+                        loadTask = current.getOrLoadEntityData((final GenericDataLoadTask.TaskResult<CompoundTag, Throwable> result) -> {
+                            isCompleted.set(true);
+                            LockSupport.unpark(waiter);
+                        });
+                        final ChunkLoadTask.EntityDataLoadTask entityLoad = current.getEntityDataLoadTask();
+
+                        if (entityLoad != null) {
+                            entityLoad.raisePriority(Priority.BLOCKING);
+                        }
+                    }
+                }
+            } finally {
+                this.taskScheduler.schedulingLockArea.unlock(schedulingLock);
+            }
+        } finally {
+            this.ticketLockArea.unlock(ticketLock);
+        }
+
+        if (loadTask != null) {
+            loadTask.schedule();
+        }
+
+        if (!transientChunk) {
+            // Note: no need to busy wait on the chunk queue, entity load will complete off-main
+            boolean interrupted = false;
+            while (!isCompleted.get()) {
+                interrupted |= Thread.interrupted();
+                LockSupport.park();
+            }
+
+            if (interrupted) {
+                Thread.currentThread().interrupt();
+            }
+        }
+
+        // now that the entity data is loaded, we can load it into the world
+
+        ret = current.loadInEntityChunk(transientChunk);
+
+        this.removeTicketAtLevel(ChunkTaskScheduler.ENTITY_LOAD, chunkX, chunkZ, MAX_TICKET_LEVEL, entityLoadId);
+
+        return ret;
+    }
+
+    public PoiChunk getPoiChunkIfLoaded(final int chunkX, final int chunkZ, final boolean checkLoadInCallback) {
+        final NewChunkHolder holder = this.getChunkHolder(chunkX, chunkZ);
+        if (holder != null) {
+            final PoiChunk ret = holder.getPoiChunk();
+            return ret == null || (checkLoadInCallback && !ret.isLoaded()) ? null : ret;
+        }
+        return null;
+    }
+
+    public PoiChunk loadPoiChunk(final int chunkX, final int chunkZ) {
+        TickThread.ensureTickThread(this.world, chunkX, chunkZ, "Cannot create poi chunk off-main");
+        PoiChunk ret;
+
+        NewChunkHolder current = this.getChunkHolder(chunkX, chunkZ);
+        if (current != null && (ret = current.getPoiChunk()) != null) {
+            ret.load();
+            return ret;
+        }
+
+        final AtomicReference<PoiChunk> completed = new AtomicReference<>();
+        final AtomicBoolean isCompleted = new AtomicBoolean();
+        final Thread waiter = Thread.currentThread();
+        final Long poiLoadId = ChunkTaskScheduler.getNextPoiLoadId();
+        NewChunkHolder.GenericDataLoadTaskCallback loadTask = null;
+        final ReentrantAreaLock.Node ticketLock = this.ticketLockArea.lock(chunkX, chunkZ);
+        try {
+            this.addTicketAtLevel(ChunkTaskScheduler.POI_LOAD, chunkX, chunkZ, MAX_TICKET_LEVEL, poiLoadId);
+            final ReentrantAreaLock.Node schedulingLock = this.taskScheduler.schedulingLockArea.lock(chunkX, chunkZ);
+            try {
+                current = this.getOrCreateChunkHolder(chunkX, chunkZ);
+                if (null == (ret = current.getPoiChunk())) {
+                    loadTask = current.getOrLoadPoiData((final GenericDataLoadTask.TaskResult<PoiChunk, Throwable> result) -> {
+                        completed.setPlain(result.left());
+                        isCompleted.set(true);
+                        LockSupport.unpark(waiter);
+                    });
+                    final ChunkLoadTask.PoiDataLoadTask poiLoad = current.getPoiDataLoadTask();
+
+                    if (poiLoad != null) {
+                        poiLoad.raisePriority(Priority.BLOCKING);
+                    }
+                }
+            } finally {
+                this.taskScheduler.schedulingLockArea.unlock(schedulingLock);
+            }
+        } finally {
+            this.ticketLockArea.unlock(ticketLock);
+        }
+
+        if (loadTask != null) {
+            loadTask.schedule();
+
+            // Note: no need to busy wait on the chunk queue, poi load will complete off-main
+
+            boolean interrupted = false;
+            while (!isCompleted.get()) {
+                interrupted |= Thread.interrupted();
+                LockSupport.park();
+            }
+
+            if (interrupted) {
+                Thread.currentThread().interrupt();
+            }
+
+            ret = completed.getPlain();
+        } // else: became loaded during the scheduling attempt, need to ensure load() is invoked
+
+        ret.load();
+
+        this.removeTicketAtLevel(ChunkTaskScheduler.POI_LOAD, chunkX, chunkZ, MAX_TICKET_LEVEL, poiLoadId);
+
+        return ret;
+    }
+
+    void addChangedStatuses(final List<NewChunkHolder> changedFullStatus) {
+        if (changedFullStatus.isEmpty()) {
+            return;
+        }
+        if (!TickThread.isTickThread()) {
+            this.taskScheduler.scheduleChunkTask(() -> {
+                final ArrayDeque<NewChunkHolder> pendingFullLoadUpdate = ChunkHolderManager.this.pendingFullLoadUpdate;
+                for (int i = 0, len = changedFullStatus.size(); i < len; ++i) {
+                    pendingFullLoadUpdate.add(changedFullStatus.get(i));
+                }
+
+                ChunkHolderManager.this.processPendingFullUpdate();
+            }, Priority.HIGHEST);
+        } else {
+            final ArrayDeque<NewChunkHolder> pendingFullLoadUpdate = this.pendingFullLoadUpdate;
+            for (int i = 0, len = changedFullStatus.size(); i < len; ++i) {
+                pendingFullLoadUpdate.add(changedFullStatus.get(i));
+            }
+        }
+    }
+
+    private void removeChunkHolder(final NewChunkHolder holder) {
+        holder.onUnload();
+        this.autoSaveQueue.remove(holder);
+        ChunkSystem.onChunkHolderDelete(this.world, holder.vanillaChunkHolder);
+        this.chunkHolders.remove(CoordinateUtils.getChunkKey(holder.chunkX, holder.chunkZ));
+    }
+
+    // note: never call while inside the chunk system, this will absolutely break everything
+    public void processUnloads() {
+        TickThread.ensureTickThread("Cannot unload chunks off-main");
+
+        if (BLOCK_TICKET_UPDATES.get() == Boolean.TRUE) {
+            throw new IllegalStateException("Cannot unload chunks recursively");
+        }
+        final int sectionShift = this.unloadQueue.coordinateShift; // sectionShift <= lock shift
+        final List<ChunkUnloadQueue.SectionToUnload> unloadSectionsForRegion = this.unloadQueue.retrieveForAllRegions();
+        int unloadCountTentative = 0;
+        for (final ChunkUnloadQueue.SectionToUnload sectionRef : unloadSectionsForRegion) {
+            final ChunkUnloadQueue.UnloadSection section
+                = this.unloadQueue.getSectionUnsynchronized(sectionRef.sectionX(), sectionRef.sectionZ());
+
+            if (section == null) {
+                // removed concurrently
+                continue;
+            }
+
+            // technically reading the size field is unsafe, and it may be incorrect.
+            // We assume that the error here cumulatively goes away over many ticks. If it did not, then it is possible
+            // for chunks to never unload or not unload fast enough.
+            unloadCountTentative += section.chunks.size();
+        }
+
+        if (unloadCountTentative <= 0) {
+            // no work to do
+            return;
+        }
+
+        // We do need to process updates here so that any addTicket that is synchronised before this call does not go missed.
+        this.processTicketUpdates();
+
+        final int toUnloadCount = Math.max(50, (int)(unloadCountTentative * 0.05));
+        int processedCount = 0;
+
+        for (final ChunkUnloadQueue.SectionToUnload sectionRef : unloadSectionsForRegion) {
+            final List<NewChunkHolder> stage1 = new ArrayList<>();
+            final List<NewChunkHolder.UnloadState> stage2 = new ArrayList<>();
+
+            final int sectionLowerX = sectionRef.sectionX() << sectionShift;
+            final int sectionLowerZ = sectionRef.sectionZ() << sectionShift;
+
+            // stage 1: set up for stage 2 while holding critical locks
+            ReentrantAreaLock.Node ticketLock = this.ticketLockArea.lock(sectionLowerX, sectionLowerZ);
+            try {
+                final ReentrantAreaLock.Node scheduleLock = this.taskScheduler.schedulingLockArea.lock(sectionLowerX, sectionLowerZ);
+                try {
+                    final ChunkUnloadQueue.UnloadSection section
+                        = this.unloadQueue.getSectionUnsynchronized(sectionRef.sectionX(), sectionRef.sectionZ());
+
+                    if (section == null) {
+                        // removed concurrently
+                        continue;
+                    }
+
+                    // collect the holders to run stage 1 on
+                    final int sectionCount = section.chunks.size();
+
+                    if ((sectionCount + processedCount) <= toUnloadCount) {
+                        // we can just drain the entire section
+
+                        for (final LongIterator iterator = section.chunks.iterator(); iterator.hasNext();) {
+                            final NewChunkHolder holder = this.chunkHolders.get(iterator.nextLong());
+                            if (holder == null) {
+                                throw new IllegalStateException();
+                            }
+                            stage1.add(holder);
+                        }
+
+                        // remove section
+                        this.unloadQueue.removeSection(sectionRef.sectionX(), sectionRef.sectionZ());
+                    } else {
+                        // processedCount + len = toUnloadCount
+                        // we cannot drain the entire section
+                        for (int i = 0, len = toUnloadCount - processedCount; i < len; ++i) {
+                            final NewChunkHolder holder = this.chunkHolders.get(section.chunks.removeFirstLong());
+                            if (holder == null) {
+                                throw new IllegalStateException();
+                            }
+                            stage1.add(holder);
+                        }
+                    }
+
+                    // run stage 1
+                    for (int i = 0, len = stage1.size(); i < len; ++i) {
+                        final NewChunkHolder chunkHolder = stage1.get(i);
+                        chunkHolder.removeFromUnloadQueue();
+                        if (chunkHolder.isSafeToUnload() != null) {
+                            LOGGER.error("Chunkholder " + chunkHolder + " is not safe to unload but is inside the unload queue?");
+                            continue;
+                        }
+                        final NewChunkHolder.UnloadState state = chunkHolder.unloadStage1();
+                        if (state == null) {
+                            // can unload immediately
+                            this.removeChunkHolder(chunkHolder);
+                            continue;
+                        }
+                        stage2.add(state);
+                    }
+                } finally {
+                    this.taskScheduler.schedulingLockArea.unlock(scheduleLock);
+                }
+            } finally {
+                this.ticketLockArea.unlock(ticketLock);
+            }
+
+            // stage 2: invoke expensive unload logic, designed to run without locks thanks to stage 1
+            final List<NewChunkHolder> stage3 = new ArrayList<>(stage2.size());
+
+            final Boolean before = this.blockTicketUpdates();
+            try {
+                for (int i = 0, len = stage2.size(); i < len; ++i) {
+                    final NewChunkHolder.UnloadState state = stage2.get(i);
+                    final NewChunkHolder holder = state.holder();
+
+                    holder.unloadStage2(state);
+                    stage3.add(holder);
+                }
+            } finally {
+                this.unblockTicketUpdates(before);
+            }
+
+            // stage 3: actually attempt to remove the chunk holders
+            ticketLock = this.ticketLockArea.lock(sectionLowerX, sectionLowerZ);
+            try {
+                final ReentrantAreaLock.Node scheduleLock = this.taskScheduler.schedulingLockArea.lock(sectionLowerX, sectionLowerZ);
+                try {
+                    for (int i = 0, len = stage3.size(); i < len; ++i) {
+                        final NewChunkHolder holder = stage3.get(i);
+
+                        if (holder.unloadStage3()) {
+                            this.removeChunkHolder(holder);
+                        } else {
+                            // add cooldown so the next unload check is not immediately next tick
+                            this.addTicketAtLevel(UNLOAD_COOLDOWN, CoordinateUtils.getChunkKey(holder.chunkX, holder.chunkZ), MAX_TICKET_LEVEL, Unit.INSTANCE, false);
+                        }
+                    }
+                } finally {
+                    this.taskScheduler.schedulingLockArea.unlock(scheduleLock);
+                }
+            } finally {
+                this.ticketLockArea.unlock(ticketLock);
+            }
+
+            processedCount += stage1.size();
+
+            if (processedCount >= toUnloadCount) {
+                break;
+            }
+        }
+    }
+
+    public enum TicketOperationType {
+        ADD, REMOVE, ADD_IF_REMOVED, ADD_AND_REMOVE
+    }
+
+    public static record TicketOperation<T, V> (
+        TicketOperationType op, long chunkCoord,
+        TicketType<T> ticketType, int ticketLevel, T identifier,
+        TicketType<V> ticketType2, int ticketLevel2, V identifier2
+    ) {
+
+        private TicketOperation(TicketOperationType op, long chunkCoord,
+                                TicketType<T> ticketType, int ticketLevel, T identifier) {
+            this(op, chunkCoord, ticketType, ticketLevel, identifier, null, 0, null);
+        }
+
+        public static <T> TicketOperation<T, T> addOp(final ChunkPos chunk, final TicketType<T> type, final int ticketLevel, final T identifier) {
+            return addOp(CoordinateUtils.getChunkKey(chunk), type, ticketLevel, identifier);
+        }
+
+        public static <T> TicketOperation<T, T> addOp(final int chunkX, final int chunkZ, final TicketType<T> type, final int ticketLevel, final T identifier) {
+            return addOp(CoordinateUtils.getChunkKey(chunkX, chunkZ), type, ticketLevel, identifier);
+        }
+
+        public static <T> TicketOperation<T, T> addOp(final long chunk, final TicketType<T> type, final int ticketLevel, final T identifier) {
+            return new TicketOperation<>(TicketOperationType.ADD, chunk, type, ticketLevel, identifier);
+        }
+
+        public static <T> TicketOperation<T, T> removeOp(final ChunkPos chunk, final TicketType<T> type, final int ticketLevel, final T identifier) {
+            return removeOp(CoordinateUtils.getChunkKey(chunk), type, ticketLevel, identifier);
+        }
+
+        public static <T> TicketOperation<T, T> removeOp(final int chunkX, final int chunkZ, final TicketType<T> type, final int ticketLevel, final T identifier) {
+            return removeOp(CoordinateUtils.getChunkKey(chunkX, chunkZ), type, ticketLevel, identifier);
+        }
+
+        public static <T> TicketOperation<T, T> removeOp(final long chunk, final TicketType<T> type, final int ticketLevel, final T identifier) {
+            return new TicketOperation<>(TicketOperationType.REMOVE, chunk, type, ticketLevel, identifier);
+        }
+
+        public static <T, V> TicketOperation<T, V> addIfRemovedOp(final long chunk,
+                                                                  final TicketType<T> addType, final int addLevel, final T addIdentifier,
+                                                                  final TicketType<V> removeType, final int removeLevel, final V removeIdentifier) {
+            return new TicketOperation<>(
+                TicketOperationType.ADD_IF_REMOVED, chunk, addType, addLevel, addIdentifier,
+                removeType, removeLevel, removeIdentifier
+            );
+        }
+
+        public static <T, V> TicketOperation<T, V> addAndRemove(final long chunk,
+                                                                final TicketType<T> addType, final int addLevel, final T addIdentifier,
+                                                                final TicketType<V> removeType, final int removeLevel, final V removeIdentifier) {
+            return new TicketOperation<>(
+                TicketOperationType.ADD_AND_REMOVE, chunk, addType, addLevel, addIdentifier,
+                removeType, removeLevel, removeIdentifier
+            );
+        }
+    }
+
+    private <T, V> boolean processTicketOp(TicketOperation<T, V> operation) {
+        boolean ret = false;
+        switch (operation.op) {
+            case ADD: {
+                ret |= this.addTicketAtLevel(operation.ticketType, operation.chunkCoord, operation.ticketLevel, operation.identifier);
+                break;
+            }
+            case REMOVE: {
+                ret |= this.removeTicketAtLevel(operation.ticketType, operation.chunkCoord, operation.ticketLevel, operation.identifier);
+                break;
+            }
+            case ADD_IF_REMOVED: {
+                ret |= this.addIfRemovedTicket(
+                    operation.chunkCoord,
+                    operation.ticketType, operation.ticketLevel, operation.identifier,
+                    operation.ticketType2, operation.ticketLevel2, operation.identifier2
+                );
+                break;
+            }
+            case ADD_AND_REMOVE: {
+                ret = true;
+                this.addAndRemoveTickets(
+                    operation.chunkCoord,
+                    operation.ticketType, operation.ticketLevel, operation.identifier,
+                    operation.ticketType2, operation.ticketLevel2, operation.identifier2
+                );
+                break;
+            }
+        }
+
+        return ret;
+    }
+
+    public void performTicketUpdates(final Collection<TicketOperation<?, ?>> operations) {
+        for (final TicketOperation<?, ?> operation : operations) {
+            this.processTicketOp(operation);
+        }
+    }
+
+    private final ThreadLocal<Boolean> BLOCK_TICKET_UPDATES = ThreadLocal.withInitial(() -> {
+        return Boolean.FALSE;
+    });
+
+    public Boolean blockTicketUpdates() {
+        final Boolean ret = BLOCK_TICKET_UPDATES.get();
+        BLOCK_TICKET_UPDATES.set(Boolean.TRUE);
+        return ret;
+    }
+
+    public void unblockTicketUpdates(final Boolean before) {
+        BLOCK_TICKET_UPDATES.set(before);
+    }
+
+    public boolean processTicketUpdates() {
+        return this.processTicketUpdates(true, null);
+    }
+
+    private static final ThreadLocal<List<ChunkProgressionTask>> CURRENT_TICKET_UPDATE_SCHEDULING = new ThreadLocal<>();
+
+    static List<ChunkProgressionTask> getCurrentTicketUpdateScheduling() {
+        return CURRENT_TICKET_UPDATE_SCHEDULING.get();
+    }
+
+    private boolean processTicketUpdates(final boolean processFullUpdates, List<ChunkProgressionTask> scheduledTasks) {
+        if (BLOCK_TICKET_UPDATES.get() == Boolean.TRUE) {
+            throw new IllegalStateException("Cannot update ticket level while unloading chunks or updating entity manager");
+        }
+        if (!PlatformHooks.get().allowAsyncTicketUpdates() && !TickThread.isTickThread()) {
+            TickThread.ensureTickThread("Cannot asynchronously process ticket updates");
+        }
+
+        List<NewChunkHolder> changedFullStatus = null;
+
+        final boolean isTickThread = TickThread.isTickThread();
+
+        boolean ret = false;
+        final boolean canProcessFullUpdates = processFullUpdates & isTickThread;
+        final boolean canProcessScheduling = scheduledTasks == null;
+
+        if (this.ticketLevelPropagator.hasPendingUpdates()) {
+            if (scheduledTasks == null) {
+                scheduledTasks = new ArrayList<>();
+            }
+            changedFullStatus = new ArrayList<>();
+
+            this.blockTicketUpdates();
+            try {
+                ret |= this.ticketLevelPropagator.performUpdates(
+                    this.ticketLockArea, this.taskScheduler.schedulingLockArea,
+                    scheduledTasks, changedFullStatus
+                );
+            } finally {
+                this.unblockTicketUpdates(Boolean.FALSE);
+            }
+        }
+
+        if (changedFullStatus != null) {
+            this.addChangedStatuses(changedFullStatus);
+        }
+
+        if (canProcessScheduling && scheduledTasks != null) {
+            for (int i = 0, len = scheduledTasks.size(); i < len; ++i) {
+                scheduledTasks.get(i).schedule();
+            }
+        }
+
+        if (canProcessFullUpdates) {
+            ret |= this.processPendingFullUpdate();
+        }
+
+        return ret;
+    }
+
+    // only call on tick thread
+    private boolean processPendingFullUpdate() {
+        final ArrayDeque<NewChunkHolder> pendingFullLoadUpdate = this.pendingFullLoadUpdate;
+
+        boolean ret = false;
+
+        final List<NewChunkHolder> changedFullStatus = new ArrayList<>();
+
+        NewChunkHolder holder;
+        while ((holder = pendingFullLoadUpdate.poll()) != null) {
+            ret |= holder.handleFullStatusChange(changedFullStatus);
+
+            if (!changedFullStatus.isEmpty()) {
+                for (int i = 0, len = changedFullStatus.size(); i < len; ++i) {
+                    pendingFullLoadUpdate.add(changedFullStatus.get(i));
+                }
+                changedFullStatus.clear();
+            }
+        }
+
+        return ret;
+    }
+
+    public JsonObject getDebugJson() {
+        final JsonObject ret = new JsonObject();
+
+        ret.add("unload_queue", this.unloadQueue.toDebugJson());
+
+        final JsonArray holders = new JsonArray();
+        ret.add("chunkholders", holders);
+
+        for (final NewChunkHolder holder : this.getChunkHolders()) {
+            holders.add(holder.getDebugJson());
+        }
+
+        final JsonArray allTicketsJson = new JsonArray();
+        ret.add("tickets", allTicketsJson);
+
+        for (final Iterator<ConcurrentLong2ReferenceChainedHashTable.TableEntry<SortedArraySet<Ticket<?>>>> iterator = this.tickets.entryIterator();
+            iterator.hasNext();) {
+            final ConcurrentLong2ReferenceChainedHashTable.TableEntry<SortedArraySet<Ticket<?>>> coordinateTickets = iterator.next();
+            final long coordinate = coordinateTickets.getKey();
+            final SortedArraySet<Ticket<?>> tickets = coordinateTickets.getValue();
+
+            final JsonObject coordinateJson = new JsonObject();
+            allTicketsJson.add(coordinateJson);
+
+            coordinateJson.addProperty("chunkX", Long.valueOf(CoordinateUtils.getChunkX(coordinate)));
+            coordinateJson.addProperty("chunkZ", Long.valueOf(CoordinateUtils.getChunkZ(coordinate)));
+
+            final JsonArray ticketsSerialized = new JsonArray();
+            coordinateJson.add("tickets", ticketsSerialized);
+
+            // note: by using a copy of the backing array, we can avoid explicit exceptions we may trip when iterating
+            // directly over the set using the iterator
+            // however, it also means we need to null-check the values, and there is a possibility that we _miss_ an
+            // entry OR iterate over an entry multiple times
+            for (final Object ticketUncasted : ((ChunkSystemSortedArraySet<Ticket<?>>)tickets).moonrise$copyBackingArray()) {
+                if (ticketUncasted == null) {
+                    continue;
+                }
+                final Ticket<?> ticket = (Ticket<?>)ticketUncasted;
+                final JsonObject ticketSerialized = new JsonObject();
+                ticketsSerialized.add(ticketSerialized);
+
+                ticketSerialized.addProperty("type", ticket.getType().toString());
+                ticketSerialized.addProperty("level", Integer.valueOf(ticket.getTicketLevel()));
+                ticketSerialized.addProperty("identifier", Objects.toString(ticket.key));
+                ticketSerialized.addProperty("remove_tick", Long.valueOf(((ChunkSystemTicket<?>)(Object)ticket).moonrise$getRemoveDelay()));
+            }
+        }
+
+        return ret;
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/ChunkTaskScheduler.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/ChunkTaskScheduler.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/ChunkTaskScheduler.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.scheduling;
+
+import ca.spottedleaf.concurrentutil.executor.PrioritisedExecutor;
+import ca.spottedleaf.concurrentutil.executor.queue.PrioritisedTaskQueue;
+import ca.spottedleaf.concurrentutil.executor.thread.PrioritisedThreadPool;
+import ca.spottedleaf.concurrentutil.lock.ReentrantAreaLock;
+import ca.spottedleaf.concurrentutil.util.ConcurrentUtil;
+import ca.spottedleaf.concurrentutil.util.Priority;
+import ca.spottedleaf.moonrise.common.util.CoordinateUtils;
+import ca.spottedleaf.moonrise.common.util.JsonUtil;
+import ca.spottedleaf.moonrise.common.util.MoonriseCommon;
+import ca.spottedleaf.moonrise.common.util.TickThread;
+import ca.spottedleaf.moonrise.common.util.WorldUtil;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemChunkStatus;
+import ca.spottedleaf.moonrise.patches.chunk_system.player.ChunkSystemServerPlayer;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.executor.RadiusAwarePrioritisedExecutor;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkFullTask;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkLightTask;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkLoadTask;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkProgressionTask;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkUpgradeGenericStatusTask;
+import ca.spottedleaf.moonrise.patches.chunk_system.server.ChunkSystemMinecraftServer;
+import ca.spottedleaf.moonrise.patches.chunk_system.status.ChunkSystemChunkStep;
+import ca.spottedleaf.moonrise.patches.chunk_system.util.ParallelSearchRadiusIteration;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonObject;
+import com.mojang.logging.LogUtils;
+import net.minecraft.CrashReport;
+import net.minecraft.CrashReportCategory;
+import net.minecraft.ReportedException;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.level.ChunkLevel;
+import net.minecraft.server.level.ChunkMap;
+import net.minecraft.server.level.FullChunkStatus;
+import net.minecraft.server.level.GenerationChunkHolder;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.server.level.TicketType;
+import net.minecraft.util.StaticCache2D;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.LevelChunk;
+import net.minecraft.world.level.chunk.status.ChunkPyramid;
+import net.minecraft.world.level.chunk.status.ChunkStatus;
+import net.minecraft.world.level.chunk.status.ChunkStep;
+import net.minecraft.world.phys.Vec3;
+import org.slf4j.Logger;
+import java.io.File;
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.function.Consumer;
+
+public final class ChunkTaskScheduler {
+
+    private static final Logger LOGGER = LogUtils.getClassLogger();
+
+    public static void init(final boolean useParallelGen) {
+        for (final PrioritisedThreadPool.ExecutorGroup.ThreadPoolExecutor executor : MoonriseCommon.RADIUS_AWARE_GROUP.getAllExecutors()) {
+            executor.setMaxParallelism(useParallelGen ? -1 : 1);
+        }
+
+        LOGGER.info("Chunk system is using population gen parallelism: " + useParallelGen);
+    }
+
+    public static final TicketType<Long> CHUNK_LOAD = TicketType.create("chunk_system:chunk_load", Long::compareTo);
+    private static final AtomicLong CHUNK_LOAD_IDS = new AtomicLong();
+
+    public static Long getNextChunkLoadId() {
+        return Long.valueOf(CHUNK_LOAD_IDS.getAndIncrement());
+    }
+
+    public static final TicketType<Long> NON_FULL_CHUNK_LOAD = TicketType.create("chunk_system:non_full_load", Long::compareTo);
+    private static final AtomicLong NON_FULL_CHUNK_LOAD_IDS = new AtomicLong();
+
+    public static Long getNextNonFullLoadId() {
+        return Long.valueOf(NON_FULL_CHUNK_LOAD_IDS.getAndIncrement());
+    }
+
+    public static final TicketType<Long> ENTITY_LOAD = TicketType.create("chunk_system:entity_load", Long::compareTo);
+    private static final AtomicLong ENTITY_LOAD_IDS = new AtomicLong();
+
+    public static Long getNextEntityLoadId() {
+        return Long.valueOf(ENTITY_LOAD_IDS.getAndIncrement());
+    }
+
+    public static final TicketType<Long> POI_LOAD = TicketType.create("chunk_system:poi_load", Long::compareTo);
+    private static final AtomicLong POI_LOAD_IDS = new AtomicLong();
+
+    public static Long getNextPoiLoadId() {
+        return Long.valueOf(POI_LOAD_IDS.getAndIncrement());
+    }
+
+    public static final TicketType<Long> CHUNK_RELIGHT = TicketType.create("starlight:chunk_relight", Long::compareTo);
+    private static final AtomicLong CHUNK_RELIGHT_IDS = new AtomicLong();
+
+    public static Long getNextChunkRelightId() {
+        return Long.valueOf(CHUNK_RELIGHT_IDS.getAndIncrement());
+    }
+
+
+    public static int getTicketLevel(final ChunkStatus status) {
+        return ChunkLevel.byStatus(status);
+    }
+
+    public final ServerLevel world;
+    public final RadiusAwarePrioritisedExecutor radiusAwareScheduler;
+    public final PrioritisedThreadPool.ExecutorGroup.ThreadPoolExecutor parallelGenExecutor;
+    private final PrioritisedThreadPool.ExecutorGroup.ThreadPoolExecutor radiusAwareGenExecutor;
+    public final PrioritisedThreadPool.ExecutorGroup.ThreadPoolExecutor loadExecutor;
+    public final PrioritisedThreadPool.ExecutorGroup.ThreadPoolExecutor ioExecutor;
+    public final PrioritisedThreadPool.ExecutorGroup.ThreadPoolExecutor compressionExecutor;
+    public final PrioritisedThreadPool.ExecutorGroup.ThreadPoolExecutor saveExecutor;
+
+    private final PrioritisedTaskQueue mainThreadExecutor = new PrioritisedTaskQueue();
+
+    public final ChunkHolderManager chunkHolderManager;
+
+    static {
+        ((ChunkSystemChunkStatus)ChunkStatus.EMPTY).moonrise$setWriteRadius(0);
+        ((ChunkSystemChunkStatus)ChunkStatus.STRUCTURE_STARTS).moonrise$setWriteRadius(0);
+        ((ChunkSystemChunkStatus)ChunkStatus.STRUCTURE_REFERENCES).moonrise$setWriteRadius(0);
+        ((ChunkSystemChunkStatus)ChunkStatus.BIOMES).moonrise$setWriteRadius(0);
+        ((ChunkSystemChunkStatus)ChunkStatus.NOISE).moonrise$setWriteRadius(0);
+        ((ChunkSystemChunkStatus)ChunkStatus.SURFACE).moonrise$setWriteRadius(0);
+        ((ChunkSystemChunkStatus)ChunkStatus.CARVERS).moonrise$setWriteRadius(0);
+        ((ChunkSystemChunkStatus)ChunkStatus.FEATURES).moonrise$setWriteRadius(1);
+        ((ChunkSystemChunkStatus)ChunkStatus.INITIALIZE_LIGHT).moonrise$setWriteRadius(0);
+        ((ChunkSystemChunkStatus)ChunkStatus.LIGHT).moonrise$setWriteRadius(2);
+        ((ChunkSystemChunkStatus)ChunkStatus.SPAWN).moonrise$setWriteRadius(0);
+        ((ChunkSystemChunkStatus)ChunkStatus.FULL).moonrise$setWriteRadius(0);
+
+        ((ChunkSystemChunkStatus)ChunkStatus.EMPTY).moonrise$setEmptyLoadStatus(true);
+        ((ChunkSystemChunkStatus)ChunkStatus.STRUCTURE_REFERENCES).moonrise$setEmptyLoadStatus(true);
+        ((ChunkSystemChunkStatus)ChunkStatus.BIOMES).moonrise$setEmptyLoadStatus(true);
+        ((ChunkSystemChunkStatus)ChunkStatus.NOISE).moonrise$setEmptyLoadStatus(true);
+        ((ChunkSystemChunkStatus)ChunkStatus.SURFACE).moonrise$setEmptyLoadStatus(true);
+        ((ChunkSystemChunkStatus)ChunkStatus.CARVERS).moonrise$setEmptyLoadStatus(true);
+        ((ChunkSystemChunkStatus)ChunkStatus.FEATURES).moonrise$setEmptyLoadStatus(true);
+        ((ChunkSystemChunkStatus)ChunkStatus.SPAWN).moonrise$setEmptyLoadStatus(true);
+
+        /*
+          It's important that the neighbour read radius is taken into account. If _any_ later status is using some chunk as
+          a neighbour, it must be also safe if that neighbour is being generated. i.e for any status later than FEATURES,
+          for a status to be parallel safe it must not read the block data from its neighbours.
+         */
+        final List<ChunkStatus> parallelCapableStatus = Arrays.asList(
+                // No-op executor.
+                ChunkStatus.EMPTY,
+
+                // This is parallel capable, as CB has fixed the concurrency issue with stronghold generations.
+                // Does not touch neighbour chunks.
+                ChunkStatus.STRUCTURE_STARTS,
+
+                // Surprisingly this is parallel capable. It is simply reading the already-created structure starts
+                // into the structure references for the chunk. So while it reads from it neighbours, its neighbours
+                // will not change, even if executed in parallel.
+                ChunkStatus.STRUCTURE_REFERENCES,
+
+                // Safe. Mojang runs it in parallel as well.
+                ChunkStatus.BIOMES,
+
+                // Safe. Mojang runs it in parallel as well.
+                ChunkStatus.NOISE,
+
+                // Parallel safe. Only touches the target chunk. Biome retrieval is now noise based, which is
+                // completely thread-safe.
+                ChunkStatus.SURFACE,
+
+                // No global state is modified in the carvers. It only touches the specified chunk. So it is parallel safe.
+                ChunkStatus.CARVERS,
+
+                // FEATURES is not parallel safe. It writes to neighbours.
+
+                // no-op executor
+                ChunkStatus.INITIALIZE_LIGHT
+
+                // LIGHT is not parallel safe. It also doesn't run on the generation executor, so no point.
+
+                // Only writes to the specified chunk. State is not read by later statuses. Parallel safe.
+                // Note: it may look unsafe because it writes to a worldgenregion, but the region size is always 0 -
+                // see the task margin.
+                // However, if the neighbouring FEATURES chunk is unloaded, but then fails to load in again (for whatever
+                // reason), then it would write to this chunk - and since this status reads blocks from itself, it's not
+                // safe to execute this in parallel.
+                // SPAWN
+
+                // FULL is executed on main.
+        );
+
+        for (final ChunkStatus status : parallelCapableStatus) {
+            ((ChunkSystemChunkStatus)status).moonrise$setParallelCapable(true);
+        }
+    }
+
+    private static final int[] ACCESS_RADIUS_TABLE_LOAD = new int[ChunkStatus.getStatusList().size()];
+    private static final int[] ACCESS_RADIUS_TABLE_GEN = new int[ChunkStatus.getStatusList().size()];
+    private static final int[] ACCESS_RADIUS_TABLE = new int[ChunkStatus.getStatusList().size()];
+    static {
+        Arrays.fill(ACCESS_RADIUS_TABLE_LOAD, -1);
+        Arrays.fill(ACCESS_RADIUS_TABLE_GEN, -1);
+        Arrays.fill(ACCESS_RADIUS_TABLE, -1);
+    }
+
+    private static int getAccessRadius0(final ChunkStatus toStatus, final ChunkPyramid pyramid) {
+        if (toStatus == ChunkStatus.EMPTY) {
+            return 0;
+        }
+
+        final ChunkStep chunkStep = pyramid.getStepTo(toStatus);
+
+        final int radius = chunkStep.getAccumulatedRadiusOf(ChunkStatus.EMPTY);
+        int maxRange = radius;
+
+        for (int dist = 0; dist <= radius; ++dist) {
+            final ChunkStatus requiredNeighbourStatus = ((ChunkSystemChunkStep)(Object)chunkStep).moonrise$getRequiredStatusAtRadius(dist);
+            final int rad = ACCESS_RADIUS_TABLE[requiredNeighbourStatus.getIndex()];
+            if (rad == -1) {
+                throw new IllegalStateException();
+            }
+
+            maxRange = Math.max(maxRange, dist + rad);
+        }
+
+        return maxRange;
+    }
+
+    private static final int MAX_ACCESS_RADIUS;
+
+    static {
+        final List<ChunkStatus> statuses = ChunkStatus.getStatusList();
+        for (int i = 0, len = statuses.size(); i < len; ++i) {
+            final ChunkStatus status = statuses.get(i);
+            ACCESS_RADIUS_TABLE_LOAD[i] = getAccessRadius0(status, ChunkPyramid.LOADING_PYRAMID);
+            ACCESS_RADIUS_TABLE_GEN[i] = getAccessRadius0(status, ChunkPyramid.GENERATION_PYRAMID);
+            ACCESS_RADIUS_TABLE[i] = Math.max(
+                    ACCESS_RADIUS_TABLE_LOAD[i],
+                    ACCESS_RADIUS_TABLE_GEN[i]
+            );
+        }
+        MAX_ACCESS_RADIUS = ACCESS_RADIUS_TABLE[ACCESS_RADIUS_TABLE.length - 1];
+    }
+
+    public static int getMaxAccessRadius() {
+        return MAX_ACCESS_RADIUS;
+    }
+
+    public static int getAccessRadius(final ChunkStatus genStatus) {
+        return ACCESS_RADIUS_TABLE[genStatus.getIndex()];
+    }
+
+    public static int getAccessRadius(final FullChunkStatus status) {
+        return (status.ordinal() - 1) + getAccessRadius(ChunkStatus.FULL);
+    }
+
+
+    public final ReentrantAreaLock schedulingLockArea;
+    private final int lockShift;
+
+    public final int getChunkSystemLockShift() {
+        return this.lockShift;
+    }
+
+    private volatile boolean shutdown;
+
+    public boolean hasShutdown() {
+        return this.shutdown;
+    }
+
+    public void setShutdown(final boolean shutdown) {
+        this.shutdown = shutdown;
+    }
+
+    public ChunkTaskScheduler(final ServerLevel world) {
+        this.world = world;
+        // must be >= region shift (in paper, doesn't exist) and must be >= ticket propagator section shift
+        // it must be >= region shift since the regioniser assumes ticket updates do not occur in parallel for the region sections
+        // it must be >= ticket propagator section shift so that the ticket propagator can assume that owning a position implies owning
+        // the entire section
+        // we just take the max, as we want the smallest shift that satisfies these properties
+        this.lockShift = Math.max(((ChunkSystemServerLevel)world).moonrise$getRegionChunkShift(), ThreadedTicketLevelPropagator.SECTION_SHIFT);
+        this.schedulingLockArea = new ReentrantAreaLock(this.getChunkSystemLockShift());
+
+        this.parallelGenExecutor = MoonriseCommon.PARALLEL_GEN_GROUP.createExecutor(-1, MoonriseCommon.WORKER_QUEUE_HOLD_TIME, 0);
+        this.radiusAwareGenExecutor = MoonriseCommon.RADIUS_AWARE_GROUP.createExecutor(1, MoonriseCommon.WORKER_QUEUE_HOLD_TIME, 0);
+        this.loadExecutor = MoonriseCommon.LOAD_GROUP.createExecutor(-1, MoonriseCommon.WORKER_QUEUE_HOLD_TIME, 0);
+        this.radiusAwareScheduler = new RadiusAwarePrioritisedExecutor(this.radiusAwareGenExecutor, 16);
+        this.ioExecutor = MoonriseCommon.SERVER_REGION_IO_GROUP.createExecutor(-1, MoonriseCommon.IO_QUEUE_HOLD_TIME, 0);
+        // we need a separate executor here so that on shutdown we can continue to process I/O tasks
+        this.compressionExecutor = MoonriseCommon.LOAD_GROUP.createExecutor(-1, MoonriseCommon.WORKER_QUEUE_HOLD_TIME, 0);
+        this.saveExecutor = MoonriseCommon.LOAD_GROUP.createExecutor(-1, MoonriseCommon.WORKER_QUEUE_HOLD_TIME, 0);
+        this.chunkHolderManager = new ChunkHolderManager(world, this);
+    }
+
+    private final AtomicBoolean failedChunkSystem = new AtomicBoolean();
+
+    public static Object stringIfNull(final Object obj) {
+        return obj == null ? "null" : obj;
+    }
+
+    public void unrecoverableChunkSystemFailure(final int chunkX, final int chunkZ, final Map<String, Object> objectsOfInterest, final Throwable thr) {
+        final NewChunkHolder holder = this.chunkHolderManager.getChunkHolder(chunkX, chunkZ);
+        LOGGER.error("Chunk system error at chunk (" + chunkX + "," + chunkZ + "), holder: " + holder + ", exception:", new Throwable(thr));
+
+        if (this.failedChunkSystem.getAndSet(true)) {
+            return;
+        }
+
+        final ReportedException reportedException = thr instanceof ReportedException ? (ReportedException)thr : new ReportedException(new CrashReport("Chunk system error", thr));
+
+        CrashReportCategory crashReportCategory = reportedException.getReport().addCategory("Chunk system details");
+        crashReportCategory.setDetail("Chunk coordinate", new ChunkPos(chunkX, chunkZ).toString());
+        crashReportCategory.setDetail("ChunkHolder", Objects.toString(holder));
+        crashReportCategory.setDetail("unrecoverableChunkSystemFailure caller thread", Thread.currentThread().getName());
+
+        crashReportCategory = reportedException.getReport().addCategory("Chunk System Objects of Interest");
+        for (final Map.Entry<String, Object> entry : objectsOfInterest.entrySet()) {
+            if (entry.getValue() instanceof Throwable thrObject) {
+                crashReportCategory.setDetailError(Objects.toString(entry.getKey()), thrObject);
+            } else {
+                crashReportCategory.setDetail(Objects.toString(entry.getKey()), Objects.toString(entry.getValue()));
+            }
+        }
+
+        final Runnable crash = () -> {
+            throw new RuntimeException("Chunk system crash propagated from unrecoverableChunkSystemFailure", reportedException);
+        };
+
+        // this may not be good enough, specifically thanks to stupid ass plugins swallowing exceptions
+        this.scheduleChunkTask(chunkX, chunkZ, crash, Priority.BLOCKING);
+        // so, make the main thread pick it up
+        ((ChunkSystemMinecraftServer)this.world.getServer()).moonrise$setChunkSystemCrash(new RuntimeException("Chunk system crash propagated from unrecoverableChunkSystemFailure", reportedException));
+    }
+
+    public boolean executeMainThreadTask() {
+        TickThread.ensureTickThread("Cannot execute main thread task off-main");
+        return this.mainThreadExecutor.executeTask();
+    }
+
+    public void raisePriority(final int x, final int z, final Priority priority) {
+        this.chunkHolderManager.raisePriority(x, z, priority);
+    }
+
+    public void setPriority(final int x, final int z, final Priority priority) {
+        this.chunkHolderManager.setPriority(x, z, priority);
+    }
+
+    public void lowerPriority(final int x, final int z, final Priority priority) {
+        this.chunkHolderManager.lowerPriority(x, z, priority);
+    }
+
+    public void scheduleTickingState(final int chunkX, final int chunkZ, final FullChunkStatus toStatus,
+                                     final boolean addTicket, final Priority priority,
+                                     final Consumer<LevelChunk> onComplete) {
+        final int radius = toStatus.ordinal() - 1; // 0 -> BORDER, 1 -> TICKING, 2 -> ENTITY_TICKING
+
+        if (!TickThread.isTickThreadFor(this.world, chunkX, chunkZ, Math.max(0, radius))) {
+            this.scheduleChunkTask(chunkX, chunkZ, () -> {
+                ChunkTaskScheduler.this.scheduleTickingState(chunkX, chunkZ, toStatus, addTicket, priority, onComplete);
+            }, priority);
+            return;
+        }
+        final int accessRadius = getAccessRadius(toStatus);
+        if (this.chunkHolderManager.ticketLockArea.isHeldByCurrentThread(chunkX, chunkZ, accessRadius)) {
+            throw new IllegalStateException("Cannot schedule chunk load during ticket level update");
+        }
+        if (this.schedulingLockArea.isHeldByCurrentThread(chunkX, chunkZ, accessRadius)) {
+            throw new IllegalStateException("Cannot schedule chunk loading recursively");
+        }
+
+        if (toStatus == FullChunkStatus.INACCESSIBLE) {
+            throw new IllegalArgumentException("Cannot wait for INACCESSIBLE status");
+        }
+
+        final int minLevel = 33 - (toStatus.ordinal() - 1);
+        final Long chunkReference = addTicket ? getNextChunkLoadId() : null;
+        final long chunkKey = CoordinateUtils.getChunkKey(chunkX, chunkZ);
+
+        if (addTicket) {
+            this.chunkHolderManager.addTicketAtLevel(CHUNK_LOAD, chunkKey, minLevel, chunkReference);
+            this.chunkHolderManager.processTicketUpdates();
+        }
+
+        final Consumer<LevelChunk> loadCallback = onComplete == null && !addTicket ? null : (final LevelChunk chunk) -> {
+            try {
+                if (onComplete != null) {
+                    onComplete.accept(chunk);
+                }
+            } finally {
+                if (addTicket) {
+                    ChunkTaskScheduler.this.chunkHolderManager.removeTicketAtLevel(CHUNK_LOAD, chunkKey, minLevel, chunkReference);
+                }
+            }
+        };
+
+        final boolean scheduled;
+        final LevelChunk chunk;
+        final ReentrantAreaLock.Node ticketLock = this.chunkHolderManager.ticketLockArea.lock(chunkX, chunkZ, accessRadius);
+        try {
+            final ReentrantAreaLock.Node schedulingLock = this.schedulingLockArea.lock(chunkX, chunkZ, accessRadius);
+            try {
+                final NewChunkHolder chunkHolder = this.chunkHolderManager.getChunkHolder(chunkKey);
+                if (chunkHolder == null || chunkHolder.getTicketLevel() > minLevel) {
+                    scheduled = false;
+                    chunk = null;
+                } else {
+                    final FullChunkStatus currStatus = chunkHolder.getChunkStatus();
+                    if (currStatus.isOrAfter(toStatus)) {
+                        scheduled = false;
+                        chunk = (LevelChunk)chunkHolder.getCurrentChunk();
+                    } else {
+                        scheduled = true;
+                        chunk = null;
+
+                        for (int dz = -radius; dz <= radius; ++dz) {
+                            for (int dx = -radius; dx <= radius; ++dx) {
+                                final NewChunkHolder neighbour =
+                                    (dx | dz) == 0 ? chunkHolder : this.chunkHolderManager.getChunkHolder(dx + chunkX, dz + chunkZ);
+                                if (neighbour != null) {
+                                    neighbour.raisePriority(priority);
+                                }
+                            }
+                        }
+
+                        // ticket level should schedule for us
+                        if (loadCallback != null) {
+                            chunkHolder.addFullStatusConsumer(toStatus, loadCallback);
+                        }
+                    }
+                }
+            } finally {
+                this.schedulingLockArea.unlock(schedulingLock);
+            }
+        } finally {
+            this.chunkHolderManager.ticketLockArea.unlock(ticketLock);
+        }
+
+        if (loadCallback != null && !scheduled) {
+            // couldn't schedule
+            try {
+                loadCallback.accept(chunk);
+            } catch (final Throwable thr) {
+                LOGGER.error("Failed to process chunk full status callback", thr);
+            }
+        }
+    }
+
+    public void scheduleChunkLoad(final int chunkX, final int chunkZ, final boolean gen, final ChunkStatus toStatus, final boolean addTicket,
+                                  final Priority priority, final Consumer<ChunkAccess> onComplete) {
+        if (gen) {
+            this.scheduleChunkLoad(chunkX, chunkZ, toStatus, addTicket, priority, onComplete);
+            return;
+        }
+        this.scheduleChunkLoad(chunkX, chunkZ, ChunkStatus.EMPTY, addTicket, priority, (final ChunkAccess chunk) -> {
+            if (chunk == null) {
+                if (onComplete != null) {
+                    onComplete.accept(null);
+                }
+            } else {
+                if (chunk.getPersistedStatus().isOrAfter(toStatus)) {
+                    this.scheduleChunkLoad(chunkX, chunkZ, toStatus, addTicket, priority, onComplete);
+                } else {
+                    if (onComplete != null) {
+                        onComplete.accept(null);
+                    }
+                }
+            }
+        });
+    }
+
+    // only appropriate to use with syncLoadNonFull
+    public boolean beginChunkLoadForNonFullSync(final int chunkX, final int chunkZ, final ChunkStatus toStatus,
+                                                final Priority priority) {
+        final int accessRadius = getAccessRadius(toStatus);
+        final long chunkKey = CoordinateUtils.getChunkKey(chunkX, chunkZ);
+        final int minLevel = ChunkTaskScheduler.getTicketLevel(toStatus);
+        final List<ChunkProgressionTask> tasks = new ArrayList<>();
+        final ReentrantAreaLock.Node ticketLock = this.chunkHolderManager.ticketLockArea.lock(chunkX, chunkZ, accessRadius); // Folia - use area based lock to reduce contention
+        try {
+            final ReentrantAreaLock.Node schedulingLock = this.schedulingLockArea.lock(chunkX, chunkZ, accessRadius); // Folia - use area based lock to reduce contention
+            try {
+                final NewChunkHolder chunkHolder = this.chunkHolderManager.getChunkHolder(chunkKey);
+                if (chunkHolder == null || chunkHolder.getTicketLevel() > minLevel) {
+                    return false;
+                } else {
+                    final ChunkStatus genStatus = chunkHolder.getCurrentGenStatus();
+                    if (genStatus != null && genStatus.isOrAfter(toStatus)) {
+                        return true;
+                    } else {
+                        chunkHolder.raisePriority(priority);
+
+                        if (!chunkHolder.upgradeGenTarget(toStatus)) {
+                            this.schedule(chunkX, chunkZ, toStatus, chunkHolder, tasks);
+                        }
+                    }
+                }
+            } finally {
+                this.schedulingLockArea.unlock(schedulingLock);
+            }
+        } finally {
+            this.chunkHolderManager.ticketLockArea.unlock(ticketLock);
+        }
+
+        for (int i = 0, len = tasks.size(); i < len; ++i) {
+            tasks.get(i).schedule();
+        }
+
+        return true;
+    }
+
+    // Note: on Moonrise the non-full sync load requires blocking on managedBlock, but this is fine since there is only
+    // one main thread. On Folia, it is required that the non-full load can occur completely asynchronously to avoid deadlock
+    // between regions
+    public ChunkAccess syncLoadNonFull(final int chunkX, final int chunkZ, final ChunkStatus status) {
+        if (status == null || status.isOrAfter(ChunkStatus.FULL)) {
+            throw new IllegalArgumentException("Status: " + status);
+        }
+
+        if (!TickThread.isTickThread()) {
+            return this.world.getChunkSource().getChunk(chunkX, chunkZ, status, true);
+        }
+
+        ChunkAccess loaded = ((ChunkSystemServerLevel)this.world).moonrise$getSpecificChunkIfLoaded(chunkX, chunkZ, status);
+        if (loaded != null) {
+            return loaded;
+        }
+
+        if (this.hasShutdown()) {
+            throw new IllegalStateException(
+                "Chunk system has shut down, cannot process chunk requests in world '" + ca.spottedleaf.moonrise.common.util.WorldUtil.getWorldName(this.world) + "' at "
+                    + "(" + chunkX + "," + chunkZ + ") status: " + status
+            );
+        }
+
+        final Long ticketId = getNextNonFullLoadId();
+        final int ticketLevel = getTicketLevel(status);
+        this.chunkHolderManager.addTicketAtLevel(NON_FULL_CHUNK_LOAD, chunkX, chunkZ, ticketLevel, ticketId);
+        this.chunkHolderManager.processTicketUpdates();
+
+        this.beginChunkLoadForNonFullSync(chunkX, chunkZ, status, Priority.BLOCKING);
+
+        // we could do a simple spinwait here, since we do not need to process tasks while performing this load
+        // but we process tasks only because it's a better use of the time spent
+        this.world.getChunkSource().mainThreadProcessor.managedBlock(() -> {
+            return ((ChunkSystemServerLevel)this.world).moonrise$getSpecificChunkIfLoaded(chunkX, chunkZ, status) != null;
+        });
+
+        loaded = ((ChunkSystemServerLevel)this.world).moonrise$getSpecificChunkIfLoaded(chunkX, chunkZ, status);
+
+        this.chunkHolderManager.removeTicketAtLevel(NON_FULL_CHUNK_LOAD, chunkX, chunkZ, ticketLevel, ticketId);
+
+        if (loaded == null) {
+            throw new IllegalStateException("Expected chunk to be loaded for status " + status);
+        }
+
+        return loaded;
+    }
+
+    public void scheduleChunkLoad(final int chunkX, final int chunkZ, final ChunkStatus toStatus, final boolean addTicket,
+                                  final Priority priority, final Consumer<ChunkAccess> onComplete) {
+        if (!TickThread.isTickThreadFor(this.world, chunkX, chunkZ)) {
+            this.scheduleChunkTask(chunkX, chunkZ, () -> {
+                ChunkTaskScheduler.this.scheduleChunkLoad(chunkX, chunkZ, toStatus, addTicket, priority, onComplete);
+            }, priority);
+            return;
+        }
+        final int accessRadius = getAccessRadius(toStatus);
+        if (this.chunkHolderManager.ticketLockArea.isHeldByCurrentThread(chunkX, chunkZ, accessRadius)) {
+            throw new IllegalStateException("Cannot schedule chunk load during ticket level update");
+        }
+        if (this.schedulingLockArea.isHeldByCurrentThread(chunkX, chunkZ, accessRadius)) {
+            throw new IllegalStateException("Cannot schedule chunk loading recursively");
+        }
+
+        if (toStatus == ChunkStatus.FULL) {
+            this.scheduleTickingState(chunkX, chunkZ, FullChunkStatus.FULL, addTicket, priority, (Consumer)onComplete);
+            return;
+        }
+
+        final int minLevel = ChunkTaskScheduler.getTicketLevel(toStatus);
+        final Long chunkReference = addTicket ? getNextChunkLoadId() : null;
+        final long chunkKey = CoordinateUtils.getChunkKey(chunkX, chunkZ);
+
+        if (addTicket) {
+            this.chunkHolderManager.addTicketAtLevel(CHUNK_LOAD, chunkKey, minLevel, chunkReference);
+            this.chunkHolderManager.processTicketUpdates();
+        }
+
+        final Consumer<ChunkAccess> loadCallback = onComplete == null && !addTicket ? null : (final ChunkAccess chunk) -> {
+            try {
+                if (onComplete != null) {
+                    onComplete.accept(chunk);
+                }
+            } finally {
+                if (addTicket) {
+                    ChunkTaskScheduler.this.chunkHolderManager.removeTicketAtLevel(CHUNK_LOAD, chunkKey, minLevel, chunkReference);
+                }
+            }
+        };
+
+        final List<ChunkProgressionTask> tasks = new ArrayList<>();
+
+        final boolean scheduled;
+        final ChunkAccess chunk;
+        final ReentrantAreaLock.Node ticketLock = this.chunkHolderManager.ticketLockArea.lock(chunkX, chunkZ, accessRadius);
+        try {
+            final ReentrantAreaLock.Node schedulingLock = this.schedulingLockArea.lock(chunkX, chunkZ, accessRadius);
+            try {
+                final NewChunkHolder chunkHolder = this.chunkHolderManager.getChunkHolder(chunkKey);
+                if (chunkHolder == null || chunkHolder.getTicketLevel() > minLevel) {
+                    scheduled = false;
+                    chunk = null;
+                } else {
+                    final ChunkStatus genStatus = chunkHolder.getCurrentGenStatus();
+                    if (genStatus != null && genStatus.isOrAfter(toStatus)) {
+                        scheduled = false;
+                        chunk = chunkHolder.getCurrentChunk();
+                    } else {
+                        scheduled = true;
+                        chunk = null;
+                        chunkHolder.raisePriority(priority);
+
+                        if (!chunkHolder.upgradeGenTarget(toStatus)) {
+                            this.schedule(chunkX, chunkZ, toStatus, chunkHolder, tasks);
+                        }
+                        if (loadCallback != null) {
+                            chunkHolder.addStatusConsumer(toStatus, loadCallback);
+                        }
+                    }
+                }
+            } finally {
+                this.schedulingLockArea.unlock(schedulingLock);
+            }
+        } finally {
+            this.chunkHolderManager.ticketLockArea.unlock(ticketLock);
+        }
+
+        for (int i = 0, len = tasks.size(); i < len; ++i) {
+            tasks.get(i).schedule();
+        }
+
+        if (loadCallback != null && !scheduled) {
+            // couldn't schedule
+            try {
+                loadCallback.accept(chunk);
+            } catch (final Throwable thr) {
+                LOGGER.error("Failed to process chunk status callback", thr);
+            }
+        }
+    }
+
+    private ChunkProgressionTask createTask(final int chunkX, final int chunkZ, final ChunkAccess chunk,
+                                            final NewChunkHolder chunkHolder, final StaticCache2D<GenerationChunkHolder> neighbours,
+                                            final ChunkStatus toStatus, final Priority initialPriority) {
+        if (toStatus == ChunkStatus.EMPTY) {
+            return new ChunkLoadTask(this, this.world, chunkX, chunkZ, chunkHolder, initialPriority);
+        }
+        if (toStatus == ChunkStatus.LIGHT) {
+            return new ChunkLightTask(this, this.world, chunkX, chunkZ, chunk, initialPriority);
+        }
+        if (toStatus == ChunkStatus.FULL) {
+            return new ChunkFullTask(this, this.world, chunkX, chunkZ, chunkHolder, chunk, initialPriority);
+        }
+
+        return new ChunkUpgradeGenericStatusTask(this, this.world, chunkX, chunkZ, chunk, neighbours, toStatus, initialPriority);
+    }
+
+    ChunkProgressionTask schedule(final int chunkX, final int chunkZ, final ChunkStatus targetStatus, final NewChunkHolder chunkHolder,
+                                  final List<ChunkProgressionTask> allTasks) {
+        return this.schedule(chunkX, chunkZ, targetStatus, chunkHolder, allTasks, chunkHolder.getEffectivePriority(Priority.NORMAL));
+    }
+
+    // rets new task scheduled for the _specified_ chunk
+    // note: this must hold the scheduling lock
+    // minPriority is only used to pass the priority through to neighbours, as priority calculation has not yet been done
+    // schedule will ignore the generation target, so it should be checked by the caller to ensure the target is not regressed!
+    private ChunkProgressionTask schedule(final int chunkX, final int chunkZ, final ChunkStatus targetStatus,
+                                          final NewChunkHolder chunkHolder, final List<ChunkProgressionTask> allTasks,
+                                          final Priority minPriority) {
+        if (!this.schedulingLockArea.isHeldByCurrentThread(chunkX, chunkZ, getAccessRadius(targetStatus))) {
+            throw new IllegalStateException("Not holding scheduling lock");
+        }
+
+        if (chunkHolder.hasGenerationTask()) {
+            chunkHolder.upgradeGenTarget(targetStatus);
+            return null;
+        }
+
+        final Priority requestedPriority = Priority.max(
+                minPriority, chunkHolder.getEffectivePriority(Priority.NORMAL)
+        );
+        final ChunkStatus currentGenStatus = chunkHolder.getCurrentGenStatus();
+        final ChunkAccess chunk = chunkHolder.getCurrentChunk();
+
+        if (currentGenStatus == null) {
+            // not yet loaded
+            final ChunkProgressionTask task = this.createTask(
+                chunkX, chunkZ, chunk, chunkHolder, null, ChunkStatus.EMPTY, requestedPriority
+            );
+
+            allTasks.add(task);
+
+            final List<NewChunkHolder> chunkHolderNeighbours = new ArrayList<>(1);
+            chunkHolderNeighbours.add(chunkHolder);
+
+            chunkHolder.setGenerationTarget(targetStatus);
+            chunkHolder.setGenerationTask(task, ChunkStatus.EMPTY, chunkHolderNeighbours);
+
+            return task;
+        }
+
+        if (currentGenStatus.isOrAfter(targetStatus)) {
+            // nothing to do
+            return null;
+        }
+
+        // we know for sure now that we want to schedule _something_, so set the target
+        chunkHolder.setGenerationTarget(targetStatus);
+
+        final ChunkStatus chunkRealStatus = chunk.getPersistedStatus();
+        final ChunkStatus toStatus = ((ChunkSystemChunkStatus)currentGenStatus).moonrise$getNextStatus();
+        final ChunkPyramid chunkPyramid = chunkRealStatus.isOrAfter(toStatus) ? ChunkPyramid.LOADING_PYRAMID : ChunkPyramid.GENERATION_PYRAMID;
+        final ChunkStep chunkStep = chunkPyramid.getStepTo(toStatus);
+
+        final int neighbourReadRadius = Math.max(
+                0,
+                chunkStep.getAccumulatedRadiusOf(ChunkStatus.EMPTY)
+        );
+
+        boolean unGeneratedNeighbours = false;
+
+        if (neighbourReadRadius > 0) {
+            final ChunkMap chunkMap = this.world.getChunkSource().chunkMap;
+            for (final long pos : ParallelSearchRadiusIteration.getSearchIteration(neighbourReadRadius)) {
+                final int x = CoordinateUtils.getChunkX(pos);
+                final int z = CoordinateUtils.getChunkZ(pos);
+                final int radius = Math.max(Math.abs(x), Math.abs(z));
+                final ChunkStatus requiredNeighbourStatus = ((ChunkSystemChunkStep)(Object)chunkStep).moonrise$getRequiredStatusAtRadius(radius);
+
+                unGeneratedNeighbours |= this.checkNeighbour(
+                        chunkX + x, chunkZ + z, requiredNeighbourStatus, chunkHolder, allTasks, requestedPriority
+                );
+            }
+        }
+
+        if (unGeneratedNeighbours) {
+            // can't schedule, but neighbour completion will schedule for us when they're ALL done
+
+            // propagate our priority to neighbours
+            chunkHolder.recalculateNeighbourPriorities();
+            return null;
+        }
+
+        // need to gather neighbours
+
+        final List<NewChunkHolder> chunkHolderNeighbours = new ArrayList<>((2 * neighbourReadRadius + 1) * (2 * neighbourReadRadius + 1));
+        final StaticCache2D<GenerationChunkHolder> neighbours = StaticCache2D
+                .create(chunkX, chunkZ, neighbourReadRadius, (final int nx, final int nz) -> {
+                    final NewChunkHolder holder = nx == chunkX && nz == chunkZ ? chunkHolder : this.chunkHolderManager.getChunkHolder(nx, nz);
+                    chunkHolderNeighbours.add(holder);
+
+                    return holder.vanillaChunkHolder;
+                });
+
+        final ChunkProgressionTask task = this.createTask(
+                chunkX, chunkZ, chunk, chunkHolder, neighbours, toStatus,
+                chunkHolder.getEffectivePriority(Priority.NORMAL)
+        );
+        allTasks.add(task);
+
+        chunkHolder.setGenerationTask(task, toStatus, chunkHolderNeighbours);
+
+        return task;
+    }
+
+    // rets true if the neighbour is not at the required status, false otherwise
+    private boolean checkNeighbour(final int chunkX, final int chunkZ, final ChunkStatus requiredStatus, final NewChunkHolder center,
+                                   final List<ChunkProgressionTask> tasks, final Priority minPriority) {
+        final NewChunkHolder chunkHolder = this.chunkHolderManager.getChunkHolder(chunkX, chunkZ);
+
+        if (chunkHolder == null) {
+            throw new IllegalStateException("Missing chunkholder when required");
+        }
+
+        final ChunkStatus holderStatus = chunkHolder.getCurrentGenStatus();
+        if (holderStatus != null && holderStatus.isOrAfter(requiredStatus)) {
+            return false;
+        }
+
+        if (chunkHolder.hasFailedGeneration()) {
+            return true;
+        }
+
+        center.addGenerationBlockingNeighbour(chunkHolder);
+        chunkHolder.addWaitingNeighbour(center, requiredStatus);
+
+        if (chunkHolder.upgradeGenTarget(requiredStatus)) {
+            return true;
+        }
+
+        // not at status required, so we need to schedule its generation
+        this.schedule(
+            chunkX, chunkZ, requiredStatus, chunkHolder, tasks, minPriority
+        );
+
+        return true;
+    }
+
+    /**
+     * @deprecated Chunk tasks must be tied to coordinates in the future
+     */
+    @Deprecated
+    public PrioritisedExecutor.PrioritisedTask scheduleChunkTask(final Runnable run) {
+        return this.scheduleChunkTask(run, Priority.NORMAL);
+    }
+
+    /**
+     * @deprecated Chunk tasks must be tied to coordinates in the future
+     */
+    @Deprecated
+    public PrioritisedExecutor.PrioritisedTask scheduleChunkTask(final Runnable run, final Priority priority) {
+        return this.mainThreadExecutor.queueTask(run, priority);
+    }
+
+    public PrioritisedExecutor.PrioritisedTask createChunkTask(final int chunkX, final int chunkZ, final Runnable run) {
+        return this.createChunkTask(chunkX, chunkZ, run, Priority.NORMAL);
+    }
+
+    public PrioritisedExecutor.PrioritisedTask createChunkTask(final int chunkX, final int chunkZ, final Runnable run,
+                                                               final Priority priority) {
+        return this.mainThreadExecutor.createTask(run, priority);
+    }
+
+    public PrioritisedExecutor.PrioritisedTask scheduleChunkTask(final int chunkX, final int chunkZ, final Runnable run) {
+        return this.scheduleChunkTask(chunkX, chunkZ, run, Priority.NORMAL);
+    }
+
+    public PrioritisedExecutor.PrioritisedTask scheduleChunkTask(final int chunkX, final int chunkZ, final Runnable run,
+                                                                 final Priority priority) {
+        return this.mainThreadExecutor.queueTask(run, priority);
+    }
+
+    public boolean halt(final boolean sync, final long maxWaitNS) {
+        this.radiusAwareGenExecutor.halt();
+        this.parallelGenExecutor.halt();
+        this.loadExecutor.halt();
+        if (sync) {
+            final long time = System.nanoTime();
+            for (long failures = 9L;; failures = ConcurrentUtil.linearLongBackoff(failures, 500_000L, 50_000_000L)) {
+                if (
+                        !this.radiusAwareGenExecutor.isActive() &&
+                        !this.parallelGenExecutor.isActive() &&
+                        !this.loadExecutor.isActive()
+                ) {
+                    return true;
+                }
+                if ((System.nanoTime() - time) >= maxWaitNS) {
+                    return false;
+                }
+            }
+        }
+
+        return true;
+    }
+
+    public boolean haltIO(final boolean sync, final long maxWaitNS) {
+        this.ioExecutor.halt();
+        this.saveExecutor.halt();
+        this.compressionExecutor.halt();
+        if (sync) {
+            final long time = System.nanoTime();
+            for (long failures = 9L;; failures = ConcurrentUtil.linearLongBackoff(failures, 500_000L, 50_000_000L)) {
+                if (
+                        !this.ioExecutor.isActive() &&
+                        !this.saveExecutor.isActive() &&
+                        !this.compressionExecutor.isActive()
+                ) {
+                    return true;
+                }
+                if ((System.nanoTime() - time) >= maxWaitNS) {
+                    return false;
+                }
+            }
+        }
+
+        return true;
+    }
+
+    public static final ArrayDeque<ChunkInfo> WAITING_CHUNKS = new ArrayDeque<>(); // stack
+
+    public static final class ChunkInfo {
+
+        public final int chunkX;
+        public final int chunkZ;
+        public final ServerLevel world;
+
+        public ChunkInfo(final int chunkX, final int chunkZ, final ServerLevel world) {
+            this.chunkX = chunkX;
+            this.chunkZ = chunkZ;
+            this.world = world;
+        }
+
+        public JsonObject toJson() {
+            final JsonObject ret = new JsonObject();
+
+            ret.addProperty("chunk-x", Integer.valueOf(this.chunkX));
+            ret.addProperty("chunk-z", Integer.valueOf(this.chunkZ));
+            ret.addProperty("world-name", WorldUtil.getWorldName(this.world));
+
+            return ret;
+        }
+
+        @Override
+        public String toString() {
+            return "[( " + this.chunkX + "," + this.chunkZ + ") in '" + WorldUtil.getWorldName(this.world) + "']";
+        }
+    }
+
+    public static void pushChunkWait(final ServerLevel world, final int chunkX, final int chunkZ) {
+        synchronized (WAITING_CHUNKS) {
+            WAITING_CHUNKS.push(new ChunkInfo(chunkX, chunkZ, world));
+        }
+    }
+
+    public static void popChunkWait() {
+        synchronized (WAITING_CHUNKS) {
+            WAITING_CHUNKS.pop();
+        }
+    }
+
+    public static ChunkInfo[] getChunkInfos() {
+        synchronized (WAITING_CHUNKS) {
+            return WAITING_CHUNKS.toArray(new ChunkInfo[0]);
+        }
+    }
+
+    private static JsonObject debugPlayer(final ServerPlayer player) {
+        final Level world = player.level();
+
+        final JsonObject ret = new JsonObject();
+
+        ret.addProperty("name", player.getScoreboardName());
+        ret.addProperty("uuid", player.getUUID().toString());
+        ret.addProperty("real", ((ChunkSystemServerPlayer)player).moonrise$isRealPlayer());
+
+        ret.addProperty("world-name", WorldUtil.getWorldName(world));
+
+        final Vec3 pos = player.position();
+
+        ret.addProperty("x", pos.x);
+        ret.addProperty("y", pos.y);
+        ret.addProperty("z", pos.z);
+
+        final Entity.RemovalReason removalReason = player.getRemovalReason();
+
+        ret.addProperty("removal-reason", removalReason == null ? "null" : removalReason.name());
+
+        ret.add("view-distances", ((ChunkSystemServerPlayer)player).moonrise$getViewDistanceHolder().toJson());
+
+        return ret;
+    }
+
+    public JsonObject getDebugJson() {
+        final JsonObject ret = new JsonObject();
+
+        ret.addProperty("lock_shift", Integer.valueOf(this.getChunkSystemLockShift()));
+        ret.addProperty("ticket_shift", Integer.valueOf(ThreadedTicketLevelPropagator.SECTION_SHIFT));
+        ret.addProperty("region_shift", Integer.valueOf(((ChunkSystemServerLevel)this.world).moonrise$getRegionChunkShift()));
+
+        ret.addProperty("name", WorldUtil.getWorldName(this.world));
+        ret.addProperty("view-distance", ((ChunkSystemServerLevel)this.world).moonrise$getPlayerChunkLoader().getAPIViewDistance());
+        ret.addProperty("tick-distance", ((ChunkSystemServerLevel)this.world).moonrise$getPlayerChunkLoader().getAPITickDistance());
+        ret.addProperty("send-distance", ((ChunkSystemServerLevel)this.world).moonrise$getPlayerChunkLoader().getAPISendViewDistance());
+
+        final JsonArray players = new JsonArray();
+        ret.add("players", players);
+
+        for (final ServerPlayer player : this.world.players()) {
+            players.add(debugPlayer(player));
+        }
+
+        ret.add("chunk-holder-manager", this.chunkHolderManager.getDebugJson());
+
+        return ret;
+    }
+
+    public static JsonObject debugAllWorlds(final MinecraftServer server) {
+        final JsonObject ret = new JsonObject();
+
+        ret.addProperty("data-version", 2);
+
+        final JsonArray allPlayers = new JsonArray();
+        ret.add("all-players", allPlayers);
+
+        for (final ServerPlayer player : server.getPlayerList().getPlayers()) {
+            allPlayers.add(debugPlayer(player));
+        }
+
+        final JsonArray chunkWaitInfos = new JsonArray();
+        ret.add("chunk-wait-infos", chunkWaitInfos);
+
+        for (final ChunkTaskScheduler.ChunkInfo info : getChunkInfos()) {
+            chunkWaitInfos.add(info.toJson());
+        }
+
+        final JsonArray worlds = new JsonArray();
+        ret.add("worlds", worlds);
+
+        for (final ServerLevel world : server.getAllLevels()) {
+            worlds.add(((ChunkSystemServerLevel)world).moonrise$getChunkTaskScheduler().getDebugJson());
+        }
+
+        return ret;
+    }
+
+    public static File getChunkDebugFile() {
+        return new File(
+                new File(new File("."), "debug"),
+                "chunks-" + DateTimeFormatter.ofPattern("yyyy-MM-dd_HH.mm.ss").format(LocalDateTime.now()) + ".txt"
+        );
+    }
+
+    public static void dumpAllChunkLoadInfo(final MinecraftServer server, final boolean writeDebugInfo) {
+        final ChunkInfo[] chunkInfos = getChunkInfos();
+        if (chunkInfos.length > 0) {
+            LOGGER.error("Chunk wait task info below: ");
+            for (final ChunkInfo chunkInfo : chunkInfos) {
+                final NewChunkHolder holder = ((ChunkSystemServerLevel)chunkInfo.world).moonrise$getChunkTaskScheduler().chunkHolderManager.getChunkHolder(chunkInfo.chunkX, chunkInfo.chunkZ);
+                LOGGER.error("Chunk wait: " + chunkInfo);
+                LOGGER.error("Chunk holder: " + holder);
+            }
+
+            if (writeDebugInfo) {
+                final File file = getChunkDebugFile();
+                LOGGER.error("Writing chunk information dump to " + file);
+                try {
+                    JsonUtil.writeJson(ChunkTaskScheduler.debugAllWorlds(server), file);
+                    LOGGER.error("Successfully written chunk information!");
+                } catch (final Throwable thr) {
+                    LOGGER.error("Failed to dump chunk information to file " + file.toString(), thr);
+                }
+            }
+        }
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/NewChunkHolder.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/NewChunkHolder.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/NewChunkHolder.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.scheduling;
+
+import ca.spottedleaf.concurrentutil.completable.CallbackCompletable;
+import ca.spottedleaf.concurrentutil.executor.Cancellable;
+import ca.spottedleaf.concurrentutil.executor.PrioritisedExecutor;
+import ca.spottedleaf.concurrentutil.lock.ReentrantAreaLock;
+import ca.spottedleaf.concurrentutil.util.ConcurrentUtil;
+import ca.spottedleaf.concurrentutil.util.Priority;
+import ca.spottedleaf.moonrise.common.PlatformHooks;
+import ca.spottedleaf.moonrise.common.misc.LazyRunnable;
+import ca.spottedleaf.moonrise.common.util.CoordinateUtils;
+import ca.spottedleaf.moonrise.common.util.TickThread;
+import ca.spottedleaf.moonrise.common.util.WorldUtil;
+import ca.spottedleaf.moonrise.common.util.ChunkSystem;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkData;
+import ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemChunkHolder;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemChunkStatus;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.entity.ChunkEntitySlices;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.poi.ChunkSystemPoiManager;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.poi.PoiChunk;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkLoadTask;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkProgressionTask;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.GenericDataLoadTask;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonNull;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonPrimitive;
+import it.unimi.dsi.fastutil.objects.Reference2ObjectLinkedOpenHashMap;
+import it.unimi.dsi.fastutil.objects.Reference2ObjectMap;
+import it.unimi.dsi.fastutil.objects.Reference2ObjectOpenHashMap;
+import it.unimi.dsi.fastutil.objects.ReferenceLinkedOpenHashSet;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.server.level.ChunkHolder;
+import net.minecraft.server.level.ChunkLevel;
+import net.minecraft.server.level.FullChunkStatus;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.progress.ChunkProgressListener;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.ImposterProtoChunk;
+import net.minecraft.world.level.chunk.LevelChunk;
+import net.minecraft.world.level.chunk.status.ChunkStatus;
+import net.minecraft.world.level.chunk.storage.SerializableChunkData;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import java.lang.invoke.VarHandle;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.Consumer;
+
+public final class NewChunkHolder {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(NewChunkHolder.class);
+
+    public final ChunkData holderData;
+
+    public final ServerLevel world;
+    public final int chunkX;
+    public final int chunkZ;
+
+    public final ChunkTaskScheduler scheduler;
+
+    // load/unload state
+
+    // chunk data state
+
+    private ChunkEntitySlices entityChunk;
+    // entity chunk that is loaded, but not yet deserialized
+    private CompoundTag pendingEntityChunk;
+
+    ChunkEntitySlices loadInEntityChunk(final boolean transientChunk) {
+        TickThread.ensureTickThread(this.world, this.chunkX, this.chunkZ, "Cannot sync load entity data off-main");
+        final CompoundTag entityChunk;
+        final ChunkEntitySlices ret;
+        final ReentrantAreaLock.Node schedulingLock = this.scheduler.schedulingLockArea.lock(this.chunkX, this.chunkZ);
+        try {
+            if (this.entityChunk != null && (transientChunk || !this.entityChunk.isTransient())) {
+                return this.entityChunk;
+            }
+            final CompoundTag pendingEntityChunk = this.pendingEntityChunk;
+            if (!transientChunk && pendingEntityChunk == null) {
+                throw new IllegalStateException("Must load entity data from disk before loading in the entity chunk!");
+            }
+
+            if (this.entityChunk == null) {
+                ret = this.entityChunk = new ChunkEntitySlices(
+                    this.world, this.chunkX, this.chunkZ, this.getChunkStatus(),
+                    this.holderData, WorldUtil.getMinSection(this.world), WorldUtil.getMaxSection(this.world)
+                );
+
+                ret.setTransient(transientChunk);
+
+                ((ChunkSystemServerLevel)this.world).moonrise$getEntityLookup().entitySectionLoad(this.chunkX, this.chunkZ, ret);
+            } else {
+                // transientChunk = false here
+                ret = this.entityChunk;
+                this.entityChunk.setTransient(false);
+            }
+
+            if (!transientChunk) {
+                this.pendingEntityChunk = null;
+                entityChunk = pendingEntityChunk == EMPTY_ENTITY_CHUNK ? null : pendingEntityChunk;
+            } else {
+                entityChunk = null;
+            }
+        } finally {
+            this.scheduler.schedulingLockArea.unlock(schedulingLock);
+        }
+
+        if (!transientChunk) {
+            if (entityChunk != null) {
+                final List<Entity> entities = ChunkEntitySlices.readEntities(this.world, entityChunk);
+
+                ((ChunkSystemServerLevel)this.world).moonrise$getEntityLookup().addEntityChunkEntities(entities, new ChunkPos(this.chunkX, this.chunkZ));
+            }
+        }
+
+        return ret;
+    }
+
+    // needed to distinguish whether the entity chunk has been read from disk but is empty or whether it has _not_
+    // been read from disk
+    private static final CompoundTag EMPTY_ENTITY_CHUNK = new CompoundTag();
+
+    private ChunkLoadTask.EntityDataLoadTask entityDataLoadTask;
+    // note: if entityDataLoadTask is cancelled, but on its completion entityDataLoadTaskWaiters.size() != 0,
+    // then the task is rescheduled
+    private List<GenericDataLoadTaskCallback> entityDataLoadTaskWaiters;
+
+    public ChunkLoadTask.EntityDataLoadTask getEntityDataLoadTask() {
+        return this.entityDataLoadTask;
+    }
+
+    // must hold schedule lock for the two below functions
+
+    // returns only if the data has been loaded from disk, DOES NOT relate to whether it has been deserialized
+    // or added into the world (or even into entityChunk)
+    public boolean isEntityChunkNBTLoaded() {
+        return (this.entityChunk != null && !this.entityChunk.isTransient()) || this.pendingEntityChunk != null;
+    }
+
+    private void completeEntityLoad(final GenericDataLoadTask.TaskResult<CompoundTag, Throwable> result) {
+        final List<GenericDataLoadTaskCallback> completeWaiters;
+        ChunkLoadTask.EntityDataLoadTask entityDataLoadTask = null;
+        boolean scheduleEntityTask = false;
+        ReentrantAreaLock.Node schedulingLock = this.scheduler.schedulingLockArea.lock(this.chunkX, this.chunkZ);
+        try {
+            final List<GenericDataLoadTaskCallback> waiters = this.entityDataLoadTaskWaiters;
+            this.entityDataLoadTask = null;
+            if (result != null) {
+                this.entityDataLoadTaskWaiters = null;
+                this.pendingEntityChunk = result.left() == null ? EMPTY_ENTITY_CHUNK : result.left();
+                if (result.right() != null) {
+                    LOGGER.error("Unhandled entity data load exception, data data will be lost: ", result.right());
+                }
+
+                for (final GenericDataLoadTaskCallback callback : waiters) {
+                    callback.markCompleted();
+                }
+
+                completeWaiters = waiters;
+            } else {
+                // cancelled
+                completeWaiters = null;
+
+                // need to re-schedule?
+                if (waiters.isEmpty()) {
+                    this.entityDataLoadTaskWaiters = null;
+                    // no tasks to schedule _for_
+                } else {
+                    entityDataLoadTask = this.entityDataLoadTask = new ChunkLoadTask.EntityDataLoadTask(
+                        this.scheduler, this.world, this.chunkX, this.chunkZ, this.getEffectivePriority(Priority.NORMAL)
+                    );
+                    entityDataLoadTask.addCallback(this::completeEntityLoad);
+                    // need one schedule() per waiter
+                    for (final GenericDataLoadTaskCallback callback : waiters) {
+                        scheduleEntityTask |= entityDataLoadTask.schedule(true);
+                    }
+                }
+            }
+        } finally {
+            this.scheduler.schedulingLockArea.unlock(schedulingLock);
+        }
+
+        if (scheduleEntityTask) {
+            entityDataLoadTask.scheduleNow();
+        }
+
+        // avoid holding the scheduling lock while completing
+        if (completeWaiters != null) {
+            for (final GenericDataLoadTaskCallback callback : completeWaiters) {
+                callback.acceptCompleted(result);
+            }
+        }
+
+        schedulingLock = this.scheduler.schedulingLockArea.lock(this.chunkX, this.chunkZ);
+        try {
+            this.checkUnload();
+        } finally {
+            this.scheduler.schedulingLockArea.unlock(schedulingLock);
+        }
+    }
+
+    // note: it is guaranteed that the consumer cannot be called for the entirety that the schedule lock is held
+    // however, when the consumer is invoked, it will hold the schedule lock
+    public GenericDataLoadTaskCallback getOrLoadEntityData(final Consumer<GenericDataLoadTask.TaskResult<CompoundTag, Throwable>> consumer) {
+        if (this.isEntityChunkNBTLoaded()) {
+            throw new IllegalStateException("Cannot load entity data, it is already loaded");
+        }
+        // why not just acquire the lock? because the caller NEEDS to call isEntityChunkNBTLoaded before this!
+        if (!this.scheduler.schedulingLockArea.isHeldByCurrentThread(this.chunkX, this.chunkZ)) {
+            throw new IllegalStateException("Must hold scheduling lock");
+        }
+
+        final GenericDataLoadTaskCallback ret = new EntityDataLoadTaskCallback((Consumer)consumer, this);
+
+        if (this.entityDataLoadTask == null) {
+            this.entityDataLoadTask = new ChunkLoadTask.EntityDataLoadTask(
+                this.scheduler, this.world, this.chunkX, this.chunkZ, this.getEffectivePriority(Priority.NORMAL)
+            );
+            this.entityDataLoadTask.addCallback(this::completeEntityLoad);
+            this.entityDataLoadTaskWaiters = new ArrayList<>();
+        }
+        this.entityDataLoadTaskWaiters.add(ret);
+        if (this.entityDataLoadTask.schedule(true)) {
+            ret.schedule = this.entityDataLoadTask;
+        }
+        this.checkUnload();
+
+        return ret;
+    }
+
+    private static final class EntityDataLoadTaskCallback extends GenericDataLoadTaskCallback {
+
+        public EntityDataLoadTaskCallback(final Consumer<GenericDataLoadTask.TaskResult<?, Throwable>> consumer, final NewChunkHolder chunkHolder) {
+            super(consumer, chunkHolder);
+        }
+
+        @Override
+        void internalCancel() {
+            this.chunkHolder.entityDataLoadTaskWaiters.remove(this);
+            this.chunkHolder.entityDataLoadTask.cancel();
+        }
+    }
+
+    private PoiChunk poiChunk;
+
+    private ChunkLoadTask.PoiDataLoadTask poiDataLoadTask;
+    // note: if entityDataLoadTask is cancelled, but on its completion entityDataLoadTaskWaiters.size() != 0,
+    // then the task is rescheduled
+    private List<GenericDataLoadTaskCallback> poiDataLoadTaskWaiters;
+
+    public ChunkLoadTask.PoiDataLoadTask getPoiDataLoadTask() {
+        return this.poiDataLoadTask;
+    }
+
+    // must hold schedule lock for the two below functions
+
+    public boolean isPoiChunkLoaded() {
+        return this.poiChunk != null;
+    }
+
+    private void completePoiLoad(final GenericDataLoadTask.TaskResult<PoiChunk, Throwable> result) {
+        final List<GenericDataLoadTaskCallback> completeWaiters;
+        ChunkLoadTask.PoiDataLoadTask poiDataLoadTask = null;
+        boolean schedulePoiTask = false;
+        ReentrantAreaLock.Node schedulingLock = this.scheduler.schedulingLockArea.lock(this.chunkX, this.chunkZ);
+        try {
+            final List<GenericDataLoadTaskCallback> waiters = this.poiDataLoadTaskWaiters;
+            this.poiDataLoadTask = null;
+            if (result != null) {
+                this.poiDataLoadTaskWaiters = null;
+                this.poiChunk = result.left();
+                if (result.right() != null) {
+                    LOGGER.error("Unhandled poi load exception, poi data will be lost: ", result.right());
+                }
+
+                for (final GenericDataLoadTaskCallback callback : waiters) {
+                    callback.markCompleted();
+                }
+
+                completeWaiters = waiters;
+            } else {
+                // cancelled
+                completeWaiters = null;
+
+                // need to re-schedule?
+                if (waiters.isEmpty()) {
+                    this.poiDataLoadTaskWaiters = null;
+                    // no tasks to schedule _for_
+                } else {
+                    poiDataLoadTask = this.poiDataLoadTask = new ChunkLoadTask.PoiDataLoadTask(
+                        this.scheduler, this.world, this.chunkX, this.chunkZ, this.getEffectivePriority(Priority.NORMAL)
+                    );
+                    poiDataLoadTask.addCallback(this::completePoiLoad);
+                    // need one schedule() per waiter
+                    for (final GenericDataLoadTaskCallback callback : waiters) {
+                        schedulePoiTask |= poiDataLoadTask.schedule(true);
+                    }
+                }
+            }
+        } finally {
+            this.scheduler.schedulingLockArea.unlock(schedulingLock);
+        }
+
+        if (schedulePoiTask) {
+            poiDataLoadTask.scheduleNow();
+        }
+
+        // avoid holding the scheduling lock while completing
+        if (completeWaiters != null) {
+            for (final GenericDataLoadTaskCallback callback : completeWaiters) {
+                callback.acceptCompleted(result);
+            }
+        }
+        schedulingLock = this.scheduler.schedulingLockArea.lock(this.chunkX, this.chunkZ);
+        try {
+            this.checkUnload();
+        } finally {
+            this.scheduler.schedulingLockArea.unlock(schedulingLock);
+        }
+    }
+
+    // note: it is guaranteed that the consumer cannot be called for the entirety that the schedule lock is held
+    // however, when the consumer is invoked, it will hold the schedule lock
+    public GenericDataLoadTaskCallback getOrLoadPoiData(final Consumer<GenericDataLoadTask.TaskResult<PoiChunk, Throwable>> consumer) {
+        if (this.isPoiChunkLoaded()) {
+            throw new IllegalStateException("Cannot load poi data, it is already loaded");
+        }
+        // why not just acquire the lock? because the caller NEEDS to call isPoiChunkLoaded before this!
+        if (!this.scheduler.schedulingLockArea.isHeldByCurrentThread(this.chunkX, this.chunkZ)) {
+            throw new IllegalStateException("Must hold scheduling lock");
+        }
+
+        final GenericDataLoadTaskCallback ret = new PoiDataLoadTaskCallback((Consumer)consumer, this);
+
+        if (this.poiDataLoadTask == null) {
+            this.poiDataLoadTask = new ChunkLoadTask.PoiDataLoadTask(
+                this.scheduler, this.world, this.chunkX, this.chunkZ, this.getEffectivePriority(Priority.NORMAL)
+            );
+            this.poiDataLoadTask.addCallback(this::completePoiLoad);
+            this.poiDataLoadTaskWaiters = new ArrayList<>();
+        }
+        this.poiDataLoadTaskWaiters.add(ret);
+        if (this.poiDataLoadTask.schedule(true)) {
+            ret.schedule = this.poiDataLoadTask;
+        }
+        this.checkUnload();
+
+        return ret;
+    }
+
+    private static final class PoiDataLoadTaskCallback extends GenericDataLoadTaskCallback {
+
+        public PoiDataLoadTaskCallback(final Consumer<GenericDataLoadTask.TaskResult<?, Throwable>> consumer, final NewChunkHolder chunkHolder) {
+            super(consumer, chunkHolder);
+        }
+
+        @Override
+        void internalCancel() {
+            this.chunkHolder.poiDataLoadTaskWaiters.remove(this);
+            this.chunkHolder.poiDataLoadTask.cancel();
+        }
+    }
+
+    public static abstract class GenericDataLoadTaskCallback implements Cancellable {
+
+        protected final Consumer<GenericDataLoadTask.TaskResult<?, Throwable>> consumer;
+        protected final NewChunkHolder chunkHolder;
+        protected boolean completed;
+        protected GenericDataLoadTask<?, ?> schedule;
+        protected final AtomicBoolean scheduled = new AtomicBoolean();
+
+        public GenericDataLoadTaskCallback(final Consumer<GenericDataLoadTask.TaskResult<?, Throwable>> consumer,
+                                           final NewChunkHolder chunkHolder) {
+            this.consumer = consumer;
+            this.chunkHolder = chunkHolder;
+        }
+
+        public void schedule() {
+            if (this.scheduled.getAndSet(true)) {
+                throw new IllegalStateException("Double calling schedule()");
+            }
+            if (this.schedule != null) {
+                this.schedule.scheduleNow();
+                this.schedule = null;
+            }
+        }
+
+        boolean isCompleted() {
+            return this.completed;
+        }
+
+        // must hold scheduling lock
+        private boolean setCompleted() {
+            if (this.completed) {
+                return false;
+            }
+            return this.completed = true;
+        }
+
+        // must hold scheduling lock
+        void markCompleted() {
+            if (this.completed) {
+                throw new IllegalStateException("May not be completed here");
+            }
+            this.completed = true;
+        }
+
+        void acceptCompleted(final GenericDataLoadTask.TaskResult<?, Throwable> result) {
+            if (result != null) {
+                if (this.completed) {
+                    this.consumer.accept(result);
+                } else {
+                    throw new IllegalStateException("Cannot be uncompleted at this point");
+                }
+            } else {
+                throw new NullPointerException("Result cannot be null (cancelled)");
+            }
+        }
+
+        // holds scheduling lock
+        abstract void internalCancel();
+
+        @Override
+        public boolean cancel() {
+            final NewChunkHolder holder = this.chunkHolder;
+            final ReentrantAreaLock.Node schedulingLock = holder.scheduler.schedulingLockArea.lock(holder.chunkX, holder.chunkZ);
+            try {
+                if (!this.completed) {
+                    this.completed = true;
+                    this.internalCancel();
+                    return true;
+                }
+                return false;
+            } finally {
+                holder.scheduler.schedulingLockArea.unlock(schedulingLock);
+            }
+        }
+    }
+
+    private ChunkAccess currentChunk;
+
+    // generation status state
+
+    /**
+     * Current status the chunk has been brought up to by the chunk system. null indicates no work at all
+     */
+    private ChunkStatus currentGenStatus;
+
+    // This allows lockless access to the chunk and last gen status
+    private static final ChunkStatus[] ALL_STATUSES = ChunkStatus.getStatusList().toArray(new ChunkStatus[0]);
+
+    public static final record ChunkCompletion(ChunkAccess chunk, ChunkStatus genStatus) {};
+    private static final VarHandle CHUNK_COMPLETION_ARRAY_HANDLE = ConcurrentUtil.getArrayHandle(ChunkCompletion[].class);
+    private final ChunkCompletion[] chunkCompletions = new ChunkCompletion[ALL_STATUSES.length];
+
+    private volatile ChunkCompletion lastChunkCompletion;
+
+    public ChunkCompletion getLastChunkCompletion() {
+        return this.lastChunkCompletion;
+    }
+
+    public ChunkAccess getChunkIfPresentUnchecked(final ChunkStatus status) {
+        final ChunkCompletion completion = (ChunkCompletion)CHUNK_COMPLETION_ARRAY_HANDLE.getVolatile(this.chunkCompletions, status.getIndex());
+        return completion == null ? null : completion.chunk;
+    }
+
+    public ChunkAccess getChunkIfPresent(final ChunkStatus status) {
+        final ChunkStatus maxStatus = ChunkLevel.generationStatus(this.getTicketLevel());
+
+        if (maxStatus == null || status.isAfter(maxStatus)) {
+            return null;
+        }
+
+        return this.getChunkIfPresentUnchecked(status);
+    }
+
+    public void replaceProtoChunk(final ImposterProtoChunk imposterProtoChunk) {
+        for (int i = 0, max = ChunkStatus.FULL.getIndex(); i < max; ++i) {
+            CHUNK_COMPLETION_ARRAY_HANDLE.setVolatile(this.chunkCompletions, i, new ChunkCompletion(imposterProtoChunk, ALL_STATUSES[i]));
+        }
+    }
+
+    /**
+     * The target final chunk status the chunk system will bring the chunk to.
+     */
+    private ChunkStatus requestedGenStatus;
+
+    private ChunkProgressionTask generationTask;
+    private ChunkStatus generationTaskStatus;
+
+    /**
+     * contains the neighbours that this chunk generation is blocking on
+     */
+    private final ReferenceLinkedOpenHashSet<NewChunkHolder> neighboursBlockingGenTask = new ReferenceLinkedOpenHashSet<>(4);
+
+    /**
+     * map of ChunkHolder -> Required Status for this chunk
+     */
+    private final Reference2ObjectLinkedOpenHashMap<NewChunkHolder, ChunkStatus> neighboursWaitingForUs = new Reference2ObjectLinkedOpenHashMap<>();
+
+    public void addGenerationBlockingNeighbour(final NewChunkHolder neighbour) {
+        this.neighboursBlockingGenTask.add(neighbour);
+    }
+
+    public void addWaitingNeighbour(final NewChunkHolder neighbour, final ChunkStatus requiredStatus) {
+        final boolean wasEmpty = this.neighboursWaitingForUs.isEmpty();
+        this.neighboursWaitingForUs.put(neighbour, requiredStatus);
+        if (wasEmpty) {
+            this.checkUnload();
+        }
+    }
+
+    // priority state
+
+    // the target priority for this chunk to generate at
+    private Priority priority = null;
+    private boolean priorityLocked;
+
+    // the priority neighbouring chunks have requested this chunk generate at
+    private Priority neighbourRequestedPriority = null;
+
+    public Priority getEffectivePriority(final Priority dfl) {
+        final Priority neighbour = this.neighbourRequestedPriority;
+        final Priority us = this.priority;
+
+        if (neighbour == null) {
+            return us == null ? dfl : us;
+        }
+        if (us == null) {
+            return neighbour;
+        }
+
+        return Priority.max(us, neighbour);
+    }
+
+    private void recalculateNeighbourRequestedPriority() {
+        if (this.neighboursWaitingForUs.isEmpty()) {
+            this.neighbourRequestedPriority = null;
+            return;
+        }
+
+        Priority max = null;
+
+        for (final NewChunkHolder holder : this.neighboursWaitingForUs.keySet()) {
+            final Priority neighbourPriority = holder.getEffectivePriority(null);
+            if (neighbourPriority != null && (max == null || neighbourPriority.isHigherPriority(max))) {
+                max = neighbourPriority;
+            }
+        }
+
+        final Priority current = this.getEffectivePriority(Priority.NORMAL);
+        this.neighbourRequestedPriority = max;
+        final Priority next = this.getEffectivePriority(Priority.NORMAL);
+
+        if (current == next) {
+            return;
+        }
+
+        // our effective priority has changed, so change our task
+        if (this.generationTask != null) {
+            this.generationTask.setPriority(next);
+        }
+
+        // now propagate this to our neighbours
+        this.recalculateNeighbourPriorities();
+    }
+
+    public void recalculateNeighbourPriorities() {
+        for (final NewChunkHolder holder : this.neighboursBlockingGenTask) {
+            holder.recalculateNeighbourRequestedPriority();
+        }
+    }
+
+    // must hold scheduling lock
+    public void raisePriority(final Priority priority) {
+        if (this.priority != null && this.priority.isHigherOrEqualPriority(priority)) {
+            return;
+        }
+        this.setPriority(priority);
+    }
+
+    private void lockPriority() {
+        this.priority = null;
+        this.priorityLocked = true;
+    }
+
+    // must hold scheduling lock
+    public void setPriority(final Priority priority) {
+        if (this.priorityLocked) {
+            return;
+        }
+        final Priority old = this.getEffectivePriority(null);
+        this.priority = priority;
+        final Priority newPriority = this.getEffectivePriority(Priority.NORMAL);
+
+        if (old != newPriority) {
+            if (this.generationTask != null) {
+                this.generationTask.setPriority(newPriority);
+            }
+        }
+
+        this.recalculateNeighbourPriorities();
+    }
+
+    // must hold scheduling lock
+    public void lowerPriority(final Priority priority) {
+        if (this.priority != null && this.priority.isLowerOrEqualPriority(priority)) {
+            return;
+        }
+        this.setPriority(priority);
+    }
+
+    // error handling state
+    private ChunkStatus failedGenStatus;
+    private Throwable genTaskException;
+    private Thread genTaskFailedThread;
+
+    private boolean failedLightUpdate;
+
+    public void failedLightUpdate() {
+        this.failedLightUpdate = true;
+    }
+
+    public boolean hasFailedGeneration() {
+        return this.genTaskException != null;
+    }
+
+    // ticket level state
+    private int oldTicketLevel = ChunkHolderManager.MAX_TICKET_LEVEL + 1;
+    private int currentTicketLevel = ChunkHolderManager.MAX_TICKET_LEVEL + 1;
+
+    public int getTicketLevel() {
+        return this.currentTicketLevel;
+    }
+
+    public final ChunkHolder vanillaChunkHolder;
+
+    public NewChunkHolder(final ServerLevel world, final int chunkX, final int chunkZ, final ChunkTaskScheduler scheduler) {
+        this.world = world;
+        this.chunkX = chunkX;
+        this.chunkZ = chunkZ;
+        this.scheduler = scheduler;
+        this.vanillaChunkHolder = new ChunkHolder(
+                new ChunkPos(chunkX, chunkZ), ChunkHolderManager.MAX_TICKET_LEVEL, world,
+                world.getLightEngine(), null, world.getChunkSource().chunkMap
+        );
+        ((ChunkSystemChunkHolder)this.vanillaChunkHolder).moonrise$setRealChunkHolder(this);
+        this.holderData = ((ChunkSystemLevel)this.world).moonrise$requestChunkData(CoordinateUtils.getChunkKey(chunkX, chunkZ));
+    }
+
+    public ChunkAccess getCurrentChunk() {
+        return this.currentChunk;
+    }
+
+    int getCurrentTicketLevel() {
+        return this.currentTicketLevel;
+    }
+
+    void updateTicketLevel(final int toLevel) {
+        this.currentTicketLevel = toLevel;
+    }
+
+    private int totalNeighboursUsingThisChunk = 0;
+
+    // holds schedule lock
+    public void addNeighbourUsingChunk() {
+        final int now = ++this.totalNeighboursUsingThisChunk;
+
+        if (now == 1) {
+            this.checkUnload();
+        }
+    }
+
+    // holds schedule lock
+    public void removeNeighbourUsingChunk() {
+        final int now = --this.totalNeighboursUsingThisChunk;
+
+        if (now == 0) {
+            this.checkUnload();
+        }
+
+        if (now < 0) {
+            throw new IllegalStateException("Neighbours using this chunk cannot be negative");
+        }
+    }
+
+    // must hold scheduling lock
+    // returns string reason for why chunk should remain loaded, null otherwise
+    public final String isSafeToUnload() {
+        // is ticket level below threshold?
+        if (this.oldTicketLevel <= ChunkHolderManager.MAX_TICKET_LEVEL) {
+            return "ticket_level";
+        }
+
+        // are we being used by another chunk for generation?
+        if (this.totalNeighboursUsingThisChunk != 0) {
+            return "neighbours_generating";
+        }
+
+        // are we going to be used by another chunk for generation?
+        if (!this.neighboursWaitingForUs.isEmpty()) {
+            return "neighbours_waiting";
+        }
+
+        // chunk must be marked inaccessible (i.e. unloaded to plugins)
+        if (this.getChunkStatus() != FullChunkStatus.INACCESSIBLE) {
+            return "fullchunkstatus";
+        }
+
+        // are we currently generating anything, or have requested generation?
+        if (this.generationTask != null) {
+            return "generating";
+        }
+        if (this.requestedGenStatus != null) {
+            return "requested_generation";
+        }
+
+        // entity data requested?
+        if (this.entityDataLoadTask != null) {
+            return "entity_data_requested";
+        }
+
+        // poi data requested?
+        if (this.poiDataLoadTask != null) {
+            return "poi_data_requested";
+        }
+
+        // are we pending serialization?
+        if (this.entityDataUnload != null) {
+            return "entity_serialization";
+        }
+        if (this.poiDataUnload != null) {
+            return "poi_serialization";
+        }
+        if (this.chunkDataUnload != null) {
+            return "chunk_serialization";
+        }
+
+        // Note: light tasks do not need a check, as they add a ticket.
+
+        // nothing is using this chunk, so it should be unloaded
+        return null;
+    }
+
+    /** Unloaded from chunk map */
+    private boolean unloaded;
+
+    void onUnload() {
+        this.unloaded = true;
+        ((ChunkSystemLevel)this.world).moonrise$releaseChunkData(CoordinateUtils.getChunkKey(this.chunkX, this.chunkZ));
+    }
+
+    private boolean inUnloadQueue = false;
+
+    void removeFromUnloadQueue() {
+        this.inUnloadQueue = false;
+    }
+
+    // must hold scheduling lock
+    private void checkUnload() {
+        if (this.unloaded) {
+            return;
+        }
+        if (this.isSafeToUnload() == null) {
+            // ensure in unload queue
+            if (!this.inUnloadQueue) {
+                this.inUnloadQueue = true;
+                this.scheduler.chunkHolderManager.unloadQueue.addChunk(this.chunkX, this.chunkZ);
+            }
+        } else {
+            // ensure not in unload queue
+            if (this.inUnloadQueue) {
+                this.inUnloadQueue = false;
+                this.scheduler.chunkHolderManager.unloadQueue.removeChunk(this.chunkX, this.chunkZ);
+            }
+        }
+    }
+
+    static final record UnloadState(NewChunkHolder holder, ChunkAccess chunk, ChunkEntitySlices entityChunk, PoiChunk poiChunk) {};
+
+    // note: these are completed with null to indicate that no write occurred
+    // they are also completed with null to indicate a null write occurred
+    private UnloadTask chunkDataUnload;
+    private UnloadTask entityDataUnload;
+    private UnloadTask poiDataUnload;
+
+    public static final record UnloadTask(CallbackCompletable<CompoundTag> completable, PrioritisedExecutor.PrioritisedTask task,
+                                          LazyRunnable toRun) {}
+
+    public UnloadTask getUnloadTask(final MoonriseRegionFileIO.RegionFileType type) {
+        switch (type) {
+            case CHUNK_DATA:
+                return this.chunkDataUnload;
+            case ENTITY_DATA:
+                return this.entityDataUnload;
+            case POI_DATA:
+                return this.poiDataUnload;
+            default:
+                throw new IllegalStateException("Unknown regionfile type " + type);
+        }
+    }
+
+    private void removeUnloadTask(final MoonriseRegionFileIO.RegionFileType type) {
+        switch (type) {
+            case CHUNK_DATA: {
+                this.chunkDataUnload = null;
+                return;
+            }
+            case ENTITY_DATA: {
+                this.entityDataUnload = null;
+                return;
+            }
+            case POI_DATA: {
+                this.poiDataUnload = null;
+                return;
+            }
+            default:
+                throw new IllegalStateException("Unknown regionfile type " + type);
+        }
+    }
+
+    private UnloadState unloadState;
+
+    // holds schedule lock
+    UnloadState unloadStage1() {
+        // because we hold the scheduling lock, we cannot actually unload anything
+        // so, what we do here instead is to null this chunk's state and setup the unload tasks
+        // the unload tasks will ensure that any loads that take place after stage1 (i.e during stage2, in which
+        // we do not hold the lock) c
+        final ChunkAccess chunk = this.currentChunk;
+        final ChunkEntitySlices entityChunk = this.entityChunk;
+        final PoiChunk poiChunk = this.poiChunk;
+        // chunk state
+        this.currentChunk = null;
+        this.currentGenStatus = null;
+        for (int i = 0; i < this.chunkCompletions.length; ++i) {
+            CHUNK_COMPLETION_ARRAY_HANDLE.setRelease(this.chunkCompletions, i, (ChunkCompletion)null);
+        }
+        this.lastChunkCompletion = null;
+        // entity chunk state
+        this.entityChunk = null;
+        this.pendingEntityChunk = null;
+
+        // poi chunk state
+        this.poiChunk = null;
+
+        // priority state
+        this.priorityLocked = false;
+
+        if (chunk != null) {
+            final LazyRunnable toRun = new LazyRunnable();
+            this.chunkDataUnload = new UnloadTask(new CallbackCompletable<>(), this.scheduler.saveExecutor.createTask(toRun), toRun);
+        }
+        if (poiChunk != null) {
+            this.poiDataUnload = new UnloadTask(new CallbackCompletable<>(), null, null);
+        }
+        if (entityChunk != null) {
+            this.entityDataUnload = new UnloadTask(new CallbackCompletable<>(), null, null);
+        }
+
+        return this.unloadState = (chunk != null || entityChunk != null || poiChunk != null) ? new UnloadState(this, chunk, entityChunk, poiChunk) : null;
+    }
+
+    // data is null if failed or does not need to be saved
+    void completeAsyncUnloadDataSave(final MoonriseRegionFileIO.RegionFileType type, final CompoundTag data) {
+        if (data != null) {
+            MoonriseRegionFileIO.scheduleSave(this.world, this.chunkX, this.chunkZ, data, type);
+        }
+
+        this.getUnloadTask(type).completable().complete(data);
+        final ReentrantAreaLock.Node schedulingLock = this.scheduler.schedulingLockArea.lock(this.chunkX, this.chunkZ);
+        try {
+            // can only write to these fields while holding the schedule lock
+            this.removeUnloadTask(type);
+            this.checkUnload();
+        } finally {
+            this.scheduler.schedulingLockArea.unlock(schedulingLock);
+        }
+    }
+
+    void unloadStage2(final UnloadState state) {
+        this.unloadState = null;
+        final ChunkAccess chunk = state.chunk();
+        final ChunkEntitySlices entityChunk = state.entityChunk();
+        final PoiChunk poiChunk = state.poiChunk();
+
+        final boolean shouldLevelChunkNotSave = PlatformHooks.get().forceNoSave(chunk);
+
+        // unload chunk data
+        if (chunk != null) {
+            if (chunk instanceof LevelChunk levelChunk) {
+                levelChunk.setLoaded(false);
+                PlatformHooks.get().chunkUnloadFromWorld(levelChunk);
+            }
+
+            if (!shouldLevelChunkNotSave) {
+                this.saveChunk(chunk, true);
+            } else {
+                this.completeAsyncUnloadDataSave(MoonriseRegionFileIO.RegionFileType.CHUNK_DATA, null);
+            }
+
+            if (chunk instanceof LevelChunk levelChunk) {
+                this.world.unload(levelChunk);
+            }
+        }
+
+        // unload entity data
+        if (entityChunk != null) {
+            this.saveEntities(entityChunk, true);
+            // yes this is a hack to pass the compound tag through...
+            final CompoundTag lastEntityUnload = this.lastEntityUnload;
+            this.lastEntityUnload = null;
+
+            if (entityChunk.unload()) {
+                final ReentrantAreaLock.Node schedulingLock = this.scheduler.schedulingLockArea.lock(this.chunkX, this.chunkZ);
+                try {
+                    entityChunk.setTransient(true);
+                    this.entityChunk = entityChunk;
+                } finally {
+                    this.scheduler.schedulingLockArea.unlock(schedulingLock);
+                }
+            } else {
+                ((ChunkSystemServerLevel)this.world).moonrise$getEntityLookup().entitySectionUnload(this.chunkX, this.chunkZ);
+            }
+            // we need to delay the callback until after determining transience, otherwise a potential loader could
+            // set entityChunk before we do
+            this.entityDataUnload.completable().complete(lastEntityUnload);
+        }
+
+        // unload poi data
+        if (poiChunk != null) {
+            if (poiChunk.isDirty() && !shouldLevelChunkNotSave) {
+                this.savePOI(poiChunk, true);
+            } else {
+                this.poiDataUnload.completable().complete(null);
+            }
+
+            if (poiChunk.isLoaded()) {
+                ((ChunkSystemPoiManager)this.world.getPoiManager()).moonrise$onUnload(CoordinateUtils.getChunkKey(this.chunkX, this.chunkZ));
+            }
+        }
+    }
+
+    boolean unloadStage3() {
+        // can only write to these while holding the schedule lock, and we instantly complete them in stage2
+        this.poiDataUnload = null;
+        this.entityDataUnload = null;
+
+        // we need to check if anything has been loaded in the meantime (or if we have transient entities)
+        if (this.entityChunk != null || this.poiChunk != null || this.currentChunk != null) {
+            return false;
+        }
+
+        return this.isSafeToUnload() == null;
+    }
+
+    private void cancelGenTask() {
+        if (this.generationTask != null) {
+            this.generationTask.cancel();
+        } else {
+            // otherwise, we are blocking on neighbours, so remove them
+            if (!this.neighboursBlockingGenTask.isEmpty()) {
+                for (final NewChunkHolder neighbour : this.neighboursBlockingGenTask) {
+                    if (neighbour.neighboursWaitingForUs.remove(this) == null) {
+                        throw new IllegalStateException("Corrupt state");
+                    }
+                    if (neighbour.neighboursWaitingForUs.isEmpty()) {
+                        neighbour.checkUnload();
+                    }
+                }
+                this.neighboursBlockingGenTask.clear();
+                this.checkUnload();
+            }
+        }
+    }
+
+    // holds: ticket level update lock
+    // holds: schedule lock
+    public void processTicketLevelUpdate(final List<ChunkProgressionTask> scheduledTasks, final List<NewChunkHolder> changedLoadStatus) {
+        final int oldLevel = this.oldTicketLevel;
+        final int newLevel = this.currentTicketLevel;
+
+        if (oldLevel == newLevel) {
+            return;
+        }
+
+        this.oldTicketLevel = newLevel;
+
+        final FullChunkStatus oldState = ChunkLevel.fullStatus(oldLevel);
+        final FullChunkStatus newState = ChunkLevel.fullStatus(newLevel);
+        final boolean oldUnloaded = oldLevel > ChunkHolderManager.MAX_TICKET_LEVEL;
+        final boolean newUnloaded = newLevel > ChunkHolderManager.MAX_TICKET_LEVEL;
+
+        final ChunkStatus maxGenerationStatusOld = ChunkLevel.generationStatus(oldLevel);
+        final ChunkStatus maxGenerationStatusNew = ChunkLevel.generationStatus(newLevel);
+
+        // check for cancellations from downgrading ticket level
+        if (this.requestedGenStatus != null && !newState.isOrAfter(FullChunkStatus.FULL) && newLevel > oldLevel) {
+            // note: cancel() may invoke onChunkGenComplete synchronously here
+            if (newUnloaded) {
+                // need to cancel all tasks
+                // note: requested status must be set to null here before cancellation, to indicate to the
+                // completion logic that we do not want rescheduling to occur
+                this.requestedGenStatus = null;
+                this.cancelGenTask();
+            } else {
+                final ChunkStatus toCancel = ((ChunkSystemChunkStatus)maxGenerationStatusNew).moonrise$getNextStatus();
+                final ChunkStatus currentRequestedStatus = this.requestedGenStatus;
+
+                if (currentRequestedStatus.isOrAfter(toCancel)) {
+                    // we do have to cancel something here
+                    // clamp requested status to the maximum
+                    if (this.currentGenStatus != null && this.currentGenStatus.isOrAfter(maxGenerationStatusNew)) {
+                        // already generated to status, so we must cancel
+                        this.requestedGenStatus = null;
+                        this.cancelGenTask();
+                    } else {
+                        // not generated to status, so we may have to cancel
+                        // note: gen task is always 1 status above current gen status if not null
+                        this.requestedGenStatus = maxGenerationStatusNew;
+                        if (this.generationTaskStatus != null && this.generationTaskStatus.isOrAfter(toCancel)) {
+                            // TOOD is this even possible? i don't think so
+                            throw new IllegalStateException("?????");
+                        }
+                    }
+                }
+            }
+        }
+
+        if (oldState != newState) {
+            if (newState.isOrAfter(oldState)) {
+                // status upgrade
+                if (!oldState.isOrAfter(FullChunkStatus.FULL) && newState.isOrAfter(FullChunkStatus.FULL)) {
+                    // may need to schedule full load
+                    if (this.currentGenStatus != ChunkStatus.FULL) {
+                        if (this.requestedGenStatus != null) {
+                            this.requestedGenStatus = ChunkStatus.FULL;
+                        } else {
+                            this.scheduler.schedule(
+                                this.chunkX, this.chunkZ, ChunkStatus.FULL, this, scheduledTasks
+                            );
+                        }
+                    }
+                }
+            } else {
+                // status downgrade
+                if (!newState.isOrAfter(FullChunkStatus.ENTITY_TICKING) && oldState.isOrAfter(FullChunkStatus.ENTITY_TICKING)) {
+                    this.completeFullStatusConsumers(FullChunkStatus.ENTITY_TICKING, null);
+                }
+
+                if (!newState.isOrAfter(FullChunkStatus.BLOCK_TICKING) && oldState.isOrAfter(FullChunkStatus.BLOCK_TICKING)) {
+                    this.completeFullStatusConsumers(FullChunkStatus.BLOCK_TICKING, null);
+                }
+
+                if (!newState.isOrAfter(FullChunkStatus.FULL) && oldState.isOrAfter(FullChunkStatus.FULL)) {
+                    this.completeFullStatusConsumers(FullChunkStatus.FULL, null);
+                }
+            }
+
+            if (this.updatePendingStatus()) {
+                changedLoadStatus.add(this);
+            }
+        }
+
+        if (oldUnloaded != newUnloaded) {
+            this.checkUnload();
+        }
+
+        // Don't really have a choice but to place this hook here
+        PlatformHooks.get().onChunkHolderTicketChange(this.world, this.vanillaChunkHolder, oldLevel, newLevel);
+    }
+
+    static final int NEIGHBOUR_RADIUS = 2;
+    private long fullNeighbourChunksLoadedBitset;
+
+    private static int getFullNeighbourIndex(final int relativeX, final int relativeZ) {
+        // index = (relativeX + NEIGHBOUR_CACHE_RADIUS) + (relativeZ + NEIGHBOUR_CACHE_RADIUS) * (NEIGHBOUR_CACHE_RADIUS * 2 + 1)
+        // optimised variant of the above by moving some of the ops to compile time
+        return relativeX + (relativeZ * (NEIGHBOUR_RADIUS * 2 + 1)) + (NEIGHBOUR_RADIUS + NEIGHBOUR_RADIUS * ((NEIGHBOUR_RADIUS * 2 + 1)));
+    }
+    public final boolean isNeighbourFullLoaded(final int relativeX, final int relativeZ) {
+        return (this.fullNeighbourChunksLoadedBitset & (1L << getFullNeighbourIndex(relativeX, relativeZ))) != 0;
+    }
+
+    // returns true if this chunk changed pending full status
+    // must hold scheduling lock
+    public final boolean setNeighbourFullLoaded(final int relativeX, final int relativeZ) {
+        final int index = getFullNeighbourIndex(relativeX, relativeZ);
+        this.fullNeighbourChunksLoadedBitset |= (1L << index);
+        return this.updatePendingStatus();
+    }
+
+    // returns true if this chunk changed pending full status
+    // must hold scheduling lock
+    public final boolean setNeighbourFullUnloaded(final int relativeX, final int relativeZ) {
+        final int index = getFullNeighbourIndex(relativeX, relativeZ);
+        this.fullNeighbourChunksLoadedBitset &= ~(1L << index);
+        return this.updatePendingStatus();
+    }
+
+    private static long getLoadedMask(final int radius) {
+        long mask = 0L;
+        for (int dx = -radius; dx <= radius; ++dx) {
+            for (int dz = -radius; dz <= radius; ++dz) {
+                mask |= (1L << getFullNeighbourIndex(dx, dz));
+            }
+        }
+
+        return mask;
+    }
+
+    private static final long CHUNK_LOADED_MASK_RAD0 = getLoadedMask(0);
+    private static final long CHUNK_LOADED_MASK_RAD1 = getLoadedMask(1);
+    private static final long CHUNK_LOADED_MASK_RAD2 = getLoadedMask(2);
+
+    // only updated while holding scheduling lock
+    private FullChunkStatus pendingFullChunkStatus = FullChunkStatus.INACCESSIBLE;
+    // updated while holding no locks, but adds a ticket before to prevent pending status from dropping
+    // so, current will never update to a value higher than pending
+    private FullChunkStatus currentFullChunkStatus = FullChunkStatus.INACCESSIBLE;
+
+    public FullChunkStatus getChunkStatus() {
+        // no volatile access, access off-main is considered racey anyways
+        return this.currentFullChunkStatus;
+    }
+
+    public boolean isEntityTickingReady() {
+        return this.getChunkStatus().isOrAfter(FullChunkStatus.ENTITY_TICKING);
+    }
+
+    public boolean isTickingReady() {
+        return this.getChunkStatus().isOrAfter(FullChunkStatus.BLOCK_TICKING);
+    }
+
+    public boolean isFullChunkReady() {
+        return this.getChunkStatus().isOrAfter(FullChunkStatus.FULL);
+    }
+
+    private static FullChunkStatus getStatusForBitset(final long bitset) {
+        if ((bitset & CHUNK_LOADED_MASK_RAD2) == CHUNK_LOADED_MASK_RAD2) {
+            return FullChunkStatus.ENTITY_TICKING;
+        } else if ((bitset & CHUNK_LOADED_MASK_RAD1) == CHUNK_LOADED_MASK_RAD1) {
+            return FullChunkStatus.BLOCK_TICKING;
+        } else if ((bitset & CHUNK_LOADED_MASK_RAD0) == CHUNK_LOADED_MASK_RAD0) {
+            return FullChunkStatus.FULL;
+        } else {
+            return FullChunkStatus.INACCESSIBLE;
+        }
+    }
+
+    // must hold scheduling lock
+    // returns whether the pending status was changed
+    private boolean updatePendingStatus() {
+        final FullChunkStatus byTicketLevel = ChunkLevel.fullStatus(this.oldTicketLevel); // oldTicketLevel is controlled by scheduling lock
+
+        FullChunkStatus pending = getStatusForBitset(this.fullNeighbourChunksLoadedBitset);
+        if (pending == FullChunkStatus.INACCESSIBLE && byTicketLevel.isOrAfter(FullChunkStatus.FULL) && this.currentGenStatus == ChunkStatus.FULL) {
+            // the bitset is only for chunks that have gone through the status updater
+            // but here we are ready to go to FULL
+            pending = FullChunkStatus.FULL;
+        }
+
+        if (pending.isOrAfter(byTicketLevel)) { // pending >= byTicketLevel
+            // cannot set above ticket level
+            pending = byTicketLevel;
+        }
+
+        if (this.pendingFullChunkStatus == pending) {
+            return false;
+        }
+
+        this.pendingFullChunkStatus = pending;
+
+        return true;
+    }
+
+    private void onFullChunkLoadChange(final boolean loaded, final List<NewChunkHolder> changedFullStatus) {
+        final ReentrantAreaLock.Node schedulingLock = this.scheduler.schedulingLockArea.lock(this.chunkX, this.chunkZ, NEIGHBOUR_RADIUS);
+        try {
+            for (int dz = -NEIGHBOUR_RADIUS; dz <= NEIGHBOUR_RADIUS; ++dz) {
+                for (int dx = -NEIGHBOUR_RADIUS; dx <= NEIGHBOUR_RADIUS; ++dx) {
+                    final NewChunkHolder holder = (dx | dz) == 0 ? this : this.scheduler.chunkHolderManager.getChunkHolder(dx + this.chunkX, dz + this.chunkZ);
+                    if (loaded) {
+                        if (holder.setNeighbourFullLoaded(-dx, -dz)) {
+                            changedFullStatus.add(holder);
+                        }
+                    } else {
+                        if (holder != null && holder.setNeighbourFullUnloaded(-dx, -dz)) {
+                            changedFullStatus.add(holder);
+                        }
+                    }
+                }
+            }
+        } finally {
+            this.scheduler.schedulingLockArea.unlock(schedulingLock);
+        }
+    }
+
+    private void changeEntityChunkStatus(final FullChunkStatus toStatus) {
+        ((ChunkSystemServerLevel)this.world).moonrise$getEntityLookup().chunkStatusChange(this.chunkX, this.chunkZ, toStatus);
+    }
+
+    private boolean processingFullStatus = false;
+
+    private void updateCurrentState(final FullChunkStatus to) {
+        this.currentFullChunkStatus = to;
+    }
+
+    // only to be called on the main thread, no locks need to be held
+    public boolean handleFullStatusChange(final List<NewChunkHolder> changedFullStatus) {
+        TickThread.ensureTickThread(this.world, this.chunkX, this.chunkZ, "Cannot update full status thread off-main");
+
+        boolean ret = false;
+
+        if (this.processingFullStatus) {
+            // we cannot process updates recursively, as we may be in the middle of logic to upgrade/downgrade status
+            return ret;
+        }
+
+        this.processingFullStatus = true;
+        try {
+            for (;;) {
+                // check if we have any remaining work to do
+
+                // we do not need to hold the scheduling lock to read pending, as changes to pending
+                // will queue a status update
+
+                final FullChunkStatus pending = this.pendingFullChunkStatus;
+                FullChunkStatus current = this.currentFullChunkStatus;
+
+                if (pending == current) {
+                    if (pending == FullChunkStatus.INACCESSIBLE) {
+                        final ReentrantAreaLock.Node schedulingLock = this.scheduler.schedulingLockArea.lock(this.chunkX, this.chunkZ);
+                        try {
+                            this.checkUnload();
+                        } finally {
+                            this.scheduler.schedulingLockArea.unlock(schedulingLock);
+                        }
+                    }
+                    return ret;
+                }
+
+                ret = true;
+
+                // note: because the chunk system delays any ticket downgrade to the chunk holder manager tick, we
+                //       do not need to consider cases where the ticket level may decrease during this call by asynchronous
+                //       ticket changes
+
+                // chunks cannot downgrade state while status is pending a change
+                // note: currentChunk must be LevelChunk, as current != pending which means that at least one is not ACCESSIBLE
+                final LevelChunk chunk = (LevelChunk)this.currentChunk;
+
+                // Note: we assume that only load/unload contain plugin logic
+                // plugin logic is anything stupid enough to possibly change the chunk status while it is already
+                // being changed (i.e during load it is possible it will try to set to full ticking)
+                // in order to allow this change, we also need this plugin logic to be contained strictly after all
+                // of the chunk system load callbacks are invoked
+                if (pending.isOrAfter(current)) {
+                    // state upgrade
+                    if (!current.isOrAfter(FullChunkStatus.FULL) && pending.isOrAfter(FullChunkStatus.FULL)) {
+                        this.updateCurrentState(FullChunkStatus.FULL);
+                        ChunkSystem.onChunkPreBorder(chunk, this.vanillaChunkHolder);
+                        this.scheduler.chunkHolderManager.ensureInAutosave(this);
+                        this.changeEntityChunkStatus(FullChunkStatus.FULL);
+                        ChunkSystem.onChunkBorder(chunk, this.vanillaChunkHolder);
+                        this.onFullChunkLoadChange(true, changedFullStatus);
+                        this.completeFullStatusConsumers(FullChunkStatus.FULL, chunk);
+                    }
+
+                    if (!current.isOrAfter(FullChunkStatus.BLOCK_TICKING) && pending.isOrAfter(FullChunkStatus.BLOCK_TICKING)) {
+                        this.updateCurrentState(FullChunkStatus.BLOCK_TICKING);
+                        this.changeEntityChunkStatus(FullChunkStatus.BLOCK_TICKING);
+                        ChunkSystem.onChunkTicking(chunk, this.vanillaChunkHolder);
+                        this.completeFullStatusConsumers(FullChunkStatus.BLOCK_TICKING, chunk);
+                    }
+
+                    if (!current.isOrAfter(FullChunkStatus.ENTITY_TICKING) && pending.isOrAfter(FullChunkStatus.ENTITY_TICKING)) {
+                        this.updateCurrentState(FullChunkStatus.ENTITY_TICKING);
+                        this.changeEntityChunkStatus(FullChunkStatus.ENTITY_TICKING);
+                        ChunkSystem.onChunkEntityTicking(chunk, this.vanillaChunkHolder);
+                        this.completeFullStatusConsumers(FullChunkStatus.ENTITY_TICKING, chunk);
+                    }
+                } else {
+                    if (current.isOrAfter(FullChunkStatus.ENTITY_TICKING) && !pending.isOrAfter(FullChunkStatus.ENTITY_TICKING)) {
+                        this.changeEntityChunkStatus(FullChunkStatus.BLOCK_TICKING);
+                        ChunkSystem.onChunkNotEntityTicking(chunk, this.vanillaChunkHolder);
+                        this.updateCurrentState(FullChunkStatus.BLOCK_TICKING);
+                    }
+
+                    if (current.isOrAfter(FullChunkStatus.BLOCK_TICKING) && !pending.isOrAfter(FullChunkStatus.BLOCK_TICKING)) {
+                        this.changeEntityChunkStatus(FullChunkStatus.FULL);
+                        ChunkSystem.onChunkNotTicking(chunk, this.vanillaChunkHolder);
+                        this.updateCurrentState(FullChunkStatus.FULL);
+                    }
+
+                    if (current.isOrAfter(FullChunkStatus.FULL) && !pending.isOrAfter(FullChunkStatus.FULL)) {
+                        this.onFullChunkLoadChange(false, changedFullStatus);
+                        this.changeEntityChunkStatus(FullChunkStatus.INACCESSIBLE);
+                        ChunkSystem.onChunkNotBorder(chunk, this.vanillaChunkHolder);
+                        ChunkSystem.onChunkPostNotBorder(chunk, this.vanillaChunkHolder);
+                        this.updateCurrentState(FullChunkStatus.INACCESSIBLE);
+                    }
+                }
+            }
+        } finally {
+            this.processingFullStatus = false;
+        }
+    }
+
+    // note: must hold scheduling lock
+    // rets true if the current requested gen status is not null (effectively, whether further scheduling is not needed)
+    boolean upgradeGenTarget(final ChunkStatus toStatus) {
+        if (toStatus == null) {
+            throw new NullPointerException("toStatus cannot be null");
+        }
+        if (this.requestedGenStatus == null && this.generationTask == null) {
+            return false;
+        }
+        if (this.requestedGenStatus == null || !this.requestedGenStatus.isOrAfter(toStatus)) {
+            this.requestedGenStatus = toStatus;
+        }
+        return true;
+    }
+
+    public void setGenerationTarget(final ChunkStatus toStatus) {
+        this.requestedGenStatus = toStatus;
+    }
+
+    public boolean hasGenerationTask() {
+        return this.generationTask != null;
+    }
+
+    public ChunkStatus getCurrentGenStatus() {
+        return this.currentGenStatus;
+    }
+
+    public ChunkStatus getRequestedGenStatus() {
+        return this.requestedGenStatus;
+    }
+
+    private final Reference2ObjectOpenHashMap<ChunkStatus, List<Consumer<ChunkAccess>>> statusWaiters = new Reference2ObjectOpenHashMap<>();
+
+    void addStatusConsumer(final ChunkStatus status, final Consumer<ChunkAccess> consumer) {
+        this.statusWaiters.computeIfAbsent(status, (final ChunkStatus keyInMap) -> {
+            return new ArrayList<>(4);
+        }).add(consumer);
+    }
+
+    private void completeStatusConsumers(ChunkStatus status, final ChunkAccess chunk) {
+        // Update progress listener for LevelLoadingScreen
+        if (chunk != null) {
+            final ChunkProgressListener progressListener = this.world.getChunkSource().chunkMap.progressListener;
+            if (progressListener != null) {
+                final ChunkStatus finalStatus = status;
+                this.scheduler.scheduleChunkTask(this.chunkX, this.chunkZ, () -> {
+                    progressListener.onStatusChange(this.vanillaChunkHolder.getPos(), finalStatus);
+                });
+            }
+        }
+
+        // need to tell future statuses to complete if cancelled
+        do {
+            this.completeStatusConsumers0(status, chunk);
+        } while (chunk == null && status != (status = ((ChunkSystemChunkStatus)status).moonrise$getNextStatus()));
+    }
+
+    private void completeStatusConsumers0(final ChunkStatus status, final ChunkAccess chunk) {
+        final List<Consumer<ChunkAccess>> consumers;
+        consumers = this.statusWaiters.remove(status);
+
+        if (consumers == null) {
+            return;
+        }
+
+        // must be scheduled to main, we do not trust the callback to not do anything stupid
+        this.scheduler.scheduleChunkTask(this.chunkX, this.chunkZ, () -> {
+            for (final Consumer<ChunkAccess> consumer : consumers) {
+                try {
+                    consumer.accept(chunk);
+                } catch (final Throwable thr) {
+                    LOGGER.error("Failed to process chunk status callback", thr);
+                }
+            }
+        }, Priority.HIGHEST);
+    }
+
+    private final Reference2ObjectOpenHashMap<FullChunkStatus, List<Consumer<LevelChunk>>> fullStatusWaiters = new Reference2ObjectOpenHashMap<>();
+
+    void addFullStatusConsumer(final FullChunkStatus status, final Consumer<LevelChunk> consumer) {
+        this.fullStatusWaiters.computeIfAbsent(status, (final FullChunkStatus keyInMap) -> {
+            return new ArrayList<>(4);
+        }).add(consumer);
+    }
+
+    private void completeFullStatusConsumers(FullChunkStatus status, final LevelChunk chunk) {
+        final List<Consumer<LevelChunk>> consumers;
+        consumers = this.fullStatusWaiters.remove(status);
+
+        if (consumers == null) {
+            return;
+        }
+
+        // must be scheduled to main, we do not trust the callback to not do anything stupid
+        this.scheduler.scheduleChunkTask(this.chunkX, this.chunkZ, () -> {
+            for (final Consumer<LevelChunk> consumer : consumers) {
+                try {
+                    consumer.accept(chunk);
+                } catch (final Throwable thr) {
+                    LOGGER.error("Failed to process chunk status callback", thr);
+                }
+            }
+        }, Priority.HIGHEST);
+    }
+
+    // note: must hold scheduling lock
+    private void onChunkGenComplete(final ChunkAccess newChunk, final ChunkStatus newStatus,
+                                    final List<ChunkProgressionTask> scheduleList, final List<NewChunkHolder> changedLoadStatus) {
+        if (!this.neighboursBlockingGenTask.isEmpty()) {
+            throw new IllegalStateException("Cannot have neighbours blocking this gen task");
+        }
+        if (newChunk != null || (this.requestedGenStatus == null || !this.requestedGenStatus.isOrAfter(newStatus))) {
+            this.completeStatusConsumers(newStatus, newChunk);
+        }
+        // done now, clear state (must be done before scheduling new tasks)
+        this.generationTask = null;
+        this.generationTaskStatus = null;
+        if (newChunk == null) {
+            // task was cancelled
+            // should be careful as this could be called while holding the schedule lock and/or inside the
+            // ticket level update
+            // while a task may be cancelled, it is possible for it to be later re-scheduled
+            // however, because generationTask is only set to null on _completion_, the scheduler leaves
+            // the rescheduling logic to us here
+            final ChunkStatus requestedGenStatus = this.requestedGenStatus;
+            this.requestedGenStatus = null;
+            if (requestedGenStatus != null) {
+                // it looks like it has been requested, so we must reschedule
+                if (!this.neighboursWaitingForUs.isEmpty()) {
+                    for (final Iterator<Reference2ObjectMap.Entry<NewChunkHolder, ChunkStatus>> iterator = this.neighboursWaitingForUs.reference2ObjectEntrySet().fastIterator(); iterator.hasNext();) {
+                        final Reference2ObjectMap.Entry<NewChunkHolder, ChunkStatus> entry = iterator.next();
+
+                        final NewChunkHolder chunkHolder = entry.getKey();
+                        final ChunkStatus toStatus = entry.getValue();
+
+                        if (!requestedGenStatus.isOrAfter(toStatus)) {
+                            // if we were cancelled, we are responsible for removing the waiter
+                            if (!chunkHolder.neighboursBlockingGenTask.remove(this)) {
+                                throw new IllegalStateException("Corrupt state");
+                            }
+                            if (chunkHolder.neighboursBlockingGenTask.isEmpty()) {
+                                chunkHolder.checkUnload();
+                            }
+                            iterator.remove();
+                            continue;
+                        }
+                    }
+                }
+
+                // note: only after generationTask -> null, generationTaskStatus -> null, and requestedGenStatus -> null
+                this.scheduler.schedule(
+                    this.chunkX, this.chunkZ, requestedGenStatus, this, scheduleList
+                );
+
+                // return, can't do anything further
+                return;
+            }
+
+            if (!this.neighboursWaitingForUs.isEmpty()) {
+                for (final NewChunkHolder chunkHolder : this.neighboursWaitingForUs.keySet()) {
+                    if (!chunkHolder.neighboursBlockingGenTask.remove(this)) {
+                        throw new IllegalStateException("Corrupt state");
+                    }
+                    if (chunkHolder.neighboursBlockingGenTask.isEmpty()) {
+                        chunkHolder.checkUnload();
+                    }
+                }
+                this.neighboursWaitingForUs.clear();
+            }
+            // reset priority, we have nothing left to generate to
+            this.setPriority(null);
+            this.checkUnload();
+            return;
+        }
+
+        this.currentChunk = newChunk;
+        this.currentGenStatus = newStatus;
+        final ChunkCompletion completion = new ChunkCompletion(newChunk, newStatus);
+        CHUNK_COMPLETION_ARRAY_HANDLE.setVolatile(this.chunkCompletions, newStatus.getIndex(), completion);
+        this.lastChunkCompletion = completion;
+
+        final ChunkStatus requestedGenStatus = this.requestedGenStatus;
+
+        List<NewChunkHolder> needsScheduling = null;
+        boolean recalculatePriority = false;
+        for (final Iterator<Reference2ObjectMap.Entry<NewChunkHolder, ChunkStatus>> iterator
+             = this.neighboursWaitingForUs.reference2ObjectEntrySet().fastIterator(); iterator.hasNext();) {
+            final Reference2ObjectMap.Entry<NewChunkHolder, ChunkStatus> entry = iterator.next();
+            final NewChunkHolder neighbour = entry.getKey();
+            final ChunkStatus requiredStatus = entry.getValue();
+
+            if (!newStatus.isOrAfter(requiredStatus)) {
+                if (requestedGenStatus == null || !requestedGenStatus.isOrAfter(requiredStatus)) {
+                    // if we're cancelled, still need to clear this map
+                    if (!neighbour.neighboursBlockingGenTask.remove(this)) {
+                        throw new IllegalStateException("Neighbour is not waiting for us?");
+                    }
+                    if (neighbour.neighboursBlockingGenTask.isEmpty()) {
+                        neighbour.checkUnload();
+                    }
+
+                    iterator.remove();
+                }
+                continue;
+            }
+
+            // doesn't matter what isCancelled is here, we need to schedule if we can
+
+            recalculatePriority = true;
+            if (!neighbour.neighboursBlockingGenTask.remove(this)) {
+                throw new IllegalStateException("Neighbour is not waiting for us?");
+            }
+
+            if (neighbour.neighboursBlockingGenTask.isEmpty()) {
+                if (neighbour.requestedGenStatus != null) {
+                    if (needsScheduling == null) {
+                        needsScheduling = new ArrayList<>();
+                    }
+                    needsScheduling.add(neighbour);
+                } else {
+                    neighbour.checkUnload();
+                }
+            }
+
+            // remove last; access to entry will throw if removed
+            iterator.remove();
+        }
+
+        if (newStatus == ChunkStatus.FULL) {
+            this.lockPriority();
+            // try to push pending to FULL
+            if (this.updatePendingStatus()) {
+                changedLoadStatus.add(this);
+            }
+        }
+
+        if (recalculatePriority) {
+            this.recalculateNeighbourRequestedPriority();
+        }
+
+        if (requestedGenStatus != null && !newStatus.isOrAfter(requestedGenStatus)) {
+            this.scheduleNeighbours(needsScheduling, scheduleList);
+
+            // we need to schedule more tasks now
+            this.scheduler.schedule(
+                this.chunkX, this.chunkZ, requestedGenStatus, this, scheduleList
+            );
+        } else {
+            // we're done now
+            if (requestedGenStatus != null) {
+                this.requestedGenStatus = null;
+            }
+            // reached final stage, so stop scheduling now
+            this.setPriority(null);
+            this.checkUnload();
+
+            this.scheduleNeighbours(needsScheduling, scheduleList);
+        }
+    }
+
+    private void scheduleNeighbours(final List<NewChunkHolder> needsScheduling, final List<ChunkProgressionTask> scheduleList) {
+        if (needsScheduling != null) {
+            for (int i = 0, len = needsScheduling.size(); i < len; ++i) {
+                final NewChunkHolder neighbour = needsScheduling.get(i);
+
+                this.scheduler.schedule(
+                    neighbour.chunkX, neighbour.chunkZ, neighbour.requestedGenStatus, neighbour, scheduleList
+                );
+            }
+        }
+    }
+
+    public void setGenerationTask(final ChunkProgressionTask generationTask, final ChunkStatus taskStatus,
+                                  final List<NewChunkHolder> neighbours) {
+        if (this.generationTask != null || (this.currentGenStatus != null && this.currentGenStatus.isOrAfter(taskStatus))) {
+            throw new IllegalStateException("Currently generating or provided task is trying to generate to a level we are already at!");
+        }
+        if (this.requestedGenStatus == null || !this.requestedGenStatus.isOrAfter(taskStatus)) {
+            throw new IllegalStateException("Cannot schedule generation task when not requested");
+        }
+        this.generationTask = generationTask;
+        this.generationTaskStatus = taskStatus;
+
+        for (int i = 0, len = neighbours.size(); i < len; ++i) {
+            neighbours.get(i).addNeighbourUsingChunk();
+        }
+
+        this.checkUnload();
+
+        generationTask.onComplete((final ChunkAccess access, final Throwable thr) -> {
+            if (generationTask != this.generationTask) {
+                throw new IllegalStateException(
+                    "Cannot complete generation task '" + generationTask + "' because we are waiting on '" + this.generationTask + "' instead!"
+                );
+            }
+            if (thr != null) {
+                if (this.genTaskException != null) {
+                    LOGGER.warn("Ignoring exception for " + this.toString(), thr);
+                    return;
+                }
+                // don't set generation task to null, so that scheduling will not attempt to create another task and it
+                // will automatically block any further scheduling usage of this chunk as it will wait forever for a failed
+                // task to complete
+                this.genTaskException = thr;
+                this.failedGenStatus = taskStatus;
+                this.genTaskFailedThread = Thread.currentThread();
+
+                this.scheduler.unrecoverableChunkSystemFailure(this.chunkX, this.chunkZ, Map.of(
+                    "Generation task", ChunkTaskScheduler.stringIfNull(generationTask),
+                    "Task to status", ChunkTaskScheduler.stringIfNull(taskStatus)
+                ), thr);
+                return;
+            }
+
+            final boolean scheduleTasks;
+            List<ChunkProgressionTask> tasks = ChunkHolderManager.getCurrentTicketUpdateScheduling();
+            if (tasks == null) {
+                scheduleTasks = true;
+                tasks = new ArrayList<>();
+            } else {
+                scheduleTasks = false;
+                // we are currently updating ticket levels, so we already hold the schedule lock
+                // this means we have to leave the ticket level update to handle the scheduling
+            }
+            final List<NewChunkHolder> changedLoadStatus = new ArrayList<>();
+            // theoretically, we could schedule a chunk at the max radius which performs another max radius access. So we need to double the radius.
+            final ReentrantAreaLock.Node schedulingLock = this.scheduler.schedulingLockArea.lock(this.chunkX, this.chunkZ, 2 * ChunkTaskScheduler.getMaxAccessRadius());
+            try {
+                for (int i = 0, len = neighbours.size(); i < len; ++i) {
+                    neighbours.get(i).removeNeighbourUsingChunk();
+                }
+                this.onChunkGenComplete(access, taskStatus, tasks, changedLoadStatus);
+            } finally {
+                this.scheduler.schedulingLockArea.unlock(schedulingLock);
+            }
+            this.scheduler.chunkHolderManager.addChangedStatuses(changedLoadStatus);
+
+            if (scheduleTasks) {
+                // can't hold the lock while scheduling, so we have to build the tasks and then schedule after
+                for (int i = 0, len = tasks.size(); i < len; ++i) {
+                    tasks.get(i).schedule();
+                }
+            }
+        });
+    }
+
+    public PoiChunk getPoiChunk() {
+        return this.poiChunk;
+    }
+
+    public ChunkEntitySlices getEntityChunk() {
+        return this.entityChunk;
+    }
+
+    public long lastAutoSave;
+
+    public static final record SaveStat(boolean savedChunk, boolean savedEntityChunk, boolean savedPoiChunk) {}
+
+    private static final MoonriseRegionFileIO.RegionFileType[] REGION_FILE_TYPES = MoonriseRegionFileIO.RegionFileType.values();
+
+    public SaveStat save(final boolean shutdown) {
+        TickThread.ensureTickThread(this.world, this.chunkX, this.chunkZ, "Cannot save data off-main");
+
+        ChunkAccess chunk = this.getCurrentChunk();
+        PoiChunk poi = this.getPoiChunk();
+        ChunkEntitySlices entities = this.getEntityChunk();
+        boolean executedUnloadTask = false;
+        final boolean[] executedUnloadTasks = new boolean[REGION_FILE_TYPES.length];
+
+        if (shutdown) {
+            // make sure that the async unloads complete
+            if (this.unloadState != null) {
+                // must have errored during unload
+                chunk = this.unloadState.chunk();
+                poi = this.unloadState.poiChunk();
+                entities = this.unloadState.entityChunk();
+            }
+            for (final MoonriseRegionFileIO.RegionFileType regionFileType : REGION_FILE_TYPES) {
+                final UnloadTask unloadTask = this.getUnloadTask(regionFileType);
+                if (unloadTask == null) {
+                    continue;
+                }
+
+                final PrioritisedExecutor.PrioritisedTask task = unloadTask.task();
+                if (task != null && task.isQueued()) {
+                    final boolean executed = task.execute();
+                    executedUnloadTask |= executed;
+                    executedUnloadTasks[regionFileType.ordinal()] = executed;
+                }
+            }
+        }
+
+        final boolean forceNoSaveChunk = PlatformHooks.get().forceNoSave(chunk);
+
+        // can only synchronously save worldgen chunks during shutdown
+        boolean canSaveChunk = !forceNoSaveChunk && (chunk != null && ((shutdown || chunk instanceof LevelChunk) && chunk.isUnsaved()));
+        boolean canSavePOI = !forceNoSaveChunk && (poi != null && poi.isDirty());
+        boolean canSaveEntities = entities != null;
+
+        if (canSaveChunk) {
+            canSaveChunk = this.saveChunk(chunk, false);
+        }
+        if (canSavePOI) {
+            canSavePOI = this.savePOI(poi, false);
+        }
+        if (canSaveEntities) {
+            // on shutdown, we need to force transient entity chunks to save
+            canSaveEntities = this.saveEntities(entities, shutdown);
+            if (shutdown) {
+                this.lastEntityUnload = null;
+            }
+        }
+
+        return executedUnloadTask | canSaveChunk | canSaveEntities | canSavePOI ?
+                new SaveStat(
+                        canSaveChunk | executedUnloadTasks[MoonriseRegionFileIO.RegionFileType.CHUNK_DATA.ordinal()],
+                        canSaveEntities | executedUnloadTasks[MoonriseRegionFileIO.RegionFileType.ENTITY_DATA.ordinal()],
+                        canSavePOI | executedUnloadTasks[MoonriseRegionFileIO.RegionFileType.POI_DATA.ordinal()]
+                )
+                : null;
+    }
+
+    private boolean saveChunk(final ChunkAccess chunk, final boolean unloading) {
+        if (!chunk.isUnsaved()) {
+            if (unloading) {
+                this.completeAsyncUnloadDataSave(MoonriseRegionFileIO.RegionFileType.CHUNK_DATA, null);
+            }
+            return false;
+        }
+        try {
+            final SerializableChunkData chunkData = SerializableChunkData.copyOf(this.world, chunk);
+            PlatformHooks.get().chunkSyncSave(this.world, chunk, chunkData);
+
+            chunk.tryMarkSaved();
+
+            final CallbackCompletable<CompoundTag> completable = new CallbackCompletable<>();
+
+            final Runnable run = () -> {
+                final CompoundTag data = chunkData.write();
+
+                completable.complete(data);
+
+                if (unloading) {
+                    NewChunkHolder.this.completeAsyncUnloadDataSave(MoonriseRegionFileIO.RegionFileType.CHUNK_DATA, data);
+                }
+            };
+
+            final PrioritisedExecutor.PrioritisedTask task;
+            if (unloading) {
+                this.chunkDataUnload.toRun().setRunnable(run);
+                task = this.chunkDataUnload.task();
+            } else {
+                task = this.scheduler.saveExecutor.createTask(run);
+            }
+
+            task.queue();
+
+            MoonriseRegionFileIO.scheduleSave(
+                this.world, this.chunkX, this.chunkZ, completable, task, MoonriseRegionFileIO.RegionFileType.CHUNK_DATA, Priority.NORMAL
+            );
+        } catch (final Throwable thr) {
+            LOGGER.error("Failed to save chunk data (" + this.chunkX + "," + this.chunkZ + ") in world '" + WorldUtil.getWorldName(this.world) + "'", thr);
+        }
+
+        return true;
+    }
+
+    private boolean lastEntitySaveNull;
+    private CompoundTag lastEntityUnload;
+    private boolean saveEntities(final ChunkEntitySlices entities, final boolean unloading) {
+        try {
+            CompoundTag mergeFrom = null;
+            if (entities.isTransient()) {
+                if (!unloading) {
+                    // if we're a transient chunk, we cannot save until unloading because otherwise a double save will
+                    // result in double adding the entities
+                    return false;
+                }
+                try {
+                    mergeFrom = MoonriseRegionFileIO.loadData(this.world, this.chunkX, this.chunkZ, MoonriseRegionFileIO.RegionFileType.ENTITY_DATA, Priority.BLOCKING);
+                } catch (final Exception ex) {
+                    LOGGER.error("Cannot merge transient entities for chunk (" + this.chunkX + "," + this.chunkZ + ") in world '" + WorldUtil.getWorldName(this.world) + "', data on disk will be replaced", ex);
+                }
+            }
+
+            final CompoundTag save = entities.save();
+            if (mergeFrom != null) {
+                if (save == null) {
+                    // don't override the data on disk with nothing
+                    return false;
+                } else {
+                    ChunkEntitySlices.copyEntities(mergeFrom, save);
+                }
+            }
+            if (save == null && this.lastEntitySaveNull) {
+                return false;
+            }
+
+            MoonriseRegionFileIO.scheduleSave(this.world, this.chunkX, this.chunkZ, save, MoonriseRegionFileIO.RegionFileType.ENTITY_DATA);
+            this.lastEntitySaveNull = save == null;
+            if (unloading) {
+                this.lastEntityUnload = save;
+            }
+        } catch (final Throwable thr) {
+            LOGGER.error("Failed to save entity data (" + this.chunkX + "," + this.chunkZ + ") in world '" + WorldUtil.getWorldName(this.world) + "'", thr);
+        }
+
+        return true;
+    }
+
+    private boolean lastPoiSaveNull;
+    private boolean savePOI(final PoiChunk poi, final boolean unloading) {
+        try {
+            final CompoundTag save = poi.save();
+            poi.setDirty(false);
+            if (save == null && this.lastPoiSaveNull) {
+                if (unloading) {
+                    this.poiDataUnload.completable().complete(null);
+                }
+                return false;
+            }
+
+            MoonriseRegionFileIO.scheduleSave(this.world, this.chunkX, this.chunkZ, save, MoonriseRegionFileIO.RegionFileType.POI_DATA);
+            this.lastPoiSaveNull = save == null;
+            if (unloading) {
+                this.poiDataUnload.completable().complete(save);
+            }
+        } catch (final Throwable thr) {
+            LOGGER.error("Failed to save poi data (" + this.chunkX + "," + this.chunkZ + ") in world '" + WorldUtil.getWorldName(this.world) + "'", thr);
+        }
+
+        return true;
+    }
+
+    @Override
+    public String toString() {
+        final ChunkCompletion lastCompletion = this.lastChunkCompletion;
+        final ChunkEntitySlices entityChunk = this.entityChunk;
+        final FullChunkStatus pendingFullStatus = this.pendingFullChunkStatus;
+        final FullChunkStatus currentFullStatus = this.currentFullChunkStatus;
+        return "NewChunkHolder{" +
+            "world=" + WorldUtil.getWorldName(this.world) +
+            ", chunkX=" + this.chunkX +
+            ", chunkZ=" + this.chunkZ +
+            ", entityChunkFromDisk=" + (entityChunk != null && !entityChunk.isTransient()) +
+            ", lastChunkCompletion={chunk_class=" + (lastCompletion == null || lastCompletion.chunk() == null ? "null" : lastCompletion.chunk().getClass().getName()) + ",status=" + (lastCompletion == null ? "null" : lastCompletion.genStatus()) + "}" +
+            ", currentGenStatus=" + this.currentGenStatus +
+            ", requestedGenStatus=" + this.requestedGenStatus +
+            ", generationTask=" + this.generationTask +
+            ", generationTaskStatus=" + this.generationTaskStatus +
+            ", priority=" + this.priority +
+            ", priorityLocked=" + this.priorityLocked +
+            ", neighbourRequestedPriority=" + this.neighbourRequestedPriority +
+            ", effective_priority=" + this.getEffectivePriority(null) +
+            ", oldTicketLevel=" + this.oldTicketLevel +
+            ", currentTicketLevel=" + this.currentTicketLevel +
+            ", totalNeighboursUsingThisChunk=" + this.totalNeighboursUsingThisChunk +
+            ", fullNeighbourChunksLoadedBitset=" + this.fullNeighbourChunksLoadedBitset +
+            ", currentChunkStatus=" + currentFullStatus +
+            ", pendingChunkStatus=" + pendingFullStatus +
+            ", is_unload_safe=" + this.isSafeToUnload() +
+            ", killed=" + this.unloaded +
+            '}';
+    }
+
+    private static JsonElement serializeStacktraceElement(final StackTraceElement element) {
+        return element == null ? JsonNull.INSTANCE : new JsonPrimitive(element.toString());
+    }
+
+    private static JsonObject serializeCompletable(final CallbackCompletable<?> completable) {
+        final JsonObject ret = new JsonObject();
+
+        if (completable == null) {
+            return ret;
+        }
+
+        ret.addProperty("valid", Boolean.TRUE);
+
+        final boolean isCompleted = completable.isCompleted();
+        ret.addProperty("completed", Boolean.valueOf(isCompleted));
+
+        if (isCompleted) {
+            final Throwable throwable = completable.getThrowable();
+            if (throwable != null) {
+                final JsonArray throwableJson = new JsonArray();
+                ret.add("throwable", throwableJson);
+
+                for (final StackTraceElement element : throwable.getStackTrace()) {
+                    throwableJson.add(serializeStacktraceElement(element));
+                }
+            } else {
+                final Object result = completable.getResult();
+                ret.add("result_class", result == null ? JsonNull.INSTANCE : new JsonPrimitive(result.getClass().getName()));
+            }
+        }
+
+        return ret;
+    }
+
+    // (probably) holds ticket and scheduling lock
+    public JsonObject getDebugJson() {
+        final JsonObject ret = new JsonObject();
+
+        final ChunkCompletion lastCompletion = this.lastChunkCompletion;
+        final ChunkEntitySlices slices = this.entityChunk;
+        final PoiChunk poiChunk = this.poiChunk;
+
+        ret.addProperty("chunkX", Integer.valueOf(this.chunkX));
+        ret.addProperty("chunkZ", Integer.valueOf(this.chunkZ));
+        ret.addProperty("entity_chunk", slices == null ? "null" : "transient=" + slices.isTransient());
+        ret.addProperty("poi_chunk", "null=" + (poiChunk == null));
+        ret.addProperty("completed_chunk_class", lastCompletion == null ? "null" : lastCompletion.chunk().getClass().getName());
+        ret.addProperty("completed_gen_status", lastCompletion == null ? "null" : lastCompletion.genStatus().toString());
+        ret.addProperty("priority", Objects.toString(this.priority));
+        ret.addProperty("neighbour_requested_priority", Objects.toString(this.neighbourRequestedPriority));
+        ret.addProperty("generation_task", Objects.toString(this.generationTask));
+        ret.addProperty("is_safe_unload", Objects.toString(this.isSafeToUnload()));
+        ret.addProperty("old_ticket_level", Integer.valueOf(this.oldTicketLevel));
+        ret.addProperty("current_ticket_level", Integer.valueOf(this.currentTicketLevel));
+        ret.addProperty("neighbours_using_chunk", Integer.valueOf(this.totalNeighboursUsingThisChunk));
+
+        final JsonObject neighbourWaitState = new JsonObject();
+        ret.add("neighbour_state", neighbourWaitState);
+
+        final JsonArray blockingGenNeighbours = new JsonArray();
+        neighbourWaitState.add("blocking_gen_task", blockingGenNeighbours);
+        for (final NewChunkHolder blockingGenNeighbour : this.neighboursBlockingGenTask) {
+            final JsonObject neighbour = new JsonObject();
+            blockingGenNeighbours.add(neighbour);
+
+            neighbour.addProperty("chunkX", Integer.valueOf(blockingGenNeighbour.chunkX));
+            neighbour.addProperty("chunkZ", Integer.valueOf(blockingGenNeighbour.chunkZ));
+        }
+
+        final JsonArray neighboursWaitingForUs = new JsonArray();
+        neighbourWaitState.add("neighbours_waiting_on_us", neighboursWaitingForUs);
+        for (final Reference2ObjectMap.Entry<NewChunkHolder, ChunkStatus> entry : this.neighboursWaitingForUs.reference2ObjectEntrySet()) {
+            final NewChunkHolder holder = entry.getKey();
+            final ChunkStatus status = entry.getValue();
+
+            final JsonObject neighbour = new JsonObject();
+            neighboursWaitingForUs.add(neighbour);
+
+
+            neighbour.addProperty("chunkX", Integer.valueOf(holder.chunkX));
+            neighbour.addProperty("chunkZ", Integer.valueOf(holder.chunkZ));
+            neighbour.addProperty("waiting_for", Objects.toString(status));
+        }
+
+        ret.addProperty("pending_chunk_full_status", Objects.toString(this.pendingFullChunkStatus));
+        ret.addProperty("current_chunk_full_status", Objects.toString(this.currentFullChunkStatus));
+        ret.addProperty("generation_task", Objects.toString(this.generationTask));
+        ret.addProperty("requested_generation", Objects.toString(this.requestedGenStatus));
+        ret.addProperty("has_entity_load_task", Boolean.valueOf(this.entityDataLoadTask != null));
+        ret.addProperty("has_poi_load_task", Boolean.valueOf(this.poiDataLoadTask != null));
+
+        final UnloadTask entityDataUnload = this.entityDataUnload;
+        final UnloadTask poiDataUnload = this.poiDataUnload;
+        final UnloadTask chunkDataUnload = this.chunkDataUnload;
+
+        ret.add("entity_unload_completable", serializeCompletable(entityDataUnload == null ? null : entityDataUnload.completable()));
+        ret.add("poi_unload_completable", serializeCompletable(poiDataUnload == null ? null : poiDataUnload.completable()));
+        ret.add("chunk_unload_completable", serializeCompletable(chunkDataUnload == null ? null : chunkDataUnload.completable()));
+
+        final PrioritisedExecutor.PrioritisedTask unloadTask = chunkDataUnload == null ? null : chunkDataUnload.task();
+        if (unloadTask == null) {
+            ret.addProperty("unload_task_priority", "null");
+            ret.addProperty("unload_task_suborder", Long.valueOf(0L));
+        } else {
+            ret.addProperty("unload_task_priority", Objects.toString(unloadTask.getPriority()));
+            ret.addProperty("unload_task_suborder", Long.valueOf(unloadTask.getSubOrder()));
+        }
+
+        ret.addProperty("killed", Boolean.valueOf(this.unloaded));
+
+        return ret;
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/PriorityHolder.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/PriorityHolder.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/PriorityHolder.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.scheduling;
+
+import ca.spottedleaf.concurrentutil.util.ConcurrentUtil;
+import ca.spottedleaf.concurrentutil.util.Priority;
+import java.lang.invoke.VarHandle;
+
+public abstract class PriorityHolder {
+
+    protected volatile int priority;
+    protected static final VarHandle PRIORITY_HANDLE = ConcurrentUtil.getVarHandle(PriorityHolder.class, "priority", int.class);
+
+    protected static final int PRIORITY_SCHEDULED = Integer.MIN_VALUE >>> 0;
+    protected static final int PRIORITY_EXECUTED  = Integer.MIN_VALUE >>> 1;
+
+    protected final int getPriorityVolatile() {
+        return (int)PRIORITY_HANDLE.getVolatile((PriorityHolder)this);
+    }
+
+    protected final int compareAndExchangePriorityVolatile(final int expect, final int update) {
+        return (int)PRIORITY_HANDLE.compareAndExchange((PriorityHolder)this, (int)expect, (int)update);
+    }
+
+    protected final int getAndOrPriorityVolatile(final int val) {
+        return (int)PRIORITY_HANDLE.getAndBitwiseOr((PriorityHolder)this, (int)val);
+    }
+
+    protected final void setPriorityPlain(final int val) {
+        PRIORITY_HANDLE.set((PriorityHolder)this, (int)val);
+    }
+
+    protected PriorityHolder(final Priority priority) {
+        if (!Priority.isValidPriority(priority)) {
+            throw new IllegalArgumentException("Invalid priority " + priority);
+        }
+        this.setPriorityPlain(priority.priority);
+    }
+
+    // used only for debug json
+    public boolean isScheduled() {
+        return (this.getPriorityVolatile() & PRIORITY_SCHEDULED) != 0;
+    }
+
+    // returns false if cancelled
+    public boolean markExecuting() {
+        return (this.getAndOrPriorityVolatile(PRIORITY_EXECUTED) & PRIORITY_EXECUTED) == 0;
+    }
+
+    public boolean isMarkedExecuted() {
+        return (this.getPriorityVolatile() & PRIORITY_EXECUTED) != 0;
+    }
+
+    public void cancel() {
+        if ((this.getAndOrPriorityVolatile(PRIORITY_EXECUTED) & PRIORITY_EXECUTED) != 0) {
+            // cancelled already
+            return;
+        }
+        this.cancelScheduled();
+    }
+
+    public void schedule() {
+        int priority = this.getPriorityVolatile();
+
+        if ((priority & PRIORITY_SCHEDULED) != 0) {
+            throw new IllegalStateException("schedule() called twice");
+        }
+
+        if ((priority & PRIORITY_EXECUTED) != 0) {
+            // cancelled
+            return;
+        }
+
+        this.scheduleTask(Priority.getPriority(priority));
+
+        int failures = 0;
+        for (;;) {
+            if (priority == (priority = this.compareAndExchangePriorityVolatile(priority, priority | PRIORITY_SCHEDULED))) {
+                return;
+            }
+
+            if ((priority & PRIORITY_SCHEDULED) != 0) {
+                throw new IllegalStateException("schedule() called twice");
+            }
+
+            if ((priority & PRIORITY_EXECUTED) != 0) {
+                // cancelled or executed
+                return;
+            }
+
+            this.setPriorityScheduled(Priority.getPriority(priority));
+
+            ++failures;
+            for (int i = 0; i < failures; ++i) {
+                ConcurrentUtil.backoff();
+            }
+        }
+    }
+
+    public final Priority getPriority() {
+        final int ret = this.getPriorityVolatile();
+        if ((ret & PRIORITY_EXECUTED) != 0) {
+            return Priority.COMPLETING;
+        }
+        if ((ret & PRIORITY_SCHEDULED) != 0) {
+            return this.getScheduledPriority();
+        }
+        return Priority.getPriority(ret);
+    }
+
+    public final void lowerPriority(final Priority priority) {
+        if (!Priority.isValidPriority(priority)) {
+            throw new IllegalArgumentException("Invalid priority " + priority);
+        }
+
+        int failures = 0;
+        for (int curr = this.getPriorityVolatile();;) {
+            if ((curr & PRIORITY_EXECUTED) != 0) {
+                return;
+            }
+
+            if ((curr & PRIORITY_SCHEDULED) != 0) {
+                this.lowerPriorityScheduled(priority);
+                return;
+            }
+
+            if (!priority.isLowerPriority(curr)) {
+                return;
+            }
+
+            if (curr == (curr = this.compareAndExchangePriorityVolatile(curr, priority.priority))) {
+                return;
+            }
+
+            // failed, retry
+
+            ++failures;
+            for (int i = 0; i < failures; ++i) {
+                ConcurrentUtil.backoff();
+            }
+        }
+    }
+
+    public final void setPriority(final Priority priority) {
+        if (!Priority.isValidPriority(priority)) {
+            throw new IllegalArgumentException("Invalid priority " + priority);
+        }
+
+        int failures = 0;
+        for (int curr = this.getPriorityVolatile();;) {
+            if ((curr & PRIORITY_EXECUTED) != 0) {
+                return;
+            }
+
+            if ((curr & PRIORITY_SCHEDULED) != 0) {
+                this.setPriorityScheduled(priority);
+                return;
+            }
+
+            if (curr == (curr = this.compareAndExchangePriorityVolatile(curr, priority.priority))) {
+                return;
+            }
+
+            // failed, retry
+
+            ++failures;
+            for (int i = 0; i < failures; ++i) {
+                ConcurrentUtil.backoff();
+            }
+        }
+    }
+
+    public final void raisePriority(final Priority priority) {
+        if (!Priority.isValidPriority(priority)) {
+            throw new IllegalArgumentException("Invalid priority " + priority);
+        }
+
+        int failures = 0;
+        for (int curr = this.getPriorityVolatile();;) {
+            if ((curr & PRIORITY_EXECUTED) != 0) {
+                return;
+            }
+
+            if ((curr & PRIORITY_SCHEDULED) != 0) {
+                this.raisePriorityScheduled(priority);
+                return;
+            }
+
+            if (!priority.isHigherPriority(curr)) {
+                return;
+            }
+
+            if (curr == (curr = this.compareAndExchangePriorityVolatile(curr, priority.priority))) {
+                return;
+            }
+
+            // failed, retry
+
+            ++failures;
+            for (int i = 0; i < failures; ++i) {
+                ConcurrentUtil.backoff();
+            }
+        }
+    }
+
+    protected abstract void cancelScheduled();
+
+    protected abstract Priority getScheduledPriority();
+
+    protected abstract void scheduleTask(final Priority priority);
+
+    protected abstract void lowerPriorityScheduled(final Priority priority);
+
+    protected abstract void setPriorityScheduled(final Priority priority);
+
+    protected abstract void raisePriorityScheduled(final Priority priority);
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/ThreadedTicketLevelPropagator.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/ThreadedTicketLevelPropagator.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/ThreadedTicketLevelPropagator.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.scheduling;
+
+import ca.spottedleaf.concurrentutil.collection.MultiThreadedQueue;
+import ca.spottedleaf.concurrentutil.lock.ReentrantAreaLock;
+import ca.spottedleaf.concurrentutil.map.ConcurrentLong2ReferenceChainedHashTable;
+import ca.spottedleaf.concurrentutil.util.ConcurrentUtil;
+import ca.spottedleaf.moonrise.common.util.CoordinateUtils;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task.ChunkProgressionTask;
+import it.unimi.dsi.fastutil.longs.Long2ByteLinkedOpenHashMap;
+import it.unimi.dsi.fastutil.shorts.Short2ByteLinkedOpenHashMap;
+import it.unimi.dsi.fastutil.shorts.Short2ByteMap;
+import it.unimi.dsi.fastutil.shorts.ShortOpenHashSet;
+import java.lang.invoke.VarHandle;
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+import java.util.concurrent.locks.LockSupport;
+
+public abstract class ThreadedTicketLevelPropagator {
+
+    // sections are 64 in length
+    public static final int SECTION_SHIFT = 6;
+    public static final int SECTION_SIZE = 1 << SECTION_SHIFT;
+    private static final int LEVEL_BITS = SECTION_SHIFT;
+    private static final int LEVEL_COUNT = 1 << LEVEL_BITS;
+    private static final int MIN_SOURCE_LEVEL = 1;
+    // we limit the max source to 62 because the de-propagation code _must_ attempt to de-propagate
+    // a 1 level to 0; and if a source was 63 then it may cross more than 2 sections in de-propagation
+    private static final int MAX_SOURCE_LEVEL = 62;
+
+    private static int getMaxSchedulingRadius() {
+        return 2 * ChunkTaskScheduler.getMaxAccessRadius();
+    }
+
+    private final UpdateQueue updateQueue;
+    private final ConcurrentLong2ReferenceChainedHashTable<Section> sections;
+
+    public ThreadedTicketLevelPropagator() {
+        this.updateQueue = new UpdateQueue();
+        this.sections = new ConcurrentLong2ReferenceChainedHashTable<>();
+    }
+
+    // must hold ticket lock for:
+    // (posX & ~(SECTION_SIZE - 1), posZ & ~(SECTION_SIZE - 1)) to (posX | (SECTION_SIZE - 1), posZ | (SECTION_SIZE - 1))
+    public void setSource(final int posX, final int posZ, final int to) {
+        if (to < 1 || to > MAX_SOURCE_LEVEL) {
+            throw new IllegalArgumentException("Source: " + to);
+        }
+
+        final int sectionX = posX >> SECTION_SHIFT;
+        final int sectionZ = posZ >> SECTION_SHIFT;
+
+        final long coordinate = CoordinateUtils.getChunkKey(sectionX, sectionZ);
+        Section section = this.sections.get(coordinate);
+        if (section == null) {
+            if (null != this.sections.putIfAbsent(coordinate, section = new Section(sectionX, sectionZ))) {
+                throw new IllegalStateException("Race condition while creating new section");
+            }
+        }
+
+        final int localIdx = (posX & (SECTION_SIZE - 1)) | ((posZ & (SECTION_SIZE - 1)) << SECTION_SHIFT);
+        final short sLocalIdx = (short)localIdx;
+
+        final short sourceAndLevel = section.levels[localIdx];
+        final int currentSource = (sourceAndLevel >>> 8) & 0xFF;
+
+        if (currentSource == to) {
+            // nothing to do
+            // make sure to kill the current update, if any
+            section.queuedSources.replace(sLocalIdx, (byte)to);
+            return;
+        }
+
+        if (section.queuedSources.put(sLocalIdx, (byte)to) == Section.NO_QUEUED_UPDATE && section.queuedSources.size() == 1) {
+            this.queueSectionUpdate(section);
+        }
+    }
+
+    // must hold ticket lock for:
+    // (posX & ~(SECTION_SIZE - 1), posZ & ~(SECTION_SIZE - 1)) to (posX | (SECTION_SIZE - 1), posZ | (SECTION_SIZE - 1))
+    public void removeSource(final int posX, final int posZ) {
+        final int sectionX = posX >> SECTION_SHIFT;
+        final int sectionZ = posZ >> SECTION_SHIFT;
+
+        final long coordinate = CoordinateUtils.getChunkKey(sectionX, sectionZ);
+        final Section section = this.sections.get(coordinate);
+
+        if (section == null) {
+            return;
+        }
+
+        final int localIdx = (posX & (SECTION_SIZE - 1)) | ((posZ & (SECTION_SIZE - 1)) << SECTION_SHIFT);
+        final short sLocalIdx = (short)localIdx;
+
+        final int currentSource = (section.levels[localIdx] >>> 8) & 0xFF;
+
+        if (currentSource == 0) {
+            // we use replace here so that we do not possibly multi-queue a section for an update
+            section.queuedSources.replace(sLocalIdx, (byte)0);
+            return;
+        }
+
+        if (section.queuedSources.put(sLocalIdx, (byte)0) == Section.NO_QUEUED_UPDATE && section.queuedSources.size() == 1) {
+            this.queueSectionUpdate(section);
+        }
+    }
+
+    private void queueSectionUpdate(final Section section) {
+        this.updateQueue.append(new UpdateQueue.UpdateQueueNode(section, null));
+    }
+
+    public boolean hasPendingUpdates() {
+        return !this.updateQueue.isEmpty();
+    }
+
+    // holds ticket lock for every chunk section represented by any position in the key set
+    // updates is modifiable and passed to processSchedulingUpdates after this call
+    protected abstract void processLevelUpdates(final Long2ByteLinkedOpenHashMap updates);
+
+    // holds ticket lock for every chunk section represented by any position in the key set
+    // holds scheduling lock in max access radius for every position held by the ticket lock
+    // updates is cleared after this call
+    protected abstract void processSchedulingUpdates(final Long2ByteLinkedOpenHashMap updates, final List<ChunkProgressionTask> scheduledTasks,
+                                                     final List<NewChunkHolder> changedFullStatus);
+
+    // must hold ticket lock for every position in the sections in one radius around sectionX,sectionZ
+    public boolean performUpdate(final int sectionX, final int sectionZ, final ReentrantAreaLock schedulingLock,
+                                 final List<ChunkProgressionTask> scheduledTasks, final List<NewChunkHolder> changedFullStatus) {
+        if (!this.hasPendingUpdates()) {
+            return false;
+        }
+
+        final long coordinate = CoordinateUtils.getChunkKey(sectionX, sectionZ);
+        final Section section = this.sections.get(coordinate);
+
+        if (section == null || section.queuedSources.isEmpty()) {
+            // no section or no updates
+            return false;
+        }
+
+        final Propagator propagator = Propagator.acquirePropagator();
+        final boolean ret = this.performUpdate(section, null, propagator,
+            null, schedulingLock, scheduledTasks, changedFullStatus
+        );
+        Propagator.returnPropagator(propagator);
+        return ret;
+    }
+
+    private boolean performUpdate(final Section section, final UpdateQueue.UpdateQueueNode node, final Propagator propagator,
+                                  final ReentrantAreaLock ticketLock, final ReentrantAreaLock schedulingLock,
+                                  final List<ChunkProgressionTask> scheduledTasks, final List<NewChunkHolder> changedFullStatus) {
+        final int sectionX = section.sectionX;
+        final int sectionZ = section.sectionZ;
+
+        final int rad1MinX = (sectionX - 1) << SECTION_SHIFT;
+        final int rad1MinZ = (sectionZ - 1) << SECTION_SHIFT;
+        final int rad1MaxX = ((sectionX + 1) << SECTION_SHIFT) | (SECTION_SIZE - 1);
+        final int rad1MaxZ = ((sectionZ + 1) << SECTION_SHIFT) | (SECTION_SIZE - 1);
+
+        // set up encode offset first as we need to queue level changes _before_
+        propagator.setupEncodeOffset(sectionX, sectionZ);
+
+        final int coordinateOffset = propagator.coordinateOffset;
+
+        final ReentrantAreaLock.Node ticketNode = ticketLock == null ? null : ticketLock.lock(rad1MinX, rad1MinZ, rad1MaxX, rad1MaxZ);
+        final boolean ret;
+        try {
+            // first, check if this update was stolen
+            if (section != this.sections.get(CoordinateUtils.getChunkKey(sectionX, sectionZ))) {
+                // occurs when a stolen update deletes this section
+                // it is possible that another update is scheduled, but that one will have the correct section
+                if (node != null) {
+                    this.updateQueue.remove(node);
+                }
+                return false;
+            }
+
+            final int oldSourceSize = section.sources.size();
+
+            // process pending sources
+            for (final Iterator<Short2ByteMap.Entry> iterator = section.queuedSources.short2ByteEntrySet().fastIterator(); iterator.hasNext();) {
+                final Short2ByteMap.Entry entry = iterator.next();
+                final int pos = (int)entry.getShortKey();
+                final int posX = (pos & (SECTION_SIZE - 1)) | (sectionX << SECTION_SHIFT);
+                final int posZ = ((pos >> SECTION_SHIFT) & (SECTION_SIZE - 1)) | (sectionZ << SECTION_SHIFT);
+                final int newSource = (int)entry.getByteValue();
+
+                final short currentEncoded = section.levels[pos];
+                final int currLevel = currentEncoded & 0xFF;
+                final int prevSource = (currentEncoded >>> 8) & 0xFF;
+
+                if (prevSource == newSource) {
+                    // nothing changed
+                    continue;
+                }
+
+                if ((prevSource < currLevel && newSource <= currLevel) || newSource == currLevel) {
+                    // just update the source, don't need to propagate change
+                    section.levels[pos] = (short)(currLevel | (newSource << 8));
+                    // level is unchanged, don't add to changed positions
+                } else {
+                    // set current level and current source to new source
+                    section.levels[pos] = (short)(newSource | (newSource << 8));
+                    // must add to updated positions in case this is final
+                    propagator.updatedPositions.put(CoordinateUtils.getChunkKey(posX, posZ), (byte)newSource);
+                    if (newSource != 0) {
+                        // queue increase with new source level
+                        propagator.appendToIncreaseQueue(
+                            ((long)(posX + (posZ << Propagator.COORDINATE_BITS) + coordinateOffset) & ((1L << (Propagator.COORDINATE_BITS + Propagator.COORDINATE_BITS)) - 1)) |
+                                ((newSource & (LEVEL_COUNT - 1L)) << (Propagator.COORDINATE_BITS + Propagator.COORDINATE_BITS)) |
+                                (Propagator.ALL_DIRECTIONS_BITSET << (Propagator.COORDINATE_BITS + Propagator.COORDINATE_BITS + LEVEL_BITS))
+                        );
+                    }
+                    // queue decrease with previous level
+                    if (newSource < currLevel) {
+                        propagator.appendToDecreaseQueue(
+                            ((long)(posX + (posZ << Propagator.COORDINATE_BITS) + coordinateOffset) & ((1L << (Propagator.COORDINATE_BITS + Propagator.COORDINATE_BITS)) - 1)) |
+                                ((currLevel & (LEVEL_COUNT - 1L)) << (Propagator.COORDINATE_BITS + Propagator.COORDINATE_BITS)) |
+                                (Propagator.ALL_DIRECTIONS_BITSET << (Propagator.COORDINATE_BITS + Propagator.COORDINATE_BITS + LEVEL_BITS))
+                        );
+                    }
+                }
+
+                if (newSource == 0) {
+                    // prevSource != newSource, so we are removing this source
+                    section.sources.remove((short)pos);
+                } else if (prevSource == 0) {
+                    // prevSource != newSource, so we are adding this source
+                    section.sources.add((short)pos);
+                }
+            }
+
+            section.queuedSources.clear();
+
+            final int newSourceSize = section.sources.size();
+
+            if (oldSourceSize == 0 && newSourceSize != 0) {
+                // need to make sure the sections in 1 radius are initialised
+                for (int dz = -1; dz <= 1; ++dz) {
+                    for (int dx = -1; dx <= 1; ++dx) {
+                        if ((dx | dz) == 0) {
+                            continue;
+                        }
+                        final int offX = dx + sectionX;
+                        final int offZ = dz + sectionZ;
+                        final long coordinate = CoordinateUtils.getChunkKey(offX, offZ);
+                        final Section neighbour = this.sections.computeIfAbsent(coordinate, (final long keyInMap) -> {
+                            return new Section(CoordinateUtils.getChunkX(keyInMap), CoordinateUtils.getChunkZ(keyInMap));
+                        });
+
+                        // increase ref count
+                        ++neighbour.oneRadNeighboursWithSources;
+                        if (neighbour.oneRadNeighboursWithSources <= 0 || neighbour.oneRadNeighboursWithSources > 8) {
+                            throw new IllegalStateException(Integer.toString(neighbour.oneRadNeighboursWithSources));
+                        }
+                    }
+                }
+            }
+
+            if (propagator.hasUpdates()) {
+                propagator.setupCaches(this, sectionX, sectionZ, 1);
+                propagator.performDecrease();
+                // don't need try-finally, as any exception will cause the propagator to not be returned
+                propagator.destroyCaches();
+            }
+
+            if (newSourceSize == 0) {
+                final boolean decrementRef = oldSourceSize != 0;
+                // check for section de-init
+                for (int dz = -1; dz <= 1; ++dz) {
+                    for (int dx = -1; dx <= 1; ++dx) {
+                        final int offX = dx + sectionX;
+                        final int offZ = dz + sectionZ;
+                        final long coordinate = CoordinateUtils.getChunkKey(offX, offZ);
+                        final Section neighbour = this.sections.get(coordinate);
+
+                        if (neighbour == null) {
+                            if (oldSourceSize == 0 && (dx | dz) != 0) {
+                                // since we don't have sources, this section is allowed to be null
+                                continue;
+                            }
+                            throw new IllegalStateException("??");
+                        }
+
+                        if (decrementRef && (dx | dz) != 0) {
+                            // decrease ref count, but only for neighbours
+                            --neighbour.oneRadNeighboursWithSources;
+                        }
+
+                        // we need to check the current section for de-init as well
+                        if (neighbour.oneRadNeighboursWithSources == 0) {
+                            if (neighbour.queuedSources.isEmpty() && neighbour.sources.isEmpty()) {
+                                // need to de-init
+                                this.sections.remove(coordinate);
+                            } // else: neighbour is queued for an update, and it will de-init itself
+                        } else if (neighbour.oneRadNeighboursWithSources < 0 || neighbour.oneRadNeighboursWithSources > 8) {
+                            throw new IllegalStateException(Integer.toString(neighbour.oneRadNeighboursWithSources));
+                        }
+                    }
+                }
+            }
+
+
+            ret = !propagator.updatedPositions.isEmpty();
+
+            if (ret) {
+                this.processLevelUpdates(propagator.updatedPositions);
+
+                if (!propagator.updatedPositions.isEmpty()) {
+                    // now we can actually update the ticket levels in the chunk holders
+                    final int maxScheduleRadius = getMaxSchedulingRadius();
+
+                    // allow the chunkholders to process ticket level updates without needing to acquire the schedule lock every time
+                    final ReentrantAreaLock.Node schedulingNode = schedulingLock.lock(
+                        rad1MinX - maxScheduleRadius, rad1MinZ - maxScheduleRadius,
+                        rad1MaxX + maxScheduleRadius, rad1MaxZ + maxScheduleRadius
+                    );
+                    try {
+                        this.processSchedulingUpdates(propagator.updatedPositions, scheduledTasks, changedFullStatus);
+                    } finally {
+                        schedulingLock.unlock(schedulingNode);
+                    }
+                }
+
+                propagator.updatedPositions.clear();
+            }
+        } finally {
+            if (ticketLock != null) {
+                ticketLock.unlock(ticketNode);
+            }
+        }
+
+        // finished
+        if (node != null) {
+            this.updateQueue.remove(node);
+        }
+
+        return ret;
+    }
+
+    public boolean performUpdates(final ReentrantAreaLock ticketLock, final ReentrantAreaLock schedulingLock,
+                                  final List<ChunkProgressionTask> scheduledTasks, final List<NewChunkHolder> changedFullStatus) {
+        if (this.updateQueue.isEmpty()) {
+            return false;
+        }
+
+        final long maxOrder = this.updateQueue.getLastOrder();
+
+        boolean updated = false;
+        Propagator propagator = null;
+
+        for (;;) {
+            final UpdateQueue.UpdateQueueNode toUpdate = this.updateQueue.acquireNextOrWait(maxOrder);
+            if (toUpdate == null) {
+                if (!this.updateQueue.hasRemainingUpdates(maxOrder)) {
+                    if (propagator != null) {
+                        Propagator.returnPropagator(propagator);
+                    }
+                    return updated;
+                }
+
+                continue;
+            }
+
+            if (propagator == null) {
+                propagator = Propagator.acquirePropagator();
+            }
+
+            updated |= this.performUpdate(toUpdate.section, toUpdate, propagator, ticketLock, schedulingLock, scheduledTasks, changedFullStatus);
+        }
+    }
+
+    // Similar implementation of concurrent FIFO queue (See MTQ in ConcurrentUtil) which has an additional node pointer
+    // for the last update node being handled
+    private static final class UpdateQueue {
+
+        private volatile UpdateQueueNode head;
+        private volatile UpdateQueueNode tail;
+
+        private static final VarHandle HEAD_HANDLE = ConcurrentUtil.getVarHandle(UpdateQueue.class, "head", UpdateQueueNode.class);
+        private static final VarHandle TAIL_HANDLE = ConcurrentUtil.getVarHandle(UpdateQueue.class, "tail", UpdateQueueNode.class);
+
+        /* head */
+
+        private final void setHeadPlain(final UpdateQueueNode newHead) {
+            HEAD_HANDLE.set(this, newHead);
+        }
+
+        private final void setHeadOpaque(final UpdateQueueNode newHead) {
+            HEAD_HANDLE.setOpaque(this, newHead);
+        }
+
+        private final UpdateQueueNode getHeadPlain() {
+            return (UpdateQueueNode)HEAD_HANDLE.get(this);
+        }
+
+        private final UpdateQueueNode getHeadOpaque() {
+            return (UpdateQueueNode)HEAD_HANDLE.getOpaque(this);
+        }
+
+        private final UpdateQueueNode getHeadAcquire() {
+            return (UpdateQueueNode)HEAD_HANDLE.getAcquire(this);
+        }
+
+        /* tail */
+
+        private final void setTailPlain(final UpdateQueueNode newTail) {
+            TAIL_HANDLE.set(this, newTail);
+        }
+
+        private final void setTailOpaque(final UpdateQueueNode newTail) {
+            TAIL_HANDLE.setOpaque(this, newTail);
+        }
+
+        private final UpdateQueueNode getTailPlain() {
+            return (UpdateQueueNode)TAIL_HANDLE.get(this);
+        }
+
+        private final UpdateQueueNode getTailOpaque() {
+            return (UpdateQueueNode)TAIL_HANDLE.getOpaque(this);
+        }
+
+        public UpdateQueue() {
+            final UpdateQueueNode dummy = new UpdateQueueNode(null, null);
+            dummy.order = -1L;
+            dummy.preventAdds();
+
+            this.setHeadPlain(dummy);
+            this.setTailPlain(dummy);
+        }
+
+        public boolean isEmpty() {
+            return this.peek() == null;
+        }
+
+        public boolean hasRemainingUpdates(final long maxUpdate) {
+            final UpdateQueueNode node = this.peek();
+            return node != null && node.order <= maxUpdate;
+        }
+
+        public long getLastOrder() {
+            for (UpdateQueueNode tail = this.getTailOpaque(), curr = tail;;) {
+                final UpdateQueueNode next = curr.getNextVolatile();
+                if (next == null) {
+                    // try to update stale tail
+                    if (this.getTailOpaque() == tail && curr != tail) {
+                        this.setTailOpaque(curr);
+                    }
+                    return curr.order;
+                }
+                curr = next;
+            }
+        }
+
+        private static void await(final UpdateQueueNode node) {
+            final Thread currThread = Thread.currentThread();
+            // we do not use add-blocking because we use the nullability of the section to block
+            // remove() does not begin to poll from the wait queue until the section is null'd,
+            // and so provided we check the nullability before parking there is no ordering of these operations
+            // such that remove() finishes polling from the wait queue while section is not null
+            node.add(currThread);
+
+            // wait until completed
+            while (node.getSectionVolatile() != null) {
+                LockSupport.park();
+            }
+        }
+
+        public UpdateQueueNode acquireNextOrWait(final long maxOrder) {
+            final List<UpdateQueueNode> blocking = new ArrayList<>();
+
+            node_search:
+            for (UpdateQueueNode curr = this.peek(); curr != null && curr.order <= maxOrder; curr = curr.getNextVolatile()) {
+                if (curr.getSectionVolatile() == null) {
+                    continue;
+                }
+
+                if (curr.getUpdatingVolatile()) {
+                    blocking.add(curr);
+                    continue;
+                }
+
+                for (int i = 0, len = blocking.size(); i < len; ++i) {
+                    final UpdateQueueNode node = blocking.get(i);
+
+                    if (node.intersects(curr)) {
+                        continue node_search;
+                    }
+                }
+
+                if (curr.getAndSetUpdatingVolatile(true)) {
+                    blocking.add(curr);
+                    continue;
+                }
+
+                return curr;
+            }
+
+            if (!blocking.isEmpty()) {
+                await(blocking.get(0));
+            }
+
+            return null;
+        }
+
+        public UpdateQueueNode peek() {
+            for (UpdateQueueNode head = this.getHeadOpaque(), curr = head;;) {
+                final UpdateQueueNode next = curr.getNextVolatile();
+                final Section element = curr.getSectionVolatile(); /* Likely in sync */
+
+                if (element != null) {
+                    if (this.getHeadOpaque() == head && curr != head) {
+                        this.setHeadOpaque(curr);
+                    }
+                    return curr;
+                }
+
+                if (next == null) {
+                    if (this.getHeadOpaque() == head && curr != head) {
+                        this.setHeadOpaque(curr);
+                    }
+                    return null;
+                }
+                curr = next;
+            }
+        }
+
+        public void remove(final UpdateQueueNode node) {
+            // mark as removed
+            node.setSectionVolatile(null);
+
+            // use peek to advance head
+            this.peek();
+
+            // unpark any waiters / block the wait queue
+            Thread unpark;
+            while ((unpark = node.poll()) != null) {
+                LockSupport.unpark(unpark);
+            }
+        }
+
+        public void append(final UpdateQueueNode node) {
+            int failures = 0;
+
+            for (UpdateQueueNode currTail = this.getTailOpaque(), curr = currTail;;) {
+                /* It has been experimentally shown that placing the read before the backoff results in significantly greater performance */
+                /* It is likely due to a cache miss caused by another write to the next field */
+                final UpdateQueueNode next = curr.getNextVolatile();
+
+                for (int i = 0; i < failures; ++i) {
+                    ConcurrentUtil.backoff();
+                }
+
+                if (next == null) {
+                    node.order = curr.order + 1L;
+                    final UpdateQueueNode compared = curr.compareExchangeNextVolatile(null, node);
+
+                    if (compared == null) {
+                        /* Added */
+                        /* Avoid CASing on tail more than we need to */
+                        /* CAS to avoid setting an out-of-date tail */
+                        if (this.getTailOpaque() == currTail) {
+                            this.setTailOpaque(node);
+                        }
+                        return;
+                    }
+
+                    ++failures;
+                    curr = compared;
+                    continue;
+                }
+
+                if (curr == currTail) {
+                    /* Tail is likely not up-to-date */
+                    curr = next;
+                } else {
+                    /* Try to update to tail */
+                    if (currTail == (currTail = this.getTailOpaque())) {
+                        curr = next;
+                    } else {
+                        curr = currTail;
+                    }
+                }
+            }
+        }
+
+        // each node also represents a set of waiters, represented by the MTQ
+        // if the queue is add-blocked, then the update is complete
+        private static final class UpdateQueueNode extends MultiThreadedQueue<Thread> {
+            private final int sectionX;
+            private final int sectionZ;
+
+            private long order;
+            private volatile Section section;
+            private volatile UpdateQueueNode next;
+            private volatile boolean updating;
+
+            private static final VarHandle SECTION_HANDLE = ConcurrentUtil.getVarHandle(UpdateQueueNode.class, "section", Section.class);
+            private static final VarHandle NEXT_HANDLE = ConcurrentUtil.getVarHandle(UpdateQueueNode.class, "next", UpdateQueueNode.class);
+            private static final VarHandle UPDATING_HANDLE = ConcurrentUtil.getVarHandle(UpdateQueueNode.class, "updating", boolean.class);
+
+            public UpdateQueueNode(final Section section, final UpdateQueueNode next) {
+                if (section == null) {
+                    this.sectionX = this.sectionZ = 0;
+                } else {
+                    this.sectionX = section.sectionX;
+                    this.sectionZ = section.sectionZ;
+                }
+
+                SECTION_HANDLE.set(this, section);
+                NEXT_HANDLE.set(this, next);
+            }
+
+            public boolean intersects(final UpdateQueueNode other) {
+                final int dist = Math.max(Math.abs(this.sectionX - other.sectionX), Math.abs(this.sectionZ - other.sectionZ));
+
+                // intersection radius is ticket update radius (1) + scheduling radius
+                return dist <= (1 + ((getMaxSchedulingRadius() + (SECTION_SIZE - 1)) >> SECTION_SHIFT));
+            }
+
+            /* section */
+
+            private final Section getSectionPlain() {
+                return (Section)SECTION_HANDLE.get(this);
+            }
+
+            private final Section getSectionVolatile() {
+                return (Section)SECTION_HANDLE.getVolatile(this);
+            }
+
+            private final void setSectionPlain(final Section update) {
+                SECTION_HANDLE.set(this, update);
+            }
+
+            private final void setSectionOpaque(final Section update) {
+                SECTION_HANDLE.setOpaque(this, update);
+            }
+
+            private final void setSectionVolatile(final Section update) {
+                SECTION_HANDLE.setVolatile(this, update);
+            }
+
+            private final Section getAndSetSectionVolatile(final Section update) {
+                return (Section)SECTION_HANDLE.getAndSet(this, update);
+            }
+
+            private final Section compareExchangeSectionVolatile(final Section expect, final Section update) {
+                return (Section)SECTION_HANDLE.compareAndExchange(this, expect, update);
+            }
+
+            /* next */
+
+            private final UpdateQueueNode getNextPlain() {
+                return (UpdateQueueNode)NEXT_HANDLE.get(this);
+            }
+
+            private final UpdateQueueNode getNextOpaque() {
+                return (UpdateQueueNode)NEXT_HANDLE.getOpaque(this);
+            }
+
+            private final UpdateQueueNode getNextAcquire() {
+                return (UpdateQueueNode)NEXT_HANDLE.getAcquire(this);
+            }
+
+            private final UpdateQueueNode getNextVolatile() {
+                return (UpdateQueueNode)NEXT_HANDLE.getVolatile(this);
+            }
+
+            private final void setNextPlain(final UpdateQueueNode next) {
+                NEXT_HANDLE.set(this, next);
+            }
+
+            private final void setNextVolatile(final UpdateQueueNode next) {
+                NEXT_HANDLE.setVolatile(this, next);
+            }
+
+            private final UpdateQueueNode compareExchangeNextVolatile(final UpdateQueueNode expect, final UpdateQueueNode set) {
+                return (UpdateQueueNode)NEXT_HANDLE.compareAndExchange(this, expect, set);
+            }
+
+            /* updating */
+
+            private final boolean getUpdatingVolatile() {
+                return (boolean)UPDATING_HANDLE.getVolatile(this);
+            }
+
+            private final boolean getAndSetUpdatingVolatile(final boolean value) {
+                return (boolean)UPDATING_HANDLE.getAndSet(this, value);
+            }
+        }
+    }
+
+    private static final class Section {
+
+        // upper 8 bits: sources, lower 8 bits: level
+        // if we REALLY wanted to get crazy, we could make the increase propagator use MethodHandles#byteArrayViewVarHandle
+        // to read and write the lower 8 bits of this array directly rather than reading, updating the bits, then writing back.
+        private final short[] levels = new short[SECTION_SIZE * SECTION_SIZE];
+        // set of local positions that represent sources
+        private final ShortOpenHashSet sources = new ShortOpenHashSet();
+        // map of local index to new source level
+        // the source level _cannot_ be updated in the backing storage immediately since the update
+        private static final byte NO_QUEUED_UPDATE = (byte)-1;
+        private final Short2ByteLinkedOpenHashMap queuedSources = new Short2ByteLinkedOpenHashMap();
+        {
+            this.queuedSources.defaultReturnValue(NO_QUEUED_UPDATE);
+        }
+        private int oneRadNeighboursWithSources = 0;
+
+        public final int sectionX;
+        public final int sectionZ;
+
+        public Section(final int sectionX, final int sectionZ) {
+            this.sectionX = sectionX;
+            this.sectionZ = sectionZ;
+        }
+
+        public boolean isZero() {
+            for (final short val : this.levels) {
+                if (val != 0) {
+                    return false;
+                }
+            }
+            return true;
+        }
+
+        @Override
+        public String toString() {
+            final StringBuilder ret = new StringBuilder();
+
+            for (int x = 0; x < SECTION_SIZE; ++x) {
+                ret.append("levels x=").append(x).append("\n");
+                for (int z = 0; z < SECTION_SIZE; ++z) {
+                    final short v = this.levels[x | (z << SECTION_SHIFT)];
+                    ret.append(v & 0xFF).append(".");
+                }
+                ret.append("\n");
+                ret.append("sources x=").append(x).append("\n");
+                for (int z = 0; z < SECTION_SIZE; ++z) {
+                    final short v = this.levels[x | (z << SECTION_SHIFT)];
+                    ret.append((v >>> 8) & 0xFF).append(".");
+                }
+                ret.append("\n\n");
+            }
+
+            return ret.toString();
+        }
+    }
+
+
+    private static final class Propagator {
+
+        private static final ArrayDeque<Propagator> CACHED_PROPAGATORS = new ArrayDeque<>();
+        private static final int MAX_PROPAGATORS = Runtime.getRuntime().availableProcessors() * 2;
+
+        private static Propagator acquirePropagator() {
+            synchronized (CACHED_PROPAGATORS) {
+                final Propagator ret = CACHED_PROPAGATORS.pollFirst();
+                if (ret != null) {
+                    return ret;
+                }
+            }
+            return new Propagator();
+        }
+
+        private static void returnPropagator(final Propagator propagator) {
+            synchronized (CACHED_PROPAGATORS) {
+                if (CACHED_PROPAGATORS.size() < MAX_PROPAGATORS) {
+                    CACHED_PROPAGATORS.add(propagator);
+                }
+            }
+        }
+
+        private static final int SECTION_RADIUS = 2;
+        private static final int SECTION_CACHE_WIDTH = 2 * SECTION_RADIUS + 1;
+        // minimum number of bits to represent [0, SECTION_SIZE * SECTION_CACHE_WIDTH)
+        private static final int COORDINATE_BITS = 9;
+        private static final int COORDINATE_SIZE = 1 << COORDINATE_BITS;
+        static {
+            if ((SECTION_SIZE * SECTION_CACHE_WIDTH) > (1 << COORDINATE_BITS)) {
+                throw new IllegalStateException("Adjust COORDINATE_BITS");
+            }
+        }
+        // index = x + (z * SECTION_CACHE_WIDTH)
+        // (this requires x >= 0 and z >= 0)
+        private final Section[] sections = new Section[SECTION_CACHE_WIDTH * SECTION_CACHE_WIDTH];
+
+        private int encodeOffsetX;
+        private int encodeOffsetZ;
+
+        private int coordinateOffset;
+
+        private int encodeSectionOffsetX;
+        private int encodeSectionOffsetZ;
+
+        private int sectionIndexOffset;
+
+        public final boolean hasUpdates() {
+            return this.decreaseQueueInitialLength != 0 || this.increaseQueueInitialLength != 0;
+        }
+
+        private final void setupEncodeOffset(final int centerSectionX, final int centerSectionZ) {
+            final int maxCoordinate = (SECTION_RADIUS * SECTION_SIZE - 1);
+            // must have that encoded >= 0
+            // coordinates can range from [-maxCoordinate + centerSection*SECTION_SIZE, maxCoordinate + centerSection*SECTION_SIZE]
+            // we want a range of [0, maxCoordinate*2]
+            // so, 0 = -maxCoordinate + centerSection*SECTION_SIZE + offset
+            this.encodeOffsetX = maxCoordinate - (centerSectionX << SECTION_SHIFT);
+            this.encodeOffsetZ = maxCoordinate - (centerSectionZ << SECTION_SHIFT);
+
+            // encoded coordinates range from [0, SECTION_SIZE * SECTION_CACHE_WIDTH)
+            // coordinate index = (x + encodeOffsetX) + ((z + encodeOffsetZ) << COORDINATE_BITS)
+            this.coordinateOffset = this.encodeOffsetX + (this.encodeOffsetZ << COORDINATE_BITS);
+
+            // need encoded values to be >= 0
+            // so, 0 = (-SECTION_RADIUS + centerSectionX) + encodeOffset
+            this.encodeSectionOffsetX = SECTION_RADIUS - centerSectionX;
+            this.encodeSectionOffsetZ = SECTION_RADIUS - centerSectionZ;
+
+            // section index = (secX + encodeSectionOffsetX) + ((secZ + encodeSectionOffsetZ) * SECTION_CACHE_WIDTH)
+            this.sectionIndexOffset = this.encodeSectionOffsetX + (this.encodeSectionOffsetZ * SECTION_CACHE_WIDTH);
+        }
+
+        // must hold ticket lock for (centerSectionX,centerSectionZ) in radius rad
+        // must call setupEncodeOffset
+        private final void setupCaches(final ThreadedTicketLevelPropagator propagator,
+                                         final int centerSectionX, final int centerSectionZ,
+                                         final int rad) {
+            for (int dz = -rad; dz <= rad; ++dz) {
+                for (int dx = -rad; dx <= rad; ++dx) {
+                    final int sectionX = centerSectionX + dx;
+                    final int sectionZ = centerSectionZ + dz;
+                    final long coordinate = CoordinateUtils.getChunkKey(sectionX, sectionZ);
+                    final Section section = propagator.sections.get(coordinate);
+
+                    if (section == null) {
+                        throw new IllegalStateException("Section at " + coordinate + " should not be null");
+                    }
+
+                    this.setSectionInCache(sectionX, sectionZ, section);
+                }
+            }
+        }
+
+        private final void setSectionInCache(final int sectionX, final int sectionZ, final Section section) {
+            this.sections[sectionX + SECTION_CACHE_WIDTH*sectionZ + this.sectionIndexOffset] = section;
+        }
+
+        private final Section getSection(final int sectionX, final int sectionZ) {
+            return this.sections[sectionX + SECTION_CACHE_WIDTH*sectionZ + this.sectionIndexOffset];
+        }
+
+        private final int getLevel(final int posX, final int posZ) {
+            final Section section = this.sections[(posX >> SECTION_SHIFT) + SECTION_CACHE_WIDTH*(posZ >> SECTION_SHIFT) + this.sectionIndexOffset];
+            if (section != null) {
+                return (int)section.levels[(posX & (SECTION_SIZE - 1)) | ((posZ & (SECTION_SIZE - 1)) << SECTION_SHIFT)] & 0xFF;
+            }
+
+            return 0;
+        }
+
+        private final void setLevel(final int posX, final int posZ, final int to) {
+            final Section section = this.sections[(posX >> SECTION_SHIFT) + SECTION_CACHE_WIDTH*(posZ >> SECTION_SHIFT) + this.sectionIndexOffset];
+            if (section != null) {
+                final int index = (posX & (SECTION_SIZE - 1)) | ((posZ & (SECTION_SIZE - 1)) << SECTION_SHIFT);
+                final short level = section.levels[index];
+                section.levels[index] = (short)((level & ~0xFF) | (to & 0xFF));
+                this.updatedPositions.put(CoordinateUtils.getChunkKey(posX, posZ), (byte)to);
+            }
+        }
+
+        private final void destroyCaches() {
+            Arrays.fill(this.sections, null);
+        }
+
+        // contains:
+        // lower (COORDINATE_BITS(9) + COORDINATE_BITS(9) = 18) bits encoded position: (x | (z << COORDINATE_BITS))
+        // next LEVEL_BITS (6) bits: propagated level [0, 63]
+        // propagation directions bitset (16 bits):
+        private static final long ALL_DIRECTIONS_BITSET = (
+                // z = -1
+                (1L << ((1 - 1) | ((1 - 1) << 2))) |
+                (1L << ((1 + 0) | ((1 - 1) << 2))) |
+                (1L << ((1 + 1) | ((1 - 1) << 2))) |
+
+                // z = 0
+                (1L << ((1 - 1) | ((1 + 0) << 2))) |
+                //(1L << ((1 + 0) | ((1 + 0) << 2))) | // exclude (0,0)
+                (1L << ((1 + 1) | ((1 + 0) << 2))) |
+
+                // z = 1
+                (1L << ((1 - 1) | ((1 + 1) << 2))) |
+                (1L << ((1 + 0) | ((1 + 1) << 2))) |
+                (1L << ((1 + 1) | ((1 + 1) << 2)))
+        );
+
+        private void ex(int bitset) {
+            for (int i = 0, len = Integer.bitCount(bitset); i < len; ++i) {
+                final int set = Integer.numberOfTrailingZeros(bitset);
+                final int tailingBit = (-bitset) & bitset;
+                // XOR to remove the trailing bit
+                bitset ^= tailingBit;
+
+                // the encoded value set is (x_val) | (z_val << 2), totaling 4 bits
+                // thus, the bitset is 16 bits wide where each one represents a direction to propagate and the
+                // index of the set bit is the encoded value
+                // the encoded coordinate has 3 valid states:
+                // 0b00 (0) -> -1
+                // 0b01 (1) -> 0
+                // 0b10 (2) -> 1
+                // the decode operation then is val - 1, and the encode operation is val + 1
+                final int xOff = (set & 3) - 1;
+                final int zOff = ((set >>> 2) & 3) - 1;
+                System.out.println("Encoded: (" + xOff + "," + zOff + ")");
+            }
+        }
+
+        private void ch(long bs, int shift) {
+            int bitset = (int)(bs >>> shift);
+            for (int i = 0, len = Integer.bitCount(bitset); i < len; ++i) {
+                final int set = Integer.numberOfTrailingZeros(bitset);
+                final int tailingBit = (-bitset) & bitset;
+                // XOR to remove the trailing bit
+                bitset ^= tailingBit;
+
+                // the encoded value set is (x_val) | (z_val << 2), totaling 4 bits
+                // thus, the bitset is 16 bits wide where each one represents a direction to propagate and the
+                // index of the set bit is the encoded value
+                // the encoded coordinate has 3 valid states:
+                // 0b00 (0) -> -1
+                // 0b01 (1) -> 0
+                // 0b10 (2) -> 1
+                // the decode operation then is val - 1, and the encode operation is val + 1
+                final int xOff = (set & 3) - 1;
+                final int zOff = ((set >>> 2) & 3) - 1;
+                if (Math.abs(xOff) > 1 || Math.abs(zOff) > 1 || (xOff | zOff) == 0) {
+                    throw new IllegalStateException();
+                }
+            }
+        }
+
+        // whether the increase propagator needs to write the propagated level to the position, used to avoid cascading
+        // updates for sources
+        private static final long FLAG_WRITE_LEVEL = Long.MIN_VALUE >>> 1;
+        // whether the propagation needs to check if its current level is equal to the expected level
+        // used only in increase propagation
+        private static final long FLAG_RECHECK_LEVEL = Long.MIN_VALUE >>> 0;
+
+        private long[] increaseQueue = new long[SECTION_SIZE * SECTION_SIZE * 2];
+        private int increaseQueueInitialLength;
+        private long[] decreaseQueue = new long[SECTION_SIZE * SECTION_SIZE * 2];
+        private int decreaseQueueInitialLength;
+
+        private final Long2ByteLinkedOpenHashMap updatedPositions = new Long2ByteLinkedOpenHashMap();
+
+        private final long[] resizeIncreaseQueue() {
+            return this.increaseQueue = Arrays.copyOf(this.increaseQueue, this.increaseQueue.length * 2);
+        }
+
+        private final long[] resizeDecreaseQueue() {
+            return this.decreaseQueue = Arrays.copyOf(this.decreaseQueue, this.decreaseQueue.length * 2);
+        }
+
+        private final void appendToIncreaseQueue(final long value) {
+            final int idx = this.increaseQueueInitialLength++;
+            long[] queue = this.increaseQueue;
+            if (idx >= queue.length) {
+                queue = this.resizeIncreaseQueue();
+                queue[idx] = value;
+                return;
+            } else {
+                queue[idx] = value;
+                return;
+            }
+        }
+
+        private final void appendToDecreaseQueue(final long value) {
+            final int idx = this.decreaseQueueInitialLength++;
+            long[] queue = this.decreaseQueue;
+            if (idx >= queue.length) {
+                queue = this.resizeDecreaseQueue();
+                queue[idx] = value;
+                return;
+            } else {
+                queue[idx] = value;
+                return;
+            }
+        }
+
+        private final void performIncrease() {
+            long[] queue = this.increaseQueue;
+            int queueReadIndex = 0;
+            int queueLength = this.increaseQueueInitialLength;
+            this.increaseQueueInitialLength = 0;
+            final int decodeOffsetX = -this.encodeOffsetX;
+            final int decodeOffsetZ = -this.encodeOffsetZ;
+            final int encodeOffset = this.coordinateOffset;
+            final int sectionOffset = this.sectionIndexOffset;
+
+            final Long2ByteLinkedOpenHashMap updatedPositions = this.updatedPositions;
+
+            while (queueReadIndex < queueLength) {
+                final long queueValue = queue[queueReadIndex++];
+
+                final int posX = ((int)queueValue & (COORDINATE_SIZE - 1)) + decodeOffsetX;
+                final int posZ = (((int)queueValue >>> COORDINATE_BITS) & (COORDINATE_SIZE - 1)) + decodeOffsetZ;
+                final int propagatedLevel = ((int)queueValue >>> (COORDINATE_BITS + COORDINATE_BITS)) & (LEVEL_COUNT - 1);
+                // note: the above code requires coordinate bits * 2 < 32
+                // bitset is 16 bits
+                int propagateDirectionBitset = (int)(queueValue >>> (COORDINATE_BITS + COORDINATE_BITS + LEVEL_BITS)) & ((1 << 16) - 1);
+
+                if ((queueValue & FLAG_RECHECK_LEVEL) != 0L) {
+                    if (this.getLevel(posX, posZ) != propagatedLevel) {
+                        // not at the level we expect, so something changed.
+                        continue;
+                    }
+                } else if ((queueValue & FLAG_WRITE_LEVEL) != 0L) {
+                    // these are used to restore sources after a propagation decrease
+                    this.setLevel(posX, posZ, propagatedLevel);
+                }
+
+                // this bitset represents the values that we have not propagated to
+                // this bitset lets us determine what directions the neighbours we set should propagate to, in most cases
+                // significantly reducing the total number of ops
+                // since we propagate in a 1 radius, we need a 2 radius bitset to hold all possible values we would possibly need
+                // but if we use only 5x5 bits, then we need to use div/mod to retrieve coordinates from the bitset, so instead
+                // we use an 8x8 bitset and luckily that can be fit into only one long value (64 bits)
+                // to make things easy, we use positions [0, 4] in the bitset, with current position being 2
+                // index = x | (z << 3)
+
+                // to start, we eliminate everything 1 radius from the current position as the previous propagator
+                // must guarantee that either we propagate everything in 1 radius or we partially propagate for 1 radius
+                // but the rest not propagated are already handled
+                long currentPropagation = ~(
+                        // z = -1
+                        (1L << ((2 - 1) | ((2 - 1) << 3))) |
+                        (1L << ((2 + 0) | ((2 - 1) << 3))) |
+                        (1L << ((2 + 1) | ((2 - 1) << 3))) |
+
+                        // z = 0
+                        (1L << ((2 - 1) | ((2 + 0) << 3))) |
+                        (1L << ((2 + 0) | ((2 + 0) << 3))) |
+                        (1L << ((2 + 1) | ((2 + 0) << 3))) |
+
+                        // z = 1
+                        (1L << ((2 - 1) | ((2 + 1) << 3))) |
+                        (1L << ((2 + 0) | ((2 + 1) << 3))) |
+                        (1L << ((2 + 1) | ((2 + 1) << 3)))
+                );
+
+                final int toPropagate = propagatedLevel - 1;
+
+                // we could use while (propagateDirectionBitset != 0), but it's not a predictable branch. By counting
+                // the bits, the cpu loop predictor should perfectly predict the loop.
+                for (int l = 0, len = Integer.bitCount(propagateDirectionBitset); l < len; ++l) {
+                    final int set = Integer.numberOfTrailingZeros(propagateDirectionBitset);
+                    final int tailingBit = (-propagateDirectionBitset) & propagateDirectionBitset;
+                    propagateDirectionBitset ^= tailingBit;
+
+                    // pDecode is from [0, 2], and 1 must be subtracted to fully decode the offset
+                    // it has been split to save some cycles via parallelism
+                    final int pDecodeX = (set & 3);
+                    final int pDecodeZ = ((set >>> 2) & 3);
+
+                    // re-ordered -1 on the position decode into pos - 1 to occur in parallel with determining pDecodeX
+                    final int offX = (posX - 1) + pDecodeX;
+                    final int offZ = (posZ - 1) + pDecodeZ;
+
+                    final int sectionIndex = (offX >> SECTION_SHIFT) + ((offZ >> SECTION_SHIFT) * SECTION_CACHE_WIDTH) + sectionOffset;
+                    final int localIndex = (offX & (SECTION_SIZE - 1)) | ((offZ & (SECTION_SIZE - 1)) << SECTION_SHIFT);
+
+                    // to retrieve a set of bits from a long value: (n_bitmask << (nstartidx)) & bitset
+                    // bitset idx = x | (z << 3)
+
+                    // read three bits, so we need 7L
+                    // note that generally: off - pos = (pos - 1) + pDecode - pos = pDecode - 1
+                    // nstartidx1 = x rel -1 for z rel -1
+                    //            = (offX - posX - 1 + 2) | ((offZ - posZ - 1 + 2) << 3)
+                    //            = (pDecodeX - 1 - 1 + 2) | ((pDecodeZ - 1 - 1 + 2) << 3)
+                    //            = pDecodeX | (pDecodeZ << 3) = start
+                    final int start = pDecodeX | (pDecodeZ << 3);
+                    final long bitsetLine1 = currentPropagation & (7L << (start));
+
+                    // nstartidx2 = x rel -1 for z rel 0 = line after line1, so we can just add 8 (row length of bitset)
+                    final long bitsetLine2 = currentPropagation & (7L << (start + 8));
+
+                    // nstartidx2 = x rel -1 for z rel 0 = line after line2, so we can just add 8 (row length of bitset)
+                    final long bitsetLine3 = currentPropagation & (7L << (start + (8 + 8)));
+
+                    // remove ("take") lines from bitset
+                    currentPropagation ^= (bitsetLine1 | bitsetLine2 | bitsetLine3);
+
+                    // now try to propagate
+                    final Section section = this.sections[sectionIndex];
+
+                    // lower 8 bits are current level, next upper 7 bits are source level, next 1 bit is updated source flag
+                    final short currentStoredLevel = section.levels[localIndex];
+                    final int currentLevel = currentStoredLevel & 0xFF;
+
+                    if (currentLevel >= toPropagate) {
+                        continue; // already at the level we want
+                    }
+
+                    // update level
+                    section.levels[localIndex] = (short)((currentStoredLevel & ~0xFF) | (toPropagate & 0xFF));
+                    updatedPositions.putAndMoveToLast(CoordinateUtils.getChunkKey(offX, offZ), (byte)toPropagate);
+
+                    // queue next
+                    if (toPropagate > 1) {
+                        // now combine into one bitset to pass to child
+                        // the child bitset is 4x4, so we just shift each line by 4
+                        // add the propagation bitset offset to each line to make it easy to OR it into the propagation queue value
+                        final long childPropagation =
+                                ((bitsetLine1 >>> (start)) << (COORDINATE_BITS + COORDINATE_BITS + LEVEL_BITS)) | // z = -1
+                                ((bitsetLine2 >>> (start + 8)) << (4 + COORDINATE_BITS + COORDINATE_BITS + LEVEL_BITS)) | // z = 0
+                                ((bitsetLine3 >>> (start + (8 + 8))) << (4 + 4 + COORDINATE_BITS + COORDINATE_BITS + LEVEL_BITS)); // z = 1
+
+                        // don't queue update if toPropagate cannot propagate anything to neighbours
+                        // (for increase, propagating 0 to neighbours is useless)
+                        if (queueLength >= queue.length) {
+                            queue = this.resizeIncreaseQueue();
+                        }
+                        queue[queueLength++] =
+                                ((long)(offX + (offZ << COORDINATE_BITS) + encodeOffset) & ((1L << (COORDINATE_BITS + COORDINATE_BITS)) - 1)) |
+                                ((toPropagate & (LEVEL_COUNT - 1L)) << (COORDINATE_BITS + COORDINATE_BITS)) |
+                                childPropagation; //(ALL_DIRECTIONS_BITSET << (COORDINATE_BITS + COORDINATE_BITS + LEVEL_BITS));
+                        continue;
+                    }
+                    continue;
+                }
+            }
+        }
+
+        private final void performDecrease() {
+            long[] queue = this.decreaseQueue;
+            long[] increaseQueue = this.increaseQueue;
+            int queueReadIndex = 0;
+            int queueLength = this.decreaseQueueInitialLength;
+            this.decreaseQueueInitialLength = 0;
+            int increaseQueueLength = this.increaseQueueInitialLength;
+            final int decodeOffsetX = -this.encodeOffsetX;
+            final int decodeOffsetZ = -this.encodeOffsetZ;
+            final int encodeOffset = this.coordinateOffset;
+            final int sectionOffset = this.sectionIndexOffset;
+
+            final Long2ByteLinkedOpenHashMap updatedPositions = this.updatedPositions;
+
+            while (queueReadIndex < queueLength) {
+                final long queueValue = queue[queueReadIndex++];
+
+                final int posX = ((int)queueValue & (COORDINATE_SIZE - 1)) + decodeOffsetX;
+                final int posZ = (((int)queueValue >>> COORDINATE_BITS) & (COORDINATE_SIZE - 1)) + decodeOffsetZ;
+                final int propagatedLevel = ((int)queueValue >>> (COORDINATE_BITS + COORDINATE_BITS)) & (LEVEL_COUNT - 1);
+                // note: the above code requires coordinate bits * 2 < 32
+                // bitset is 16 bits
+                int propagateDirectionBitset = (int)(queueValue >>> (COORDINATE_BITS + COORDINATE_BITS + LEVEL_BITS)) & ((1 << 16) - 1);
+
+                // this bitset represents the values that we have not propagated to
+                // this bitset lets us determine what directions the neighbours we set should propagate to, in most cases
+                // significantly reducing the total number of ops
+                // since we propagate in a 1 radius, we need a 2 radius bitset to hold all possible values we would possibly need
+                // but if we use only 5x5 bits, then we need to use div/mod to retrieve coordinates from the bitset, so instead
+                // we use an 8x8 bitset and luckily that can be fit into only one long value (64 bits)
+                // to make things easy, we use positions [0, 4] in the bitset, with current position being 2
+                // index = x | (z << 3)
+
+                // to start, we eliminate everything 1 radius from the current position as the previous propagator
+                // must guarantee that either we propagate everything in 1 radius or we partially propagate for 1 radius
+                // but the rest not propagated are already handled
+                long currentPropagation = ~(
+                        // z = -1
+                        (1L << ((2 - 1) | ((2 - 1) << 3))) |
+                        (1L << ((2 + 0) | ((2 - 1) << 3))) |
+                        (1L << ((2 + 1) | ((2 - 1) << 3))) |
+
+                        // z = 0
+                        (1L << ((2 - 1) | ((2 + 0) << 3))) |
+                        (1L << ((2 + 0) | ((2 + 0) << 3))) |
+                        (1L << ((2 + 1) | ((2 + 0) << 3))) |
+
+                        // z = 1
+                        (1L << ((2 - 1) | ((2 + 1) << 3))) |
+                        (1L << ((2 + 0) | ((2 + 1) << 3))) |
+                        (1L << ((2 + 1) | ((2 + 1) << 3)))
+                );
+
+                final int toPropagate = propagatedLevel - 1;
+
+                // we could use while (propagateDirectionBitset != 0), but it's not a predictable branch. By counting
+                // the bits, the cpu loop predictor should perfectly predict the loop.
+                for (int l = 0, len = Integer.bitCount(propagateDirectionBitset); l < len; ++l) {
+                    final int set = Integer.numberOfTrailingZeros(propagateDirectionBitset);
+                    final int tailingBit = (-propagateDirectionBitset) & propagateDirectionBitset;
+                    propagateDirectionBitset ^= tailingBit;
+
+
+                    // pDecode is from [0, 2], and 1 must be subtracted to fully decode the offset
+                    // it has been split to save some cycles via parallelism
+                    final int pDecodeX = (set & 3);
+                    final int pDecodeZ = ((set >>> 2) & 3);
+
+                    // re-ordered -1 on the position decode into pos - 1 to occur in parallel with determining pDecodeX
+                    final int offX = (posX - 1) + pDecodeX;
+                    final int offZ = (posZ - 1) + pDecodeZ;
+
+                    final int sectionIndex = (offX >> SECTION_SHIFT) + ((offZ >> SECTION_SHIFT) * SECTION_CACHE_WIDTH) + sectionOffset;
+                    final int localIndex = (offX & (SECTION_SIZE - 1)) | ((offZ & (SECTION_SIZE - 1)) << SECTION_SHIFT);
+
+                    // to retrieve a set of bits from a long value: (n_bitmask << (nstartidx)) & bitset
+                    // bitset idx = x | (z << 3)
+
+                    // read three bits, so we need 7L
+                    // note that generally: off - pos = (pos - 1) + pDecode - pos = pDecode - 1
+                    // nstartidx1 = x rel -1 for z rel -1
+                    //            = (offX - posX - 1 + 2) | ((offZ - posZ - 1 + 2) << 3)
+                    //            = (pDecodeX - 1 - 1 + 2) | ((pDecodeZ - 1 - 1 + 2) << 3)
+                    //            = pDecodeX | (pDecodeZ << 3) = start
+                    final int start = pDecodeX | (pDecodeZ << 3);
+                    final long bitsetLine1 = currentPropagation & (7L << (start));
+
+                    // nstartidx2 = x rel -1 for z rel 0 = line after line1, so we can just add 8 (row length of bitset)
+                    final long bitsetLine2 = currentPropagation & (7L << (start + 8));
+
+                    // nstartidx2 = x rel -1 for z rel 0 = line after line2, so we can just add 8 (row length of bitset)
+                    final long bitsetLine3 = currentPropagation & (7L << (start + (8 + 8)));
+
+                    // now try to propagate
+                    final Section section = this.sections[sectionIndex];
+
+                    // lower 8 bits are current level, next upper 7 bits are source level, next 1 bit is updated source flag
+                    final short currentStoredLevel = section.levels[localIndex];
+                    final int currentLevel = currentStoredLevel & 0xFF;
+                    final int sourceLevel = (currentStoredLevel >>> 8) & 0xFF;
+
+                    if (currentLevel == 0) {
+                        continue; // already at the level we want
+                    }
+
+                    if (currentLevel > toPropagate) {
+                        // it looks like another source propagated here, so re-propagate it
+                        if (increaseQueueLength >= increaseQueue.length) {
+                            increaseQueue = this.resizeIncreaseQueue();
+                        }
+                        increaseQueue[increaseQueueLength++] =
+                                ((long)(offX + (offZ << COORDINATE_BITS) + encodeOffset) & ((1L << (COORDINATE_BITS + COORDINATE_BITS)) - 1)) |
+                                ((currentLevel & (LEVEL_COUNT - 1L)) << (COORDINATE_BITS + COORDINATE_BITS)) |
+                                (FLAG_RECHECK_LEVEL | (ALL_DIRECTIONS_BITSET << (COORDINATE_BITS + COORDINATE_BITS + LEVEL_BITS)));
+                        continue;
+                    }
+
+                    // remove ("take") lines from bitset
+                    // can't do this during decrease, TODO WHY?
+                    //currentPropagation ^= (bitsetLine1 | bitsetLine2 | bitsetLine3);
+
+                    // update level
+                    section.levels[localIndex] = (short)((currentStoredLevel & ~0xFF));
+                    updatedPositions.putAndMoveToLast(CoordinateUtils.getChunkKey(offX, offZ), (byte)0);
+
+                    if (sourceLevel != 0) {
+                        // re-propagate source
+                        // note: do not set recheck level, or else the propagation will fail
+                        if (increaseQueueLength >= increaseQueue.length) {
+                            increaseQueue = this.resizeIncreaseQueue();
+                        }
+                        increaseQueue[increaseQueueLength++] =
+                                ((long)(offX + (offZ << COORDINATE_BITS) + encodeOffset) & ((1L << (COORDINATE_BITS + COORDINATE_BITS)) - 1)) |
+                                ((sourceLevel & (LEVEL_COUNT - 1L)) << (COORDINATE_BITS + COORDINATE_BITS)) |
+                                (FLAG_WRITE_LEVEL | (ALL_DIRECTIONS_BITSET << (COORDINATE_BITS + COORDINATE_BITS + LEVEL_BITS)));
+                    }
+
+                    // queue next
+                    // note: targetLevel > 0 here, since toPropagate >= currentLevel and currentLevel > 0
+                    // now combine into one bitset to pass to child
+                    // the child bitset is 4x4, so we just shift each line by 4
+                    // add the propagation bitset offset to each line to make it easy to OR it into the propagation queue value
+                    final long childPropagation =
+                            ((bitsetLine1 >>> (start)) << (COORDINATE_BITS + COORDINATE_BITS + LEVEL_BITS)) | // z = -1
+                            ((bitsetLine2 >>> (start + 8)) << (4 + COORDINATE_BITS + COORDINATE_BITS + LEVEL_BITS)) | // z = 0
+                            ((bitsetLine3 >>> (start + (8 + 8))) << (4 + 4 + COORDINATE_BITS + COORDINATE_BITS + LEVEL_BITS)); // z = 1
+
+                    // don't queue update if toPropagate cannot propagate anything to neighbours
+                    // (for increase, propagating 0 to neighbours is useless)
+                    if (queueLength >= queue.length) {
+                        queue = this.resizeDecreaseQueue();
+                    }
+                    queue[queueLength++] =
+                            ((long)(offX + (offZ << COORDINATE_BITS) + encodeOffset) & ((1L << (COORDINATE_BITS + COORDINATE_BITS)) - 1)) |
+                            ((toPropagate & (LEVEL_COUNT - 1L)) << (COORDINATE_BITS + COORDINATE_BITS)) |
+                            (ALL_DIRECTIONS_BITSET << (COORDINATE_BITS + COORDINATE_BITS + LEVEL_BITS)); //childPropagation;
+                    continue;
+                }
+            }
+
+            // propagate sources we clobbered
+            this.increaseQueueInitialLength = increaseQueueLength;
+            this.performIncrease();
+        }
+    }
+
+    /*
+    private static final java.util.Random random = new java.util.Random(4L);
+    private static final List<io.papermc.paper.chunk.system.RegionizedPlayerChunkLoader.SingleUserAreaMap<Void>> walkers =
+        new java.util.ArrayList<>();
+    static final int PLAYERS = 0;
+    static final int RAD_BLOCKS = 10000;
+    static final int RAD = RAD_BLOCKS >> 4;
+    static final int RAD_BIG_BLOCKS = 100_000;
+    static final int RAD_BIG = RAD_BIG_BLOCKS >> 4;
+    static final int VD = 4;
+    static final int BIG_PLAYERS = 50;
+    static final double WALK_CHANCE = 0.10;
+    static final double TP_CHANCE = 0.01;
+    static final int TP_BACK_PLAYERS = 200;
+    static final double TP_BACK_CHANCE = 0.25;
+    static final double TP_STEAL_CHANCE = 0.25;
+    private static final List<io.papermc.paper.chunk.system.RegionizedPlayerChunkLoader.SingleUserAreaMap<Void>> tpBack =
+        new java.util.ArrayList<>();
+
+    public static void main(final String[] args) {
+        final ReentrantAreaLock ticketLock = new ReentrantAreaLock(SECTION_SHIFT);
+        final ReentrantAreaLock schedulingLock = new ReentrantAreaLock(SECTION_SHIFT);
+        final Long2ByteLinkedOpenHashMap levelMap = new Long2ByteLinkedOpenHashMap();
+        final Long2ByteLinkedOpenHashMap refMap = new Long2ByteLinkedOpenHashMap();
+        final io.papermc.paper.util.misc.Delayed8WayDistancePropagator2D ref = new io.papermc.paper.util.misc.Delayed8WayDistancePropagator2D((final long coordinate, final byte oldLevel, final byte newLevel) -> {
+            if (newLevel == 0) {
+                refMap.remove(coordinate);
+            } else {
+                refMap.put(coordinate, newLevel);
+            }
+        });
+        final ThreadedTicketLevelPropagator propagator = new ThreadedTicketLevelPropagator() {
+            @Override
+            protected void processLevelUpdates(Long2ByteLinkedOpenHashMap updates) {
+                for (final long key : updates.keySet()) {
+                    final byte val = updates.get(key);
+                    if (val == 0) {
+                        levelMap.remove(key);
+                    } else {
+                        levelMap.put(key, val);
+                    }
+                }
+            }
+
+            @Override
+            protected void processSchedulingUpdates(Long2ByteLinkedOpenHashMap updates, List<ChunkProgressionTask> scheduledTasks, List<NewChunkHolder> changedFullStatus) {}
+        };
+
+        for (;;) {
+            if (walkers.isEmpty() && tpBack.isEmpty()) {
+                for (int i = 0; i < PLAYERS; ++i) {
+                    int rad = i < BIG_PLAYERS ? RAD_BIG : RAD;
+                    int posX = random.nextInt(-rad, rad + 1);
+                    int posZ = random.nextInt(-rad, rad + 1);
+
+                    io.papermc.paper.chunk.system.RegionizedPlayerChunkLoader.SingleUserAreaMap<Void> map = new io.papermc.paper.chunk.system.RegionizedPlayerChunkLoader.SingleUserAreaMap<>(null) {
+                        @Override
+                        protected void addCallback(Void parameter, int chunkX, int chunkZ) {
+                            int src = 45 - 31 + 1;
+                            ref.setSource(chunkX, chunkZ, src);
+                            propagator.setSource(chunkX, chunkZ, src);
+                        }
+
+                        @Override
+                        protected void removeCallback(Void parameter, int chunkX, int chunkZ) {
+                            ref.removeSource(chunkX, chunkZ);
+                            propagator.removeSource(chunkX, chunkZ);
+                        }
+                    };
+
+                    map.add(posX, posZ, VD);
+
+                    walkers.add(map);
+                }
+                for (int i = 0; i < TP_BACK_PLAYERS; ++i) {
+                    int rad = RAD_BIG;
+                    int posX = random.nextInt(-rad, rad + 1);
+                    int posZ = random.nextInt(-rad, rad + 1);
+
+                    io.papermc.paper.chunk.system.RegionizedPlayerChunkLoader.SingleUserAreaMap<Void> map = new io.papermc.paper.chunk.system.RegionizedPlayerChunkLoader.SingleUserAreaMap<>(null) {
+                        @Override
+                        protected void addCallback(Void parameter, int chunkX, int chunkZ) {
+                            int src = 45 - 31 + 1;
+                            ref.setSource(chunkX, chunkZ, src);
+                            propagator.setSource(chunkX, chunkZ, src);
+                        }
+
+                        @Override
+                        protected void removeCallback(Void parameter, int chunkX, int chunkZ) {
+                            ref.removeSource(chunkX, chunkZ);
+                            propagator.removeSource(chunkX, chunkZ);
+                        }
+                    };
+
+                    map.add(posX, posZ, random.nextInt(1, 63));
+
+                    tpBack.add(map);
+                }
+            } else {
+                for (int i = 0; i < PLAYERS; ++i) {
+                    if (random.nextDouble() > WALK_CHANCE) {
+                        continue;
+                    }
+
+                    io.papermc.paper.chunk.system.RegionizedPlayerChunkLoader.SingleUserAreaMap<Void> map = walkers.get(i);
+
+                    int updateX = random.nextInt(-1, 2);
+                    int updateZ = random.nextInt(-1, 2);
+
+                    map.update(map.lastChunkX + updateX, map.lastChunkZ + updateZ, VD);
+                }
+
+                for (int i = 0; i < PLAYERS; ++i) {
+                    if (random.nextDouble() > TP_CHANCE) {
+                        continue;
+                    }
+
+                    int rad = i < BIG_PLAYERS ? RAD_BIG : RAD;
+                    int posX = random.nextInt(-rad, rad + 1);
+                    int posZ = random.nextInt(-rad, rad + 1);
+
+                    io.papermc.paper.chunk.system.RegionizedPlayerChunkLoader.SingleUserAreaMap<Void> map = walkers.get(i);
+
+                    map.update(posX, posZ, VD);
+                }
+
+                for (int i = 0; i < TP_BACK_PLAYERS; ++i) {
+                    if (random.nextDouble() > TP_BACK_CHANCE) {
+                        continue;
+                    }
+
+                    io.papermc.paper.chunk.system.RegionizedPlayerChunkLoader.SingleUserAreaMap<Void> map = tpBack.get(i);
+
+                    map.update(-map.lastChunkX, -map.lastChunkZ, random.nextInt(1, 63));
+
+                    if (random.nextDouble() > TP_STEAL_CHANCE) {
+                        propagator.performUpdate(
+                            map.lastChunkX >> SECTION_SHIFT, map.lastChunkZ >> SECTION_SHIFT, schedulingLock, null, null
+                        );
+                        propagator.performUpdate(
+                            (-map.lastChunkX >> SECTION_SHIFT), (-map.lastChunkZ >> SECTION_SHIFT), schedulingLock, null, null
+                        );
+                    }
+                }
+            }
+
+            ref.propagateUpdates();
+            propagator.performUpdates(ticketLock, schedulingLock, null, null);
+
+            if (!refMap.equals(levelMap)) {
+                throw new IllegalStateException("Error!");
+            }
+        }
+    }
+     */
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/executor/RadiusAwarePrioritisedExecutor.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/executor/RadiusAwarePrioritisedExecutor.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/executor/RadiusAwarePrioritisedExecutor.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.scheduling.executor;
+
+import ca.spottedleaf.concurrentutil.executor.PrioritisedExecutor;
+import ca.spottedleaf.concurrentutil.util.Priority;
+import ca.spottedleaf.moonrise.common.util.CoordinateUtils;
+import it.unimi.dsi.fastutil.longs.Long2ReferenceOpenHashMap;
+import it.unimi.dsi.fastutil.objects.ReferenceOpenHashSet;
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.List;
+import java.util.PriorityQueue;
+
+public class RadiusAwarePrioritisedExecutor {
+
+    private static final Comparator<DependencyNode> DEPENDENCY_NODE_COMPARATOR = (final DependencyNode t1, final DependencyNode t2) -> {
+        return Long.compare(t1.id, t2.id);
+    };
+
+    private final PrioritisedExecutor executor;
+    private final DependencyTree[] queues = new DependencyTree[Priority.TOTAL_SCHEDULABLE_PRIORITIES];
+    private static final int NO_TASKS_QUEUED = -1;
+    private int selectedQueue = NO_TASKS_QUEUED;
+    private boolean canQueueTasks = true;
+
+    public RadiusAwarePrioritisedExecutor(final PrioritisedExecutor executor, final int maxToSchedule) {
+        this.executor = executor;
+
+        for (int i = 0; i < this.queues.length; ++i) {
+            this.queues[i] = new DependencyTree(this, executor, maxToSchedule);
+        }
+    }
+
+    public void setMaxToSchedule(final int maxToSchedule) {
+        final List<PrioritisedExecutor.PrioritisedTask> tasks;
+
+        synchronized (this) {
+            for (final DependencyTree dependencyTree : this.queues) {
+                dependencyTree.maxToSchedule = maxToSchedule;
+            }
+
+            if (this.selectedQueue == NO_TASKS_QUEUED || !this.canQueueTasks) {
+                return;
+            }
+
+            tasks = this.queues[this.selectedQueue].tryPushTasks();
+        }
+
+        scheduleTasks(tasks);
+    }
+
+    private boolean canQueueTasks() {
+        return this.canQueueTasks;
+    }
+
+    private List<PrioritisedExecutor.PrioritisedTask> treeFinished() {
+        this.canQueueTasks = true;
+        for (int priority = 0; priority < this.queues.length; ++priority) {
+            final DependencyTree queue = this.queues[priority];
+            if (queue.hasWaitingTasks()) {
+                final List<PrioritisedExecutor.PrioritisedTask> ret = queue.tryPushTasks();
+
+                if (ret == null || ret.isEmpty()) {
+                    // this happens when the tasks in the wait queue were purged
+                    // in this case, the queue was actually empty, we just had to purge it
+                    // if we set the selected queue without scheduling any tasks, the queue will never be unselected
+                    // as that requires a scheduled task completing...
+                    continue;
+                }
+
+                this.selectedQueue = priority;
+                return ret;
+            }
+        }
+
+        this.selectedQueue = NO_TASKS_QUEUED;
+
+        return null;
+    }
+
+    private List<PrioritisedExecutor.PrioritisedTask> queue(final Task task, final Priority priority) {
+        final int priorityId = priority.priority;
+        final DependencyTree queue = this.queues[priorityId];
+
+        final DependencyNode node = new DependencyNode(task, queue);
+
+        if (task.dependencyNode != null) {
+            throw new IllegalStateException();
+        }
+        task.dependencyNode = node;
+
+        queue.pushNode(node);
+
+        if (this.selectedQueue == NO_TASKS_QUEUED) {
+            this.canQueueTasks = true;
+            this.selectedQueue = priorityId;
+            return queue.tryPushTasks();
+        }
+
+        if (!this.canQueueTasks) {
+            return null;
+        }
+
+        if (Priority.isHigherPriority(priorityId, this.selectedQueue)) {
+            // prevent the lower priority tree from queueing more tasks
+            this.canQueueTasks = false;
+            return null;
+        }
+
+        // priorityId != selectedQueue: lower priority, don't care - treeFinished will pick it up
+        return priorityId == this.selectedQueue ? queue.tryPushTasks() : null;
+    }
+
+    public PrioritisedExecutor.PrioritisedTask createTask(final int chunkX, final int chunkZ, final int radius,
+                                                          final Runnable run, final Priority priority) {
+        if (radius < 0) {
+            throw new IllegalArgumentException("Radius must be > 0: " + radius);
+        }
+        return new Task(this, chunkX, chunkZ, radius, run, priority);
+    }
+
+    public PrioritisedExecutor.PrioritisedTask createTask(final int chunkX, final int chunkZ, final int radius,
+                                                          final Runnable run) {
+        return this.createTask(chunkX, chunkZ, radius, run, Priority.NORMAL);
+    }
+
+    public PrioritisedExecutor.PrioritisedTask queueTask(final int chunkX, final int chunkZ, final int radius,
+                                                         final Runnable run, final Priority priority) {
+        final PrioritisedExecutor.PrioritisedTask ret = this.createTask(chunkX, chunkZ, radius, run, priority);
+
+        ret.queue();
+
+        return ret;
+    }
+
+    public PrioritisedExecutor.PrioritisedTask queueTask(final int chunkX, final int chunkZ, final int radius,
+                                                         final Runnable run) {
+        final PrioritisedExecutor.PrioritisedTask ret = this.createTask(chunkX, chunkZ, radius, run);
+
+        ret.queue();
+
+        return ret;
+    }
+
+    public PrioritisedExecutor.PrioritisedTask createInfiniteRadiusTask(final Runnable run, final Priority priority) {
+        return new Task(this, 0, 0, -1, run, priority);
+    }
+
+    public PrioritisedExecutor.PrioritisedTask createInfiniteRadiusTask(final Runnable run) {
+        return this.createInfiniteRadiusTask(run, Priority.NORMAL);
+    }
+
+    public PrioritisedExecutor.PrioritisedTask queueInfiniteRadiusTask(final Runnable run, final Priority priority) {
+        final PrioritisedExecutor.PrioritisedTask ret = this.createInfiniteRadiusTask(run, priority);
+
+        ret.queue();
+
+        return ret;
+    }
+
+    public PrioritisedExecutor.PrioritisedTask queueInfiniteRadiusTask(final Runnable run) {
+        final PrioritisedExecutor.PrioritisedTask ret = this.createInfiniteRadiusTask(run, Priority.NORMAL);
+
+        ret.queue();
+
+        return ret;
+    }
+
+    private static void scheduleTasks(final List<PrioritisedExecutor.PrioritisedTask> toSchedule) {
+        if (toSchedule != null) {
+            for (int i = 0, len = toSchedule.size(); i < len; ++i) {
+                toSchedule.get(i).queue();
+            }
+        }
+    }
+
+    // all accesses must be synchronised by the radius aware object
+    private static final class DependencyTree {
+
+        private final RadiusAwarePrioritisedExecutor scheduler;
+        private final PrioritisedExecutor executor;
+        private int maxToSchedule;
+
+        private int currentlyExecuting;
+        private long idGenerator;
+
+        private final PriorityQueue<DependencyNode> awaiting = new PriorityQueue<>(DEPENDENCY_NODE_COMPARATOR);
+
+        private final PriorityQueue<DependencyNode> infiniteRadius = new PriorityQueue<>(DEPENDENCY_NODE_COMPARATOR);
+        private boolean isInfiniteRadiusScheduled;
+
+        private final Long2ReferenceOpenHashMap<DependencyNode> nodeByPosition = new Long2ReferenceOpenHashMap<>();
+
+        public DependencyTree(final RadiusAwarePrioritisedExecutor scheduler, final PrioritisedExecutor executor,
+                              final int maxToSchedule) {
+            this.scheduler = scheduler;
+            this.executor = executor;
+            this.maxToSchedule = maxToSchedule;
+        }
+
+        public boolean hasWaitingTasks() {
+            return !this.awaiting.isEmpty() || !this.infiniteRadius.isEmpty();
+        }
+
+        private long nextId() {
+            return this.idGenerator++;
+        }
+
+        private boolean isExecutingAnyTasks() {
+            return this.currentlyExecuting != 0;
+        }
+
+        private void pushNode(final DependencyNode node) {
+            if (!node.task.isFiniteRadius()) {
+                this.infiniteRadius.add(node);
+                return;
+            }
+
+            // set up dependency for node
+            final Task task = node.task;
+
+            final int centerX = task.chunkX;
+            final int centerZ = task.chunkZ;
+            final int radius = task.radius;
+
+            final int minX = centerX - radius;
+            final int maxX = centerX + radius;
+
+            final int minZ = centerZ - radius;
+            final int maxZ = centerZ + radius;
+
+            ReferenceOpenHashSet<DependencyNode> parents = null;
+            for (int currZ = minZ; currZ <= maxZ; ++currZ) {
+                for (int currX = minX; currX <= maxX; ++currX) {
+                    final DependencyNode dependency = this.nodeByPosition.put(CoordinateUtils.getChunkKey(currX, currZ), node);
+                    if (dependency != null) {
+                        if (parents == null) {
+                            parents = new ReferenceOpenHashSet<>();
+                        }
+                        if (parents.add(dependency)) {
+                            // added a dependency, so we need to add as a child to the dependency
+                            if (dependency.children == null) {
+                                dependency.children = new ArrayList<>();
+                            }
+                            dependency.children.add(node);
+                        }
+                    }
+                }
+            }
+
+            if (parents == null) {
+                // no dependencies, add straight to awaiting
+                this.awaiting.add(node);
+            } else {
+                node.parents = parents.size();
+                // we will be added to awaiting once we have no parents
+            }
+        }
+
+        // called only when a node is returned after being executed
+        private List<PrioritisedExecutor.PrioritisedTask> returnNode(final DependencyNode node) {
+            final Task task = node.task;
+
+            // now that the task is completed, we can push its children to the awaiting queue
+            this.pushChildren(node);
+
+            if (task.isFiniteRadius()) {
+                // remove from dependency map
+                this.removeNodeFromMap(node);
+            } else {
+                // mark as no longer executing infinite radius
+                if (!this.isInfiniteRadiusScheduled) {
+                    throw new IllegalStateException();
+                }
+                this.isInfiniteRadiusScheduled = false;
+            }
+
+            // decrement executing count, we are done executing this task
+            --this.currentlyExecuting;
+
+            if (this.currentlyExecuting == 0) {
+                return this.scheduler.treeFinished();
+            }
+
+            return this.scheduler.canQueueTasks() ? this.tryPushTasks() : null;
+        }
+
+        private List<PrioritisedExecutor.PrioritisedTask> tryPushTasks() {
+            // tasks are not queued, but only created here - we do hold the lock for the map
+            List<PrioritisedExecutor.PrioritisedTask> ret = null;
+            PrioritisedExecutor.PrioritisedTask pushedTask;
+            while ((pushedTask = this.tryPushTask()) != null) {
+                if (ret == null) {
+                    ret = new ArrayList<>();
+                }
+                ret.add(pushedTask);
+            }
+
+            return ret;
+        }
+
+        private void removeNodeFromMap(final DependencyNode node) {
+            final Task task = node.task;
+
+            final int centerX = task.chunkX;
+            final int centerZ = task.chunkZ;
+            final int radius = task.radius;
+
+            final int minX = centerX - radius;
+            final int maxX = centerX + radius;
+
+            final int minZ = centerZ - radius;
+            final int maxZ = centerZ + radius;
+
+            for (int currZ = minZ; currZ <= maxZ; ++currZ) {
+                for (int currX = minX; currX <= maxX; ++currX) {
+                    this.nodeByPosition.remove(CoordinateUtils.getChunkKey(currX, currZ), node);
+                }
+            }
+        }
+
+        private void pushChildren(final DependencyNode node) {
+            // add all the children that we can into awaiting
+            final List<DependencyNode> children = node.children;
+            if (children != null) {
+                for (int i = 0, len = children.size(); i < len; ++i) {
+                    final DependencyNode child = children.get(i);
+                    int newParents = --child.parents;
+                    if (newParents == 0) {
+                        // no more dependents, we can push to awaiting
+                        // even if the child is purged, we need to push it so that its children will be pushed
+                        this.awaiting.add(child);
+                    } else if (newParents < 0) {
+                        throw new IllegalStateException();
+                    }
+                }
+            }
+        }
+
+        private DependencyNode pollAwaiting() {
+            final DependencyNode ret = this.awaiting.poll();
+            if (ret == null) {
+                return ret;
+            }
+
+            if (ret.parents != 0) {
+                throw new IllegalStateException();
+            }
+
+            if (ret.purged) {
+                // need to manually remove from state here
+                this.pushChildren(ret);
+                this.removeNodeFromMap(ret);
+            } // else: delay children push until the task has finished
+
+            return ret;
+        }
+
+        private DependencyNode pollInfinite() {
+            return this.infiniteRadius.poll();
+        }
+
+        public PrioritisedExecutor.PrioritisedTask tryPushTask() {
+            if (this.currentlyExecuting >= this.maxToSchedule || this.isInfiniteRadiusScheduled) {
+                return null;
+            }
+
+            DependencyNode firstInfinite;
+            while ((firstInfinite = this.infiniteRadius.peek()) != null && firstInfinite.purged) {
+                this.pollInfinite();
+            }
+
+            DependencyNode firstAwaiting;
+            while ((firstAwaiting = this.awaiting.peek()) != null && firstAwaiting.purged) {
+                this.pollAwaiting();
+            }
+
+            if (firstInfinite == null && firstAwaiting == null) {
+                return null;
+            }
+
+            // firstAwaiting compared to firstInfinite
+            final int compare;
+
+            if (firstAwaiting == null) {
+                // we choose first infinite, or infinite < awaiting
+                compare = 1;
+            } else if (firstInfinite == null) {
+                // we choose first awaiting, or awaiting < infinite
+                compare = -1;
+            } else {
+                compare = DEPENDENCY_NODE_COMPARATOR.compare(firstAwaiting, firstInfinite);
+            }
+
+            if (compare >= 0) {
+                if (this.currentlyExecuting != 0) {
+                    // don't queue infinite task while other tasks are executing in parallel
+                    return null;
+                }
+                ++this.currentlyExecuting;
+                this.pollInfinite();
+                this.isInfiniteRadiusScheduled = true;
+                return firstInfinite.task.pushTask(this.executor);
+            } else {
+                ++this.currentlyExecuting;
+                this.pollAwaiting();
+                return firstAwaiting.task.pushTask(this.executor);
+            }
+        }
+    }
+
+    private static final class DependencyNode {
+
+        private final Task task;
+        private final DependencyTree tree;
+
+        // dependency tree fields
+        // (must hold lock on the scheduler to use)
+        // null is the same as empty, we just use it so that we don't allocate the set unless we need to
+        private List<DependencyNode> children;
+        // 0 indicates that this task is considered "awaiting"
+        private int parents;
+        // false -> scheduled and not cancelled
+        // true -> scheduled but cancelled
+        private boolean purged;
+        private final long id;
+
+        public DependencyNode(final Task task, final DependencyTree tree) {
+            this.task = task;
+            this.id = tree.nextId();
+            this.tree = tree;
+        }
+    }
+
+    private static final class Task implements PrioritisedExecutor.PrioritisedTask, Runnable {
+
+        // task specific fields
+        private final RadiusAwarePrioritisedExecutor scheduler;
+        private final int chunkX;
+        private final int chunkZ;
+        private final int radius;
+        private Runnable run;
+        private Priority priority;
+
+        private DependencyNode dependencyNode;
+        private PrioritisedExecutor.PrioritisedTask queuedTask;
+
+        private Task(final RadiusAwarePrioritisedExecutor scheduler, final int chunkX, final int chunkZ, final int radius,
+                     final Runnable run, final Priority priority) {
+            this.scheduler = scheduler;
+            this.chunkX = chunkX;
+            this.chunkZ = chunkZ;
+            this.radius = radius;
+            this.run = run;
+            this.priority = priority;
+        }
+
+        private boolean isFiniteRadius() {
+            return this.radius >= 0;
+        }
+
+        private PrioritisedExecutor.PrioritisedTask pushTask(final PrioritisedExecutor executor) {
+            return this.queuedTask = executor.createTask(this, this.priority);
+        }
+
+        private void executeTask() {
+            final Runnable run = this.run;
+            this.run = null;
+            run.run();
+        }
+
+        private void returnNode() {
+            final List<PrioritisedExecutor.PrioritisedTask> toSchedule;
+            synchronized (this.scheduler) {
+                final DependencyNode node = this.dependencyNode;
+                this.dependencyNode = null;
+                toSchedule = node.tree.returnNode(node);
+            }
+
+            scheduleTasks(toSchedule);
+        }
+
+        @Override
+        public PrioritisedExecutor getExecutor() {
+            return this.scheduler.executor;
+        }
+
+        @Override
+        public void run() {
+            final Runnable run = this.run;
+            this.run = null;
+            try {
+                run.run();
+            } finally {
+                this.returnNode();
+            }
+        }
+
+        @Override
+        public boolean queue() {
+            final List<PrioritisedExecutor.PrioritisedTask> toSchedule;
+            synchronized (this.scheduler) {
+                if (this.queuedTask != null || this.dependencyNode != null || this.priority == Priority.COMPLETING) {
+                    return false;
+                }
+
+                toSchedule = this.scheduler.queue(this, this.priority);
+            }
+
+            scheduleTasks(toSchedule);
+            return true;
+        }
+
+        @Override
+        public boolean isQueued() {
+            synchronized (this.scheduler) {
+                return (this.queuedTask != null || this.dependencyNode != null) && this.priority != Priority.COMPLETING;
+            }
+        }
+
+        @Override
+        public boolean cancel() {
+            final PrioritisedExecutor.PrioritisedTask task;
+            synchronized (this.scheduler) {
+                if ((task = this.queuedTask) == null) {
+                    if (this.priority == Priority.COMPLETING) {
+                        return false;
+                    }
+
+                    this.priority = Priority.COMPLETING;
+                    if (this.dependencyNode != null) {
+                        this.dependencyNode.purged = true;
+                        this.dependencyNode = null;
+                    }
+
+                    return true;
+                }
+            }
+
+            if (task.cancel()) {
+                // must manually return the node
+                this.run = null;
+                this.returnNode();
+                return true;
+            }
+            return false;
+        }
+
+        @Override
+        public boolean execute() {
+            final PrioritisedExecutor.PrioritisedTask task;
+            synchronized (this.scheduler) {
+                if ((task = this.queuedTask) == null) {
+                    if (this.priority == Priority.COMPLETING) {
+                        return false;
+                    }
+
+                    this.priority = Priority.COMPLETING;
+                    if (this.dependencyNode != null) {
+                        this.dependencyNode.purged = true;
+                        this.dependencyNode = null;
+                    }
+                    // fall through to execution logic
+                }
+            }
+
+            if (task != null) {
+                // will run the return node logic automatically
+                return task.execute();
+            } else {
+                // don't run node removal/insertion logic, we aren't actually removed from the dependency tree
+                this.executeTask();
+                return true;
+            }
+        }
+
+        @Override
+        public Priority getPriority() {
+            final PrioritisedExecutor.PrioritisedTask task;
+            synchronized (this.scheduler) {
+                if ((task = this.queuedTask) == null) {
+                    return this.priority;
+                }
+            }
+
+            return task.getPriority();
+        }
+
+        @Override
+        public boolean setPriority(final Priority priority) {
+            if (!Priority.isValidPriority(priority)) {
+                throw new IllegalArgumentException("Invalid priority " + priority);
+            }
+
+            final PrioritisedExecutor.PrioritisedTask task;
+            List<PrioritisedExecutor.PrioritisedTask> toSchedule = null;
+            synchronized (this.scheduler) {
+                if ((task = this.queuedTask) == null) {
+                    if (this.priority == Priority.COMPLETING) {
+                        return false;
+                    }
+
+                    if (this.priority == priority) {
+                        return true;
+                    }
+
+                    this.priority = priority;
+                    if (this.dependencyNode != null) {
+                        // need to re-insert node
+                        this.dependencyNode.purged = true;
+                        this.dependencyNode = null;
+                        toSchedule = this.scheduler.queue(this, priority);
+                    }
+                }
+            }
+
+            if (task != null) {
+                return task.setPriority(priority);
+            }
+
+            scheduleTasks(toSchedule);
+
+            return true;
+        }
+
+        @Override
+        public boolean raisePriority(final Priority priority) {
+            if (!Priority.isValidPriority(priority)) {
+                throw new IllegalArgumentException("Invalid priority " + priority);
+            }
+
+            final PrioritisedExecutor.PrioritisedTask task;
+            List<PrioritisedExecutor.PrioritisedTask> toSchedule = null;
+            synchronized (this.scheduler) {
+                if ((task = this.queuedTask) == null) {
+                    if (this.priority == Priority.COMPLETING) {
+                        return false;
+                    }
+
+                    if (this.priority.isHigherOrEqualPriority(priority)) {
+                        return true;
+                    }
+
+                    this.priority = priority;
+                    if (this.dependencyNode != null) {
+                        // need to re-insert node
+                        this.dependencyNode.purged = true;
+                        this.dependencyNode = null;
+                        toSchedule = this.scheduler.queue(this, priority);
+                    }
+                }
+            }
+
+            if (task != null) {
+                return task.raisePriority(priority);
+            }
+
+            scheduleTasks(toSchedule);
+
+            return true;
+        }
+
+        @Override
+        public boolean lowerPriority(final Priority priority) {
+            if (!Priority.isValidPriority(priority)) {
+                throw new IllegalArgumentException("Invalid priority " + priority);
+            }
+
+            final PrioritisedExecutor.PrioritisedTask task;
+            List<PrioritisedExecutor.PrioritisedTask> toSchedule = null;
+            synchronized (this.scheduler) {
+                if ((task = this.queuedTask) == null) {
+                    if (this.priority == Priority.COMPLETING) {
+                        return false;
+                    }
+
+                    if (this.priority.isLowerOrEqualPriority(priority)) {
+                        return true;
+                    }
+
+                    this.priority = priority;
+                    if (this.dependencyNode != null) {
+                        // need to re-insert node
+                        this.dependencyNode.purged = true;
+                        this.dependencyNode = null;
+                        toSchedule = this.scheduler.queue(this, priority);
+                    }
+                }
+            }
+
+            if (task != null) {
+                return task.lowerPriority(priority);
+            }
+
+            scheduleTasks(toSchedule);
+
+            return true;
+        }
+
+        @Override
+        public long getSubOrder() {
+            // TODO implement
+            return 0;
+        }
+
+        @Override
+        public boolean setSubOrder(final long subOrder) {
+            // TODO implement
+            return false;
+        }
+
+        @Override
+        public boolean raiseSubOrder(final long subOrder) {
+            // TODO implement
+            return false;
+        }
+
+        @Override
+        public boolean lowerSubOrder(final long subOrder) {
+            // TODO implement
+            return false;
+        }
+
+        @Override
+        public boolean setPriorityAndSubOrder(final Priority priority, final long subOrder) {
+            // TODO implement
+            return this.setPriority(priority);
+        }
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/task/ChunkFullTask.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/task/ChunkFullTask.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/task/ChunkFullTask.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task;
+
+import ca.spottedleaf.concurrentutil.executor.PrioritisedExecutor;
+import ca.spottedleaf.concurrentutil.util.ConcurrentUtil;
+import ca.spottedleaf.concurrentutil.util.Priority;
+import ca.spottedleaf.moonrise.common.PlatformHooks;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemLevelChunk;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.poi.ChunkSystemPoiManager;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.poi.PoiChunk;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder;
+import net.minecraft.server.level.ServerChunkCache;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.ImposterProtoChunk;
+import net.minecraft.world.level.chunk.LevelChunk;
+import net.minecraft.world.level.chunk.ProtoChunk;
+import net.minecraft.world.level.chunk.status.ChunkStatus;
+import net.minecraft.world.level.chunk.status.ChunkStatusTasks;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import java.lang.invoke.VarHandle;
+
+public final class ChunkFullTask extends ChunkProgressionTask implements Runnable {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(ChunkFullTask.class);
+
+    private final NewChunkHolder chunkHolder;
+    private final ChunkAccess fromChunk;
+    private final PrioritisedExecutor.PrioritisedTask convertToFullTask;
+
+    public ChunkFullTask(final ChunkTaskScheduler scheduler, final ServerLevel world, final int chunkX, final int chunkZ,
+                         final NewChunkHolder chunkHolder, final ChunkAccess fromChunk, final Priority priority) {
+        super(scheduler, world, chunkX, chunkZ);
+        this.chunkHolder = chunkHolder;
+        this.fromChunk = fromChunk;
+        this.convertToFullTask = scheduler.createChunkTask(chunkX, chunkZ, this, priority);
+    }
+
+    @Override
+    public ChunkStatus getTargetStatus() {
+        return ChunkStatus.FULL;
+    }
+
+    @Override
+    public void run() {
+        final PlatformHooks platformHooks = PlatformHooks.get();
+
+        // See Vanilla ChunkPyramid#LOADING_PYRAMID.FULL for what this function should be doing
+        final LevelChunk chunk;
+        try {
+            // moved from the load from nbt stage into here
+            final PoiChunk poiChunk = this.chunkHolder.getPoiChunk();
+            if (poiChunk == null) {
+                LOGGER.error("Expected poi chunk to be loaded with chunk for task " + this.toString());
+            } else {
+                poiChunk.load();
+                ((ChunkSystemPoiManager)this.world.getPoiManager()).moonrise$checkConsistency(this.fromChunk);
+            }
+
+            if (this.fromChunk instanceof ImposterProtoChunk wrappedFull) {
+                chunk = wrappedFull.getWrapped();
+            } else {
+                final ServerLevel world = this.world;
+                final ProtoChunk protoChunk = (ProtoChunk)this.fromChunk;
+                chunk = new LevelChunk(this.world, protoChunk, (final LevelChunk unused) -> {
+                    PlatformHooks.get().postLoadProtoChunk(world, protoChunk);
+                });
+                this.chunkHolder.replaceProtoChunk(new ImposterProtoChunk(chunk, false));
+            }
+
+            ((ChunkSystemLevelChunk)chunk).moonrise$setChunkAndHolder(new ServerChunkCache.ChunkAndHolder(chunk, this.chunkHolder.vanillaChunkHolder));
+
+            final NewChunkHolder chunkHolder = this.chunkHolder;
+
+            chunk.setFullStatus(chunkHolder::getChunkStatus);
+            try {
+                platformHooks.setCurrentlyLoading(this.chunkHolder.vanillaChunkHolder, chunk);
+                chunk.runPostLoad();
+                // Unlike Vanilla, we load the entity chunk here, as we load the NBT in empty status (unlike Vanilla)
+                // This brings entity addition back in line with older versions of the game
+                // Since we load the NBT in the empty status, this will never block for I/O
+                ((ChunkSystemServerLevel)this.world).moonrise$getChunkTaskScheduler().chunkHolderManager.getOrCreateEntityChunk(this.chunkX, this.chunkZ, false);
+                chunk.setLoaded(true);
+                chunk.registerAllBlockEntitiesAfterLevelLoad();
+                chunk.registerTickContainerInLevel(this.world);
+                chunk.setUnsavedListener(this.world.getChunkSource().chunkMap.worldGenContext.unsavedListener());
+                platformHooks.chunkFullStatusComplete(chunk, (ProtoChunk)this.fromChunk);
+            } finally {
+                platformHooks.setCurrentlyLoading(this.chunkHolder.vanillaChunkHolder, null);
+            }
+        } catch (final Throwable throwable) {
+            this.complete(null, throwable);
+            return;
+        }
+        this.complete(chunk, null);
+    }
+
+    protected volatile boolean scheduled;
+    protected static final VarHandle SCHEDULED_HANDLE = ConcurrentUtil.getVarHandle(ChunkFullTask.class, "scheduled", boolean.class);
+
+    @Override
+    public boolean isScheduled() {
+        return this.scheduled;
+    }
+
+    @Override
+    public void schedule() {
+        if ((boolean)SCHEDULED_HANDLE.getAndSet((ChunkFullTask)this, true)) {
+            throw new IllegalStateException("Cannot double call schedule()");
+        }
+        this.convertToFullTask.queue();
+    }
+
+    @Override
+    public void cancel() {
+        if (this.convertToFullTask.cancel()) {
+            this.complete(null, null);
+        }
+    }
+
+    @Override
+    public Priority getPriority() {
+        return this.convertToFullTask.getPriority();
+    }
+
+    @Override
+    public void lowerPriority(final Priority priority) {
+        if (!Priority.isValidPriority(priority)) {
+            throw new IllegalArgumentException("Invalid priority " + priority);
+        }
+        this.convertToFullTask.lowerPriority(priority);
+    }
+
+    @Override
+    public void setPriority(final Priority priority) {
+        if (!Priority.isValidPriority(priority)) {
+            throw new IllegalArgumentException("Invalid priority " + priority);
+        }
+        this.convertToFullTask.setPriority(priority);
+    }
+
+    @Override
+    public void raisePriority(final Priority priority) {
+        if (!Priority.isValidPriority(priority)) {
+            throw new IllegalArgumentException("Invalid priority " + priority);
+        }
+        this.convertToFullTask.raisePriority(priority);
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/task/ChunkLightTask.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/task/ChunkLightTask.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/task/ChunkLightTask.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task;
+
+import ca.spottedleaf.concurrentutil.util.Priority;
+import ca.spottedleaf.moonrise.common.util.WorldUtil;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.PriorityHolder;
+import ca.spottedleaf.moonrise.patches.starlight.light.StarLightEngine;
+import ca.spottedleaf.moonrise.patches.starlight.light.StarLightInterface;
+import ca.spottedleaf.moonrise.patches.starlight.light.StarLightLightingProvider;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.ProtoChunk;
+import net.minecraft.world.level.chunk.status.ChunkStatus;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import java.util.function.BooleanSupplier;
+
+public final class ChunkLightTask extends ChunkProgressionTask {
+
+    private static final Logger LOGGER = LogManager.getLogger();
+
+    private final ChunkAccess fromChunk;
+
+    private final LightTaskPriorityHolder priorityHolder;
+
+    public ChunkLightTask(final ChunkTaskScheduler scheduler, final ServerLevel world, final int chunkX, final int chunkZ,
+                          final ChunkAccess chunk, final Priority priority) {
+        super(scheduler, world, chunkX, chunkZ);
+        if (!Priority.isValidPriority(priority)) {
+            throw new IllegalArgumentException("Invalid priority " + priority);
+        }
+        this.priorityHolder = new LightTaskPriorityHolder(priority, this);
+        this.fromChunk = chunk;
+    }
+
+    @Override
+    public boolean isScheduled() {
+        return this.priorityHolder.isScheduled();
+    }
+
+    @Override
+    public ChunkStatus getTargetStatus() {
+        return ChunkStatus.LIGHT;
+    }
+
+    @Override
+    public void schedule() {
+        this.priorityHolder.schedule();
+    }
+
+    @Override
+    public void cancel() {
+        this.priorityHolder.cancel();
+    }
+
+    @Override
+    public Priority getPriority() {
+        return this.priorityHolder.getPriority();
+    }
+
+    @Override
+    public void lowerPriority(final Priority priority) {
+        this.priorityHolder.raisePriority(priority);
+    }
+
+    @Override
+    public void setPriority(final Priority priority) {
+        this.priorityHolder.setPriority(priority);
+    }
+
+    @Override
+    public void raisePriority(final Priority priority) {
+        this.priorityHolder.raisePriority(priority);
+    }
+
+    private static final class LightTaskPriorityHolder extends PriorityHolder {
+
+        private final ChunkLightTask task;
+
+        private LightTaskPriorityHolder(final Priority priority, final ChunkLightTask task) {
+            super(priority);
+            this.task = task;
+        }
+
+        @Override
+        protected void cancelScheduled() {
+            final ChunkLightTask task = this.task;
+            task.complete(null, null);
+        }
+
+        @Override
+        protected Priority getScheduledPriority() {
+            final ChunkLightTask task = this.task;
+            return ((StarLightLightingProvider)task.world.getChunkSource().getLightEngine()).starlight$getLightEngine().getServerLightQueue().getPriority(task.chunkX, task.chunkZ);
+        }
+
+        @Override
+        protected void scheduleTask(final Priority priority) {
+            final ChunkLightTask task = this.task;
+            final StarLightInterface starLightInterface = ((StarLightLightingProvider)task.world.getChunkSource().getLightEngine()).starlight$getLightEngine();
+            final StarLightInterface.ServerLightQueue lightQueue = starLightInterface.getServerLightQueue();
+            lightQueue.queueChunkLightTask(new ChunkPos(task.chunkX, task.chunkZ), new LightTask(starLightInterface, task), priority);
+            lightQueue.setPriority(task.chunkX, task.chunkZ, priority);
+        }
+
+        @Override
+        protected void lowerPriorityScheduled(final Priority priority) {
+            final ChunkLightTask task = this.task;
+            final StarLightInterface starLightInterface = ((StarLightLightingProvider)task.world.getChunkSource().getLightEngine()).starlight$getLightEngine();
+            final StarLightInterface.ServerLightQueue lightQueue = starLightInterface.getServerLightQueue();
+            lightQueue.lowerPriority(task.chunkX, task.chunkZ, priority);
+        }
+
+        @Override
+        protected void setPriorityScheduled(final Priority priority) {
+            final ChunkLightTask task = this.task;
+            final StarLightInterface starLightInterface = ((StarLightLightingProvider)task.world.getChunkSource().getLightEngine()).starlight$getLightEngine();
+            final StarLightInterface.ServerLightQueue lightQueue = starLightInterface.getServerLightQueue();
+            lightQueue.setPriority(task.chunkX, task.chunkZ, priority);
+        }
+
+        @Override
+        protected void raisePriorityScheduled(final Priority priority) {
+            final ChunkLightTask task = this.task;
+            final StarLightInterface starLightInterface = ((StarLightLightingProvider)task.world.getChunkSource().getLightEngine()).starlight$getLightEngine();
+            final StarLightInterface.ServerLightQueue lightQueue = starLightInterface.getServerLightQueue();
+            lightQueue.raisePriority(task.chunkX, task.chunkZ, priority);
+        }
+    }
+
+    private static final class LightTask implements BooleanSupplier {
+
+        private final StarLightInterface lightEngine;
+        private final ChunkLightTask task;
+
+        public LightTask(final StarLightInterface lightEngine, final ChunkLightTask task) {
+            this.lightEngine = lightEngine;
+            this.task = task;
+        }
+
+        @Override
+        public boolean getAsBoolean() {
+            final ChunkLightTask task = this.task;
+            // executed on light thread
+            if (!task.priorityHolder.markExecuting()) {
+                // cancelled
+                return false;
+            }
+
+            try {
+                final Boolean[] emptySections = StarLightEngine.getEmptySectionsForChunk(task.fromChunk);
+
+                if (task.fromChunk.isLightCorrect() && task.fromChunk.getPersistedStatus().isOrAfter(ChunkStatus.LIGHT)) {
+                    this.lightEngine.forceLoadInChunk(task.fromChunk, emptySections);
+                    this.lightEngine.checkChunkEdges(task.chunkX, task.chunkZ);
+                } else {
+                    task.fromChunk.setLightCorrect(false);
+                    this.lightEngine.lightChunk(task.fromChunk, emptySections);
+                    task.fromChunk.setLightCorrect(true);
+                }
+                // we need to advance status
+                if (task.fromChunk instanceof ProtoChunk chunk && chunk.getPersistedStatus() == ChunkStatus.LIGHT.getParent()) {
+                    chunk.setPersistedStatus(ChunkStatus.LIGHT);
+                }
+            } catch (final Throwable thr) {
+                LOGGER.fatal(
+                        "Failed to light chunk " + task.fromChunk.getPos().toString()
+                                + " in world '" + WorldUtil.getWorldName(this.lightEngine.getWorld()) + "'", thr
+                );
+
+                task.complete(null, thr);
+
+                return true;
+            }
+
+            task.complete(task.fromChunk, null);
+            return true;
+        }
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/task/ChunkLoadTask.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/task/ChunkLoadTask.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/task/ChunkLoadTask.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task;
+
+import ca.spottedleaf.concurrentutil.collection.MultiThreadedQueue;
+import ca.spottedleaf.concurrentutil.executor.PrioritisedExecutor;
+import ca.spottedleaf.concurrentutil.lock.ReentrantAreaLock;
+import ca.spottedleaf.concurrentutil.util.ConcurrentUtil;
+import ca.spottedleaf.concurrentutil.util.Priority;
+import ca.spottedleaf.moonrise.common.PlatformHooks;
+import ca.spottedleaf.moonrise.patches.chunk_system.ChunkSystemConverters;
+import ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.poi.PoiChunk;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder;
+import net.minecraft.core.registries.Registries;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.ProtoChunk;
+import net.minecraft.world.level.chunk.UpgradeData;
+import net.minecraft.world.level.chunk.status.ChunkStatus;
+import net.minecraft.world.level.chunk.storage.SerializableChunkData;
+import net.minecraft.world.level.levelgen.blending.BlendingData;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import java.lang.invoke.VarHandle;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Consumer;
+
+public final class ChunkLoadTask extends ChunkProgressionTask {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(ChunkLoadTask.class);
+
+    private final NewChunkHolder chunkHolder;
+    private final ChunkDataLoadTask loadTask;
+
+    private volatile boolean cancelled;
+    private NewChunkHolder.GenericDataLoadTaskCallback entityLoadTask;
+    private NewChunkHolder.GenericDataLoadTaskCallback poiLoadTask;
+    private GenericDataLoadTask.TaskResult<ChunkAccess, Throwable> loadResult;
+    private final AtomicInteger taskCountToComplete = new AtomicInteger(3); // one for poi, one for entity, and one for chunk data
+
+    public ChunkLoadTask(final ChunkTaskScheduler scheduler, final ServerLevel world, final int chunkX, final int chunkZ,
+                         final NewChunkHolder chunkHolder, final Priority priority) {
+        super(scheduler, world, chunkX, chunkZ);
+        this.chunkHolder = chunkHolder;
+        this.loadTask = new ChunkDataLoadTask(scheduler, world, chunkX, chunkZ, priority);
+        this.loadTask.addCallback((final GenericDataLoadTask.TaskResult<ChunkAccess, Throwable> result) -> {
+            ChunkLoadTask.this.loadResult = result; // must be before getAndDecrement
+            ChunkLoadTask.this.tryCompleteLoad();
+        });
+    }
+
+    private void tryCompleteLoad() {
+        final int count = this.taskCountToComplete.decrementAndGet();
+        if (count == 0) {
+            final GenericDataLoadTask.TaskResult<ChunkAccess, Throwable> result = this.cancelled ? null : this.loadResult; // only after the getAndDecrement
+            ChunkLoadTask.this.complete(result == null ? null : result.left(), result == null ? null : result.right());
+        } else if (count < 0) {
+            throw new IllegalStateException("Called tryCompleteLoad() too many times");
+        }
+    }
+
+    @Override
+    public ChunkStatus getTargetStatus() {
+        return ChunkStatus.EMPTY;
+    }
+
+    private boolean scheduled;
+
+    @Override
+    public boolean isScheduled() {
+        return this.scheduled;
+    }
+
+    @Override
+    public void schedule() {
+        final NewChunkHolder.GenericDataLoadTaskCallback entityLoadTask;
+        final NewChunkHolder.GenericDataLoadTaskCallback poiLoadTask;
+
+        final Consumer<GenericDataLoadTask.TaskResult<?, ?>> scheduleLoadTask = (final GenericDataLoadTask.TaskResult<?, ?> result) -> {
+            ChunkLoadTask.this.tryCompleteLoad();
+        };
+
+        // NOTE: it is IMPOSSIBLE for getOrLoadEntityData/getOrLoadPoiData to complete synchronously, because
+        // they must schedule a task to off main or to on main to complete
+        final ReentrantAreaLock.Node schedulingLock = this.scheduler.schedulingLockArea.lock(this.chunkX, this.chunkZ);
+        try {
+            if (this.scheduled) {
+                throw new IllegalStateException("schedule() called twice");
+            }
+            this.scheduled = true;
+            if (this.cancelled) {
+                return;
+            }
+            if (!this.chunkHolder.isEntityChunkNBTLoaded()) {
+                entityLoadTask = this.chunkHolder.getOrLoadEntityData((Consumer)scheduleLoadTask);
+            } else {
+                entityLoadTask = null;
+                this.tryCompleteLoad();
+            }
+
+            if (!this.chunkHolder.isPoiChunkLoaded()) {
+                poiLoadTask = this.chunkHolder.getOrLoadPoiData((Consumer)scheduleLoadTask);
+            } else {
+                poiLoadTask = null;
+                this.tryCompleteLoad();
+            }
+
+            this.entityLoadTask = entityLoadTask;
+            this.poiLoadTask = poiLoadTask;
+        } finally {
+            this.scheduler.schedulingLockArea.unlock(schedulingLock);
+        }
+
+        if (entityLoadTask != null) {
+            entityLoadTask.schedule();
+        }
+
+        if (poiLoadTask != null) {
+            poiLoadTask.schedule();
+        }
+
+        this.loadTask.schedule(false);
+    }
+
+    @Override
+    public void cancel() {
+        // must be before load task access, so we can synchronise with the writes to the fields
+        final boolean scheduled;
+        final ReentrantAreaLock.Node schedulingLock = this.scheduler.schedulingLockArea.lock(this.chunkX, this.chunkZ);
+        try {
+            // must read field here, as it may be written later conucrrently -
+            // we need to know if we scheduled _before_ cancellation
+            scheduled = this.scheduled;
+            this.cancelled = true;
+        } finally {
+            this.scheduler.schedulingLockArea.unlock(schedulingLock);
+        }
+
+        /*
+        Note: The entityLoadTask/poiLoadTask do not complete when cancelled,
+        so we need to manually try to complete in those cases
+        It is also important to note that we set the cancelled field first, just in case
+        the chunk load task attempts to complete with a non-null value
+        */
+
+        if (scheduled) {
+            // since we scheduled, we need to cancel the tasks
+            if (this.entityLoadTask != null) {
+                if (this.entityLoadTask.cancel()) {
+                    this.tryCompleteLoad();
+                }
+            }
+            if (this.poiLoadTask != null) {
+                if (this.poiLoadTask.cancel()) {
+                    this.tryCompleteLoad();
+                }
+            }
+        } else {
+            // since nothing was scheduled, we need to decrement the task count here ourselves
+
+            // for entity load task
+            this.tryCompleteLoad();
+
+            // for poi load task
+            this.tryCompleteLoad();
+        }
+        this.loadTask.cancel();
+    }
+
+    @Override
+    public Priority getPriority() {
+        return this.loadTask.getPriority();
+    }
+
+    @Override
+    public void lowerPriority(final Priority priority) {
+        final EntityDataLoadTask entityLoad = this.chunkHolder.getEntityDataLoadTask();
+        if (entityLoad != null) {
+            entityLoad.lowerPriority(priority);
+        }
+
+        final PoiDataLoadTask poiLoad = this.chunkHolder.getPoiDataLoadTask();
+
+        if (poiLoad != null) {
+            poiLoad.lowerPriority(priority);
+        }
+
+        this.loadTask.lowerPriority(priority);
+    }
+
+    @Override
+    public void setPriority(final Priority priority) {
+        final EntityDataLoadTask entityLoad = this.chunkHolder.getEntityDataLoadTask();
+        if (entityLoad != null) {
+            entityLoad.setPriority(priority);
+        }
+
+        final PoiDataLoadTask poiLoad = this.chunkHolder.getPoiDataLoadTask();
+
+        if (poiLoad != null) {
+            poiLoad.setPriority(priority);
+        }
+
+        this.loadTask.setPriority(priority);
+    }
+
+    @Override
+    public void raisePriority(final Priority priority) {
+        final EntityDataLoadTask entityLoad = this.chunkHolder.getEntityDataLoadTask();
+        if (entityLoad != null) {
+            entityLoad.raisePriority(priority);
+        }
+
+        final PoiDataLoadTask poiLoad = this.chunkHolder.getPoiDataLoadTask();
+
+        if (poiLoad != null) {
+            poiLoad.raisePriority(priority);
+        }
+
+        this.loadTask.raisePriority(priority);
+    }
+
+    protected static abstract class CallbackDataLoadTask<OnMain,FinalCompletion> extends GenericDataLoadTask<OnMain,FinalCompletion> {
+
+        private TaskResult<FinalCompletion, Throwable> result;
+        private final MultiThreadedQueue<Consumer<TaskResult<FinalCompletion, Throwable>>> waiters = new MultiThreadedQueue<>();
+
+        protected volatile boolean completed;
+        protected static final VarHandle COMPLETED_HANDLE = ConcurrentUtil.getVarHandle(CallbackDataLoadTask.class, "completed", boolean.class);
+
+        protected CallbackDataLoadTask(final ChunkTaskScheduler scheduler, final ServerLevel world, final int chunkX,
+                                       final int chunkZ, final MoonriseRegionFileIO.RegionFileType type,
+                                       final Priority priority) {
+            super(scheduler, world, chunkX, chunkZ, type, priority);
+        }
+
+        public void addCallback(final Consumer<TaskResult<FinalCompletion, Throwable>> consumer) {
+            if (!this.waiters.add(consumer)) {
+                try {
+                    consumer.accept(this.result);
+                } catch (final Throwable throwable) {
+                    this.scheduler.unrecoverableChunkSystemFailure(this.chunkX, this.chunkZ, Map.of(
+                        "Consumer", ChunkTaskScheduler.stringIfNull(consumer),
+                        "Completed throwable", ChunkTaskScheduler.stringIfNull(this.result.right()),
+                        "CallbackDataLoadTask impl", this.getClass().getName()
+                    ), throwable);
+                }
+            }
+        }
+
+        @Override
+        protected void onComplete(final TaskResult<FinalCompletion, Throwable> result) {
+            if ((boolean)COMPLETED_HANDLE.getAndSet((CallbackDataLoadTask)this, (boolean)true)) {
+                throw new IllegalStateException("Already completed");
+            }
+            this.result = result;
+            Consumer<TaskResult<FinalCompletion, Throwable>> consumer;
+            while ((consumer = this.waiters.pollOrBlockAdds()) != null) {
+                try {
+                    consumer.accept(result);
+                } catch (final Throwable throwable) {
+                    this.scheduler.unrecoverableChunkSystemFailure(this.chunkX, this.chunkZ, Map.of(
+                        "Consumer", ChunkTaskScheduler.stringIfNull(consumer),
+                        "Completed throwable", ChunkTaskScheduler.stringIfNull(result.right()),
+                        "CallbackDataLoadTask impl", this.getClass().getName()
+                    ), throwable);
+                    return;
+                }
+            }
+        }
+    }
+
+
+    private static record ReadChunk(ProtoChunk protoChunk, SerializableChunkData chunkData) {}
+
+    private static final class ChunkDataLoadTask extends CallbackDataLoadTask<ReadChunk, ChunkAccess> {
+        private ChunkDataLoadTask(final ChunkTaskScheduler scheduler, final ServerLevel world, final int chunkX,
+                                  final int chunkZ, final Priority priority) {
+            super(scheduler, world, chunkX, chunkZ, MoonriseRegionFileIO.RegionFileType.CHUNK_DATA, priority);
+        }
+
+        @Override
+        protected boolean hasOffMain() {
+            return true;
+        }
+
+        @Override
+        protected boolean hasOnMain() {
+            return true;
+        }
+
+        @Override
+        protected PrioritisedExecutor.PrioritisedTask createOffMain(final Runnable run, final Priority priority) {
+            return this.scheduler.loadExecutor.createTask(run, priority);
+        }
+
+        @Override
+        protected PrioritisedExecutor.PrioritisedTask createOnMain(final Runnable run, final Priority priority) {
+            return this.scheduler.createChunkTask(this.chunkX, this.chunkZ, run, priority);
+        }
+
+        @Override
+        protected TaskResult<ChunkAccess, Throwable> completeOnMainOffMain(final ReadChunk data, final Throwable throwable) {
+            if (throwable != null) {
+                return new TaskResult<>(null, throwable);
+            }
+
+            if (data == null || data.protoChunk() == null) {
+                return new TaskResult<>(this.getEmptyChunk(), null);
+            }
+
+            if (!PlatformHooks.get().hasMainChunkLoadHook()) {
+                return new TaskResult<>(data.protoChunk(), null);
+            }
+
+            // need to invoke the callback for loading on the main thread
+            return null;
+        }
+
+        private ProtoChunk getEmptyChunk() {
+            return new ProtoChunk(
+                new ChunkPos(this.chunkX, this.chunkZ), UpgradeData.EMPTY, this.world,
+                this.world.registryAccess().lookupOrThrow(Registries.BIOME), (BlendingData)null
+            );
+        }
+
+        @Override
+        protected TaskResult<ReadChunk, Throwable> runOffMain(final CompoundTag data, final Throwable throwable) {
+            if (throwable != null) {
+                LOGGER.error("Failed to load chunk data for task: " + this.toString() + ", chunk data will be lost", throwable);
+                return new TaskResult<>(null, null);
+            }
+
+            if (data == null) {
+                return new TaskResult<>(null, null);
+            }
+
+            try {
+                // run converters
+                final CompoundTag converted = this.world.getChunkSource().chunkMap.upgradeChunkTag(data, new ChunkPos(this.chunkX, this.chunkZ)); // Paper
+
+                // unpack the data
+                final SerializableChunkData chunkData = SerializableChunkData.parse(
+                    this.world, this.world.registryAccess(), converted
+                );
+
+                if (chunkData == null) {
+                    LOGGER.error("Deserialized chunk for task: " + this.toString() + " produced null, chunk data will be lost?");
+                }
+
+                // read into ProtoChunk
+                final ProtoChunk chunk = chunkData == null ? null : chunkData.read(
+                    this.world, this.world.getPoiManager(), this.world.getChunkSource().chunkMap.storageInfo(),
+                    new ChunkPos(this.chunkX, this.chunkZ)
+                );
+
+                return new TaskResult<>(new ReadChunk(chunk, chunkData), null);
+            } catch (final Throwable thr2) {
+                LOGGER.error("Failed to parse chunk data for task: " + this.toString() + ", chunk data will be lost", thr2);
+                return new TaskResult<>(null, null);
+            }
+        }
+
+        @Override
+        protected TaskResult<ChunkAccess, Throwable> runOnMain(final ReadChunk data, final Throwable throwable) {
+            PlatformHooks.get().mainChunkLoad(data.protoChunk(), data.chunkData());
+
+            return new TaskResult<>(data.protoChunk(), null);
+        }
+    }
+
+    public static final class PoiDataLoadTask extends CallbackDataLoadTask<PoiChunk, PoiChunk> {
+
+        public PoiDataLoadTask(final ChunkTaskScheduler scheduler, final ServerLevel world, final int chunkX,
+                               final int chunkZ, final Priority priority) {
+            super(scheduler, world, chunkX, chunkZ, MoonriseRegionFileIO.RegionFileType.POI_DATA, priority);
+        }
+
+        @Override
+        protected boolean hasOffMain() {
+            return true;
+        }
+
+        @Override
+        protected boolean hasOnMain() {
+            return false;
+        }
+
+        @Override
+        protected PrioritisedExecutor.PrioritisedTask createOffMain(final Runnable run, final Priority priority) {
+            return this.scheduler.loadExecutor.createTask(run, priority);
+        }
+
+        @Override
+        protected PrioritisedExecutor.PrioritisedTask createOnMain(final Runnable run, final Priority priority) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        protected TaskResult<PoiChunk, Throwable> completeOnMainOffMain(final PoiChunk data, final Throwable throwable) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        protected TaskResult<PoiChunk, Throwable> runOffMain(final CompoundTag data, final Throwable throwable) {
+            if (throwable != null) {
+                LOGGER.error("Failed to load poi data for task: " + this.toString() + ", poi data will be lost", throwable);
+                return new TaskResult<>(PoiChunk.empty(this.world, this.chunkX, this.chunkZ), null);
+            }
+
+            if (data == null || data.isEmpty()) {
+                // nothing to do
+                return new TaskResult<>(PoiChunk.empty(this.world, this.chunkX, this.chunkZ), null);
+            }
+
+            try {
+                // run converters
+                final CompoundTag converted = ChunkSystemConverters.convertPoiCompoundTag(data, this.world);
+
+                // now we need to parse it
+                return new TaskResult<>(PoiChunk.parse(this.world, this.chunkX, this.chunkZ, converted), null);
+            } catch (final Throwable thr2) {
+                LOGGER.error("Failed to run parse poi data for task: " + this.toString() + ", poi data will be lost", thr2);
+                return new TaskResult<>(PoiChunk.empty(this.world, this.chunkX, this.chunkZ), null);
+            }
+        }
+
+        @Override
+        protected TaskResult<PoiChunk, Throwable> runOnMain(final PoiChunk data, final Throwable throwable) {
+            throw new UnsupportedOperationException();
+        }
+    }
+
+    public static final class EntityDataLoadTask extends CallbackDataLoadTask<CompoundTag, CompoundTag> {
+
+        public EntityDataLoadTask(final ChunkTaskScheduler scheduler, final ServerLevel world, final int chunkX,
+                                  final int chunkZ, final Priority priority) {
+            super(scheduler, world, chunkX, chunkZ, MoonriseRegionFileIO.RegionFileType.ENTITY_DATA, priority);
+        }
+
+        @Override
+        protected boolean hasOffMain() {
+            return true;
+        }
+
+        @Override
+        protected boolean hasOnMain() {
+            return false;
+        }
+
+        @Override
+        protected PrioritisedExecutor.PrioritisedTask createOffMain(final Runnable run, final Priority priority) {
+            return this.scheduler.loadExecutor.createTask(run, priority);
+        }
+
+        @Override
+        protected PrioritisedExecutor.PrioritisedTask createOnMain(final Runnable run, final Priority priority) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        protected TaskResult<CompoundTag, Throwable> completeOnMainOffMain(final CompoundTag data, final Throwable throwable) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        protected TaskResult<CompoundTag, Throwable> runOffMain(final CompoundTag data, final Throwable throwable) {
+            if (throwable != null) {
+                LOGGER.error("Failed to load entity data for task: " + this.toString() + ", entity data will be lost", throwable);
+                return new TaskResult<>(null, null);
+            }
+
+            if (data == null || data.isEmpty()) {
+                // nothing to do
+                return new TaskResult<>(null, null);
+            }
+
+            try {
+                return new TaskResult<>(ChunkSystemConverters.convertEntityChunkCompoundTag(data, this.world), null);
+            } catch (final Throwable thr2) {
+                LOGGER.error("Failed to run converters for entity data for task: " + this.toString() + ", entity data will be lost", thr2);
+                return new TaskResult<>(null, thr2);
+            }
+        }
+
+        @Override
+        protected TaskResult<CompoundTag, Throwable> runOnMain(final CompoundTag data, final Throwable throwable) {
+            throw new UnsupportedOperationException();
+        }
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/task/ChunkProgressionTask.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/task/ChunkProgressionTask.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/task/ChunkProgressionTask.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task;
+
+import ca.spottedleaf.concurrentutil.collection.MultiThreadedQueue;
+import ca.spottedleaf.concurrentutil.util.ConcurrentUtil;
+import ca.spottedleaf.concurrentutil.util.Priority;
+import ca.spottedleaf.moonrise.common.util.WorldUtil;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.status.ChunkStatus;
+import java.lang.invoke.VarHandle;
+import java.util.Map;
+import java.util.function.BiConsumer;
+
+public abstract class ChunkProgressionTask {
+
+    private final MultiThreadedQueue<BiConsumer<ChunkAccess, Throwable>> waiters = new MultiThreadedQueue<>();
+    private ChunkAccess completedChunk;
+    private Throwable completedThrowable;
+
+    protected final ChunkTaskScheduler scheduler;
+    protected final ServerLevel world;
+    protected final int chunkX;
+    protected final int chunkZ;
+
+    protected volatile boolean completed;
+    protected static final VarHandle COMPLETED_HANDLE = ConcurrentUtil.getVarHandle(ChunkProgressionTask.class, "completed", boolean.class);
+
+    protected ChunkProgressionTask(final ChunkTaskScheduler scheduler, final ServerLevel world, final int chunkX, final int chunkZ) {
+        this.scheduler = scheduler;
+        this.world = world;
+        this.chunkX = chunkX;
+        this.chunkZ = chunkZ;
+    }
+
+    // Used only for debug json
+    public abstract boolean isScheduled();
+
+    // Note: It is the responsibility of the task to set the chunk's status once it has completed
+    public abstract ChunkStatus getTargetStatus();
+
+    /* Only executed once */
+    /* Implementations must be prepared to handle cases where cancel() is called before schedule() */
+    public abstract void schedule();
+
+    /* May be called multiple times */
+    public abstract void cancel();
+
+    public abstract Priority getPriority();
+
+    /* Schedule lock is always held for the priority update calls */
+
+    public abstract void lowerPriority(final Priority priority);
+
+    public abstract void setPriority(final Priority priority);
+
+    public abstract void raisePriority(final Priority priority);
+
+    public final void onComplete(final BiConsumer<ChunkAccess, Throwable> onComplete) {
+        if (!this.waiters.add(onComplete)) {
+            try {
+                onComplete.accept(this.completedChunk, this.completedThrowable);
+            } catch (final Throwable throwable) {
+                this.scheduler.unrecoverableChunkSystemFailure(this.chunkX, this.chunkZ, Map.of(
+                    "Consumer", ChunkTaskScheduler.stringIfNull(onComplete),
+                    "Completed throwable", ChunkTaskScheduler.stringIfNull(this.completedThrowable)
+                ), throwable);
+            }
+        }
+    }
+
+    protected final void complete(final ChunkAccess chunk, final Throwable throwable) {
+        try {
+            this.complete0(chunk, throwable);
+        } catch (final Throwable thr2) {
+            this.scheduler.unrecoverableChunkSystemFailure(this.chunkX, this.chunkZ, Map.of(
+                "Completed throwable", ChunkTaskScheduler.stringIfNull(throwable)
+            ), thr2);
+        }
+    }
+
+    private void complete0(final ChunkAccess chunk, final Throwable throwable) {
+        if ((boolean)COMPLETED_HANDLE.getAndSet((ChunkProgressionTask)this, (boolean)true)) {
+            throw new IllegalStateException("Already completed");
+        }
+        this.completedChunk = chunk;
+        this.completedThrowable = throwable;
+
+        BiConsumer<ChunkAccess, Throwable> consumer;
+        while ((consumer = this.waiters.pollOrBlockAdds()) != null) {
+            consumer.accept(chunk, throwable);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return "ChunkProgressionTask{class: " + this.getClass().getName() + ", for world: " + WorldUtil.getWorldName(this.world) +
+            ", chunk: (" + this.chunkX + "," + this.chunkZ + "), hashcode: " + System.identityHashCode(this) + ", priority: " + this.getPriority() +
+            ", status: " + this.getTargetStatus().toString() + ", scheduled: " + this.isScheduled() + "}";
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/task/ChunkUpgradeGenericStatusTask.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/task/ChunkUpgradeGenericStatusTask.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/task/ChunkUpgradeGenericStatusTask.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task;
+
+import ca.spottedleaf.concurrentutil.executor.PrioritisedExecutor;
+import ca.spottedleaf.concurrentutil.util.ConcurrentUtil;
+import ca.spottedleaf.concurrentutil.util.Priority;
+import ca.spottedleaf.moonrise.common.util.WorldUtil;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemChunkStatus;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler;
+import net.minecraft.server.level.ChunkHolder;
+import net.minecraft.server.level.ChunkMap;
+import net.minecraft.server.level.GenerationChunkHolder;
+import net.minecraft.server.level.ServerChunkCache;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.util.StaticCache2D;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.ProtoChunk;
+import net.minecraft.world.level.chunk.status.ChunkPyramid;
+import net.minecraft.world.level.chunk.status.ChunkStatus;
+import net.minecraft.world.level.chunk.status.WorldGenContext;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import java.lang.invoke.VarHandle;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.CompletableFuture;
+
+public final class ChunkUpgradeGenericStatusTask extends ChunkProgressionTask implements Runnable {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(ChunkUpgradeGenericStatusTask.class);
+
+    private final ChunkAccess fromChunk;
+    private final ChunkStatus fromStatus;
+    private final ChunkStatus toStatus;
+    private final StaticCache2D<GenerationChunkHolder> neighbours;
+
+    private final PrioritisedExecutor.PrioritisedTask generateTask;
+
+    public ChunkUpgradeGenericStatusTask(final ChunkTaskScheduler scheduler, final ServerLevel world, final int chunkX,
+                                         final int chunkZ, final ChunkAccess chunk, final StaticCache2D<GenerationChunkHolder> neighbours,
+                                         final ChunkStatus toStatus, final Priority priority) {
+        super(scheduler, world, chunkX, chunkZ);
+        if (!Priority.isValidPriority(priority)) {
+            throw new IllegalArgumentException("Invalid priority " + priority);
+        }
+        this.fromChunk = chunk;
+        this.fromStatus = chunk.getPersistedStatus();
+        this.toStatus = toStatus;
+        this.neighbours = neighbours;
+        if (((ChunkSystemChunkStatus)this.toStatus).moonrise$isParallelCapable()) {
+            this.generateTask = this.scheduler.parallelGenExecutor.createTask(this, priority);
+        } else {
+            final int writeRadius = ((ChunkSystemChunkStatus)this.toStatus).moonrise$getWriteRadius();
+            if (writeRadius < 0) {
+                this.generateTask = this.scheduler.radiusAwareScheduler.createInfiniteRadiusTask(this, priority);
+            } else {
+                this.generateTask = this.scheduler.radiusAwareScheduler.createTask(chunkX, chunkZ, writeRadius, this, priority);
+            }
+        }
+    }
+
+    @Override
+    public ChunkStatus getTargetStatus() {
+        return this.toStatus;
+    }
+
+    private boolean isEmptyTask() {
+        // must use fromStatus here to avoid any race condition with run() overwriting the status
+        final boolean generation = !this.fromStatus.isOrAfter(this.toStatus);
+        return (generation && ((ChunkSystemChunkStatus)this.toStatus).moonrise$isEmptyGenStatus()) || (!generation && ((ChunkSystemChunkStatus)this.toStatus).moonrise$isEmptyLoadStatus());
+    }
+
+    @Override
+    public void run() {
+        final ChunkAccess chunk = this.fromChunk;
+
+        final ServerChunkCache serverChunkCache = this.world.getChunkSource();
+        final ChunkMap chunkMap = serverChunkCache.chunkMap;
+
+        final CompletableFuture<ChunkAccess> completeFuture;
+
+        final boolean generation;
+        boolean completing = false;
+
+        // note: should optimise the case where the chunk does not need to execute the status, because
+        // schedule() calls this synchronously if it will run through that path
+
+        final WorldGenContext ctx = chunkMap.worldGenContext;
+        try {
+            generation = !chunk.getPersistedStatus().isOrAfter(this.toStatus);
+            if (generation) {
+                if (((ChunkSystemChunkStatus)this.toStatus).moonrise$isEmptyGenStatus()) {
+                    if (chunk instanceof ProtoChunk) {
+                        ((ProtoChunk)chunk).setPersistedStatus(this.toStatus);
+                    }
+                    completing = true;
+                    this.complete(chunk, null);
+                    return;
+                }
+                completeFuture = ChunkPyramid.GENERATION_PYRAMID.getStepTo(this.toStatus).apply(ctx, this.neighbours, this.fromChunk)
+                        .whenComplete((final ChunkAccess either, final Throwable throwable) -> {
+                                    if (either instanceof ProtoChunk proto) {
+                                        proto.setPersistedStatus(ChunkUpgradeGenericStatusTask.this.toStatus);
+                                    }
+                                }
+                        );
+            } else {
+                if (((ChunkSystemChunkStatus)this.toStatus).moonrise$isEmptyLoadStatus()) {
+                    completing = true;
+                    this.complete(chunk, null);
+                    return;
+                }
+                completeFuture = ChunkPyramid.LOADING_PYRAMID.getStepTo(this.toStatus).apply(ctx, this.neighbours, this.fromChunk);
+            }
+        } catch (final Throwable throwable) {
+            if (!completing) {
+                this.complete(null, throwable);
+                return;
+            }
+
+            this.scheduler.unrecoverableChunkSystemFailure(this.chunkX, this.chunkZ, Map.of(
+                "Target status", ChunkTaskScheduler.stringIfNull(this.toStatus),
+                "From status", ChunkTaskScheduler.stringIfNull(this.fromStatus),
+                "Generation task", this
+            ), throwable);
+
+            LOGGER.error(
+                    "Failed to complete status for chunk: status:" + this.toStatus + ", chunk: (" + this.chunkX +
+                            "," + this.chunkZ + "), world: " + WorldUtil.getWorldName(this.world),
+                    throwable
+            );
+
+            return;
+        }
+
+        if (!completeFuture.isDone() && !((ChunkSystemChunkStatus)this.toStatus).moonrise$getWarnedAboutNoImmediateComplete().getAndSet(true)) {
+            LOGGER.warn("Future status not complete after scheduling: " + this.toStatus.toString() + ", generate: " + generation);
+        }
+
+        final ChunkAccess newChunk;
+
+        try {
+            newChunk = completeFuture.join();
+        } catch (final Throwable throwable) {
+            this.complete(null, throwable);
+            return;
+        }
+
+        if (newChunk == null) {
+            this.complete(null,
+                    new IllegalStateException(
+                            "Chunk for status: " + ChunkUpgradeGenericStatusTask.this.toStatus.toString()
+                                    + ", generation: " + generation + " should not be null! Future: " + completeFuture
+                    ).fillInStackTrace()
+            );
+            return;
+        }
+
+        this.complete(newChunk, null);
+    }
+
+    private volatile boolean scheduled;
+    private static final VarHandle SCHEDULED_HANDLE = ConcurrentUtil.getVarHandle(ChunkUpgradeGenericStatusTask.class, "scheduled", boolean.class);
+
+    @Override
+    public boolean isScheduled() {
+        return this.scheduled;
+    }
+
+    @Override
+    public void schedule() {
+        if ((boolean)SCHEDULED_HANDLE.getAndSet((ChunkUpgradeGenericStatusTask)this, true)) {
+            throw new IllegalStateException("Cannot double call schedule()");
+        }
+        if (this.isEmptyTask()) {
+            if (this.generateTask.cancel()) {
+                this.run();
+            }
+        } else {
+            this.generateTask.queue();
+        }
+    }
+
+    @Override
+    public void cancel() {
+        if (this.generateTask.cancel()) {
+            this.complete(null, null);
+        }
+    }
+
+    @Override
+    public Priority getPriority() {
+        return this.generateTask.getPriority();
+    }
+
+    @Override
+    public void lowerPriority(final Priority priority) {
+        if (!Priority.isValidPriority(priority)) {
+            throw new IllegalArgumentException("Invalid priority " + priority);
+        }
+        this.generateTask.lowerPriority(priority);
+    }
+
+    @Override
+    public void setPriority(final Priority priority) {
+        if (!Priority.isValidPriority(priority)) {
+            throw new IllegalArgumentException("Invalid priority " + priority);
+        }
+        this.generateTask.setPriority(priority);
+    }
+
+    @Override
+    public void raisePriority(final Priority priority) {
+        if (!Priority.isValidPriority(priority)) {
+            throw new IllegalArgumentException("Invalid priority " + priority);
+        }
+        this.generateTask.raisePriority(priority);
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/task/GenericDataLoadTask.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/task/GenericDataLoadTask.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/scheduling/task/GenericDataLoadTask.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.scheduling.task;
+
+import ca.spottedleaf.concurrentutil.completable.CallbackCompletable;
+import ca.spottedleaf.concurrentutil.completable.Completable;
+import ca.spottedleaf.concurrentutil.executor.Cancellable;
+import ca.spottedleaf.concurrentutil.executor.PrioritisedExecutor;
+import ca.spottedleaf.concurrentutil.util.ConcurrentUtil;
+import ca.spottedleaf.concurrentutil.util.Priority;
+import ca.spottedleaf.moonrise.common.util.WorldUtil;
+import ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.server.level.ServerLevel;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import java.lang.invoke.VarHandle;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.function.BiConsumer;
+
+public abstract class GenericDataLoadTask<OnMain,FinalCompletion> {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(GenericDataLoadTask.class);
+
+    protected static final CompoundTag CANCELLED_DATA = new CompoundTag();
+
+    // reference count is the upper 32 bits
+    protected final AtomicLong stageAndReferenceCount = new AtomicLong(STAGE_NOT_STARTED);
+
+    protected static final long STAGE_MASK        = 0xFFFFFFFFL;
+    protected static final long STAGE_CANCELLED   = 0xFFFFFFFFL;
+    protected static final long STAGE_NOT_STARTED = 0L;
+    protected static final long STAGE_LOADING     = 1L;
+    protected static final long STAGE_PROCESSING  = 2L;
+    protected static final long STAGE_COMPLETED   = 3L;
+
+    // for loading data off disk
+    protected final LoadDataFromDiskTask loadDataFromDiskTask;
+    // processing off-main
+    protected final PrioritisedExecutor.PrioritisedTask processOffMain;
+    // processing on-main
+    protected final PrioritisedExecutor.PrioritisedTask processOnMain;
+
+    protected final ChunkTaskScheduler scheduler;
+    protected final ServerLevel world;
+    protected final int chunkX;
+    protected final int chunkZ;
+    protected final MoonriseRegionFileIO.RegionFileType type;
+
+    public GenericDataLoadTask(final ChunkTaskScheduler scheduler, final ServerLevel world, final int chunkX,
+                               final int chunkZ, final MoonriseRegionFileIO.RegionFileType type,
+                               final Priority priority) {
+        this.scheduler = scheduler;
+        this.world = world;
+        this.chunkX = chunkX;
+        this.chunkZ = chunkZ;
+        this.type = type;
+
+        final ProcessOnMainTask mainTask;
+        if (this.hasOnMain()) {
+            mainTask = new ProcessOnMainTask();
+            this.processOnMain = this.createOnMain(mainTask, priority);
+        } else {
+            mainTask = null;
+            this.processOnMain = null;
+        }
+
+        final ProcessOffMainTask offMainTask;
+        if (this.hasOffMain()) {
+            offMainTask = new ProcessOffMainTask(mainTask);
+            this.processOffMain = this.createOffMain(offMainTask, priority);
+        } else {
+            offMainTask = null;
+            this.processOffMain = null;
+        }
+
+        if (this.processOffMain == null && this.processOnMain == null) {
+            throw new IllegalStateException("Illegal class implementation: " + this.getClass().getName() + ", should be able to schedule at least one task!");
+        }
+
+        this.loadDataFromDiskTask = new LoadDataFromDiskTask(world, chunkX, chunkZ, type, new DataLoadCallback(offMainTask, mainTask), priority);
+    }
+
+    public static final record TaskResult<L, R>(L left, R right) {}
+
+    protected abstract boolean hasOffMain();
+
+    protected abstract boolean hasOnMain();
+
+    protected abstract PrioritisedExecutor.PrioritisedTask createOffMain(final Runnable run, final Priority priority);
+
+    protected abstract PrioritisedExecutor.PrioritisedTask createOnMain(final Runnable run, final Priority priority);
+
+    protected abstract TaskResult<OnMain, Throwable> runOffMain(final CompoundTag data, final Throwable throwable);
+
+    protected abstract TaskResult<FinalCompletion, Throwable> runOnMain(final OnMain data, final Throwable throwable);
+
+    protected abstract void onComplete(final TaskResult<FinalCompletion,Throwable> result);
+
+    protected abstract TaskResult<FinalCompletion, Throwable> completeOnMainOffMain(final OnMain data, final Throwable throwable);
+
+    @Override
+    public String toString() {
+        return "GenericDataLoadTask{class: " + this.getClass().getName() + ", world: " + WorldUtil.getWorldName(this.world) +
+            ", chunk: (" + this.chunkX + "," + this.chunkZ + "), hashcode: " + System.identityHashCode(this) + ", priority: " + this.getPriority() +
+            ", type: " + this.type.toString() + "}";
+    }
+
+    public Priority getPriority() {
+        if (this.processOnMain != null) {
+            return this.processOnMain.getPriority();
+        } else {
+            return this.processOffMain.getPriority();
+        }
+    }
+
+    public void lowerPriority(final Priority priority) {
+        // can't lower I/O tasks, we don't know what they affect
+        if (this.processOffMain != null) {
+            this.processOffMain.lowerPriority(priority);
+        }
+        if (this.processOnMain != null) {
+            this.processOnMain.lowerPriority(priority);
+        }
+    }
+
+    public void setPriority(final Priority priority) {
+        // can't lower I/O tasks, we don't know what they affect
+        this.loadDataFromDiskTask.raisePriority(priority);
+        if (this.processOffMain != null) {
+            this.processOffMain.setPriority(priority);
+        }
+        if (this.processOnMain != null) {
+            this.processOnMain.setPriority(priority);
+        }
+    }
+
+    public void raisePriority(final Priority priority) {
+        // can't lower I/O tasks, we don't know what they affect
+        this.loadDataFromDiskTask.raisePriority(priority);
+        if (this.processOffMain != null) {
+            this.processOffMain.raisePriority(priority);
+        }
+        if (this.processOnMain != null) {
+            this.processOnMain.raisePriority(priority);
+        }
+    }
+
+    // returns whether scheduleNow() needs to be called
+    public boolean schedule(final boolean delay) {
+        if (this.stageAndReferenceCount.get() != STAGE_NOT_STARTED ||
+            !this.stageAndReferenceCount.compareAndSet(STAGE_NOT_STARTED, (1L << 32) | STAGE_LOADING)) {
+            // try and increment reference count
+            int failures = 0;
+            for (long curr = this.stageAndReferenceCount.get();;) {
+                if ((curr & STAGE_MASK) == STAGE_CANCELLED || (curr & STAGE_MASK) == STAGE_COMPLETED) {
+                    // cancelled or completed, nothing to do here
+                    return false;
+                }
+
+                if (curr == (curr = this.stageAndReferenceCount.compareAndExchange(curr, curr + (1L << 32)))) {
+                    // successful
+                    return false;
+                }
+
+                ++failures;
+                for (int i = 0; i < failures; ++i) {
+                    ConcurrentUtil.backoff();
+                }
+            }
+        }
+
+        if (!delay) {
+            this.scheduleNow();
+            return false;
+        }
+        return true;
+    }
+
+    public void scheduleNow() {
+        this.loadDataFromDiskTask.schedule(); // will schedule the rest
+    }
+
+    // assumes the current stage cannot be completed
+    // returns false if cancelled, returns true if can proceed
+    private boolean advanceStage(final long expect, final long to) {
+        int failures = 0;
+        for (long curr = this.stageAndReferenceCount.get();;) {
+            if ((curr & STAGE_MASK) != expect) {
+                // must be cancelled
+                return false;
+            }
+
+            final long newVal = (curr & ~STAGE_MASK) | to;
+            if (curr == (curr = this.stageAndReferenceCount.compareAndExchange(curr, newVal))) {
+                return true;
+            }
+
+            ++failures;
+            for (int i = 0; i < failures; ++i) {
+                ConcurrentUtil.backoff();
+            }
+        }
+    }
+
+    public boolean cancel() {
+        int failures = 0;
+        for (long curr = this.stageAndReferenceCount.get();;) {
+            if ((curr & STAGE_MASK) == STAGE_COMPLETED || (curr & STAGE_MASK) == STAGE_CANCELLED) {
+                return false;
+            }
+
+             if ((curr & STAGE_MASK) == STAGE_NOT_STARTED || (curr & ~STAGE_MASK) == (1L << 32)) {
+                // no other references, so we can cancel
+                final long newVal = STAGE_CANCELLED;
+                if (curr == (curr = this.stageAndReferenceCount.compareAndExchange(curr, newVal))) {
+                    this.loadDataFromDiskTask.cancel();
+                    if (this.processOffMain != null) {
+                        this.processOffMain.cancel();
+                    }
+                    if (this.processOnMain != null) {
+                        this.processOnMain.cancel();
+                    }
+                    this.onComplete(null);
+                    return true;
+                }
+            } else {
+                if ((curr & ~STAGE_MASK) == (0L << 32)) {
+                    throw new IllegalStateException("Reference count cannot be zero here");
+                }
+                // just decrease the reference count
+                final long newVal = curr - (1L << 32);
+                if (curr == (curr = this.stageAndReferenceCount.compareAndExchange(curr, newVal))) {
+                    return false;
+                }
+            }
+
+            ++failures;
+            for (int i = 0; i < failures; ++i) {
+                ConcurrentUtil.backoff();
+            }
+        }
+    }
+
+    private final class DataLoadCallback implements BiConsumer<CompoundTag, Throwable> {
+
+        private final ProcessOffMainTask offMainTask;
+        private final ProcessOnMainTask onMainTask;
+
+        public DataLoadCallback(final ProcessOffMainTask offMainTask, final ProcessOnMainTask onMainTask) {
+            this.offMainTask = offMainTask;
+            this.onMainTask = onMainTask;
+        }
+
+        @Override
+        public void accept(final CompoundTag compoundTag, final Throwable throwable) {
+            if (GenericDataLoadTask.this.stageAndReferenceCount.get() == STAGE_CANCELLED) {
+                // don't try to schedule further
+                return;
+            }
+
+            try {
+                if (compoundTag == CANCELLED_DATA) {
+                    // cancelled, except this isn't possible
+                    LOGGER.error("Data callback says cancelled, but stage does not?");
+                    return;
+                }
+
+                // get off of the regionfile callback ASAP, no clue what locks are held right now...
+                if (GenericDataLoadTask.this.processOffMain != null) {
+                    this.offMainTask.data = compoundTag;
+                    this.offMainTask.throwable = throwable;
+                    GenericDataLoadTask.this.processOffMain.queue();
+                    return;
+                } else {
+                    // no off-main task, so go straight to main
+                    this.onMainTask.data = (OnMain)compoundTag;
+                    this.onMainTask.throwable = throwable;
+                    GenericDataLoadTask.this.processOnMain.queue();
+                }
+            } catch (final Throwable thr2) {
+                LOGGER.error("Failed I/O callback for task: " + GenericDataLoadTask.this.toString(), thr2);
+                GenericDataLoadTask.this.scheduler.unrecoverableChunkSystemFailure(
+                    GenericDataLoadTask.this.chunkX, GenericDataLoadTask.this.chunkZ, Map.of(
+                        "Callback throwable", ChunkTaskScheduler.stringIfNull(throwable)
+                    ), thr2
+                );
+            }
+        }
+    }
+
+    private final class ProcessOffMainTask implements Runnable {
+
+        private CompoundTag data;
+        private Throwable throwable;
+        private final ProcessOnMainTask schedule;
+
+        public ProcessOffMainTask(final ProcessOnMainTask schedule) {
+            this.schedule = schedule;
+        }
+
+        @Override
+        public void run() {
+            if (!GenericDataLoadTask.this.advanceStage(STAGE_LOADING, this.schedule == null ? STAGE_COMPLETED : STAGE_PROCESSING)) {
+                // cancelled
+                return;
+            }
+            final TaskResult<OnMain, Throwable> newData = GenericDataLoadTask.this.runOffMain(this.data, this.throwable);
+
+            if (GenericDataLoadTask.this.stageAndReferenceCount.get() == STAGE_CANCELLED) {
+                // don't try to schedule further
+                return;
+            }
+
+            if (this.schedule != null) {
+                final TaskResult<FinalCompletion, Throwable> syncComplete = GenericDataLoadTask.this.completeOnMainOffMain(newData.left, newData.right);
+
+                if (syncComplete != null) {
+                    if (GenericDataLoadTask.this.advanceStage(STAGE_PROCESSING, STAGE_COMPLETED)) {
+                        GenericDataLoadTask.this.onComplete(syncComplete);
+                    } // else: cancelled
+                    return;
+                }
+
+                this.schedule.data = newData.left;
+                this.schedule.throwable = newData.right;
+
+                GenericDataLoadTask.this.processOnMain.queue();
+            } else {
+                GenericDataLoadTask.this.onComplete((TaskResult<FinalCompletion, Throwable>)newData);
+            }
+        }
+    }
+
+    private final class ProcessOnMainTask implements Runnable {
+
+        private OnMain data;
+        private Throwable throwable;
+
+        @Override
+        public void run() {
+            if (!GenericDataLoadTask.this.advanceStage(STAGE_PROCESSING, STAGE_COMPLETED)) {
+                // cancelled
+                return;
+            }
+            final TaskResult<FinalCompletion, Throwable> result = GenericDataLoadTask.this.runOnMain(this.data, this.throwable);
+
+            GenericDataLoadTask.this.onComplete(result);
+        }
+    }
+
+    protected static final class LoadDataFromDiskTask {
+
+        private volatile int priority;
+        private static final VarHandle PRIORITY_HANDLE = ConcurrentUtil.getVarHandle(LoadDataFromDiskTask.class, "priority", int.class);
+
+        private static final int PRIORITY_EXECUTED         = Integer.MIN_VALUE >>> 0;
+        private static final int PRIORITY_LOAD_SCHEDULED   = Integer.MIN_VALUE >>> 1;
+        private static final int PRIORITY_UNLOAD_SCHEDULED = Integer.MIN_VALUE >>> 2;
+
+        private static final int PRIORITY_FLAGS = ~Character.MAX_VALUE;
+
+        private final int getPriorityVolatile() {
+            return (int)PRIORITY_HANDLE.getVolatile((LoadDataFromDiskTask)this);
+        }
+
+        private final int compareAndExchangePriorityVolatile(final int expect, final int update) {
+            return (int)PRIORITY_HANDLE.compareAndExchange((LoadDataFromDiskTask)this, (int)expect, (int)update);
+        }
+
+        private final int getAndOrPriorityVolatile(final int val) {
+            return (int)PRIORITY_HANDLE.getAndBitwiseOr((LoadDataFromDiskTask)this, (int)val);
+        }
+
+        private final void setPriorityPlain(final int val) {
+            PRIORITY_HANDLE.set((LoadDataFromDiskTask)this, (int)val);
+        }
+
+        private final ServerLevel world;
+        private final int chunkX;
+        private final int chunkZ;
+
+        private final MoonriseRegionFileIO.RegionFileType type;
+        private Cancellable dataLoadTask;
+        private Cancellable dataUnloadCancellable;
+        private PrioritisedExecutor.PrioritisedTask dataUnloadTask;
+
+        private final BiConsumer<CompoundTag, Throwable> onComplete;
+        private final AtomicBoolean scheduled = new AtomicBoolean();
+
+        // onComplete should be caller sensitive, it may complete synchronously with schedule() - which does
+        // hold a priority lock.
+        public LoadDataFromDiskTask(final ServerLevel world, final int chunkX, final int chunkZ,
+                                    final MoonriseRegionFileIO.RegionFileType type,
+                                    final BiConsumer<CompoundTag, Throwable> onComplete,
+                                    final Priority priority) {
+            if (!Priority.isValidPriority(priority)) {
+                throw new IllegalArgumentException("Invalid priority " + priority);
+            }
+            this.world = world;
+            this.chunkX = chunkX;
+            this.chunkZ = chunkZ;
+            this.type = type;
+            this.onComplete = onComplete;
+            this.setPriorityPlain(priority.priority);
+        }
+
+        private void complete(final CompoundTag data, final Throwable throwable) {
+            try {
+                this.onComplete.accept(data, throwable);
+            } catch (final Throwable thr2) {
+                ((ChunkSystemServerLevel)this.world).moonrise$getChunkTaskScheduler().unrecoverableChunkSystemFailure(this.chunkX, this.chunkZ, Map.of(
+                    "Completed throwable", ChunkTaskScheduler.stringIfNull(throwable),
+                    "Regionfile type", ChunkTaskScheduler.stringIfNull(this.type)
+                ), thr2);
+            }
+        }
+
+        private boolean markExecuting() {
+            return (this.getAndOrPriorityVolatile(PRIORITY_EXECUTED) & PRIORITY_EXECUTED) == 0;
+        }
+
+        private boolean isMarkedExecuted() {
+            return (this.getPriorityVolatile() & PRIORITY_EXECUTED) != 0;
+        }
+
+        public void lowerPriority(final Priority priority) {
+            if (!Priority.isValidPriority(priority)) {
+                throw new IllegalArgumentException("Invalid priority " + priority);
+            }
+
+            int failures = 0;
+            for (int curr = this.getPriorityVolatile();;) {
+                if ((curr & PRIORITY_EXECUTED) != 0) {
+                    // cancelled or executed
+                    return;
+                }
+
+                if ((curr & PRIORITY_LOAD_SCHEDULED) != 0) {
+                    MoonriseRegionFileIO.lowerPriority(this.world, this.chunkX, this.chunkZ, this.type, priority);
+                    return;
+                }
+
+                if ((curr & PRIORITY_UNLOAD_SCHEDULED) != 0) {
+                    if (this.dataUnloadTask != null) {
+                        this.dataUnloadTask.lowerPriority(priority);
+                    }
+                    // no return - we need to propagate priority
+                }
+
+                if (!priority.isHigherPriority(curr & ~PRIORITY_FLAGS)) {
+                    return;
+                }
+
+                if (curr == (curr = this.compareAndExchangePriorityVolatile(curr, priority.priority | (curr & PRIORITY_FLAGS)))) {
+                    return;
+                }
+
+                // failed, retry
+
+                ++failures;
+                for (int i = 0; i < failures; ++i) {
+                    ConcurrentUtil.backoff();
+                }
+            }
+        }
+
+        public void setPriority(final Priority priority) {
+            if (!Priority.isValidPriority(priority)) {
+                throw new IllegalArgumentException("Invalid priority " + priority);
+            }
+
+            int failures = 0;
+            for (int curr = this.getPriorityVolatile();;) {
+                if ((curr & PRIORITY_EXECUTED) != 0) {
+                    // cancelled or executed
+                    return;
+                }
+
+                if ((curr & PRIORITY_LOAD_SCHEDULED) != 0) {
+                    MoonriseRegionFileIO.setPriority(this.world, this.chunkX, this.chunkZ, this.type, priority);
+                    return;
+                }
+
+                if ((curr & PRIORITY_UNLOAD_SCHEDULED) != 0) {
+                    if (this.dataUnloadTask != null) {
+                        this.dataUnloadTask.setPriority(priority);
+                    }
+                    // no return - we need to propagate priority
+                }
+
+                if (curr == (curr = this.compareAndExchangePriorityVolatile(curr, priority.priority | (curr & PRIORITY_FLAGS)))) {
+                    return;
+                }
+
+                // failed, retry
+
+                ++failures;
+                for (int i = 0; i < failures; ++i) {
+                    ConcurrentUtil.backoff();
+                }
+            }
+        }
+
+        public void raisePriority(final Priority priority) {
+            if (!Priority.isValidPriority(priority)) {
+                throw new IllegalArgumentException("Invalid priority " + priority);
+            }
+
+            int failures = 0;
+            for (int curr = this.getPriorityVolatile();;) {
+                if ((curr & PRIORITY_EXECUTED) != 0) {
+                    // cancelled or executed
+                    return;
+                }
+
+                if ((curr & PRIORITY_LOAD_SCHEDULED) != 0) {
+                    MoonriseRegionFileIO.raisePriority(this.world, this.chunkX, this.chunkZ, this.type, priority);
+                    return;
+                }
+
+                if ((curr & PRIORITY_UNLOAD_SCHEDULED) != 0) {
+                    if (this.dataUnloadTask != null) {
+                        this.dataUnloadTask.raisePriority(priority);
+                    }
+                    // no return - we need to propagate priority
+                }
+
+                if (!priority.isLowerPriority(curr & ~PRIORITY_FLAGS)) {
+                    return;
+                }
+
+                if (curr == (curr = this.compareAndExchangePriorityVolatile(curr, priority.priority | (curr & PRIORITY_FLAGS)))) {
+                    return;
+                }
+
+                // failed, retry
+
+                ++failures;
+                for (int i = 0; i < failures; ++i) {
+                    ConcurrentUtil.backoff();
+                }
+            }
+        }
+
+        public void cancel() {
+            if ((this.getAndOrPriorityVolatile(PRIORITY_EXECUTED) & PRIORITY_EXECUTED) != 0) {
+                // cancelled or executed already
+                return;
+            }
+
+            // OK if we miss the field read, the task cannot complete if the cancelled bit is set and
+            // the write to dataLoadTask will check for the cancelled bit
+            if (this.dataUnloadCancellable != null) {
+                this.dataUnloadCancellable.cancel();
+            }
+
+            if (this.dataLoadTask != null) {
+                this.dataLoadTask.cancel();
+            }
+
+            this.complete(CANCELLED_DATA, null);
+        }
+
+        public void schedule() {
+            if (this.scheduled.getAndSet(true)) {
+                throw new IllegalStateException("schedule() called twice");
+            }
+            int priority = this.getPriorityVolatile();
+
+            if ((priority & PRIORITY_EXECUTED) != 0) {
+                // cancelled
+                return;
+            }
+
+            final BiConsumer<CompoundTag, Throwable> consumer = (final CompoundTag data, final Throwable thr) -> {
+                // because cancelScheduled() cannot actually stop this task from executing in every case, we need
+                // to mark complete here to ensure we do not double complete
+                if (LoadDataFromDiskTask.this.markExecuting()) {
+                    LoadDataFromDiskTask.this.complete(data, thr);
+                } // else: cancelled
+            };
+
+            final Priority initialPriority = Priority.getPriority(priority);
+            boolean scheduledUnload = false;
+
+            final NewChunkHolder holder = ((ChunkSystemServerLevel)this.world).moonrise$getChunkTaskScheduler().chunkHolderManager.getChunkHolder(this.chunkX, this.chunkZ);
+            if (holder != null) {
+                final BiConsumer<CompoundTag, Throwable> unloadConsumer = (final CompoundTag data, final Throwable thr) -> {
+                    if (data != null) {
+                        consumer.accept(data, null);
+                    } else {
+                        // need to schedule task
+                        LoadDataFromDiskTask.this.schedule(false, consumer, Priority.getPriority(LoadDataFromDiskTask.this.getPriorityVolatile() & ~PRIORITY_FLAGS));
+                    }
+                };
+                Cancellable unloadCancellable = null;
+                CompoundTag syncComplete = null;
+                final NewChunkHolder.UnloadTask unloadTask = holder.getUnloadTask(this.type); // can be null if no task exists
+                final CallbackCompletable<CompoundTag> unloadCompletable = unloadTask == null ? null : unloadTask.completable();
+                if (unloadCompletable != null) {
+                    unloadCancellable = unloadCompletable.addAsynchronousWaiter(unloadConsumer);
+                    if (unloadCancellable == null) {
+                        syncComplete = unloadCompletable.getResult();
+                    }
+                }
+
+                if (syncComplete != null) {
+                    consumer.accept(syncComplete, null);
+                    return;
+                }
+
+                if (unloadCancellable != null) {
+                    scheduledUnload = true;
+                    this.dataUnloadCancellable = unloadCancellable;
+                    this.dataUnloadTask = unloadTask.task();
+                }
+            }
+
+            this.schedule(scheduledUnload, consumer, initialPriority);
+        }
+
+        private void schedule(final boolean scheduledUnload, final BiConsumer<CompoundTag, Throwable> consumer, final Priority initialPriority) {
+            int priority = this.getPriorityVolatile();
+
+            if ((priority & PRIORITY_EXECUTED) != 0) {
+                // cancelled
+                return;
+            }
+
+            if (!scheduledUnload) {
+                this.dataLoadTask = MoonriseRegionFileIO.loadDataAsync(
+                    this.world, this.chunkX, this.chunkZ, this.type, consumer,
+                    initialPriority.isHigherPriority(Priority.NORMAL), initialPriority
+                );
+            }
+
+            int failures = 0;
+            for (;;) {
+                if (priority == (priority = this.compareAndExchangePriorityVolatile(priority, priority | (scheduledUnload ? PRIORITY_UNLOAD_SCHEDULED : PRIORITY_LOAD_SCHEDULED)))) {
+                    return;
+                }
+
+                if ((priority & PRIORITY_EXECUTED) != 0) {
+                    // cancelled or executed
+                    if (this.dataUnloadCancellable != null) {
+                        this.dataUnloadCancellable.cancel();
+                    }
+
+                    if (this.dataLoadTask != null) {
+                        this.dataLoadTask.cancel();
+                    }
+                    return;
+                }
+
+                if (scheduledUnload) {
+                    if (this.dataUnloadTask != null) {
+                        this.dataUnloadTask.setPriority(Priority.getPriority(priority & ~PRIORITY_FLAGS));
+                    }
+                } else {
+                    MoonriseRegionFileIO.setPriority(this.world, this.chunkX, this.chunkZ, this.type, Priority.getPriority(priority & ~PRIORITY_FLAGS));
+                }
+
+                ++failures;
+                for (int i = 0; i < failures; ++i) {
+                    ConcurrentUtil.backoff();
+                }
+            }
+        }
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/server/ChunkSystemMinecraftServer.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/server/ChunkSystemMinecraftServer.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/server/ChunkSystemMinecraftServer.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.server;
+
+public interface ChunkSystemMinecraftServer {
+
+    public void moonrise$setChunkSystemCrash(final Throwable throwable);
+
+    public void moonrise$executeMidTickTasks();
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/status/ChunkSystemChunkStep.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/status/ChunkSystemChunkStep.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/status/ChunkSystemChunkStep.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.status;
+
+import net.minecraft.world.level.chunk.status.ChunkStatus;
+
+public interface ChunkSystemChunkStep {
+
+    public ChunkStatus moonrise$getRequiredStatusAtRadius(final int radius);
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/storage/ChunkSystemChunkBuffer.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/storage/ChunkSystemChunkBuffer.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/storage/ChunkSystemChunkBuffer.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.storage;
+
+import net.minecraft.world.level.chunk.storage.RegionFile;
+import java.io.IOException;
+
+public interface ChunkSystemChunkBuffer {
+    public boolean moonrise$getWriteOnClose();
+
+    public void moonrise$setWriteOnClose(final boolean value);
+
+    public void moonrise$write(final RegionFile regionFile) throws IOException;
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/storage/ChunkSystemChunkStorage.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/storage/ChunkSystemChunkStorage.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/storage/ChunkSystemChunkStorage.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.storage;
+
+import net.minecraft.world.level.chunk.storage.RegionFileStorage;
+
+public interface ChunkSystemChunkStorage {
+
+    public RegionFileStorage moonrise$getRegionStorage();
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/storage/ChunkSystemRegionFile.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/storage/ChunkSystemRegionFile.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/storage/ChunkSystemRegionFile.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.storage;
+
+import ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.world.level.ChunkPos;
+import java.io.IOException;
+
+public interface ChunkSystemRegionFile {
+
+    public MoonriseRegionFileIO.RegionDataController.WriteData moonrise$startWrite(final CompoundTag data, final ChunkPos pos) throws IOException;
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/ticket/ChunkSystemTicket.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/ticket/ChunkSystemTicket.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/ticket/ChunkSystemTicket.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.ticket;
+
+public interface ChunkSystemTicket<T> {
+
+    public long moonrise$getRemoveDelay();
+
+    public void moonrise$setRemoveDelay(final long removeDelay);
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/ticks/ChunkSystemLevelChunkTicks.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/ticks/ChunkSystemLevelChunkTicks.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/ticks/ChunkSystemLevelChunkTicks.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.ticks;
+
+public interface ChunkSystemLevelChunkTicks {
+
+    public boolean moonrise$isDirty(final long tick);
+
+    public void moonrise$clearDirty();
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/util/ChunkSystemSortedArraySet.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/util/ChunkSystemSortedArraySet.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/util/ChunkSystemSortedArraySet.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.util;
+
+import net.minecraft.util.SortedArraySet;
+
+public interface ChunkSystemSortedArraySet<T> {
+
+    public SortedArraySet<T> moonrise$copy();
+
+    public Object[] moonrise$copyBackingArray();
+
+    public T moonrise$replace(final T object);
+
+    public T moonrise$removeAndGet(final T object);
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/util/ParallelSearchRadiusIteration.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/util/ParallelSearchRadiusIteration.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/util/ParallelSearchRadiusIteration.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.util;
+
+import ca.spottedleaf.moonrise.common.util.CoordinateUtils;
+import ca.spottedleaf.moonrise.common.util.MoonriseConstants;
+import it.unimi.dsi.fastutil.HashCommon;
+import it.unimi.dsi.fastutil.longs.LongArrayList;
+import it.unimi.dsi.fastutil.longs.LongIterator;
+import it.unimi.dsi.fastutil.longs.LongLinkedOpenHashSet;
+import it.unimi.dsi.fastutil.longs.LongOpenHashSet;
+import java.util.Arrays;
+import java.util.Objects;
+
+public final class ParallelSearchRadiusIteration {
+
+    // expected that this list returns for a given radius, the set of chunks ordered
+    // by manhattan distance
+    private static final long[][] SEARCH_RADIUS_ITERATION_LIST = new long[MoonriseConstants.MAX_VIEW_DISTANCE+2+1][];
+    static {
+        for (int i = 0; i < SEARCH_RADIUS_ITERATION_LIST.length; ++i) {
+            // a BFS around -x, -z, +x, +z will give increasing manhatten distance
+            SEARCH_RADIUS_ITERATION_LIST[i] = generateBFSOrder(i);
+        }
+    }
+
+    public static long[] getSearchIteration(final int radius) {
+        return SEARCH_RADIUS_ITERATION_LIST[radius];
+    }
+
+    private static class CustomLongArray extends LongArrayList {
+
+        public CustomLongArray() {
+            super();
+        }
+
+        public CustomLongArray(final int expected) {
+            super(expected);
+        }
+
+        public boolean addAll(final CustomLongArray list) {
+            this.addElements(this.size, list.a, 0, list.size);
+            return list.size != 0;
+        }
+
+        public void addUnchecked(final long value) {
+            this.a[this.size++] = value;
+        }
+
+        public void forceSize(final int to) {
+            this.size = to;
+        }
+
+        @Override
+        public int hashCode() {
+            long h = 1L;
+
+            Objects.checkFromToIndex(0, this.size, this.a.length);
+
+            for (int i = 0; i < this.size; ++i) {
+                h = HashCommon.mix(h + this.a[i]);
+            }
+
+            return (int)h;
+        }
+
+        @Override
+        public boolean equals(final Object o) {
+            if (o == this) {
+                return true;
+            }
+
+            if (!(o instanceof CustomLongArray other)) {
+                return false;
+            }
+
+            return this.size == other.size && Arrays.equals(this.a, 0, this.size, other.a, 0, this.size);
+        }
+    }
+
+    private static int getDistanceSize(final int radius, final int max) {
+        if (radius == 0) {
+            return 1;
+        }
+        final int diff = radius - max;
+        if (diff <= 0) {
+            return 4*radius;
+        }
+        return 4*(max - Math.max(0, diff - 1));
+    }
+
+    private static int getQ1DistanceSize(final int radius, final int max) {
+        if (radius == 0) {
+            return 1;
+        }
+        final int diff = radius - max;
+        if (diff <= 0) {
+            return radius+1;
+        }
+        return max - diff + 1;
+    }
+
+    private static final class BasicFIFOLQueue {
+
+        private final long[] values;
+        private int head, tail;
+
+        public BasicFIFOLQueue(final int cap) {
+            if (cap <= 1) {
+                throw new IllegalArgumentException();
+            }
+            this.values = new long[cap];
+        }
+
+        public boolean isEmpty() {
+            return this.head == this.tail;
+        }
+
+        public long removeFirst() {
+            final long ret = this.values[this.head];
+
+            if (this.head == this.tail) {
+                throw new IllegalStateException();
+            }
+
+            ++this.head;
+            if (this.head == this.values.length) {
+                this.head = 0;
+            }
+
+            return ret;
+        }
+
+        public void addLast(final long value) {
+            this.values[this.tail++] = value;
+
+            if (this.tail == this.head) {
+                throw new IllegalStateException();
+            }
+
+            if (this.tail == this.values.length) {
+                this.tail = 0;
+            }
+        }
+    }
+
+    private static CustomLongArray[] makeQ1BFS(final int radius) {
+        final CustomLongArray[] ret = new CustomLongArray[2 * radius + 1];
+        final BasicFIFOLQueue queue = new BasicFIFOLQueue(Math.max(1, 4 * radius) + 1);
+        final LongOpenHashSet seen = new LongOpenHashSet((radius + 1) * (radius + 1));
+
+        seen.add(CoordinateUtils.getChunkKey(0, 0));
+        queue.addLast(CoordinateUtils.getChunkKey(0, 0));
+        while (!queue.isEmpty()) {
+            final long chunk = queue.removeFirst();
+            final int chunkX = CoordinateUtils.getChunkX(chunk);
+            final int chunkZ = CoordinateUtils.getChunkZ(chunk);
+
+            final int index = Math.abs(chunkX) + Math.abs(chunkZ);
+            final CustomLongArray list = ret[index];
+            if (list != null) {
+                list.addUnchecked(chunk);
+            } else {
+                (ret[index] = new CustomLongArray(getQ1DistanceSize(index, radius))).addUnchecked(chunk);
+            }
+
+            for (int i = 0; i < 4; ++i) {
+                // 0 -> -1, 0
+                // 1 -> 0, -1
+                // 2 -> 1, 0
+                // 3 -> 0, 1
+
+                final int signInv = -(i >>> 1); // 2/3 -> -(1), 0/1 -> -(0)
+                // note: -n = (~n) + 1
+                // (n ^ signInv) - signInv = signInv == 0 ? ((n ^ 0) - 0 = n) : ((n ^ -1) - (-1) = ~n + 1)
+
+                final int axis = i & 1; // 0/2 -> 0, 1/3 -> 1
+                final int dx = ((axis - 1) ^ signInv) - signInv; // 0 -> -1, 1 -> 0
+                final int dz = (-axis ^ signInv) - signInv; // 0 -> 0, 1 -> -1
+
+                final int neighbourX = chunkX + dx;
+                final int neighbourZ = chunkZ + dz;
+                final long neighbour = CoordinateUtils.getChunkKey(neighbourX, neighbourZ);
+
+                if ((neighbourX | neighbourZ) < 0 || Math.max(Math.abs(neighbourX), Math.abs(neighbourZ)) > radius) {
+                    // don't enqueue out of range
+                    continue;
+                }
+
+                if (!seen.add(neighbour)) {
+                    continue;
+                }
+
+                queue.addLast(neighbour);
+            }
+        }
+
+        return ret;
+    }
+
+    // doesn't appear worth optimising this function now, even though it's 70% of the call
+    private static CustomLongArray spread(final CustomLongArray input, final int size) {
+        final LongLinkedOpenHashSet notAdded = new LongLinkedOpenHashSet(input);
+        final CustomLongArray added = new CustomLongArray(size);
+
+        while (!notAdded.isEmpty()) {
+            if (added.isEmpty()) {
+                added.addUnchecked(notAdded.removeLastLong());
+                continue;
+            }
+
+            long maxChunk = -1L;
+            int maxDist = 0;
+
+            // select the chunk from the not yet added set that has the largest minimum distance from
+            // the current set of added chunks
+
+            for (final LongIterator iterator = notAdded.iterator(); iterator.hasNext();) {
+                final long chunkKey = iterator.nextLong();
+                final int chunkX = CoordinateUtils.getChunkX(chunkKey);
+                final int chunkZ = CoordinateUtils.getChunkZ(chunkKey);
+
+                int minDist = Integer.MAX_VALUE;
+
+                final int len = added.size();
+                final long[] addedArr = added.elements();
+                Objects.checkFromToIndex(0, len, addedArr.length);
+                for (int i = 0; i < len; ++i) {
+                    final long addedKey = addedArr[i];
+                    final int addedX = CoordinateUtils.getChunkX(addedKey);
+                    final int addedZ = CoordinateUtils.getChunkZ(addedKey);
+
+                    // here we use square distance because chunk generation uses neighbours in a square radius
+                    final int dist = Math.max(Math.abs(addedX - chunkX), Math.abs(addedZ - chunkZ));
+
+                    minDist = Math.min(dist, minDist);
+                }
+
+                if (minDist > maxDist) {
+                    maxDist = minDist;
+                    maxChunk = chunkKey;
+                }
+            }
+
+            // move the selected chunk from the not added set to the added set
+
+            if (!notAdded.remove(maxChunk)) {
+                throw new IllegalStateException();
+            }
+
+            added.addUnchecked(maxChunk);
+        }
+
+        return added;
+    }
+
+    private static void expandQuadrants(final CustomLongArray input, final int size) {
+        final int len = input.size();
+        final long[] array = input.elements();
+
+        int writeIndex = size - 1;
+        for (int i = len - 1; i >= 0; --i) {
+            final long key = array[i];
+            final int chunkX = CoordinateUtils.getChunkX(key);
+            final int chunkZ = CoordinateUtils.getChunkZ(key);
+
+            if ((chunkX | chunkZ) < 0 || (i != 0 && chunkX == 0 && chunkZ == 0)) {
+                throw new IllegalStateException();
+            }
+
+            // Q4
+            if (chunkZ != 0) {
+                array[writeIndex--] = CoordinateUtils.getChunkKey(chunkX, -chunkZ);
+            }
+            // Q3
+            if (chunkX != 0 && chunkZ != 0) {
+                array[writeIndex--] = CoordinateUtils.getChunkKey(-chunkX, -chunkZ);
+            }
+            // Q2
+            if (chunkX != 0) {
+                array[writeIndex--] = CoordinateUtils.getChunkKey(-chunkX, chunkZ);
+            }
+
+            array[writeIndex--] = key;
+        }
+
+        input.forceSize(size);
+
+        if (writeIndex != -1) {
+            throw new IllegalStateException();
+        }
+    }
+
+    private static long[] generateBFSOrder(final int radius) {
+        // by using only the first quadrant, we can reduce the total element size by 4 when spreading
+        final CustomLongArray[] byDistance = makeQ1BFS(radius);
+
+        // to increase generation parallelism, we want to space the chunks out so that they are not nearby when generating
+        // this also means we are minimising locality
+        // but, we need to maintain sorted order by manhatten distance
+
+        // per manhatten distance we transform the chunk list so that each element is maximally spaced out from each other
+        for (int i = 0, len = byDistance.length; i < len; ++i) {
+            final CustomLongArray points = byDistance[i];
+            final int expectedSize = getDistanceSize(i, radius);
+
+            final CustomLongArray spread = spread(points, expectedSize);
+            // add in Q2, Q3, Q4
+            expandQuadrants(spread, expectedSize);
+
+            byDistance[i] = spread;
+        }
+
+        // now, rebuild the list so that it still maintains manhatten distance order
+        final CustomLongArray ret = new CustomLongArray((2 * radius + 1) * (2 * radius + 1));
+
+        for (final CustomLongArray dist : byDistance) {
+            ret.addAll(dist);
+        }
+
+        return ret.elements();
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/util/stream/ExternalChunkStreamMarker.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/util/stream/ExternalChunkStreamMarker.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/util/stream/ExternalChunkStreamMarker.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.util.stream;
+
+import java.io.DataInputStream;
+import java.io.FilterInputStream;
+import java.io.InputStream;
+import java.lang.reflect.Field;
+
+/**
+ * Used to mark chunk data streams that are on external files
+ */
+public class ExternalChunkStreamMarker extends DataInputStream {
+
+    private static final Field IN_FIELD;
+    static {
+        Field field;
+        try {
+            field = FilterInputStream.class.getDeclaredField("in");
+            field.setAccessible(true);
+        } catch (final Throwable throwable) {
+            field = null;
+        }
+
+        IN_FIELD = field;
+    }
+
+    private static InputStream getWrapped(final FilterInputStream in) {
+        try {
+            return (InputStream)IN_FIELD.get(in);
+        } catch (final Throwable throwable) {
+            return in;
+        }
+    }
+
+    public ExternalChunkStreamMarker(final DataInputStream in) {
+        super(getWrapped(in));
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/world/ChunkSystemEntityGetter.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/world/ChunkSystemEntityGetter.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/world/ChunkSystemEntityGetter.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.world;
+
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.phys.AABB;
+import java.util.List;
+import java.util.function.Predicate;
+
+public interface ChunkSystemEntityGetter {
+
+    public List<Entity> moonrise$getHardCollidingEntities(final Entity entity, final AABB box, final Predicate<? super Entity> predicate);
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/world/ChunkSystemServerChunkCache.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/world/ChunkSystemServerChunkCache.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/world/ChunkSystemServerChunkCache.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_system.world;
+
+import net.minecraft.world.level.chunk.LevelChunk;
+
+public interface ChunkSystemServerChunkCache {
+
+    public void moonrise$setFullChunk(final int chunkX, final int chunkZ, final LevelChunk chunk);
+
+    public LevelChunk moonrise$getFullChunkIfLoaded(final int chunkX, final int chunkZ);
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_tick_iteration/ChunkTickConstants.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_tick_iteration/ChunkTickConstants.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_tick_iteration/ChunkTickConstants.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_tick_iteration;
+
+public final class ChunkTickConstants {
+
+    public static final int PLAYER_SPAWN_TRACK_RANGE = 8;
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_tick_iteration/ChunkTickDistanceManager.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_tick_iteration/ChunkTickDistanceManager.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_tick_iteration/ChunkTickDistanceManager.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_tick_iteration;
+
+import net.minecraft.core.SectionPos;
+import net.minecraft.server.level.ServerPlayer;
+
+public interface ChunkTickDistanceManager {
+
+    public void moonrise$addPlayer(final ServerPlayer player, final SectionPos pos);
+
+    public void moonrise$removePlayer(final ServerPlayer player, final SectionPos pos);
+
+    public void moonrise$updatePlayer(final ServerPlayer player,
+                                      final SectionPos oldPos, final SectionPos newPos,
+                                      final boolean oldIgnore, final boolean newIgnore);
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_tick_iteration/ChunkTickServerLevel.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_tick_iteration/ChunkTickServerLevel.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_tick_iteration/ChunkTickServerLevel.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.chunk_tick_iteration;
+
+import ca.spottedleaf.moonrise.common.list.ReferenceList;
+import net.minecraft.server.level.ServerChunkCache;
+import net.minecraft.world.level.chunk.LevelChunk;
+
+public interface ChunkTickServerLevel {
+
+    public ReferenceList<ServerChunkCache.ChunkAndHolder> moonrise$getPlayerTickingChunks();
+
+    public void moonrise$markChunkForPlayerTicking(final LevelChunk chunk);
+
+    public void moonrise$removeChunkForPlayerTicking(final LevelChunk chunk);
+
+    public void moonrise$addPlayerTickingRequest(final int chunkX, final int chunkZ);
+
+    public void moonrise$removePlayerTickingRequest(final int chunkX, final int chunkZ);
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/collisions/CollisionUtil.java b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/CollisionUtil.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/CollisionUtil.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.collisions;
+
+import ca.spottedleaf.moonrise.common.util.WorldUtil;
+import ca.spottedleaf.moonrise.patches.chunk_system.world.ChunkSystemEntityGetter;
+import ca.spottedleaf.moonrise.patches.collisions.block.CollisionBlockState;
+import ca.spottedleaf.moonrise.patches.chunk_system.entity.ChunkSystemEntity;
+import ca.spottedleaf.moonrise.patches.collisions.shape.CachedShapeData;
+import ca.spottedleaf.moonrise.patches.collisions.shape.CollisionDiscreteVoxelShape;
+import ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape;
+import ca.spottedleaf.moonrise.patches.block_counting.BlockCountingChunkSection;
+import it.unimi.dsi.fastutil.doubles.DoubleArrayList;
+import it.unimi.dsi.fastutil.doubles.DoubleList;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.Direction;
+import net.minecraft.util.Mth;
+import net.minecraft.world.entity.Entity;
+import net.minecraft.world.entity.vehicle.AbstractMinecart;
+import net.minecraft.world.item.Item;
+import net.minecraft.world.level.CollisionGetter;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.block.Blocks;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.border.WorldBorder;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.ChunkSource;
+import net.minecraft.world.level.chunk.LevelChunkSection;
+import net.minecraft.world.level.chunk.PalettedContainer;
+import net.minecraft.world.level.chunk.status.ChunkStatus;
+import net.minecraft.world.level.material.FluidState;
+import net.minecraft.world.phys.AABB;
+import net.minecraft.world.phys.Vec3;
+import net.minecraft.world.phys.shapes.ArrayVoxelShape;
+import net.minecraft.world.phys.shapes.BitSetDiscreteVoxelShape;
+import net.minecraft.world.phys.shapes.BooleanOp;
+import net.minecraft.world.phys.shapes.CollisionContext;
+import net.minecraft.world.phys.shapes.DiscreteVoxelShape;
+import net.minecraft.world.phys.shapes.EntityCollisionContext;
+import net.minecraft.world.phys.shapes.OffsetDoubleList;
+import net.minecraft.world.phys.shapes.Shapes;
+import net.minecraft.world.phys.shapes.SliceShape;
+import net.minecraft.world.phys.shapes.VoxelShape;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Objects;
+import java.util.function.BiPredicate;
+import java.util.function.Predicate;
+
+public final class CollisionUtil {
+
+    public static final double COLLISION_EPSILON = 1.0E-7;
+    public static final DoubleArrayList ZERO_ONE = DoubleArrayList.wrap(new double[] { 0.0, 1.0 });
+
+    public static boolean isSpecialCollidingBlock(final net.minecraft.world.level.block.state.BlockBehaviour.BlockStateBase block) {
+        return block.hasLargeCollisionShape() || block.getBlock() == Blocks.MOVING_PISTON;
+    }
+
+    public static boolean isEmpty(final AABB aabb) {
+        return (aabb.maxX - aabb.minX) < COLLISION_EPSILON || (aabb.maxY - aabb.minY) < COLLISION_EPSILON || (aabb.maxZ - aabb.minZ) < COLLISION_EPSILON;
+    }
+
+    public static boolean isEmpty(final double minX, final double minY, final double minZ,
+                                  final double maxX, final double maxY, final double maxZ) {
+        return (maxX - minX) < COLLISION_EPSILON || (maxY - minY) < COLLISION_EPSILON || (maxZ - minZ) < COLLISION_EPSILON;
+    }
+
+    public static AABB getBoxForChunk(final int chunkX, final int chunkZ) {
+        double x = (double)(chunkX << 4);
+        double z = (double)(chunkZ << 4);
+        // use a bounding box bigger than the chunk to prevent entities from entering it on move
+        return new AABB(x - 3*COLLISION_EPSILON, Double.NEGATIVE_INFINITY, z - 3*COLLISION_EPSILON,
+            x + (16.0 + 3*COLLISION_EPSILON), Double.POSITIVE_INFINITY, z + (16.0 + 3*COLLISION_EPSILON));
+    }
+
+    /*
+      A couple of rules for VoxelShape collisions:
+      Two shapes only intersect if they are actually more than EPSILON units into each other. This also applies to movement
+      checks.
+      If the two shapes strictly collide, then the return value of a collide call will return a value in the opposite
+      direction of the source move. However, this value will not be greater in magnitude than EPSILON. Collision code
+      will automatically round it to 0.
+     */
+
+    public static boolean voxelShapeIntersect(final double minX1, final double minY1, final double minZ1, final double maxX1,
+                                              final double maxY1, final double maxZ1, final double minX2, final double minY2,
+                                              final double minZ2, final double maxX2, final double maxY2, final double maxZ2) {
+        return (minX1 - maxX2) < -COLLISION_EPSILON && (maxX1 - minX2) > COLLISION_EPSILON &&
+               (minY1 - maxY2) < -COLLISION_EPSILON && (maxY1 - minY2) > COLLISION_EPSILON &&
+               (minZ1 - maxZ2) < -COLLISION_EPSILON && (maxZ1 - minZ2) > COLLISION_EPSILON;
+    }
+
+    public static boolean voxelShapeIntersect(final AABB box, final double minX, final double minY, final double minZ,
+                                              final double maxX, final double maxY, final double maxZ) {
+        return (box.minX - maxX) < -COLLISION_EPSILON && (box.maxX - minX) > COLLISION_EPSILON &&
+               (box.minY - maxY) < -COLLISION_EPSILON && (box.maxY - minY) > COLLISION_EPSILON &&
+               (box.minZ - maxZ) < -COLLISION_EPSILON && (box.maxZ - minZ) > COLLISION_EPSILON;
+    }
+
+    public static boolean voxelShapeIntersect(final AABB box1, final AABB box2) {
+        return (box1.minX - box2.maxX) < -COLLISION_EPSILON && (box1.maxX - box2.minX) > COLLISION_EPSILON &&
+               (box1.minY - box2.maxY) < -COLLISION_EPSILON && (box1.maxY - box2.minY) > COLLISION_EPSILON &&
+               (box1.minZ - box2.maxZ) < -COLLISION_EPSILON && (box1.maxZ - box2.minZ) > COLLISION_EPSILON;
+    }
+
+    // assume !isEmpty(target) && abs(source_move) >= COLLISION_EPSILON
+    public static double collideX(final AABB target, final AABB source, final double source_move) {
+        if ((source.minY - target.maxY) < -COLLISION_EPSILON && (source.maxY - target.minY) > COLLISION_EPSILON &&
+            (source.minZ - target.maxZ) < -COLLISION_EPSILON && (source.maxZ - target.minZ) > COLLISION_EPSILON) {
+            if (source_move >= 0.0) {
+                final double max_move = target.minX - source.maxX; // < 0.0 if no strict collision
+                if (max_move < -COLLISION_EPSILON) {
+                    return source_move;
+                }
+                return Math.min(max_move, source_move);
+            } else {
+                final double max_move = target.maxX - source.minX; // > 0.0 if no strict collision
+                if (max_move > COLLISION_EPSILON) {
+                    return source_move;
+                }
+                return Math.max(max_move, source_move);
+            }
+        }
+        return source_move;
+    }
+
+    // assume !isEmpty(target) && abs(source_move) >= COLLISION_EPSILON
+    public static double collideY(final AABB target, final AABB source, final double source_move) {
+        if ((source.minX - target.maxX) < -COLLISION_EPSILON && (source.maxX - target.minX) > COLLISION_EPSILON &&
+            (source.minZ - target.maxZ) < -COLLISION_EPSILON && (source.maxZ - target.minZ) > COLLISION_EPSILON) {
+            if (source_move >= 0.0) {
+                final double max_move = target.minY - source.maxY; // < 0.0 if no strict collision
+                if (max_move < -COLLISION_EPSILON) {
+                    return source_move;
+                }
+                return Math.min(max_move, source_move);
+            } else {
+                final double max_move = target.maxY - source.minY; // > 0.0 if no strict collision
+                if (max_move > COLLISION_EPSILON) {
+                    return source_move;
+                }
+                return Math.max(max_move, source_move);
+            }
+        }
+        return source_move;
+    }
+
+    // assume !isEmpty(target) && abs(source_move) >= COLLISION_EPSILON
+    public static double collideZ(final AABB target, final AABB source, final double source_move) {
+        if ((source.minX - target.maxX) < -COLLISION_EPSILON && (source.maxX - target.minX) > COLLISION_EPSILON &&
+            (source.minY - target.maxY) < -COLLISION_EPSILON && (source.maxY - target.minY) > COLLISION_EPSILON) {
+            if (source_move >= 0.0) {
+                final double max_move = target.minZ - source.maxZ; // < 0.0 if no strict collision
+                if (max_move < -COLLISION_EPSILON) {
+                    return source_move;
+                }
+                return Math.min(max_move, source_move);
+            } else {
+                final double max_move = target.maxZ - source.minZ; // > 0.0 if no strict collision
+                if (max_move > COLLISION_EPSILON) {
+                    return source_move;
+                }
+                return Math.max(max_move, source_move);
+            }
+        }
+        return source_move;
+    }
+
+    // startIndex and endIndex inclusive
+    // assumes indices are in range of array
+    public static int findFloor(final double[] values, final double offset, final double value, int startIndex, int endIndex) {
+        Objects.checkFromToIndex(startIndex, endIndex + 1, values.length);
+        do {
+            final int middle = (startIndex + endIndex) >>> 1;
+            final double middleVal = (values[middle] + offset);
+
+            if (value < middleVal) {
+                endIndex = middle - 1;
+            } else {
+                startIndex = middle + 1;
+            }
+        } while (startIndex <= endIndex);
+
+        return startIndex - 1;
+    }
+
+    private static VoxelShape sliceShapeVanilla(final VoxelShape src, final Direction.Axis axis,
+                                                final int index) {
+        return new SliceShape(src, axis, index);
+    }
+
+    private static DoubleList offsetList(final double[] src, final double by) {
+        final DoubleArrayList wrap = DoubleArrayList.wrap(src);
+        if (by == 0.0) {
+            return wrap;
+        }
+        return new OffsetDoubleList(wrap, by);
+    }
+
+    private static VoxelShape sliceShapeOptimised(final VoxelShape src, final Direction.Axis axis,
+                                                  final int index) {
+        // assume index in range
+        final double off_x = ((CollisionVoxelShape)src).moonrise$offsetX();
+        final double off_y = ((CollisionVoxelShape)src).moonrise$offsetY();
+        final double off_z = ((CollisionVoxelShape)src).moonrise$offsetZ();
+
+        final double[] coords_x = ((CollisionVoxelShape)src).moonrise$rootCoordinatesX();
+        final double[] coords_y = ((CollisionVoxelShape)src).moonrise$rootCoordinatesY();
+        final double[] coords_z = ((CollisionVoxelShape)src).moonrise$rootCoordinatesZ();
+
+        final CachedShapeData cached_shape_data = ((CollisionVoxelShape)src).moonrise$getCachedVoxelData();
+
+        // note: size = coords.length - 1
+        final int size_x = cached_shape_data.sizeX();
+        final int size_y = cached_shape_data.sizeY();
+        final int size_z = cached_shape_data.sizeZ();
+
+        final long[] bitset = cached_shape_data.voxelSet();
+
+        final DoubleList list_x;
+        final DoubleList list_y;
+        final DoubleList list_z;
+        final int shape_sx;
+        final int shape_ex;
+        final int shape_sy;
+        final int shape_ey;
+        final int shape_sz;
+        final int shape_ez;
+
+        switch (axis) {
+            case X: {
+                // validate index
+                if (index < 0 || index >= size_x) {
+                    return Shapes.empty();
+                }
+
+                // test if input is already "sliced"
+                if (coords_x.length == 2 && (coords_x[0] + off_x) == 0.0 && (coords_x[1] + off_x) == 1.0) {
+                    return src;
+                }
+
+                // test if result would be full box
+                if (coords_y.length == 2 && coords_z.length == 2 &&
+                    (coords_y[0] + off_y) == 0.0 && (coords_y[1] + off_y) == 1.0 &&
+                    (coords_z[0] + off_z) == 0.0 && (coords_z[1] + off_z) == 1.0) {
+                    // note: size_y == size_z == 1
+                    final int bitIdx = 0 + 0*size_z + index*(size_z*size_y);
+                    return (bitset[bitIdx >>> 6] & (1L << bitIdx)) == 0L ? Shapes.empty() : Shapes.block();
+                }
+
+                list_x = ZERO_ONE;
+                list_y = offsetList(coords_y, off_y);
+                list_z = offsetList(coords_z, off_z);
+                shape_sx = index;
+                shape_ex = index + 1;
+                shape_sy = 0;
+                shape_ey = size_y;
+                shape_sz = 0;
+                shape_ez = size_z;
+
+                break;
+            }
+            case Y: {
+                // validate index
+                if (index < 0 || index >= size_y) {
+                    return Shapes.empty();
+                }
+
+                // test if input is already "sliced"
+                if (coords_y.length == 2 && (coords_y[0] + off_y) == 0.0 && (coords_y[1] + off_y) == 1.0) {
+                    return src;
+                }
+
+                // test if result would be full box
+                if (coords_x.length == 2 && coords_z.length == 2 &&
+                    (coords_x[0] + off_x) == 0.0 && (coords_x[1] + off_x) == 1.0 &&
+                    (coords_z[0] + off_z) == 0.0 && (coords_z[1] + off_z) == 1.0) {
+                    // note: size_x == size_z == 1
+                    final int bitIdx = 0 + index*size_z + 0*(size_z*size_y);
+                    return (bitset[bitIdx >>> 6] & (1L << bitIdx)) == 0L ? Shapes.empty() : Shapes.block();
+                }
+
+                list_x = offsetList(coords_x, off_x);
+                list_y = ZERO_ONE;
+                list_z = offsetList(coords_z, off_z);
+                shape_sx = 0;
+                shape_ex = size_x;
+                shape_sy = index;
+                shape_ey = index + 1;
+                shape_sz = 0;
+                shape_ez = size_z;
+
+                break;
+            }
+            case Z: {
+                // validate index
+                if (index < 0 || index >= size_z) {
+                    return Shapes.empty();
+                }
+
+                // test if input is already "sliced"
+                if (coords_z.length == 2 && (coords_z[0] + off_z) == 0.0 && (coords_z[1] + off_z) == 1.0) {
+                    return src;
+                }
+
+                // test if result would be full box
+                if (coords_x.length == 2 && coords_y.length == 2 &&
+                    (coords_x[0] + off_x) == 0.0 && (coords_x[1] + off_x) == 1.0 &&
+                    (coords_y[0] + off_y) == 0.0 && (coords_y[1] + off_y) == 1.0) {
+                    // note: size_x == size_y == 1
+                    final int bitIdx = index + 0*size_z + 0*(size_z*size_y);
+                    return (bitset[bitIdx >>> 6] & (1L << bitIdx)) == 0L ? Shapes.empty() : Shapes.block();
+                }
+
+                list_x = offsetList(coords_x, off_x);
+                list_y = offsetList(coords_y, off_y);
+                list_z = ZERO_ONE;
+                shape_sx = 0;
+                shape_ex = size_x;
+                shape_sy = 0;
+                shape_ey = size_y;
+                shape_sz = index;
+                shape_ez = index + 1;
+
+                break;
+            }
+            default: {
+                throw new IllegalStateException("Unknown axis: " + axis);
+            }
+        }
+
+        final int local_len_x = shape_ex - shape_sx;
+        final int local_len_y = shape_ey - shape_sy;
+        final int local_len_z = shape_ez - shape_sz;
+
+        final BitSetDiscreteVoxelShape shape = new BitSetDiscreteVoxelShape(local_len_x, local_len_y, local_len_z);
+
+        final int bitset_mul_x = size_z*size_y;
+        final int idx_off = shape_sz + shape_sy*size_z + shape_sx*bitset_mul_x;
+        final int shape_mul_x = local_len_y*local_len_z;
+        for (int x = 0; x < local_len_x; ++x) {
+            boolean setX = false;
+            for (int y = 0; y < local_len_y; ++y) {
+                boolean setY = false;
+                for (int z = 0; z < local_len_z; ++z) {
+                    final int unslicedIdx = idx_off + z + y*size_z + x*bitset_mul_x;
+                    if ((bitset[unslicedIdx >>> 6] & (1L << unslicedIdx)) == 0L) {
+                        continue;
+                    }
+
+                    setY = true;
+                    setX = true;
+                    shape.zMin = Math.min(shape.zMin, z);
+                    shape.zMax = Math.max(shape.zMax, z + 1);
+
+                    shape.storage.set(
+                        z + y*local_len_z + x*shape_mul_x
+                    );
+                }
+
+                if (setY) {
+                    shape.yMin = Math.min(shape.yMin, y);
+                    shape.yMax = Math.max(shape.yMax, y + 1);
+                }
+            }
+            if (setX) {
+                shape.xMin = Math.min(shape.xMin, x);
+                shape.xMax = Math.max(shape.xMax, x + 1);
+            }
+        }
+
+        return shape.isEmpty() ? Shapes.empty() : new ArrayVoxelShape(
+            shape, list_x, list_y, list_z
+        );
+    }
+
+    private static final boolean DEBUG_SLICE_SHAPE = false;
+
+    public static VoxelShape sliceShape(final VoxelShape src, final Direction.Axis axis,
+                                        final int index) {
+        final VoxelShape ret = sliceShapeOptimised(src, axis, index);
+        if (DEBUG_SLICE_SHAPE) {
+            final VoxelShape vanilla = sliceShapeVanilla(src, axis, index);
+            if (!equals(ret, vanilla)) {
+                // special case: SliceShape is not empty when it should be!
+                if (areAnyFull(ret.shape) || areAnyFull(vanilla.shape)) {
+                    equals(ret, vanilla);
+                    sliceShapeOptimised(src, axis, index);
+                    throw new IllegalStateException("Slice shape mismatch");
+                }
+            }
+        }
+
+        return ret;
+    }
+
+    public static boolean voxelShapeIntersectNoEmpty(final VoxelShape voxel, final AABB aabb) {
+        if (voxel.isEmpty()) {
+            return false;
+        }
+
+        // note: this function assumes that for any i in coords that coord[i + 1] - coord[i] > COLLISION_EPSILON is true
+
+        // offsets that should be applied to coords
+        final double off_x = ((CollisionVoxelShape)voxel).moonrise$offsetX();
+        final double off_y = ((CollisionVoxelShape)voxel).moonrise$offsetY();
+        final double off_z = ((CollisionVoxelShape)voxel).moonrise$offsetZ();
+
+        final double[] coords_x = ((CollisionVoxelShape)voxel).moonrise$rootCoordinatesX();
+        final double[] coords_y = ((CollisionVoxelShape)voxel).moonrise$rootCoordinatesY();
+        final double[] coords_z = ((CollisionVoxelShape)voxel).moonrise$rootCoordinatesZ();
+
+        final CachedShapeData cached_shape_data = ((CollisionVoxelShape)voxel).moonrise$getCachedVoxelData();
+
+        // note: size = coords.length - 1
+        final int size_x = cached_shape_data.sizeX();
+        final int size_y = cached_shape_data.sizeY();
+        final int size_z = cached_shape_data.sizeZ();
+
+        // note: voxel bitset with set index (x, y, z) indicates that
+        //       an AABB(coords_x[x], coords_y[y], coords_z[z], coords_x[x + 1], coords_y[y + 1], coords_z[z + 1])
+        //       is collidable. this is the fundamental principle of operation for the voxel collision operation
+
+        // note: for intersection, one we find the floor of the min we can use that as the start index
+        //       for the next check as source max >= source min
+        // note: we can fast check intersection on the two other axis by seeing if the min index is >= size,
+        //       as this implies that coords[coords.length - 1] < source min
+        //       we can also fast check by seeing if max index is < 0, as this implies that coords[0] > source max
+
+        final int floor_min_x = Math.max(
+                0,
+                findFloor(coords_x, off_x, aabb.minX + COLLISION_EPSILON, 0, size_x)
+        );
+        if (floor_min_x >= size_x) {
+            // cannot intersect
+            return false;
+        }
+
+        final int ceil_max_x = Math.min(
+                size_x,
+                findFloor(coords_x, off_x, aabb.maxX - COLLISION_EPSILON, floor_min_x, size_x) + 1
+        );
+        if (floor_min_x >= ceil_max_x) {
+            // cannot intersect
+            return false;
+        }
+
+        final int floor_min_y = Math.max(
+                0,
+                findFloor(coords_y, off_y, aabb.minY + COLLISION_EPSILON, 0, size_y)
+        );
+        if (floor_min_y >= size_y) {
+            // cannot intersect
+            return false;
+        }
+
+        final int ceil_max_y = Math.min(
+                size_y,
+                findFloor(coords_y, off_y, aabb.maxY - COLLISION_EPSILON, floor_min_y, size_y) + 1
+        );
+        if (floor_min_y >= ceil_max_y) {
+            // cannot intersect
+            return false;
+        }
+
+        final int floor_min_z = Math.max(
+                0,
+                findFloor(coords_z, off_z, aabb.minZ + COLLISION_EPSILON, 0, size_z)
+        );
+        if (floor_min_z >= size_z) {
+            // cannot intersect
+            return false;
+        }
+
+        final int ceil_max_z = Math.min(
+                size_z,
+                findFloor(coords_z, off_z, aabb.maxZ - COLLISION_EPSILON, floor_min_z, size_z) + 1
+        );
+        if (floor_min_z >= ceil_max_z) {
+            // cannot intersect
+            return false;
+        }
+
+        final long[] bitset = cached_shape_data.voxelSet();
+
+        // check bitset to check if any shapes in range are full
+
+        final int mul_x = size_y*size_z;
+        for (int curr_x = floor_min_x; curr_x < ceil_max_x; ++curr_x) {
+            for (int curr_y = floor_min_y; curr_y < ceil_max_y; ++curr_y) {
+                for (int curr_z = floor_min_z; curr_z < ceil_max_z; ++curr_z) {
+                    final int index = curr_z + curr_y*size_z + curr_x*mul_x;
+                    // note: JLS states long shift operators ANDS shift by 63
+                    if ((bitset[index >>> 6] & (1L << index)) != 0L) {
+                        return true;
+                    }
+                }
+            }
+        }
+
+        return false;
+    }
+
+    // assume !target.isEmpty() && abs(source_move) >= COLLISION_EPSILON
+    public static double collideX(final VoxelShape target, final AABB source, final double source_move) {
+        final AABB single_aabb = ((CollisionVoxelShape)target).moonrise$getSingleAABBRepresentation();
+        if (single_aabb != null) {
+            return collideX(single_aabb, source, source_move);
+        }
+        // note: this function assumes that for any i in coords that coord[i + 1] - coord[i] > COLLISION_EPSILON is true
+
+        // offsets that should be applied to coords
+        final double off_x = ((CollisionVoxelShape)target).moonrise$offsetX();
+        final double off_y = ((CollisionVoxelShape)target).moonrise$offsetY();
+        final double off_z = ((CollisionVoxelShape)target).moonrise$offsetZ();
+
+        final double[] coords_x = ((CollisionVoxelShape)target).moonrise$rootCoordinatesX();
+        final double[] coords_y = ((CollisionVoxelShape)target).moonrise$rootCoordinatesY();
+        final double[] coords_z = ((CollisionVoxelShape)target).moonrise$rootCoordinatesZ();
+
+        final CachedShapeData cached_shape_data = ((CollisionVoxelShape)target).moonrise$getCachedVoxelData();
+
+        // note: size = coords.length - 1
+        final int size_x = cached_shape_data.sizeX();
+        final int size_y = cached_shape_data.sizeY();
+        final int size_z = cached_shape_data.sizeZ();
+
+        // note: voxel bitset with set index (x, y, z) indicates that
+        //       an AABB(coords_x[x], coords_y[y], coords_z[z], coords_x[x + 1], coords_y[y + 1], coords_z[z + 1])
+        //       is collidable. this is the fundamental principle of operation for the voxel collision operation
+
+
+        // note: for intersection, one we find the floor of the min we can use that as the start index
+        //       for the next check as source max >= source min
+        // note: we can fast check intersection on the two other axis by seeing if the min index is >= size,
+        //       as this implies that coords[coords.length - 1] < source min
+        //       we can also fast check by seeing if max index is < 0, as this implies that coords[0] > source max
+
+        final int floor_min_y = Math.max(
+                0,
+                findFloor(coords_y, off_y, source.minY + COLLISION_EPSILON, 0, size_y)
+        );
+        if (floor_min_y >= size_y) {
+            // cannot intersect
+            return source_move;
+        }
+
+        final int ceil_max_y = Math.min(
+                size_y,
+                findFloor(coords_y, off_y, source.maxY - COLLISION_EPSILON, floor_min_y, size_y) + 1
+        );
+        if (floor_min_y >= ceil_max_y) {
+            // cannot intersect
+            return source_move;
+        }
+
+        final int floor_min_z = Math.max(
+                0,
+                findFloor(coords_z, off_z, source.minZ + COLLISION_EPSILON, 0, size_z)
+        );
+        if (floor_min_z >= size_z) {
+            // cannot intersect
+            return source_move;
+        }
+
+        final int ceil_max_z = Math.min(
+                size_z,
+                findFloor(coords_z, off_z, source.maxZ - COLLISION_EPSILON, floor_min_z, size_z) + 1
+        );
+        if (floor_min_z >= ceil_max_z) {
+            // cannot intersect
+            return source_move;
+        }
+
+        // index = z + y*size_z + x*(size_z*size_y)
+
+        final long[] bitset = cached_shape_data.voxelSet();
+
+        if (source_move > 0.0) {
+            final double source_max = source.maxX;
+            final int ceil_max_x = findFloor(
+                    coords_x, off_x, source_max - COLLISION_EPSILON, 0, size_x
+            ) + 1; // add one, we are not interested in (coords[i] + COLLISION_EPSILON) < max
+
+            // note: only the order of the first loop matters
+
+            // note: we cannot collide with the face at index size on the collision axis for forward movement
+
+            final int mul_x = size_y*size_z;
+            for (int curr_x = ceil_max_x; curr_x < size_x; ++curr_x) {
+                double max_dist = (coords_x[curr_x] + off_x) - source_max;
+                if (max_dist >= source_move) {
+                    // if we reach here, then we will never have a case where
+                    // coords[curr + n] - source_max < source_move, as coords[curr + n] < coords[curr + n + 1]
+                    // thus, we can return immediately
+
+                    // this optimization is important since this loop is bounded by size, and _not_ by
+                    // a calculated max index based off of source_move - so it would be possible to check
+                    // the whole intersected shape for collisions when we didn't need to!
+                    return source_move;
+                }
+                if (max_dist >= -COLLISION_EPSILON) { // only push out by up to COLLISION_EPSILON
+                    max_dist = Math.min(max_dist, source_move);
+                }
+                for (int curr_y = floor_min_y; curr_y < ceil_max_y; ++curr_y) {
+                    for (int curr_z = floor_min_z; curr_z < ceil_max_z; ++curr_z) {
+                        final int index = curr_z + curr_y*size_z + curr_x*mul_x;
+                        // note: JLS states long shift operators ANDS shift by 63
+                        if ((bitset[index >>> 6] & (1L << index)) != 0L) {
+                            return max_dist;
+                        }
+                    }
+                }
+            }
+
+            return source_move;
+        } else {
+            final double source_min = source.minX;
+            final int floor_min_x = findFloor(
+                    coords_x, off_x, source_min + COLLISION_EPSILON, 0, size_x
+            );
+
+            // note: only the order of the first loop matters
+
+            // note: we cannot collide with the face at index 0 on the collision axis for backwards movement
+
+            // note: we offset the collision axis by - 1 for the voxel bitset index, but use + 1 for the
+            //       coordinate index as the voxelset stores whether the shape is solid for [index, index + 1]
+            //       thus, we need to use the voxel index i-1 if we want to check that the face at index i is solid
+            final int mul_x = size_y*size_z;
+            for (int curr_x = floor_min_x - 1; curr_x >= 0; --curr_x) {
+                double max_dist = (coords_x[curr_x + 1] + off_x) - source_min;
+                if (max_dist <= source_move) {
+                    // if we reach here, then we will never have a case where
+                    // coords[curr + n] - source_max > source_move, as coords[curr + n] > coords[curr + n - 1]
+                    // thus, we can return immediately
+
+                    // this optimization is important since this loop is possibly bounded by size, and _not_ by
+                    // a calculated max index based off of source_move - so it would be possible to check
+                    // the whole intersected shape for collisions when we didn't need to!
+                    return source_move;
+                }
+                if (max_dist <= COLLISION_EPSILON) { // only push out by up to COLLISION_EPSILON
+                    max_dist = Math.max(max_dist, source_move);
+                }
+                for (int curr_y = floor_min_y; curr_y < ceil_max_y; ++curr_y) {
+                    for (int curr_z = floor_min_z; curr_z < ceil_max_z; ++curr_z) {
+                        final int index = curr_z + curr_y*size_z + curr_x*mul_x;
+                        // note: JLS states long shift operators ANDS shift by 63
+                        if ((bitset[index >>> 6] & (1L << index)) != 0L) {
+                            return max_dist;
+                        }
+                    }
+                }
+            }
+
+            return source_move;
+        }
+    }
+
+    public static double collideY(final VoxelShape target, final AABB source, final double source_move) {
+        final AABB single_aabb = ((CollisionVoxelShape)target).moonrise$getSingleAABBRepresentation();
+        if (single_aabb != null) {
+            return collideY(single_aabb, source, source_move);
+        }
+        // note: this function assumes that for any i in coords that coord[i + 1] - coord[i] > COLLISION_EPSILON is true
+
+        // offsets that should be applied to coords
+        final double off_x = ((CollisionVoxelShape)target).moonrise$offsetX();
+        final double off_y = ((CollisionVoxelShape)target).moonrise$offsetY();
+        final double off_z = ((CollisionVoxelShape)target).moonrise$offsetZ();
+
+        final double[] coords_x = ((CollisionVoxelShape)target).moonrise$rootCoordinatesX();
+        final double[] coords_y = ((CollisionVoxelShape)target).moonrise$rootCoordinatesY();
+        final double[] coords_z = ((CollisionVoxelShape)target).moonrise$rootCoordinatesZ();
+
+        final CachedShapeData cached_shape_data = ((CollisionVoxelShape)target).moonrise$getCachedVoxelData();
+
+        // note: size = coords.length - 1
+        final int size_x = cached_shape_data.sizeX();
+        final int size_y = cached_shape_data.sizeY();
+        final int size_z = cached_shape_data.sizeZ();
+
+        // note: voxel bitset with set index (x, y, z) indicates that
+        //       an AABB(coords_x[x], coords_y[y], coords_z[z], coords_x[x + 1], coords_y[y + 1], coords_z[z + 1])
+        //       is collidable. this is the fundamental principle of operation for the voxel collision operation
+
+
+        // note: for intersection, one we find the floor of the min we can use that as the start index
+        //       for the next check as source max >= source min
+        // note: we can fast check intersection on the two other axis by seeing if the min index is >= size,
+        //       as this implies that coords[coords.length - 1] < source min
+        //       we can also fast check by seeing if max index is < 0, as this implies that coords[0] > source max
+
+        final int floor_min_x = Math.max(
+                0,
+                findFloor(coords_x, off_x, source.minX + COLLISION_EPSILON, 0, size_x)
+        );
+        if (floor_min_x >= size_x) {
+            // cannot intersect
+            return source_move;
+        }
+
+        final int ceil_max_x = Math.min(
+                size_x,
+                findFloor(coords_x, off_x, source.maxX - COLLISION_EPSILON, floor_min_x, size_x) + 1
+        );
+        if (floor_min_x >= ceil_max_x) {
+            // cannot intersect
+            return source_move;
+        }
+
+        final int floor_min_z = Math.max(
+                0,
+                findFloor(coords_z, off_z, source.minZ + COLLISION_EPSILON, 0, size_z)
+        );
+        if (floor_min_z >= size_z) {
+            // cannot intersect
+            return source_move;
+        }
+
+        final int ceil_max_z = Math.min(
+                size_z,
+                findFloor(coords_z, off_z, source.maxZ - COLLISION_EPSILON, floor_min_z, size_z) + 1
+        );
+        if (floor_min_z >= ceil_max_z) {
+            // cannot intersect
+            return source_move;
+        }
+
+        // index = z + y*size_z + x*(size_z*size_y)
+
+        final long[] bitset = cached_shape_data.voxelSet();
+
+        if (source_move > 0.0) {
+            final double source_max = source.maxY;
+            final int ceil_max_y = findFloor(
+                    coords_y, off_y, source_max - COLLISION_EPSILON, 0, size_y
+            ) + 1; // add one, we are not interested in (coords[i] + COLLISION_EPSILON) < max
+
+            // note: only the order of the first loop matters
+
+            // note: we cannot collide with the face at index size on the collision axis for forward movement
+
+            final int mul_x = size_y*size_z;
+            for (int curr_y = ceil_max_y; curr_y < size_y; ++curr_y) {
+                double max_dist = (coords_y[curr_y] + off_y) - source_max;
+                if (max_dist >= source_move) {
+                    // if we reach here, then we will never have a case where
+                    // coords[curr + n] - source_max < source_move, as coords[curr + n] < coords[curr + n + 1]
+                    // thus, we can return immediately
+
+                    // this optimization is important since this loop is bounded by size, and _not_ by
+                    // a calculated max index based off of source_move - so it would be possible to check
+                    // the whole intersected shape for collisions when we didn't need to!
+                    return source_move;
+                }
+                if (max_dist >= -COLLISION_EPSILON) { // only push out by up to COLLISION_EPSILON
+                    max_dist = Math.min(max_dist, source_move);
+                }
+                for (int curr_x = floor_min_x; curr_x < ceil_max_x; ++curr_x) {
+                    for (int curr_z = floor_min_z; curr_z < ceil_max_z; ++curr_z) {
+                        final int index = curr_z + curr_y*size_z + curr_x*mul_x;
+                        // note: JLS states long shift operators ANDS shift by 63
+                        if ((bitset[index >>> 6] & (1L << index)) != 0L) {
+                            return max_dist;
+                        }
+                    }
+                }
+            }
+
+            return source_move;
+        } else {
+            final double source_min = source.minY;
+            final int floor_min_y = findFloor(
+                    coords_y, off_y, source_min + COLLISION_EPSILON, 0, size_y
+            );
+
+            // note: only the order of the first loop matters
+
+            // note: we cannot collide with the face at index 0 on the collision axis for backwards movement
+
+            // note: we offset the collision axis by - 1 for the voxel bitset index, but use + 1 for the
+            //       coordinate index as the voxelset stores whether the shape is solid for [index, index + 1]
+            //       thus, we need to use the voxel index i-1 if we want to check that the face at index i is solid
+            final int mul_x = size_y*size_z;
+            for (int curr_y = floor_min_y - 1; curr_y >= 0; --curr_y) {
+                double max_dist = (coords_y[curr_y + 1] + off_y) - source_min;
+                if (max_dist <= source_move) {
+                    // if we reach here, then we will never have a case where
+                    // coords[curr + n] - source_max > source_move, as coords[curr + n] > coords[curr + n - 1]
+                    // thus, we can return immediately
+
+                    // this optimization is important since this loop is possibly bounded by size, and _not_ by
+                    // a calculated max index based off of source_move - so it would be possible to check
+                    // the whole intersected shape for collisions when we didn't need to!
+                    return source_move;
+                }
+                if (max_dist <= COLLISION_EPSILON) { // only push out by up to COLLISION_EPSILON
+                    max_dist = Math.max(max_dist, source_move);
+                }
+                for (int curr_x = floor_min_x; curr_x < ceil_max_x; ++curr_x) {
+                    for (int curr_z = floor_min_z; curr_z < ceil_max_z; ++curr_z) {
+                        final int index = curr_z + curr_y*size_z + curr_x*mul_x;
+                        // note: JLS states long shift operators ANDS shift by 63
+                        if ((bitset[index >>> 6] & (1L << index)) != 0L) {
+                            return max_dist;
+                        }
+                    }
+                }
+            }
+
+            return source_move;
+        }
+    }
+
+    public static double collideZ(final VoxelShape target, final AABB source, final double source_move) {
+        final AABB single_aabb = ((CollisionVoxelShape)target).moonrise$getSingleAABBRepresentation();
+        if (single_aabb != null) {
+            return collideZ(single_aabb, source, source_move);
+        }
+        // note: this function assumes that for any i in coords that coord[i + 1] - coord[i] > COLLISION_EPSILON is true
+
+        // offsets that should be applied to coords
+        final double off_x = ((CollisionVoxelShape)target).moonrise$offsetX();
+        final double off_y = ((CollisionVoxelShape)target).moonrise$offsetY();
+        final double off_z = ((CollisionVoxelShape)target).moonrise$offsetZ();
+
+        final double[] coords_x = ((CollisionVoxelShape)target).moonrise$rootCoordinatesX();
+        final double[] coords_y = ((CollisionVoxelShape)target).moonrise$rootCoordinatesY();
+        final double[] coords_z = ((CollisionVoxelShape)target).moonrise$rootCoordinatesZ();
+
+        final CachedShapeData cached_shape_data = ((CollisionVoxelShape)target).moonrise$getCachedVoxelData();
+
+        // note: size = coords.length - 1
+        final int size_x = cached_shape_data.sizeX();
+        final int size_y = cached_shape_data.sizeY();
+        final int size_z = cached_shape_data.sizeZ();
+
+        // note: voxel bitset with set index (x, y, z) indicates that
+        //       an AABB(coords_x[x], coords_y[y], coords_z[z], coords_x[x + 1], coords_y[y + 1], coords_z[z + 1])
+        //       is collidable. this is the fundamental principle of operation for the voxel collision operation
+
+
+        // note: for intersection, one we find the floor of the min we can use that as the start index
+        //       for the next check as source max >= source min
+        // note: we can fast check intersection on the two other axis by seeing if the min index is >= size,
+        //       as this implies that coords[coords.length - 1] < source min
+        //       we can also fast check by seeing if max index is < 0, as this implies that coords[0] > source max
+
+        final int floor_min_x = Math.max(
+                0,
+                findFloor(coords_x, off_x, source.minX + COLLISION_EPSILON, 0, size_x)
+        );
+        if (floor_min_x >= size_x) {
+            // cannot intersect
+            return source_move;
+        }
+
+        final int ceil_max_x = Math.min(
+                size_x,
+                findFloor(coords_x, off_x, source.maxX - COLLISION_EPSILON, floor_min_x, size_x) + 1
+        );
+        if (floor_min_x >= ceil_max_x) {
+            // cannot intersect
+            return source_move;
+        }
+
+        final int floor_min_y = Math.max(
+                0,
+                findFloor(coords_y, off_y, source.minY + COLLISION_EPSILON, 0, size_y)
+        );
+        if (floor_min_y >= size_y) {
+            // cannot intersect
+            return source_move;
+        }
+
+        final int ceil_max_y = Math.min(
+                size_y,
+                findFloor(coords_y, off_y, source.maxY - COLLISION_EPSILON, floor_min_y, size_y) + 1
+        );
+        if (floor_min_y >= ceil_max_y) {
+            // cannot intersect
+            return source_move;
+        }
+
+        // index = z + y*size_z + x*(size_z*size_y)
+
+        final long[] bitset = cached_shape_data.voxelSet();
+
+        if (source_move > 0.0) {
+            final double source_max = source.maxZ;
+            final int ceil_max_z = findFloor(
+                    coords_z, off_z, source_max - COLLISION_EPSILON, 0, size_z
+            ) + 1; // add one, we are not interested in (coords[i] + COLLISION_EPSILON) < max
+
+            // note: only the order of the first loop matters
+
+            // note: we cannot collide with the face at index size on the collision axis for forward movement
+
+            final int mul_x = size_y*size_z;
+            for (int curr_z = ceil_max_z; curr_z < size_z; ++curr_z) {
+                double max_dist = (coords_z[curr_z] + off_z) - source_max;
+                if (max_dist >= source_move) {
+                    // if we reach here, then we will never have a case where
+                    // coords[curr + n] - source_max < source_move, as coords[curr + n] < coords[curr + n + 1]
+                    // thus, we can return immediately
+
+                    // this optimization is important since this loop is bounded by size, and _not_ by
+                    // a calculated max index based off of source_move - so it would be possible to check
+                    // the whole intersected shape for collisions when we didn't need to!
+                    return source_move;
+                }
+                if (max_dist >= -COLLISION_EPSILON) { // only push out by up to COLLISION_EPSILON
+                    max_dist = Math.min(max_dist, source_move);
+                }
+                for (int curr_x = floor_min_x; curr_x < ceil_max_x; ++curr_x) {
+                    for (int curr_y = floor_min_y; curr_y < ceil_max_y; ++curr_y) {
+                        final int index = curr_z + curr_y*size_z + curr_x*mul_x;
+                        // note: JLS states long shift operators ANDS shift by 63
+                        if ((bitset[index >>> 6] & (1L << index)) != 0L) {
+                            return max_dist;
+                        }
+                    }
+                }
+            }
+
+            return source_move;
+        } else {
+            final double source_min = source.minZ;
+            final int floor_min_z = findFloor(
+                    coords_z, off_z, source_min + COLLISION_EPSILON, 0, size_z
+            );
+
+            // note: only the order of the first loop matters
+
+            // note: we cannot collide with the face at index 0 on the collision axis for backwards movement
+
+            // note: we offset the collision axis by - 1 for the voxel bitset index, but use + 1 for the
+            //       coordinate index as the voxelset stores whether the shape is solid for [index, index + 1]
+            //       thus, we need to use the voxel index i-1 if we want to check that the face at index i is solid
+            final int mul_x = size_y*size_z;
+            for (int curr_z = floor_min_z - 1; curr_z >= 0; --curr_z) {
+                double max_dist = (coords_z[curr_z + 1] + off_z) - source_min;
+                if (max_dist <= source_move) {
+                    // if we reach here, then we will never have a case where
+                    // coords[curr + n] - source_max > source_move, as coords[curr + n] > coords[curr + n - 1]
+                    // thus, we can return immediately
+
+                    // this optimization is important since this loop is possibly bounded by size, and _not_ by
+                    // a calculated max index based off of source_move - so it would be possible to check
+                    // the whole intersected shape for collisions when we didn't need to!
+                    return source_move;
+                }
+                if (max_dist <= COLLISION_EPSILON) { // only push out by up to COLLISION_EPSILON
+                    max_dist = Math.max(max_dist, source_move);
+                }
+                for (int curr_x = floor_min_x; curr_x < ceil_max_x; ++curr_x) {
+                    for (int curr_y = floor_min_y; curr_y < ceil_max_y; ++curr_y) {
+                        final int index = curr_z + curr_y*size_z + curr_x*mul_x;
+                        // note: JLS states long shift operators ANDS shift by 63
+                        if ((bitset[index >>> 6] & (1L << index)) != 0L) {
+                            return max_dist;
+                        }
+                    }
+                }
+            }
+
+            return source_move;
+        }
+    }
+
+    // does not use epsilon
+    public static boolean strictlyContains(final VoxelShape voxel, final Vec3 point) {
+        return strictlyContains(voxel, point.x, point.y, point.z);
+    }
+
+    // does not use epsilon
+    public static boolean strictlyContains(final VoxelShape voxel, final double x, final double y, final double z) {
+        final AABB single_aabb = ((CollisionVoxelShape)voxel).moonrise$getSingleAABBRepresentation();
+        if (single_aabb != null) {
+            return single_aabb.contains(x, y, z);
+        }
+
+        if (voxel.isEmpty()) {
+            // bitset is clear, no point in searching
+            return false;
+        }
+
+        final double off_x = ((CollisionVoxelShape)voxel).moonrise$offsetX();
+        final double off_y = ((CollisionVoxelShape)voxel).moonrise$offsetY();
+        final double off_z = ((CollisionVoxelShape)voxel).moonrise$offsetZ();
+
+        final double[] coords_x = ((CollisionVoxelShape)voxel).moonrise$rootCoordinatesX();
+        final double[] coords_y = ((CollisionVoxelShape)voxel).moonrise$rootCoordinatesY();
+        final double[] coords_z = ((CollisionVoxelShape)voxel).moonrise$rootCoordinatesZ();
+
+        final CachedShapeData cached_shape_data = ((CollisionVoxelShape)voxel).moonrise$getCachedVoxelData();
+
+        // note: size = coords.length - 1
+        final int size_x = cached_shape_data.sizeX();
+        final int size_y = cached_shape_data.sizeY();
+        final int size_z = cached_shape_data.sizeZ();
+
+        // note: should mirror AABB#contains, which is that for any point X that X >= min and X < max.
+        //       specifically, it cannot collide on the max bounds of the shape
+
+        final int index_x = findFloor(coords_x, off_x, x, 0, size_x);
+        if (index_x < 0 || index_x >= size_x) {
+            return false;
+        }
+
+        final int index_y = findFloor(coords_y, off_y, y, 0, size_y);
+        if (index_y < 0 || index_y >= size_y) {
+            return false;
+        }
+
+        final int index_z = findFloor(coords_z, off_z, z, 0, size_z);
+        if (index_z < 0 || index_z >= size_z) {
+            return false;
+        }
+
+        // index = z + y*size_z + x*(size_z*size_y)
+
+        final int index = index_z + index_y*size_z + index_x*(size_z*size_y);
+
+        final long[] bitset = cached_shape_data.voxelSet();
+
+        return (bitset[index >>> 6] & (1L << index)) != 0L;
+    }
+
+    private static int makeBitset(final boolean ft, final boolean tf, final boolean tt) {
+        // idx ff -> 0
+        // idx ft -> 1
+        // idx tf -> 2
+        // idx tt -> 3
+        return ((ft ? 1 : 0) << 1) | ((tf ? 1 : 0) << 2) | ((tt ? 1 : 0) << 3);
+    }
+
+    private static BitSetDiscreteVoxelShape merge(final CachedShapeData shapeDataFirst, final CachedShapeData shapeDataSecond,
+                                                  final MergedVoxelCoordinateList mergedX, final MergedVoxelCoordinateList mergedY,
+                                                  final MergedVoxelCoordinateList mergedZ,
+                                                  final int booleanOp) {
+        final int sizeX = mergedX.voxels;
+        final int sizeY = mergedY.voxels;
+        final int sizeZ = mergedZ.voxels;
+
+        final long[] s1Voxels = shapeDataFirst.voxelSet();
+        final long[] s2Voxels = shapeDataSecond.voxelSet();
+
+        final int s1Mul1 = shapeDataFirst.sizeZ();
+        final int s1Mul2 = s1Mul1 * shapeDataFirst.sizeY();
+
+        final int s2Mul1 = shapeDataSecond.sizeZ();
+        final int s2Mul2 = s2Mul1 * shapeDataSecond.sizeY();
+
+        // note: indices may contain -1, but nothing > size
+        final BitSetDiscreteVoxelShape ret = new BitSetDiscreteVoxelShape(sizeX, sizeY, sizeZ);
+
+        boolean empty = true;
+
+        int mergedIdx = 0;
+        for (int idxX = 0; idxX < sizeX; ++idxX) {
+            final int s1x = mergedX.firstIndices[idxX];
+            final int s2x = mergedX.secondIndices[idxX];
+            boolean setX = false;
+            for (int idxY = 0; idxY < sizeY; ++idxY) {
+                final int s1y = mergedY.firstIndices[idxY];
+                final int s2y = mergedY.secondIndices[idxY];
+                boolean setY = false;
+                for (int idxZ = 0; idxZ < sizeZ; ++idxZ) {
+                    final int s1z = mergedZ.firstIndices[idxZ];
+                    final int s2z = mergedZ.secondIndices[idxZ];
+
+                    int idx1;
+                    int idx2;
+
+                    final int isS1Full = (s1x | s1y | s1z) < 0 ? 0 : (int)((s1Voxels[(idx1 = s1z + s1y*s1Mul1 + s1x*s1Mul2) >>> 6] >>> idx1) & 1L);
+                    final int isS2Full = (s2x | s2y | s2z) < 0 ? 0 : (int)((s2Voxels[(idx2 = s2z + s2y*s2Mul1 + s2x*s2Mul2) >>> 6] >>> idx2) & 1L);
+
+                    // idx ff -> 0
+                    // idx ft -> 1
+                    // idx tf -> 2
+                    // idx tt -> 3
+
+                    final boolean res = (booleanOp & (1 << (isS2Full | (isS1Full << 1)))) != 0;
+                    setY |= res;
+                    setX |= res;
+
+                    if (res) {
+                        empty = false;
+                        // inline and optimize fill operation
+                        ret.zMin = Math.min(ret.zMin, idxZ);
+                        ret.zMax = Math.max(ret.zMax, idxZ + 1);
+                        ret.storage.set(mergedIdx);
+                    }
+
+                    ++mergedIdx;
+                }
+                if (setY) {
+                    ret.yMin = Math.min(ret.yMin, idxY);
+                    ret.yMax = Math.max(ret.yMax, idxY + 1);
+                }
+            }
+            if (setX) {
+                ret.xMin = Math.min(ret.xMin, idxX);
+                ret.xMax = Math.max(ret.xMax, idxX + 1);
+            }
+        }
+
+        return empty ? null : ret;
+    }
+
+    private static boolean isMergeEmpty(final CachedShapeData shapeDataFirst, final CachedShapeData shapeDataSecond,
+                                        final MergedVoxelCoordinateList mergedX, final MergedVoxelCoordinateList mergedY,
+                                        final MergedVoxelCoordinateList mergedZ,
+                                        final int booleanOp) {
+        final int sizeX = mergedX.voxels;
+        final int sizeY = mergedY.voxels;
+        final int sizeZ = mergedZ.voxels;
+
+        final long[] s1Voxels = shapeDataFirst.voxelSet();
+        final long[] s2Voxels = shapeDataSecond.voxelSet();
+
+        final int s1Mul1 = shapeDataFirst.sizeZ();
+        final int s1Mul2 = s1Mul1 * shapeDataFirst.sizeY();
+
+        final int s2Mul1 = shapeDataSecond.sizeZ();
+        final int s2Mul2 = s2Mul1 * shapeDataSecond.sizeY();
+
+        // note: indices may contain -1, but nothing > size
+        for (int idxX = 0; idxX < sizeX; ++idxX) {
+            final int s1x = mergedX.firstIndices[idxX];
+            final int s2x = mergedX.secondIndices[idxX];
+            for (int idxY = 0; idxY < sizeY; ++idxY) {
+                final int s1y = mergedY.firstIndices[idxY];
+                final int s2y = mergedY.secondIndices[idxY];
+                for (int idxZ = 0; idxZ < sizeZ; ++idxZ) {
+                    final int s1z = mergedZ.firstIndices[idxZ];
+                    final int s2z = mergedZ.secondIndices[idxZ];
+
+                    int idx1;
+                    int idx2;
+
+                    final int isS1Full = (s1x | s1y | s1z) < 0 ? 0 : (int)((s1Voxels[(idx1 = s1z + s1y*s1Mul1 + s1x*s1Mul2) >>> 6] >>> idx1) & 1L);
+                    final int isS2Full = (s2x | s2y | s2z) < 0 ? 0 : (int)((s2Voxels[(idx2 = s2z + s2y*s2Mul1 + s2x*s2Mul2) >>> 6] >>> idx2) & 1L);
+
+                    // idx ff -> 0
+                    // idx ft -> 1
+                    // idx tf -> 2
+                    // idx tt -> 3
+
+                    final boolean res = (booleanOp & (1 << (isS2Full | (isS1Full << 1)))) != 0;
+
+                    if (res) {
+                        return false;
+                    }
+                }
+            }
+        }
+
+        return true;
+    }
+
+    public static VoxelShape joinOptimized(final VoxelShape first, final VoxelShape second, final BooleanOp operator) {
+        return joinUnoptimized(first, second, operator).optimize();
+    }
+
+    public static VoxelShape joinUnoptimized(final VoxelShape first, final VoxelShape second, final BooleanOp operator) {
+        final boolean ff = operator.apply(false, false);
+        if (ff) {
+            // technically, should be an infinite box but that's clearly an error
+            throw new UnsupportedOperationException("Ambiguous operator: (false, false) -> true");
+        }
+
+        final boolean tt = operator.apply(true, true);
+
+        if (first == second) {
+            return tt ? first : Shapes.empty();
+        }
+
+        final boolean ft = operator.apply(false, true);
+        final boolean tf = operator.apply(true, false);
+
+        if (first.isEmpty()) {
+            return ft ? second : Shapes.empty();
+        }
+        if (second.isEmpty()) {
+            return tf ? first : Shapes.empty();
+        }
+
+        if (!tt) {
+            // try to check for no intersection, since tt = false
+            final AABB aabbF = ((CollisionVoxelShape)first).moonrise$getSingleAABBRepresentation();
+            final AABB aabbS = ((CollisionVoxelShape)second).moonrise$getSingleAABBRepresentation();
+
+            final boolean intersect;
+
+            final boolean hasAABBF = aabbF != null;
+            final boolean hasAABBS = aabbS != null;
+            if (hasAABBF | hasAABBS) {
+                if (hasAABBF & hasAABBS) {
+                    intersect = voxelShapeIntersect(aabbF, aabbS);
+                } else if (hasAABBF) {
+                    intersect = voxelShapeIntersectNoEmpty(second, aabbF);
+                } else {
+                    intersect = voxelShapeIntersectNoEmpty(first, aabbS);
+                }
+            } else {
+                // expect cached bounds
+                intersect = voxelShapeIntersect(first.bounds(), second.bounds());
+            }
+
+            if (!intersect) {
+                if (!tf & !ft) {
+                    return Shapes.empty();
+                }
+                if (!tf | !ft) {
+                    return tf ? first : second;
+                }
+            }
+        }
+
+        final MergedVoxelCoordinateList mergedX = MergedVoxelCoordinateList.merge(
+                ((CollisionVoxelShape)first).moonrise$rootCoordinatesX(), ((CollisionVoxelShape)first).moonrise$offsetX(),
+                ((CollisionVoxelShape)second).moonrise$rootCoordinatesX(), ((CollisionVoxelShape)second).moonrise$offsetX(),
+                ft, tf
+        );
+        if (mergedX == null) {
+            return Shapes.empty();
+        }
+        final MergedVoxelCoordinateList mergedY = MergedVoxelCoordinateList.merge(
+                ((CollisionVoxelShape)first).moonrise$rootCoordinatesY(), ((CollisionVoxelShape)first).moonrise$offsetY(),
+                ((CollisionVoxelShape)second).moonrise$rootCoordinatesY(), ((CollisionVoxelShape)second).moonrise$offsetY(),
+                ft, tf
+        );
+        if (mergedY == null) {
+            return Shapes.empty();
+        }
+        final MergedVoxelCoordinateList mergedZ = MergedVoxelCoordinateList.merge(
+                ((CollisionVoxelShape)first).moonrise$rootCoordinatesZ(), ((CollisionVoxelShape)first).moonrise$offsetZ(),
+                ((CollisionVoxelShape)second).moonrise$rootCoordinatesZ(), ((CollisionVoxelShape)second).moonrise$offsetZ(),
+                ft, tf
+        );
+        if (mergedZ == null) {
+            return Shapes.empty();
+        }
+
+        final CachedShapeData shapeDataFirst = ((CollisionVoxelShape)first).moonrise$getCachedVoxelData();
+        final CachedShapeData shapeDataSecond = ((CollisionVoxelShape)second).moonrise$getCachedVoxelData();
+
+        final BitSetDiscreteVoxelShape mergedShape = merge(
+                shapeDataFirst, shapeDataSecond,
+                mergedX, mergedY, mergedZ,
+                makeBitset(ft, tf, tt)
+        );
+
+        if (mergedShape == null) {
+            return Shapes.empty();
+        }
+
+        return new ArrayVoxelShape(
+                mergedShape, mergedX.wrapCoords(), mergedY.wrapCoords(), mergedZ.wrapCoords()
+        );
+    }
+
+    public static boolean isJoinNonEmpty(final VoxelShape first, final VoxelShape second, final BooleanOp operator) {
+        final boolean ff = operator.apply(false, false);
+        if (ff) {
+            // technically, should be an infinite box but that's clearly an error
+            throw new UnsupportedOperationException("Ambiguous operator: (false, false) -> true");
+        }
+        final boolean firstEmpty = first.isEmpty();
+        final boolean secondEmpty = second.isEmpty();
+        if (firstEmpty | secondEmpty) {
+            return operator.apply(!firstEmpty, !secondEmpty);
+        }
+
+        final boolean tt = operator.apply(true, true);
+
+        if (first == second) {
+            return tt;
+        }
+
+        final boolean ft = operator.apply(false, true);
+        final boolean tf = operator.apply(true, false);
+
+        // try to check intersection
+        final AABB aabbF = ((CollisionVoxelShape)first).moonrise$getSingleAABBRepresentation();
+        final AABB aabbS = ((CollisionVoxelShape)second).moonrise$getSingleAABBRepresentation();
+
+        final boolean intersect;
+
+        final boolean hasAABBF = aabbF != null;
+        final boolean hasAABBS = aabbS != null;
+        if (hasAABBF | hasAABBS) {
+            if (hasAABBF & hasAABBS) {
+                intersect = voxelShapeIntersect(aabbF, aabbS);
+            } else if (hasAABBF) {
+                intersect = voxelShapeIntersectNoEmpty(second, aabbF);
+            } else {
+                // hasAABBS -> true
+                intersect = voxelShapeIntersectNoEmpty(first, aabbS);
+            }
+
+            if (!intersect) {
+                // is only non-empty if we take from first or second, as there is no overlap AND both shapes are non-empty
+                return tf | ft;
+            } else if (tt) {
+                // intersect = true && tt = true -> non-empty merged shape
+                return true;
+            }
+        } else {
+            // expect cached bounds
+            intersect = voxelShapeIntersect(first.bounds(), second.bounds());
+            if (!intersect) {
+                // is only non-empty if we take from first or second, as there is no intersection
+                return tf | ft;
+            }
+        }
+
+        final MergedVoxelCoordinateList mergedX = MergedVoxelCoordinateList.merge(
+                ((CollisionVoxelShape)first).moonrise$rootCoordinatesX(), ((CollisionVoxelShape)first).moonrise$offsetX(),
+                ((CollisionVoxelShape)second).moonrise$rootCoordinatesX(), ((CollisionVoxelShape)second).moonrise$offsetX(),
+                ft, tf
+        );
+        if (mergedX == null) {
+            return false;
+        }
+        final MergedVoxelCoordinateList mergedY = MergedVoxelCoordinateList.merge(
+                ((CollisionVoxelShape)first).moonrise$rootCoordinatesY(), ((CollisionVoxelShape)first).moonrise$offsetY(),
+                ((CollisionVoxelShape)second).moonrise$rootCoordinatesY(), ((CollisionVoxelShape)second).moonrise$offsetY(),
+                ft, tf
+        );
+        if (mergedY == null) {
+            return false;
+        }
+        final MergedVoxelCoordinateList mergedZ = MergedVoxelCoordinateList.merge(
+                ((CollisionVoxelShape)first).moonrise$rootCoordinatesZ(), ((CollisionVoxelShape)first).moonrise$offsetZ(),
+                ((CollisionVoxelShape)second).moonrise$rootCoordinatesZ(), ((CollisionVoxelShape)second).moonrise$offsetZ(),
+                ft, tf
+        );
+        if (mergedZ == null) {
+            return false;
+        }
+
+        final CachedShapeData shapeDataFirst = ((CollisionVoxelShape)first).moonrise$getCachedVoxelData();
+        final CachedShapeData shapeDataSecond = ((CollisionVoxelShape)second).moonrise$getCachedVoxelData();
+
+        return !isMergeEmpty(
+                shapeDataFirst, shapeDataSecond,
+                mergedX, mergedY, mergedZ,
+                makeBitset(ft, tf, tt)
+        );
+    }
+
+    private static final class MergedVoxelCoordinateList {
+
+        private static final int[][] SIMPLE_INDICES_CACHE = new int[64][];
+        static {
+            for (int i = 0; i < SIMPLE_INDICES_CACHE.length; ++i) {
+                SIMPLE_INDICES_CACHE[i] = getIndices(i);
+            }
+        }
+
+        private static int[] getIndices(final int length) {
+            final int[] ret = new int[length];
+
+            for (int i = 1; i < length; ++i) {
+                ret[i] = i;
+            }
+
+            return ret;
+        }
+
+        // indices above voxel size are always set to -1
+        public final double[] coordinates;
+        public final double coordinateOffset;
+        public final int[] firstIndices;
+        public final int[] secondIndices;
+        public final int voxels;
+
+        private MergedVoxelCoordinateList(final double[] coordinates, final double coordinateOffset,
+                                          final int[] firstIndices, final int[] secondIndices, final int voxels) {
+            this.coordinates = coordinates;
+            this.coordinateOffset = coordinateOffset;
+            this.firstIndices = firstIndices;
+            this.secondIndices = secondIndices;
+            this.voxels = voxels;
+        }
+
+        public DoubleList wrapCoords() {
+            if (this.coordinateOffset == 0.0) {
+                return DoubleArrayList.wrap(this.coordinates, this.voxels + 1);
+            }
+            return new OffsetDoubleList(DoubleArrayList.wrap(this.coordinates, this.voxels + 1), this.coordinateOffset);
+        }
+
+        // assume coordinates.length > 1
+        public static MergedVoxelCoordinateList getForSingle(final double[] coordinates, final double offset) {
+            final int voxels = coordinates.length - 1;
+            final int[] indices = voxels < SIMPLE_INDICES_CACHE.length ? SIMPLE_INDICES_CACHE[voxels] : getIndices(voxels);
+
+            return new MergedVoxelCoordinateList(coordinates, offset, indices, indices, voxels);
+        }
+
+        // assume coordinates.length > 1
+        public static MergedVoxelCoordinateList merge(final double[] firstCoordinates, final double firstOffset,
+                                                      final double[] secondCoordinates, final double secondOffset,
+                                                      final boolean ft, final boolean tf) {
+            if (firstCoordinates == secondCoordinates && firstOffset == secondOffset) {
+                return getForSingle(firstCoordinates, firstOffset);
+            }
+
+            final int firstCount = firstCoordinates.length;
+            final int secondCount = secondCoordinates.length;
+
+            final int voxelsFirst = firstCount - 1;
+            final int voxelsSecond = secondCount - 1;
+
+            final int maxCount = firstCount + secondCount;
+
+            final double[] coordinates = new double[maxCount];
+            final int[] firstIndices = new int[maxCount];
+            final int[] secondIndices = new int[maxCount];
+
+            final boolean notTF = !tf;
+            final boolean notFT = !ft;
+
+            int firstIndex = 0;
+            int secondIndex = 0;
+            int resultSize = 0;
+
+            // note: operations on NaN are false
+            double last = Double.NaN;
+
+            for (;;) {
+                final boolean noneLeftFirst = firstIndex >= firstCount;
+                final boolean noneLeftSecond = secondIndex >= secondCount;
+
+                if ((noneLeftFirst & noneLeftSecond) | (noneLeftSecond & notTF) | (noneLeftFirst & notFT)) {
+                    break;
+                }
+
+                final boolean firstZero = firstIndex == 0;
+                final boolean secondZero = secondIndex == 0;
+
+                final double select;
+
+                if (noneLeftFirst) {
+                    // noneLeftSecond -> false
+                    // notFT -> false
+                    select = secondCoordinates[secondIndex] + secondOffset;
+                    ++secondIndex;
+                } else if (noneLeftSecond) {
+                    // noneLeftFirst -> false
+                    // notTF -> false
+                    select = firstCoordinates[firstIndex] + firstOffset;
+                    ++firstIndex;
+                } else {
+                    // noneLeftFirst | noneLeftSecond -> false
+                    // notTF -> ??
+                    // notFT -> ??
+                    final boolean breakFirst = notTF & secondZero;
+                    final boolean breakSecond = notFT & firstZero;
+
+                    final double first = firstCoordinates[firstIndex] + firstOffset;
+                    final double second = secondCoordinates[secondIndex] + secondOffset;
+                    final boolean useFirst = first < (second + COLLISION_EPSILON);
+                    final boolean cont = (useFirst & breakFirst) | (!useFirst & breakSecond);
+
+                    select = useFirst ? first : second;
+                    firstIndex += useFirst ? 1 : 0;
+                    secondIndex += 1 ^ (useFirst ? 1 : 0);
+
+                    if (cont) {
+                        continue;
+                    }
+                }
+
+                int prevFirst = firstIndex - 1;
+                prevFirst = prevFirst >= voxelsFirst ? -1 : prevFirst;
+                int prevSecond = secondIndex - 1;
+                prevSecond = prevSecond >= voxelsSecond ? -1 : prevSecond;
+
+                if (last >= (select - COLLISION_EPSILON)) {
+                    // note: any operations on NaN is false
+                    firstIndices[resultSize - 1] = prevFirst;
+                    secondIndices[resultSize - 1] = prevSecond;
+                } else {
+                    firstIndices[resultSize] = prevFirst;
+                    secondIndices[resultSize] = prevSecond;
+                    coordinates[resultSize] = select;
+
+                    ++resultSize;
+                    last = select;
+                }
+            }
+
+            return resultSize <= 1 ? null : new MergedVoxelCoordinateList(coordinates, 0.0, firstIndices, secondIndices, resultSize - 1);
+        }
+    }
+
+    public static boolean equals(final DiscreteVoxelShape shape1, final DiscreteVoxelShape shape2) {
+        final CachedShapeData cachedShapeData1 = ((CollisionDiscreteVoxelShape)shape1).moonrise$getOrCreateCachedShapeData();
+        final CachedShapeData cachedShapeData2 = ((CollisionDiscreteVoxelShape)shape2).moonrise$getOrCreateCachedShapeData();
+
+        final boolean isEmpty1 = cachedShapeData1.isEmpty();
+        final boolean isEmpty2 = cachedShapeData2.isEmpty();
+
+        if (isEmpty1 & isEmpty2) {
+            return true;
+        } else if (isEmpty1 ^ isEmpty2) {
+            return false;
+        } // else: isEmpty1 = isEmpty2 = false
+
+        if (cachedShapeData1.hasSingleAABB() != cachedShapeData2.hasSingleAABB()) {
+            return false;
+        }
+
+        if (cachedShapeData1.sizeX() != cachedShapeData2.sizeX()) {
+            return false;
+        }
+        if (cachedShapeData1.sizeY() != cachedShapeData2.sizeY()) {
+            return false;
+        }
+        if (cachedShapeData1.sizeZ() != cachedShapeData2.sizeZ()) {
+            return false;
+        }
+
+        return Arrays.equals(cachedShapeData1.voxelSet(), cachedShapeData2.voxelSet());
+    }
+
+    // useful only for testing
+    public static boolean equals(final VoxelShape shape1, final VoxelShape shape2) {
+        if (shape1.isEmpty() & shape2.isEmpty()) {
+            return true;
+        } else if (shape1.isEmpty() ^ shape2.isEmpty()) {
+            return false;
+        }
+
+        if (!equals(shape1.shape, shape2.shape)) {
+            return false;
+        }
+
+        return shape1.getCoords(Direction.Axis.X).equals(shape2.getCoords(Direction.Axis.X)) &&
+                shape1.getCoords(Direction.Axis.Y).equals(shape2.getCoords(Direction.Axis.Y)) &&
+                shape1.getCoords(Direction.Axis.Z).equals(shape2.getCoords(Direction.Axis.Z));
+    }
+
+    public static boolean areAnyFull(final DiscreteVoxelShape shape) {
+        if (shape.isEmpty()) {
+            return false;
+        }
+
+        final int sizeX = shape.getXSize();
+        final int sizeY = shape.getYSize();
+        final int sizeZ = shape.getZSize();
+
+        for (int x = 0; x < sizeX; ++x) {
+            for (int y = 0; y < sizeY; ++y) {
+                for (int z = 0; z < sizeZ; ++z) {
+                    if (shape.isFull(x, y, z)) {
+                        return true;
+                    }
+                }
+            }
+        }
+
+        return false;
+    }
+
+    public static String shapeMismatch(final DiscreteVoxelShape shape1, final DiscreteVoxelShape shape2) {
+        final CachedShapeData cachedShapeData1 = ((CollisionDiscreteVoxelShape)shape1).moonrise$getOrCreateCachedShapeData();
+        final CachedShapeData cachedShapeData2 = ((CollisionDiscreteVoxelShape)shape2).moonrise$getOrCreateCachedShapeData();
+
+        final boolean isEmpty1 = cachedShapeData1.isEmpty();
+        final boolean isEmpty2 = cachedShapeData2.isEmpty();
+
+        if (isEmpty1 & isEmpty2) {
+            return null;
+        } else if (isEmpty1 ^ isEmpty2) {
+            return null;
+        } // else: isEmpty1 = isEmpty2 = false
+
+        if (cachedShapeData1.sizeX() != cachedShapeData2.sizeX()) {
+            return "size x: " + cachedShapeData1.sizeX() + " != " + cachedShapeData2.sizeX();
+        }
+        if (cachedShapeData1.sizeY() != cachedShapeData2.sizeY()) {
+            return "size y: " + cachedShapeData1.sizeY() + " != " + cachedShapeData2.sizeY();
+        }
+        if (cachedShapeData1.sizeZ() != cachedShapeData2.sizeZ()) {
+            return "size z: " + cachedShapeData1.sizeZ() + " != " + cachedShapeData2.sizeZ();
+        }
+
+        final StringBuilder ret = new StringBuilder();
+
+        final int sizeX = cachedShapeData1.sizeX();;
+        final int sizeY = cachedShapeData1.sizeY();
+        final int sizeZ = cachedShapeData1.sizeZ();
+
+        boolean first = true;
+
+        for (int x = 0; x < sizeX; ++x) {
+            for (int y = 0; y < sizeY; ++y) {
+                for (int z = 0; z < sizeZ; ++z) {
+                    final boolean isFull1 = shape1.isFull(x, y, z);
+                    final boolean isFull2 = shape2.isFull(x, y, z);
+
+                    if (isFull1 == isFull2) {
+                        continue;
+                    }
+
+                    if (first) {
+                        first = false;
+                    } else {
+                        ret.append(", ");
+                    }
+
+                    ret.append("(").append(x).append(",").append(y).append(",").append(z)
+                        .append("): shape1: ").append(isFull1).append(", shape2: ").append(isFull2);
+                }
+            }
+        }
+
+        return ret.isEmpty() ? null : ret.toString();
+    }
+
+    public static AABB offsetX(final AABB box, final double dx) {
+        return new AABB(box.minX + dx, box.minY, box.minZ, box.maxX + dx, box.maxY, box.maxZ);
+    }
+
+    public static AABB offsetY(final AABB box, final double dy) {
+        return new AABB(box.minX, box.minY + dy, box.minZ, box.maxX, box.maxY + dy, box.maxZ);
+    }
+
+    public static AABB offsetZ(final AABB box, final double dz) {
+        return new AABB(box.minX, box.minY, box.minZ + dz, box.maxX, box.maxY, box.maxZ + dz);
+    }
+
+    public static AABB expandRight(final AABB box, final double dx) { // dx > 0.0
+        return new AABB(box.minX, box.minY, box.minZ, box.maxX + dx, box.maxY, box.maxZ);
+    }
+
+    public static AABB expandLeft(final AABB box, final double dx) { // dx < 0.0
+        return new AABB(box.minX - dx, box.minY, box.minZ, box.maxX, box.maxY, box.maxZ);
+    }
+
+    public static AABB expandUpwards(final AABB box, final double dy) { // dy > 0.0
+        return new AABB(box.minX, box.minY, box.minZ, box.maxX, box.maxY + dy, box.maxZ);
+    }
+
+    public static AABB expandDownwards(final AABB box, final double dy) { // dy < 0.0
+        return new AABB(box.minX, box.minY - dy, box.minZ, box.maxX, box.maxY, box.maxZ);
+    }
+
+    public static AABB expandForwards(final AABB box, final double dz) { // dz > 0.0
+        return new AABB(box.minX, box.minY, box.minZ, box.maxX, box.maxY, box.maxZ + dz);
+    }
+
+    public static AABB expandBackwards(final AABB box, final double dz) { // dz < 0.0
+        return new AABB(box.minX, box.minY, box.minZ - dz, box.maxX, box.maxY, box.maxZ);
+    }
+
+    public static AABB cutRight(final AABB box, final double dx) { // dx > 0.0
+        return new AABB(box.maxX, box.minY, box.minZ, box.maxX + dx, box.maxY, box.maxZ);
+    }
+
+    public static AABB cutLeft(final AABB box, final double dx) { // dx < 0.0
+        return new AABB(box.minX + dx, box.minY, box.minZ, box.minX, box.maxY, box.maxZ);
+    }
+
+    public static AABB cutUpwards(final AABB box, final double dy) { // dy > 0.0
+        return new AABB(box.minX, box.maxY, box.minZ, box.maxX, box.maxY + dy, box.maxZ);
+    }
+
+    public static AABB cutDownwards(final AABB box, final double dy) { // dy < 0.0
+        return new AABB(box.minX, box.minY + dy, box.minZ, box.maxX, box.minY, box.maxZ);
+    }
+
+    public static AABB cutForwards(final AABB box, final double dz) { // dz > 0.0
+        return new AABB(box.minX, box.minY, box.maxZ, box.maxX, box.maxY, box.maxZ + dz);
+    }
+
+    public static AABB cutBackwards(final AABB box, final double dz) { // dz < 0.0
+        return new AABB(box.minX, box.minY, box.minZ + dz, box.maxX, box.maxY, box.minZ);
+    }
+
+    public static double performAABBCollisionsX(final AABB currentBoundingBox, double value, final List<AABB> potentialCollisions) {
+        for (int i = 0, len = potentialCollisions.size(); i < len; ++i) {
+            final AABB target = potentialCollisions.get(i);
+            value = collideX(target, currentBoundingBox, value);
+        }
+
+        return value;
+    }
+
+    public static double performAABBCollisionsY(final AABB currentBoundingBox, double value, final List<AABB> potentialCollisions) {
+        for (int i = 0, len = potentialCollisions.size(); i < len; ++i) {
+            final AABB target = potentialCollisions.get(i);
+            value = collideY(target, currentBoundingBox, value);
+        }
+
+        return value;
+    }
+
+    public static double performAABBCollisionsZ(final AABB currentBoundingBox, double value, final List<AABB> potentialCollisions) {
+        for (int i = 0, len = potentialCollisions.size(); i < len; ++i) {
+            final AABB target = potentialCollisions.get(i);
+            value = collideZ(target, currentBoundingBox, value);
+        }
+
+        return value;
+    }
+
+    public static double performVoxelCollisionsX(final AABB currentBoundingBox, double value, final List<VoxelShape> potentialCollisions) {
+        for (int i = 0, len = potentialCollisions.size(); i < len; ++i) {
+            final VoxelShape target = potentialCollisions.get(i);
+            value = collideX(target, currentBoundingBox, value);
+        }
+
+        return value;
+    }
+
+    public static double performVoxelCollisionsY(final AABB currentBoundingBox, double value, final List<VoxelShape> potentialCollisions) {
+        for (int i = 0, len = potentialCollisions.size(); i < len; ++i) {
+            final VoxelShape target = potentialCollisions.get(i);
+            value = collideY(target, currentBoundingBox, value);
+        }
+
+        return value;
+    }
+
+    public static double performVoxelCollisionsZ(final AABB currentBoundingBox, double value, final List<VoxelShape> potentialCollisions) {
+        for (int i = 0, len = potentialCollisions.size(); i < len; ++i) {
+            final VoxelShape target = potentialCollisions.get(i);
+            value = collideZ(target, currentBoundingBox, value);
+        }
+
+        return value;
+    }
+
+    public static Vec3 performVoxelCollisions(final Vec3 moveVector, AABB axisalignedbb, final List<VoxelShape> potentialCollisions) {
+        double x = moveVector.x;
+        double y = moveVector.y;
+        double z = moveVector.z;
+
+        if (y != 0.0) {
+            y = performVoxelCollisionsY(axisalignedbb, y, potentialCollisions);
+            if (y != 0.0) {
+                axisalignedbb = offsetY(axisalignedbb, y);
+            }
+        }
+
+        final boolean xSmaller = Math.abs(x) < Math.abs(z);
+
+        if (xSmaller && z != 0.0) {
+            z = performVoxelCollisionsZ(axisalignedbb, z, potentialCollisions);
+            if (z != 0.0) {
+                axisalignedbb = offsetZ(axisalignedbb, z);
+            }
+        }
+
+        if (x != 0.0) {
+            x = performVoxelCollisionsX(axisalignedbb, x, potentialCollisions);
+            if (!xSmaller && x != 0.0) {
+                axisalignedbb = offsetX(axisalignedbb, x);
+            }
+        }
+
+        if (!xSmaller && z != 0.0) {
+            z = performVoxelCollisionsZ(axisalignedbb, z, potentialCollisions);
+        }
+
+        return new Vec3(x, y, z);
+    }
+
+    public static Vec3 performAABBCollisions(final Vec3 moveVector, AABB axisalignedbb, final List<AABB> potentialCollisions) {
+        double x = moveVector.x;
+        double y = moveVector.y;
+        double z = moveVector.z;
+
+        if (y != 0.0) {
+            y = performAABBCollisionsY(axisalignedbb, y, potentialCollisions);
+            if (y != 0.0) {
+                axisalignedbb = offsetY(axisalignedbb, y);
+            }
+        }
+
+        final boolean xSmaller = Math.abs(x) < Math.abs(z);
+
+        if (xSmaller && z != 0.0) {
+            z = performAABBCollisionsZ(axisalignedbb, z, potentialCollisions);
+            if (z != 0.0) {
+                axisalignedbb = offsetZ(axisalignedbb, z);
+            }
+        }
+
+        if (x != 0.0) {
+            x = performAABBCollisionsX(axisalignedbb, x, potentialCollisions);
+            if (!xSmaller && x != 0.0) {
+                axisalignedbb = offsetX(axisalignedbb, x);
+            }
+        }
+
+        if (!xSmaller && z != 0.0) {
+            z = performAABBCollisionsZ(axisalignedbb, z, potentialCollisions);
+        }
+
+        return new Vec3(x, y, z);
+    }
+
+    public static Vec3 performCollisions(final Vec3 moveVector, AABB axisalignedbb,
+                                         final List<VoxelShape> voxels,
+                                         final List<AABB> aabbs) {
+        if (voxels.isEmpty()) {
+            // fast track only AABBs
+            return performAABBCollisions(moveVector, axisalignedbb, aabbs);
+        }
+
+        double x = moveVector.x;
+        double y = moveVector.y;
+        double z = moveVector.z;
+
+        if (y != 0.0) {
+            y = performAABBCollisionsY(axisalignedbb, y, aabbs);
+            y = performVoxelCollisionsY(axisalignedbb, y, voxels);
+            if (y != 0.0) {
+                axisalignedbb = offsetY(axisalignedbb, y);
+            }
+        }
+
+        final boolean xSmaller = Math.abs(x) < Math.abs(z);
+
+        if (xSmaller && z != 0.0) {
+            z = performAABBCollisionsZ(axisalignedbb, z, aabbs);
+            z = performVoxelCollisionsZ(axisalignedbb, z, voxels);
+            if (z != 0.0) {
+                axisalignedbb = offsetZ(axisalignedbb, z);
+            }
+        }
+
+        if (x != 0.0) {
+            x = performAABBCollisionsX(axisalignedbb, x, aabbs);
+            x = performVoxelCollisionsX(axisalignedbb, x, voxels);
+            if (!xSmaller && x != 0.0) {
+                axisalignedbb = offsetX(axisalignedbb, x);
+            }
+        }
+
+        if (!xSmaller && z != 0.0) {
+            z = performAABBCollisionsZ(axisalignedbb, z, aabbs);
+            z = performVoxelCollisionsZ(axisalignedbb, z, voxels);
+        }
+
+        return new Vec3(x, y, z);
+    }
+
+    public static boolean isCollidingWithBorder(final WorldBorder worldborder, final AABB boundingBox) {
+        return isCollidingWithBorder(worldborder, boundingBox.minX, boundingBox.maxX, boundingBox.minZ, boundingBox.maxZ);
+    }
+
+    public static boolean isCollidingWithBorder(final WorldBorder worldborder,
+                                                final double boxMinX, final double boxMaxX,
+                                                final double boxMinZ, final double boxMaxZ) {
+        final double borderMinX = Math.floor(worldborder.getMinX()); // -X
+        final double borderMaxX = Math.ceil(worldborder.getMaxX()); // +X
+
+        final double borderMinZ = Math.floor(worldborder.getMinZ()); // -Z
+        final double borderMaxZ = Math.ceil(worldborder.getMaxZ()); // +Z
+
+        // inverted check for world border enclosing the specified box expanded by -EPSILON
+        return (borderMinX - boxMinX) > CollisionUtil.COLLISION_EPSILON || (borderMaxX - boxMaxX) < -CollisionUtil.COLLISION_EPSILON ||
+                (borderMinZ - boxMinZ) > CollisionUtil.COLLISION_EPSILON || (borderMaxZ - boxMaxZ) < -CollisionUtil.COLLISION_EPSILON;
+    }
+
+    /* Math.max/min specify that any NaN argument results in a NaN return, unlike these functions */
+    private static double min(final double x, final double y) {
+        return x < y ? x : y;
+    }
+
+    private static double max(final double x, final double y) {
+        return x > y ? x : y;
+    }
+
+    public static final int COLLISION_FLAG_LOAD_CHUNKS = 1 << 0;
+    public static final int COLLISION_FLAG_COLLIDE_WITH_UNLOADED_CHUNKS = 1 << 1;
+    public static final int COLLISION_FLAG_CHECK_BORDER = 1 << 2;
+    public static final int COLLISION_FLAG_CHECK_ONLY = 1 << 3;
+
+    public static boolean getCollisionsForBlocksOrWorldBorder(final Level world, final Entity entity, final AABB aabb,
+                                                              final List<VoxelShape> intoVoxel, final List<AABB> intoAABB,
+                                                              final int collisionFlags, final BiPredicate<BlockState, BlockPos> predicate) {
+        final boolean checkOnly = (collisionFlags & COLLISION_FLAG_CHECK_ONLY) != 0;
+        boolean ret = false;
+
+        if ((collisionFlags & COLLISION_FLAG_CHECK_BORDER) != 0) {
+            final WorldBorder worldBorder = world.getWorldBorder();
+            if (CollisionUtil.isCollidingWithBorder(worldBorder, aabb) && entity != null && worldBorder.isInsideCloseToBorder(entity, aabb)) {
+                if (checkOnly) {
+                    return true;
+                } else {
+                    final VoxelShape borderShape = worldBorder.getCollisionShape();
+                    intoVoxel.add(borderShape);
+                    ret = true;
+                }
+            }
+        }
+
+        final int minSection = WorldUtil.getMinSection(world);
+
+        final int minBlockX = Mth.floor(aabb.minX - COLLISION_EPSILON) - 1;
+        final int maxBlockX = Mth.floor(aabb.maxX + COLLISION_EPSILON) + 1;
+
+        final int minBlockY = Math.max((minSection << 4) - 1, Mth.floor(aabb.minY - COLLISION_EPSILON) - 1);
+        final int maxBlockY = Math.min((WorldUtil.getMaxSection(world) << 4) + 16, Mth.floor(aabb.maxY + COLLISION_EPSILON) + 1);
+
+        final int minBlockZ = Mth.floor(aabb.minZ - COLLISION_EPSILON) - 1;
+        final int maxBlockZ = Mth.floor(aabb.maxZ + COLLISION_EPSILON) + 1;
+
+        final BlockPos.MutableBlockPos mutablePos = new BlockPos.MutableBlockPos();
+        final CollisionContext collisionShape = new LazyEntityCollisionContext(entity);
+        final boolean useEntityCollisionShape = LazyEntityCollisionContext.useEntityCollisionShape(world, entity);
+
+        // special cases:
+        if (minBlockY > maxBlockY) {
+            // no point in checking
+            return ret;
+        }
+
+        final int minChunkX = minBlockX >> 4;
+        final int maxChunkX = maxBlockX >> 4;
+
+        final int minChunkY = minBlockY >> 4;
+        final int maxChunkY = maxBlockY >> 4;
+
+        final int minChunkZ = minBlockZ >> 4;
+        final int maxChunkZ = maxBlockZ >> 4;
+
+        final boolean loadChunks = (collisionFlags & COLLISION_FLAG_LOAD_CHUNKS) != 0;
+        final ChunkSource chunkSource = world.getChunkSource();
+
+        for (int currChunkZ = minChunkZ; currChunkZ <= maxChunkZ; ++currChunkZ) {
+            for (int currChunkX = minChunkX; currChunkX <= maxChunkX; ++currChunkX) {
+                final ChunkAccess chunk = chunkSource.getChunk(currChunkX, currChunkZ, ChunkStatus.FULL, loadChunks);
+
+                if (chunk == null) {
+                    if ((collisionFlags & COLLISION_FLAG_COLLIDE_WITH_UNLOADED_CHUNKS) != 0) {
+                        if (checkOnly) {
+                            return true;
+                        } else {
+                            intoAABB.add(getBoxForChunk(currChunkX, currChunkZ));
+                            ret = true;
+                        }
+                    }
+                    continue;
+                }
+
+                final LevelChunkSection[] sections = chunk.getSections();
+
+                // bound y
+                for (int currChunkY = minChunkY; currChunkY <= maxChunkY; ++currChunkY) {
+                    final int sectionIdx = currChunkY - minSection;
+                    if (sectionIdx < 0 || sectionIdx >= sections.length) {
+                        continue;
+                    }
+                    final LevelChunkSection section = sections[sectionIdx];
+                    if (section.hasOnlyAir()) {
+                        // empty
+                        continue;
+                    }
+
+                    final boolean hasSpecial = ((BlockCountingChunkSection)section).moonrise$hasSpecialCollidingBlocks();
+                    final int sectionAdjust = !hasSpecial ? 1 : 0;
+
+                    final PalettedContainer<BlockState> blocks = section.states;
+
+                    final int minXIterate = currChunkX == minChunkX ? (minBlockX & 15) + sectionAdjust : 0;
+                    final int maxXIterate = currChunkX == maxChunkX ? (maxBlockX & 15) - sectionAdjust : 15;
+                    final int minZIterate = currChunkZ == minChunkZ ? (minBlockZ & 15) + sectionAdjust : 0;
+                    final int maxZIterate = currChunkZ == maxChunkZ ? (maxBlockZ & 15) - sectionAdjust : 15;
+                    final int minYIterate = currChunkY == minChunkY ? (minBlockY & 15) + sectionAdjust : 0;
+                    final int maxYIterate = currChunkY == maxChunkY ? (maxBlockY & 15) - sectionAdjust : 15;
+
+                    for (int currY = minYIterate; currY <= maxYIterate; ++currY) {
+                        final int blockY = currY | (currChunkY << 4);
+                        for (int currZ = minZIterate; currZ <= maxZIterate; ++currZ) {
+                            final int blockZ = currZ | (currChunkZ << 4);
+                            for (int currX = minXIterate; currX <= maxXIterate; ++currX) {
+                                final int localBlockIndex = (currX) | (currZ << 4) | ((currY) << 8);
+                                final int blockX = currX | (currChunkX << 4);
+
+                                final int edgeCount = hasSpecial ? ((blockX == minBlockX || blockX == maxBlockX) ? 1 : 0) +
+                                    ((blockY == minBlockY || blockY == maxBlockY) ? 1 : 0) +
+                                    ((blockZ == minBlockZ || blockZ == maxBlockZ) ? 1 : 0) : 0;
+                                if (edgeCount == 3) {
+                                    continue;
+                                }
+
+                                final BlockState blockData = blocks.get(localBlockIndex);
+
+                                if (((CollisionBlockState)blockData).moonrise$emptyContextCollisionShape()) {
+                                    continue;
+                                }
+
+                                VoxelShape blockCollision = ((CollisionBlockState)blockData).moonrise$getConstantContextCollisionShape();
+
+                                if (edgeCount == 0 || ((edgeCount != 1 || blockData.hasLargeCollisionShape()) && (edgeCount != 2 || blockData.getBlock() == Blocks.MOVING_PISTON))) {
+                                    if (useEntityCollisionShape) {
+                                        mutablePos.set(blockX, blockY, blockZ);
+                                        blockCollision = collisionShape.getCollisionShape(blockData, world, mutablePos);
+                                    } else if (blockCollision == null) {
+                                        mutablePos.set(blockX, blockY, blockZ);
+                                        blockCollision = blockData.getCollisionShape(world, mutablePos, collisionShape);
+                                    }
+
+                                    AABB singleAABB = ((CollisionVoxelShape)blockCollision).moonrise$getSingleAABBRepresentation();
+                                    if (singleAABB != null) {
+                                        singleAABB = singleAABB.move((double)blockX, (double)blockY, (double)blockZ);
+                                        if (!voxelShapeIntersect(aabb, singleAABB)) {
+                                            continue;
+                                        }
+
+                                        if (predicate != null) {
+                                            mutablePos.set(blockX, blockY, blockZ);
+                                            if (!predicate.test(blockData, mutablePos)) {
+                                                continue;
+                                            }
+                                        }
+
+                                        if (checkOnly) {
+                                            return true;
+                                        } else {
+                                            ret = true;
+                                            intoAABB.add(singleAABB);
+                                            continue;
+                                        }
+                                    }
+
+                                    if (blockCollision.isEmpty()) {
+                                        continue;
+                                    }
+
+                                    final VoxelShape blockCollisionOffset = blockCollision.move((double)blockX, (double)blockY, (double)blockZ);
+
+                                    if (!voxelShapeIntersectNoEmpty(blockCollisionOffset, aabb)) {
+                                        continue;
+                                    }
+
+                                    if (predicate != null) {
+                                        mutablePos.set(blockX, blockY, blockZ);
+                                        if (!predicate.test(blockData, mutablePos)) {
+                                            continue;
+                                        }
+                                    }
+
+                                    if (checkOnly) {
+                                        return true;
+                                    } else {
+                                        ret = true;
+                                        intoVoxel.add(blockCollisionOffset);
+                                        continue;
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        return ret;
+    }
+
+    public static boolean getEntityHardCollisions(final Level world, final Entity entity, AABB aabb,
+                                                  final List<AABB> into, final int collisionFlags, final Predicate<Entity> predicate) {
+        final boolean checkOnly = (collisionFlags & COLLISION_FLAG_CHECK_ONLY) != 0;
+
+        boolean ret = false;
+
+        // to comply with vanilla intersection rules, expand by -epsilon so that we only get stuff we definitely collide with.
+        // Vanilla for hard collisions has this backwards, and they expand by +epsilon but this causes terrible problems
+        // specifically with boat collisions.
+        aabb = aabb.inflate(-COLLISION_EPSILON, -COLLISION_EPSILON, -COLLISION_EPSILON);
+        final List<Entity> entities;
+        if (entity != null && ((ChunkSystemEntity)entity).moonrise$isHardColliding()) {
+            entities = world.getEntities(entity, aabb, predicate);
+        } else {
+            entities = ((ChunkSystemEntityGetter)world).moonrise$getHardCollidingEntities(entity, aabb, predicate);
+        }
+
+        for (int i = 0, len = entities.size(); i < len; ++i) {
+            final Entity otherEntity = entities.get(i);
+
+            if (otherEntity.isSpectator()) {
+                continue;
+            }
+
+            if ((entity == null && otherEntity.canBeCollidedWith()) || (entity != null && entity.canCollideWith(otherEntity))) {
+                if (checkOnly) {
+                    return true;
+                } else {
+                    into.add(otherEntity.getBoundingBox());
+                    ret = true;
+                }
+            }
+        }
+
+        return ret;
+    }
+
+    public static boolean getCollisions(final Level world, final Entity entity, final AABB aabb,
+                                        final List<VoxelShape> intoVoxel, final List<AABB> intoAABB, final int collisionFlags,
+                                        final BiPredicate<BlockState, BlockPos> blockPredicate,
+                                        final Predicate<Entity> entityPredicate) {
+        if ((collisionFlags & COLLISION_FLAG_CHECK_ONLY) != 0) {
+            return getCollisionsForBlocksOrWorldBorder(world, entity, aabb, intoVoxel, intoAABB, collisionFlags, blockPredicate)
+                || getEntityHardCollisions(world, entity, aabb, intoAABB, collisionFlags, entityPredicate);
+        } else {
+            return getCollisionsForBlocksOrWorldBorder(world, entity, aabb, intoVoxel, intoAABB, collisionFlags, blockPredicate)
+                | getEntityHardCollisions(world, entity, aabb, intoAABB, collisionFlags, entityPredicate);
+        }
+    }
+
+    public static final class LazyEntityCollisionContext extends EntityCollisionContext {
+
+        private CollisionContext delegate;
+        private boolean delegated;
+
+        public LazyEntityCollisionContext(final Entity entity) {
+            super(false, 0.0, null, null, entity);
+        }
+
+        public static boolean useEntityCollisionShape(final Level world, final Entity entity) {
+            return entity instanceof AbstractMinecart && AbstractMinecart.useExperimentalMovement(world);
+        }
+
+        public boolean isDelegated() {
+            final boolean delegated = this.delegated;
+            this.delegated = false;
+            return delegated;
+        }
+
+        public CollisionContext getDelegate() {
+            this.delegated = true;
+            final Entity entity = super.getEntity();
+            return this.delegate == null ? this.delegate = (entity == null ? CollisionContext.empty() : CollisionContext.of(entity)) : this.delegate;
+        }
+
+        @Override
+        public Entity getEntity() {
+            this.getDelegate();
+            return super.getEntity();
+        }
+
+        @Override
+        public boolean isDescending() {
+            return this.getDelegate().isDescending();
+        }
+
+        @Override
+        public boolean isAbove(final VoxelShape shape, final BlockPos pos, final boolean defaultValue) {
+            return this.getDelegate().isAbove(shape, pos, defaultValue);
+        }
+
+        @Override
+        public boolean isHoldingItem(final Item item) {
+            return this.getDelegate().isHoldingItem(item);
+        }
+
+        @Override
+        public boolean canStandOnFluid(final FluidState state, final FluidState fluidState) {
+            return this.getDelegate().canStandOnFluid(state, fluidState);
+        }
+
+        @Override
+        public VoxelShape getCollisionShape(final BlockState blockState, final CollisionGetter collisionGetter, final BlockPos blockPos) {
+            return this.getDelegate().getCollisionShape(blockState, collisionGetter, blockPos);
+        }
+    }
+
+    private CollisionUtil() {
+        throw new RuntimeException();
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/collisions/ExplosionBlockCache.java b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/ExplosionBlockCache.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/ExplosionBlockCache.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.collisions;
+
+import net.minecraft.core.BlockPos;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.material.FluidState;
+import net.minecraft.world.phys.shapes.VoxelShape;
+
+public final class ExplosionBlockCache {
+
+    public final long key;
+    public final BlockPos immutablePos;
+    public final BlockState blockState;
+    public final FluidState fluidState;
+    public final float resistance;
+    public final boolean outOfWorld;
+    public Boolean shouldExplode; // null -> not called yet
+    public VoxelShape cachedCollisionShape;
+
+    public ExplosionBlockCache(final long key, final BlockPos immutablePos, final BlockState blockState,
+                               final FluidState fluidState, final float resistance, final boolean outOfWorld) {
+        this.key = key;
+        this.immutablePos = immutablePos;
+        this.blockState = blockState;
+        this.fluidState = fluidState;
+        this.resistance = resistance;
+        this.outOfWorld = outOfWorld;
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/collisions/block/CollisionBlockState.java b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/block/CollisionBlockState.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/block/CollisionBlockState.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.collisions.block;
+
+import net.minecraft.world.phys.shapes.VoxelShape;
+
+public interface CollisionBlockState {
+
+    // note: this does not consider canOcclude, it is only based on the cached collision shape (i.e hasCache())
+    // and whether Shapes.faceShapeOccludes(EMPTY, cached shape) is true
+    public boolean moonrise$occludesFullBlock();
+
+    // whether the cached collision shape exists and is empty
+    public boolean moonrise$emptyCollisionShape();
+
+    // whether the context-sensitive shape is constant and is empty
+    public boolean moonrise$emptyContextCollisionShape();
+
+    // indicates that occludesFullBlock is cached for the collision shape
+    public boolean moonrise$hasCache();
+
+    // note: this is HashCommon#murmurHash3(incremental id); and since murmurHash3 has an inverse function the returned
+    // value is still unique
+    public int moonrise$uniqueId1();
+
+    // note: this is HashCommon#murmurHash3(incremental id); and since murmurHash3 has an inverse function the returned
+    // value is still unique
+    public int moonrise$uniqueId2();
+
+    public VoxelShape moonrise$getConstantContextCollisionShape();
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/collisions/shape/CachedShapeData.java b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/shape/CachedShapeData.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/shape/CachedShapeData.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.collisions.shape;
+
+public record CachedShapeData(
+        int sizeX, int sizeY, int sizeZ,
+        long[] voxelSet,
+        int minFullX, int minFullY, int minFullZ,
+        int maxFullX, int maxFullY, int maxFullZ,
+        boolean isEmpty, boolean hasSingleAABB
+) {
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/collisions/shape/CachedToAABBs.java b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/shape/CachedToAABBs.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/shape/CachedToAABBs.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.collisions.shape;
+
+import net.minecraft.world.phys.AABB;
+import java.util.ArrayList;
+import java.util.List;
+
+public record CachedToAABBs(
+        List<AABB> aabbs,
+        boolean isOffset,
+        double offX, double offY, double offZ
+) {
+
+    public CachedToAABBs removeOffset() {
+        final List<AABB> toOffset = this.aabbs;
+        final double offX = this.offX;
+        final double offY = this.offY;
+        final double offZ = this.offZ;
+
+        final List<AABB> ret = new ArrayList<>(toOffset.size());
+
+        for (int i = 0, len = toOffset.size(); i < len; ++i) {
+            ret.add(toOffset.get(i).move(offX, offY, offZ));
+        }
+
+        return new CachedToAABBs(ret, false, 0.0, 0.0, 0.0);
+    }
+
+    public static CachedToAABBs offset(final CachedToAABBs cache, final double offX, final double offY, final double offZ) {
+        if (offX == 0.0 && offY == 0.0 && offZ == 0.0) {
+            return cache;
+        }
+
+        final double resX = cache.offX + offX;
+        final double resY = cache.offY + offY;
+        final double resZ = cache.offZ + offZ;
+
+        return new CachedToAABBs(cache.aabbs, true, resX, resY, resZ);
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/collisions/shape/CollisionDiscreteVoxelShape.java b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/shape/CollisionDiscreteVoxelShape.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/shape/CollisionDiscreteVoxelShape.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.collisions.shape;
+
+public interface CollisionDiscreteVoxelShape {
+
+    public CachedShapeData moonrise$getOrCreateCachedShapeData();
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/collisions/shape/CollisionVoxelShape.java b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/shape/CollisionVoxelShape.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/shape/CollisionVoxelShape.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.collisions.shape;
+
+import net.minecraft.core.Direction;
+import net.minecraft.world.phys.AABB;
+import net.minecraft.world.phys.shapes.VoxelShape;
+
+public interface CollisionVoxelShape {
+
+    public double moonrise$offsetX();
+
+    public double moonrise$offsetY();
+
+    public double moonrise$offsetZ();
+
+    public double[] moonrise$rootCoordinatesX();
+
+    public double[] moonrise$rootCoordinatesY();
+
+    public double[] moonrise$rootCoordinatesZ();
+
+    public CachedShapeData moonrise$getCachedVoxelData();
+
+    // rets null if not possible to represent this shape as one AABB
+    public AABB moonrise$getSingleAABBRepresentation();
+
+    // ONLY USE INTERNALLY, ONLY FOR INITIALISING IN CONSTRUCTOR: VOXELSHAPES ARE STATIC
+    public void moonrise$initCache();
+
+    // this returns empty if not clamped to 1.0 or 0.0 depending on direction
+    public VoxelShape moonrise$getFaceShapeClamped(final Direction direction);
+
+    public boolean moonrise$isFullBlock();
+
+    public boolean moonrise$occludesFullBlock();
+
+    public boolean moonrise$occludesFullBlockIfCached();
+
+    // uses a cache internally
+    public VoxelShape moonrise$orUnoptimized(final VoxelShape other);
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/collisions/shape/MergedORCache.java b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/shape/MergedORCache.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/shape/MergedORCache.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.collisions.shape;
+
+import net.minecraft.world.phys.shapes.VoxelShape;
+
+public record MergedORCache(
+    VoxelShape key,
+    VoxelShape result
+) {
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/collisions/util/CollisionDirection.java b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/util/CollisionDirection.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/util/CollisionDirection.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.collisions.util;
+
+public interface CollisionDirection {
+
+    // note: this is HashCommon#murmurHash3(some unique id) and since murmurHash3 has an inverse function the returned
+    // value is still unique
+    public int moonrise$uniqueId();
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/collisions/util/FluidOcclusionCacheKey.java b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/util/FluidOcclusionCacheKey.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/collisions/util/FluidOcclusionCacheKey.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.collisions.util;
+
+import net.minecraft.core.Direction;
+import net.minecraft.world.level.block.state.BlockState;
+
+public record FluidOcclusionCacheKey(BlockState first, BlockState second, Direction direction, boolean result) {
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/entity_tracker/EntityTrackerEntity.java b/src/main/java/ca/spottedleaf/moonrise/patches/entity_tracker/EntityTrackerEntity.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/entity_tracker/EntityTrackerEntity.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.entity_tracker;
+
+import net.minecraft.server.level.ChunkMap;
+
+public interface EntityTrackerEntity {
+
+    public ChunkMap.TrackedEntity moonrise$getTrackedEntity();
+
+    public void moonrise$setTrackedEntity(final ChunkMap.TrackedEntity trackedEntity);
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/entity_tracker/EntityTrackerTrackedEntity.java b/src/main/java/ca/spottedleaf/moonrise/patches/entity_tracker/EntityTrackerTrackedEntity.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/entity_tracker/EntityTrackerTrackedEntity.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.entity_tracker;
+
+import ca.spottedleaf.moonrise.common.misc.NearbyPlayers;
+
+public interface EntityTrackerTrackedEntity {
+
+    public void moonrise$tick(final NearbyPlayers.TrackedChunk chunk);
+
+    public void moonrise$removeNonTickThreadPlayers();
+
+    public void moonrise$clearPlayers();
+
+    public boolean moonrise$hasPlayers();
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/fast_palette/FastPalette.java b/src/main/java/ca/spottedleaf/moonrise/patches/fast_palette/FastPalette.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/fast_palette/FastPalette.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.fast_palette;
+
+public interface FastPalette<T> {
+
+    public default T[] moonrise$getRawPalette(final FastPaletteData<T> src) {
+        return null;
+    }
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/fast_palette/FastPaletteData.java b/src/main/java/ca/spottedleaf/moonrise/patches/fast_palette/FastPaletteData.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/fast_palette/FastPaletteData.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.fast_palette;
+
+public interface FastPaletteData<T> {
+
+    public T[] moonrise$getPalette();
+
+    public void moonrise$setPalette(final T[] palette);
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/fluid/FluidFluidState.java b/src/main/java/ca/spottedleaf/moonrise/patches/fluid/FluidFluidState.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/fluid/FluidFluidState.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.fluid;
+
+public interface FluidFluidState {
+    public void moonrise$initCaches();
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/getblock/GetBlockChunk.java b/src/main/java/ca/spottedleaf/moonrise/patches/getblock/GetBlockChunk.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/getblock/GetBlockChunk.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.getblock;
+
+import net.minecraft.world.level.block.state.BlockState;
+
+public interface GetBlockChunk {
+
+    public BlockState moonrise$getBlock(final int x, final int y, final int z);
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/starlight/blockstate/StarlightAbstractBlockState.java b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/blockstate/StarlightAbstractBlockState.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/blockstate/StarlightAbstractBlockState.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.starlight.blockstate;
+
+public interface StarlightAbstractBlockState {
+
+    public boolean starlight$isConditionallyFullOpaque();
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/starlight/chunk/StarlightChunk.java b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/chunk/StarlightChunk.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/chunk/StarlightChunk.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.starlight.chunk;
+
+import ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray;
+
+public interface StarlightChunk {
+
+    public SWMRNibbleArray[] starlight$getBlockNibbles();
+    public void starlight$setBlockNibbles(final SWMRNibbleArray[] nibbles);
+
+    public SWMRNibbleArray[] starlight$getSkyNibbles();
+    public void starlight$setSkyNibbles(final SWMRNibbleArray[] nibbles);
+
+    public boolean[] starlight$getSkyEmptinessMap();
+    public void starlight$setSkyEmptinessMap(final boolean[] emptinessMap);
+
+    public boolean[] starlight$getBlockEmptinessMap();
+    public void starlight$setBlockEmptinessMap(final boolean[] emptinessMap);
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/starlight/light/BlockStarLightEngine.java b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/light/BlockStarLightEngine.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/light/BlockStarLightEngine.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.starlight.light;
+
+import ca.spottedleaf.moonrise.common.PlatformHooks;
+import ca.spottedleaf.moonrise.patches.starlight.blockstate.StarlightAbstractBlockState;
+import ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk;
+import net.minecraft.core.BlockPos;
+import net.minecraft.world.level.BlockGetter;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.LevelChunkSection;
+import net.minecraft.world.level.chunk.LightChunkGetter;
+import net.minecraft.world.level.chunk.PalettedContainer;
+import net.minecraft.world.level.chunk.status.ChunkStatus;
+import net.minecraft.world.phys.shapes.Shapes;
+import net.minecraft.world.phys.shapes.VoxelShape;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
+
+public final class BlockStarLightEngine extends StarLightEngine {
+
+    public BlockStarLightEngine(final Level world) {
+        super(false, world);
+    }
+
+    @Override
+    protected boolean[] getEmptinessMap(final ChunkAccess chunk) {
+        return ((StarlightChunk)chunk).starlight$getBlockEmptinessMap();
+    }
+
+    @Override
+    protected void setEmptinessMap(final ChunkAccess chunk, final boolean[] to) {
+        ((StarlightChunk)chunk).starlight$setBlockEmptinessMap(to);
+    }
+
+    @Override
+    protected SWMRNibbleArray[] getNibblesOnChunk(final ChunkAccess chunk) {
+        return ((StarlightChunk)chunk).starlight$getBlockNibbles();
+    }
+
+    @Override
+    protected void setNibbles(final ChunkAccess chunk, final SWMRNibbleArray[] to) {
+        ((StarlightChunk)chunk).starlight$setBlockNibbles(to);
+    }
+
+    @Override
+    protected boolean canUseChunk(final ChunkAccess chunk) {
+        return chunk.getPersistedStatus().isOrAfter(ChunkStatus.LIGHT) && (this.isClientSide || chunk.isLightCorrect());
+    }
+
+    @Override
+    protected void setNibbleNull(final int chunkX, final int chunkY, final int chunkZ) {
+        final SWMRNibbleArray nibble = this.getNibbleFromCache(chunkX, chunkY, chunkZ);
+        if (nibble != null) {
+            // de-initialisation is not as straightforward as with sky data, since deinit of block light is typically
+            // because a block was removed - which can decrease light. with sky data, block breaking can only result
+            // in increases, and thus the existing sky block check will actually correctly propagate light through
+            // a null section. so in order to propagate decreases correctly, we can do a couple of things: not remove
+            // the data section, or do edge checks on ALL axis (x, y, z). however I do not want edge checks running
+            // for clients at all, as they are expensive. so we don't remove the section, but to maintain the appearence
+            // of vanilla data management we "hide" them.
+            nibble.setHidden();
+        }
+    }
+
+    @Override
+    protected void initNibble(final int chunkX, final int chunkY, final int chunkZ, final boolean extrude, final boolean initRemovedNibbles) {
+        if (chunkY < this.minLightSection || chunkY > this.maxLightSection || this.getChunkInCache(chunkX, chunkZ) == null) {
+            return;
+        }
+
+        final SWMRNibbleArray nibble = this.getNibbleFromCache(chunkX, chunkY, chunkZ);
+        if (nibble == null) {
+            if (!initRemovedNibbles) {
+                throw new IllegalStateException();
+            } else {
+                this.setNibbleInCache(chunkX, chunkY, chunkZ, new SWMRNibbleArray());
+            }
+        } else {
+            nibble.setNonNull();
+        }
+    }
+
+    @Override
+    protected final void checkBlock(final LightChunkGetter lightAccess, final int worldX, final int worldY, final int worldZ) {
+        // blocks can change opacity
+        // blocks can change emitted light
+        // blocks can change direction of propagation
+
+        final int encodeOffset = this.coordinateOffset;
+        final int emittedMask = this.emittedLightMask;
+
+        final int currentLevel = this.getLightLevel(worldX, worldY, worldZ);
+        final BlockState blockState = this.getBlockState(worldX, worldY, worldZ);
+        final int emittedLevel = (PlatformHooks.get().getLightEmission(blockState, lightAccess.getLevel(), this.lightEmissionPos.set(worldX, worldY, worldZ))) & emittedMask;
+
+        this.setLightLevel(worldX, worldY, worldZ, emittedLevel);
+        // this accounts for change in emitted light that would cause an increase
+        if (emittedLevel != 0) {
+            this.appendToIncreaseQueue(
+                    ((worldX + (worldZ << 6) + (worldY << (6 + 6)) + encodeOffset) & ((1L << (6 + 6 + 16)) - 1))
+                            | (emittedLevel & 0xFL) << (6 + 6 + 16)
+                            | (((long)ALL_DIRECTIONS_BITSET) << (6 + 6 + 16 + 4))
+                            | (((StarlightAbstractBlockState)blockState).starlight$isConditionallyFullOpaque() ? FLAG_HAS_SIDED_TRANSPARENT_BLOCKS : 0)
+            );
+        }
+        // this also accounts for a change in emitted light that would cause a decrease
+        // this also accounts for the change of direction of propagation (i.e old block was full transparent, new block is full opaque or vice versa)
+        // as it checks all neighbours (even if current level is 0)
+        this.appendToDecreaseQueue(
+                ((worldX + (worldZ << 6) + (worldY << (6 + 6)) + encodeOffset) & ((1L << (6 + 6 + 16)) - 1))
+                        | (currentLevel & 0xFL) << (6 + 6 + 16)
+                        | (((long)ALL_DIRECTIONS_BITSET) << (6 + 6 + 16 + 4))
+                        // always keep sided transparent false here, new block might be conditionally transparent which would
+                        // prevent us from decreasing sources in the directions where the new block is opaque
+                        // if it turns out we were wrong to de-propagate the source, the re-propagate logic WILL always
+                        // catch that and fix it.
+        );
+        // re-propagating neighbours (done by the decrease queue) will also account for opacity changes in this block
+    }
+
+    protected final BlockPos.MutableBlockPos recalcCenterPos = new BlockPos.MutableBlockPos();
+
+    @Override
+    protected int calculateLightValue(final LightChunkGetter lightAccess, final int worldX, final int worldY, final int worldZ,
+                                      final int expect) {
+        this.recalcCenterPos.set(worldX, worldY, worldZ);
+
+        final BlockState centerState = this.getBlockState(worldX, worldY, worldZ);
+        final BlockGetter world = lightAccess.getLevel();
+        int level = (PlatformHooks.get().getLightEmission(centerState, world, this.recalcCenterPos)) & this.emittedLightMask;
+
+        if (level >= (15 - 1) || level > expect) {
+            return level;
+        }
+
+        final int opacity = Math.max(1, centerState.getLightBlock());
+        if (opacity >= 15) {
+            return level;
+        }
+        final BlockState conditionallyOpaqueState;
+        if (((StarlightAbstractBlockState)centerState).starlight$isConditionallyFullOpaque()) {
+            conditionallyOpaqueState = centerState;
+        } else {
+            conditionallyOpaqueState = null;
+        }
+
+        final int sectionOffset = this.chunkSectionIndexOffset;
+        for (final AxisDirection direction : AXIS_DIRECTIONS) {
+            final int offX = worldX + direction.x;
+            final int offY = worldY + direction.y;
+            final int offZ = worldZ + direction.z;
+
+            final int sectionIndex = (offX >> 4) + 5 * (offZ >> 4) + (5 * 5) * (offY >> 4) + sectionOffset;
+
+            final int neighbourLevel = this.getLightLevel(sectionIndex, (offX & 15) | ((offZ & 15) << 4) | ((offY & 15) << 8));
+
+            if ((neighbourLevel - 1) <= level) {
+                // don't need to test transparency, we know it wont affect the result.
+                continue;
+            }
+
+            final BlockState neighbourState = this.getBlockState(offX, offY, offZ);
+            if (((StarlightAbstractBlockState)neighbourState).starlight$isConditionallyFullOpaque()) {
+                // here the block can be conditionally opaque (i.e light cannot propagate from it), so we need to test that
+                // we don't read the blockstate because most of the time this is false, so using the faster
+                // known transparency lookup results in a net win
+                final VoxelShape neighbourFace = neighbourState.getFaceOcclusionShape(direction.opposite.nms);
+                final VoxelShape thisFace = conditionallyOpaqueState == null ? Shapes.empty() : conditionallyOpaqueState.getFaceOcclusionShape(direction.nms);
+                if (Shapes.faceShapeOccludes(thisFace, neighbourFace)) {
+                    // not allowed to propagate
+                    continue;
+                }
+            }
+
+            // passed transparency,
+
+            final int calculated = neighbourLevel - opacity;
+            level = Math.max(calculated, level);
+            if (level > expect) {
+                return level;
+            }
+        }
+
+        return level;
+    }
+
+    @Override
+    protected void propagateBlockChanges(final LightChunkGetter lightAccess, final ChunkAccess atChunk, final Set<BlockPos> positions) {
+        for (final BlockPos pos : positions) {
+            this.checkBlock(lightAccess, pos.getX(), pos.getY(), pos.getZ());
+        }
+
+        this.performLightDecrease(lightAccess);
+    }
+
+    protected List<BlockPos> getSources(final LightChunkGetter lightAccess, final ChunkAccess chunk) {
+        final List<BlockPos> sources = new ArrayList<>();
+
+        final int offX = chunk.getPos().x << 4;
+        final int offZ = chunk.getPos().z << 4;
+
+        final PlatformHooks platformHooks = PlatformHooks.get();
+
+        final BlockGetter world = lightAccess.getLevel();
+        final LevelChunkSection[] sections = chunk.getSections();
+        for (int sectionY = this.minSection; sectionY <= this.maxSection; ++sectionY) {
+            final LevelChunkSection section = sections[sectionY - this.minSection];
+            if (section.hasOnlyAir()) {
+                // no sources in empty sections
+                continue;
+            }
+            if (!section.maybeHas(platformHooks.maybeHasLightEmission())) {
+                // no light sources in palette
+                continue;
+            }
+            final PalettedContainer<BlockState> states = section.states;
+            final int offY = sectionY << 4;
+
+            final BlockPos.MutableBlockPos mutablePos = this.lightEmissionPos;
+            for (int index = 0; index < (16 * 16 * 16); ++index) {
+                final BlockState state = states.get(index);
+                mutablePos.set(offX | (index & 15), offY | (index >>> 8), offZ | ((index >>> 4) & 15));
+
+                if ((platformHooks.getLightEmission(state, world, mutablePos)) == 0) {
+                    continue;
+                }
+
+                // index = x | (z << 4) | (y << 8)
+                sources.add(mutablePos.immutable());
+            }
+        }
+
+        return sources;
+    }
+
+    @Override
+    public void lightChunk(final LightChunkGetter lightAccess, final ChunkAccess chunk, final boolean needsEdgeChecks) {
+        // setup sources
+        final BlockGetter world = lightAccess.getLevel();
+        final PlatformHooks platformHooks = PlatformHooks.get();
+
+        final int emittedMask = this.emittedLightMask;
+        final List<BlockPos> positions = this.getSources(lightAccess, chunk);
+        for (int i = 0, len = positions.size(); i < len; ++i) {
+            final BlockPos pos = positions.get(i);
+            final BlockState blockState = this.getBlockState(pos.getX(), pos.getY(), pos.getZ());
+            final int emittedLight = platformHooks.getLightEmission(blockState, world, pos) & emittedMask;
+
+            if (emittedLight <= this.getLightLevel(pos.getX(), pos.getY(), pos.getZ())) {
+                // some other source is brighter
+                continue;
+            }
+
+            this.appendToIncreaseQueue(
+                    ((pos.getX() + (pos.getZ() << 6) + (pos.getY() << (6 + 6)) + this.coordinateOffset) & ((1L << (6 + 6 + 16)) - 1))
+                            | (emittedLight & 0xFL) << (6 + 6 + 16)
+                            | (((long)ALL_DIRECTIONS_BITSET) << (6 + 6 + 16 + 4))
+                            | (((StarlightAbstractBlockState)blockState).starlight$isConditionallyFullOpaque() ? FLAG_HAS_SIDED_TRANSPARENT_BLOCKS : 0)
+            );
+
+
+            // propagation wont set this for us
+            this.setLightLevel(pos.getX(), pos.getY(), pos.getZ(), emittedLight);
+        }
+
+        if (needsEdgeChecks) {
+            // not required to propagate here, but this will reduce the hit of the edge checks
+            this.performLightIncrease(lightAccess);
+
+            // verify neighbour edges
+            this.checkChunkEdges(lightAccess, chunk, this.minLightSection, this.maxLightSection);
+        } else {
+            this.propagateNeighbourLevels(lightAccess, chunk, this.minLightSection, this.maxLightSection);
+
+            this.performLightIncrease(lightAccess);
+        }
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/starlight/light/SWMRNibbleArray.java b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/light/SWMRNibbleArray.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/light/SWMRNibbleArray.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.starlight.light;
+
+import net.minecraft.world.level.chunk.DataLayer;
+import java.util.ArrayDeque;
+import java.util.Arrays;
+
+// SWMR -> Single Writer Multi Reader Nibble Array
+public final class SWMRNibbleArray {
+
+    /*
+     * Null nibble - nibble does not exist, and should not be written to. Just like vanilla - null
+     * nibbles are always 0 - and they are never written to directly. Only initialised/uninitialised
+     * nibbles can be written to.
+     *
+     * Uninitialised nibble - They are all 0, but the backing array isn't initialised.
+     *
+     * Initialised nibble - Has light data.
+     */
+
+    protected static final int INIT_STATE_NULL   = 0; // null
+    protected static final int INIT_STATE_UNINIT = 1; // uninitialised
+    protected static final int INIT_STATE_INIT   = 2; // initialised
+    protected static final int INIT_STATE_HIDDEN = 3; // initialised, but conversion to Vanilla data should be treated as if NULL
+
+    public static final int ARRAY_SIZE = 16 * 16 * 16 / (8/4); // blocks / bytes per block
+    // this allows us to maintain only 1 byte array when we're not updating
+    static final ThreadLocal<ArrayDeque<byte[]>> WORKING_BYTES_POOL = ThreadLocal.withInitial(ArrayDeque::new);
+
+    private static byte[] allocateBytes() {
+        final byte[] inPool = WORKING_BYTES_POOL.get().pollFirst();
+        if (inPool != null) {
+            return inPool;
+        }
+
+        return new byte[ARRAY_SIZE];
+    }
+
+    private static void freeBytes(final byte[] bytes) {
+        WORKING_BYTES_POOL.get().addFirst(bytes);
+    }
+
+    public static SWMRNibbleArray fromVanilla(final DataLayer nibble) {
+        if (nibble == null) {
+            return new SWMRNibbleArray(null, true);
+        } else if (nibble.isEmpty()) {
+            return new SWMRNibbleArray();
+        } else {
+            return new SWMRNibbleArray(nibble.getData().clone()); // make sure we don't write to the parameter later
+        }
+    }
+
+    protected int stateUpdating;
+    protected volatile int stateVisible;
+
+    protected byte[] storageUpdating;
+    protected boolean updatingDirty; // only returns whether storageUpdating is dirty
+    protected volatile byte[] storageVisible;
+
+    public SWMRNibbleArray() {
+        this(null, false); // lazy init
+    }
+
+    public SWMRNibbleArray(final byte[] bytes) {
+        this(bytes, false);
+    }
+
+    public SWMRNibbleArray(final byte[] bytes, final boolean isNullNibble) {
+        if (bytes != null && bytes.length != ARRAY_SIZE) {
+            throw new IllegalArgumentException("Data of wrong length: " + bytes.length);
+        }
+        this.stateVisible = this.stateUpdating = bytes == null ? (isNullNibble ? INIT_STATE_NULL : INIT_STATE_UNINIT) : INIT_STATE_INIT;
+        this.storageUpdating = this.storageVisible = bytes;
+    }
+
+    public SWMRNibbleArray(final byte[] bytes, final int state) {
+        if (bytes != null && bytes.length != ARRAY_SIZE) {
+            throw new IllegalArgumentException("Data of wrong length: " + bytes.length);
+        }
+        if (bytes == null && (state == INIT_STATE_INIT || state == INIT_STATE_HIDDEN)) {
+            throw new IllegalArgumentException("Data cannot be null and have state be initialised");
+        }
+        this.stateUpdating = this.stateVisible = state;
+        this.storageUpdating = this.storageVisible = bytes;
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder stringBuilder = new StringBuilder();
+        stringBuilder.append("State: ");
+        switch (this.stateVisible) {
+            case INIT_STATE_NULL:
+                stringBuilder.append("null");
+                break;
+            case INIT_STATE_UNINIT:
+                stringBuilder.append("uninitialised");
+                break;
+            case INIT_STATE_INIT:
+                stringBuilder.append("initialised");
+                break;
+            case INIT_STATE_HIDDEN:
+                stringBuilder.append("hidden");
+                break;
+            default:
+                stringBuilder.append("unknown");
+                break;
+        }
+        stringBuilder.append("\nData:\n");
+
+        final byte[] data = this.storageVisible;
+        if (data != null) {
+            for (int i = 0; i < 4096; ++i) {
+                // Copied from NibbleArray#toString
+                final int level = ((data[i >>> 1] >>> ((i & 1) << 2)) & 0xF);
+
+                stringBuilder.append(Integer.toHexString(level));
+                if ((i & 15) == 15) {
+                    stringBuilder.append("\n");
+                }
+
+                if ((i & 255) == 255) {
+                    stringBuilder.append("\n");
+                }
+            }
+        } else {
+            stringBuilder.append("null");
+        }
+
+        return stringBuilder.toString();
+    }
+
+    public SaveState getSaveState() {
+        synchronized (this) {
+            final int state = this.stateVisible;
+            final byte[] data = this.storageVisible;
+            if (state == INIT_STATE_NULL) {
+                return null;
+            }
+            if (state == INIT_STATE_UNINIT) {
+                return new SaveState(null, state);
+            }
+            final boolean zero = isAllZero(data);
+            if (zero) {
+                return state == INIT_STATE_INIT ? new SaveState(null, INIT_STATE_UNINIT) : null;
+            } else {
+                return new SaveState(data.clone(), state);
+            }
+        }
+    }
+
+    protected static boolean isAllZero(final byte[] data) {
+        for (int i = 0; i < (ARRAY_SIZE >>> 4); ++i) {
+            byte whole = data[i << 4];
+
+            for (int k = 1; k < (1 << 4); ++k) {
+                whole |= data[(i << 4) | k];
+            }
+
+            if (whole != 0) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    // operation type: updating on src, updating on other
+    public void extrudeLower(final SWMRNibbleArray other) {
+        if (other.stateUpdating == INIT_STATE_NULL) {
+            throw new IllegalArgumentException();
+        }
+
+        if (other.storageUpdating == null) {
+            this.setUninitialised();
+            return;
+        }
+
+        final byte[] src = other.storageUpdating;
+        final byte[] into;
+
+        if (!this.updatingDirty) {
+            if (this.storageUpdating != null) {
+                into = this.storageUpdating = allocateBytes();
+            } else {
+                this.storageUpdating = into = allocateBytes();
+                this.stateUpdating = INIT_STATE_INIT;
+            }
+            this.updatingDirty = true;
+        } else {
+            into = this.storageUpdating;
+        }
+
+        final int start = 0;
+        final int end = (15 | (15 << 4)) >>> 1;
+
+        /* x | (z << 4) | (y << 8) */
+        for (int y = 0; y <= 15; ++y) {
+            System.arraycopy(src, start, into, y << (8 - 1), end - start + 1);
+        }
+    }
+
+    // operation type: updating
+    public void setFull() {
+        if (this.stateUpdating != INIT_STATE_HIDDEN) {
+            this.stateUpdating = INIT_STATE_INIT;
+        }
+        Arrays.fill(this.storageUpdating == null || !this.updatingDirty ? this.storageUpdating = allocateBytes() : this.storageUpdating, (byte)-1);
+        this.updatingDirty = true;
+    }
+
+    // operation type: updating
+    public void setZero() {
+        if (this.stateUpdating != INIT_STATE_HIDDEN) {
+            this.stateUpdating = INIT_STATE_INIT;
+        }
+        Arrays.fill(this.storageUpdating == null || !this.updatingDirty ? this.storageUpdating = allocateBytes() : this.storageUpdating, (byte)0);
+        this.updatingDirty = true;
+    }
+
+    // operation type: updating
+    public void setNonNull() {
+        if (this.stateUpdating == INIT_STATE_HIDDEN) {
+            this.stateUpdating = INIT_STATE_INIT;
+            return;
+        }
+        if (this.stateUpdating != INIT_STATE_NULL) {
+            return;
+        }
+        this.stateUpdating = INIT_STATE_UNINIT;
+    }
+
+    // operation type: updating
+    public void setNull() {
+        this.stateUpdating = INIT_STATE_NULL;
+        if (this.updatingDirty && this.storageUpdating != null) {
+            freeBytes(this.storageUpdating);
+        }
+        this.storageUpdating = null;
+        this.updatingDirty = false;
+    }
+
+    // operation type: updating
+    public void setUninitialised() {
+        this.stateUpdating = INIT_STATE_UNINIT;
+        if (this.storageUpdating != null && this.updatingDirty) {
+            freeBytes(this.storageUpdating);
+        }
+        this.storageUpdating = null;
+        this.updatingDirty = false;
+    }
+
+    // operation type: updating
+    public void setHidden() {
+        if (this.stateUpdating == INIT_STATE_HIDDEN) {
+            return;
+        }
+        if (this.stateUpdating != INIT_STATE_INIT) {
+            this.setNull();
+        } else {
+            this.stateUpdating = INIT_STATE_HIDDEN;
+        }
+    }
+
+    // operation type: updating
+    public boolean isDirty() {
+        return this.stateUpdating != this.stateVisible || this.updatingDirty;
+    }
+
+    // operation type: updating
+    public boolean isNullNibbleUpdating() {
+        return this.stateUpdating == INIT_STATE_NULL;
+    }
+
+    // operation type: visible
+    public boolean isNullNibbleVisible() {
+        return this.stateVisible == INIT_STATE_NULL;
+    }
+
+    // opeartion type: updating
+    public boolean isUninitialisedUpdating() {
+        return this.stateUpdating == INIT_STATE_UNINIT;
+    }
+
+    // operation type: visible
+    public boolean isUninitialisedVisible() {
+        return this.stateVisible == INIT_STATE_UNINIT;
+    }
+
+    // operation type: updating
+    public boolean isInitialisedUpdating() {
+        return this.stateUpdating == INIT_STATE_INIT;
+    }
+
+    // operation type: visible
+    public boolean isInitialisedVisible() {
+        return this.stateVisible == INIT_STATE_INIT;
+    }
+
+    // operation type: updating
+    public boolean isHiddenUpdating() {
+        return this.stateUpdating == INIT_STATE_HIDDEN;
+    }
+
+    // operation type: updating
+    public boolean isHiddenVisible() {
+        return this.stateVisible == INIT_STATE_HIDDEN;
+    }
+
+    // operation type: updating
+    protected void swapUpdatingAndMarkDirty() {
+        if (this.updatingDirty) {
+            return;
+        }
+
+        if (this.storageUpdating == null) {
+            this.storageUpdating = allocateBytes();
+            Arrays.fill(this.storageUpdating, (byte)0);
+        } else {
+            System.arraycopy(this.storageUpdating, 0, this.storageUpdating = allocateBytes(), 0, ARRAY_SIZE);
+        }
+
+        if (this.stateUpdating != INIT_STATE_HIDDEN) {
+            this.stateUpdating = INIT_STATE_INIT;
+        }
+        this.updatingDirty = true;
+    }
+
+    // operation type: updating
+    public boolean updateVisible() {
+        if (!this.isDirty()) {
+            return false;
+        }
+
+        synchronized (this) {
+            if (this.stateUpdating == INIT_STATE_NULL || this.stateUpdating == INIT_STATE_UNINIT) {
+                this.storageVisible = null;
+            } else {
+                if (this.storageVisible == null) {
+                    this.storageVisible = this.storageUpdating.clone();
+                } else {
+                    if (this.storageUpdating != this.storageVisible) {
+                        System.arraycopy(this.storageUpdating, 0, this.storageVisible, 0, ARRAY_SIZE);
+                    }
+                }
+
+                if (this.storageUpdating != this.storageVisible) {
+                    freeBytes(this.storageUpdating);
+                }
+                this.storageUpdating = this.storageVisible;
+            }
+            this.updatingDirty = false;
+            this.stateVisible = this.stateUpdating;
+        }
+
+        return true;
+    }
+
+    // operation type: visible
+    public DataLayer toVanillaNibble() {
+        synchronized (this) {
+            switch (this.stateVisible) {
+                case INIT_STATE_HIDDEN:
+                case INIT_STATE_NULL:
+                    return null;
+                case INIT_STATE_UNINIT:
+                    return new DataLayer();
+                case INIT_STATE_INIT:
+                    return new DataLayer(this.storageVisible.clone());
+                default:
+                    throw new IllegalStateException();
+            }
+        }
+    }
+
+    /* x | (z << 4) | (y << 8) */
+
+    // operation type: updating
+    public int getUpdating(final int x, final int y, final int z) {
+        return this.getUpdating((x & 15) | ((z & 15) << 4) | ((y & 15) << 8));
+    }
+
+    // operation type: updating
+    public int getUpdating(final int index) {
+        // indices range from 0 -> 4096
+        final byte[] bytes = this.storageUpdating;
+        if (bytes == null) {
+            return 0;
+        }
+        final byte value = bytes[index >>> 1];
+
+        // if we are an even index, we want lower 4 bits
+        // if we are an odd index, we want upper 4 bits
+        return ((value >>> ((index & 1) << 2)) & 0xF);
+    }
+
+    // operation type: visible
+    public int getVisible(final int x, final int y, final int z) {
+        return this.getVisible((x & 15) | ((z & 15) << 4) | ((y & 15) << 8));
+    }
+
+    // operation type: visible
+    public int getVisible(final int index) {
+        // indices range from 0 -> 4096
+        final byte[] visibleBytes = this.storageVisible;
+        if (visibleBytes == null) {
+            return 0;
+        }
+        final byte value = visibleBytes[index >>> 1];
+
+        // if we are an even index, we want lower 4 bits
+        // if we are an odd index, we want upper 4 bits
+        return ((value >>> ((index & 1) << 2)) & 0xF);
+    }
+
+    // operation type: updating
+    public void set(final int x, final int y, final int z, final int value) {
+        this.set((x & 15) | ((z & 15) << 4) | ((y & 15) << 8), value);
+    }
+
+    // operation type: updating
+    public void set(final int index, final int value) {
+        if (!this.updatingDirty) {
+            this.swapUpdatingAndMarkDirty();
+        }
+        final int shift = (index & 1) << 2;
+        final int i = index >>> 1;
+
+        this.storageUpdating[i] = (byte)((this.storageUpdating[i] & (0xF0 >>> shift)) | (value << shift));
+    }
+
+    public static final class SaveState {
+
+        public final byte[] data;
+        public final int state;
+
+        public SaveState(final byte[] data, final int state) {
+            this.data = data;
+            this.state = state;
+        }
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/starlight/light/SkyStarLightEngine.java b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/light/SkyStarLightEngine.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/light/SkyStarLightEngine.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.starlight.light;
+
+import ca.spottedleaf.moonrise.common.util.WorldUtil;
+import ca.spottedleaf.moonrise.patches.starlight.blockstate.StarlightAbstractBlockState;
+import ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk;
+import it.unimi.dsi.fastutil.shorts.ShortCollection;
+import it.unimi.dsi.fastutil.shorts.ShortIterator;
+import net.minecraft.core.BlockPos;
+import net.minecraft.world.level.BlockGetter;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.LevelChunkSection;
+import net.minecraft.world.level.chunk.LightChunkGetter;
+import net.minecraft.world.level.chunk.status.ChunkStatus;
+import net.minecraft.world.phys.shapes.Shapes;
+import net.minecraft.world.phys.shapes.VoxelShape;
+import java.util.Arrays;
+import java.util.Set;
+
+public final class SkyStarLightEngine extends StarLightEngine {
+
+    /*
+      Specification for managing the initialisation and de-initialisation of skylight nibble arrays:
+
+      Skylight nibble initialisation requires that non-empty chunk sections have 1 radius nibbles non-null.
+
+      This presents some problems, as vanilla is only guaranteed to have 0 radius neighbours loaded when editing blocks.
+      However starlight fixes this so that it has 1 radius loaded. Still, we don't actually have guarantees
+      that we have the necessary chunks loaded to de-initialise neighbour sections (but we do have enough to de-initialise
+      our own) - we need a radius of 2 to de-initialise neighbour nibbles.
+      How do we solve this?
+
+      Each chunk will store the last known "emptiness" of sections for each of their 1 radius neighbour chunk sections.
+      If the chunk does not have full data, then its nibbles are NOT de-initialised. This is because obviously the
+      chunk did not go through the light stage yet - or its neighbours are not lit. In either case, once the last
+      known "emptiness" of neighbouring sections is filled with data, the chunk will run a full check of the data
+      to see if any of its nibbles need to be de-initialised.
+
+      The emptiness map allows us to de-initialise neighbour nibbles if the neighbour has it filled with data,
+      and if it doesn't have data then we know it will correctly de-initialise once it fills up.
+
+      Unlike vanilla, we store whether nibbles are uninitialised on disk - so we don't need any dumb hacking
+      around those.
+     */
+
+    protected final int[] heightMapBlockChange = new int[16 * 16];
+    {
+        Arrays.fill(this.heightMapBlockChange, Integer.MIN_VALUE); // clear heightmap
+    }
+
+    protected final boolean[] nullPropagationCheckCache;
+
+    public SkyStarLightEngine(final Level world) {
+        super(true, world);
+        this.nullPropagationCheckCache = new boolean[WorldUtil.getTotalLightSections(world)];
+    }
+
+    @Override
+    protected void initNibble(final int chunkX, final int chunkY, final int chunkZ, final boolean extrude, final boolean initRemovedNibbles) {
+        if (chunkY < this.minLightSection || chunkY > this.maxLightSection || this.getChunkInCache(chunkX, chunkZ) == null) {
+            return;
+        }
+        SWMRNibbleArray nibble = this.getNibbleFromCache(chunkX, chunkY, chunkZ);
+        if (nibble == null) {
+            if (!initRemovedNibbles) {
+                throw new IllegalStateException();
+            } else {
+                this.setNibbleInCache(chunkX, chunkY, chunkZ, nibble = new SWMRNibbleArray(null, true));
+            }
+        }
+        this.initNibble(nibble, chunkX, chunkY, chunkZ, extrude);
+    }
+
+    @Override
+    protected void setNibbleNull(final int chunkX, final int chunkY, final int chunkZ) {
+        final SWMRNibbleArray nibble = this.getNibbleFromCache(chunkX, chunkY, chunkZ);
+        if (nibble != null) {
+            nibble.setNull();
+        }
+    }
+
+    protected final void initNibble(final SWMRNibbleArray currNibble, final int chunkX, final int chunkY, final int chunkZ, final boolean extrude) {
+        if (!currNibble.isNullNibbleUpdating()) {
+            // already initialised
+            return;
+        }
+
+        final boolean[] emptinessMap = this.getEmptinessMap(chunkX, chunkZ);
+
+        // are we above this chunk's lowest empty section?
+        int lowestY = this.minLightSection - 1;
+        for (int currY = this.maxSection; currY >= this.minSection; --currY) {
+            if (emptinessMap == null) {
+                // cannot delay nibble init for lit chunks, as we need to init to propagate into them.
+                final LevelChunkSection current = this.getChunkSection(chunkX, currY, chunkZ);
+                if (current == null || current.hasOnlyAir()) {
+                    continue;
+                }
+            } else {
+                if (emptinessMap[currY - this.minSection]) {
+                    continue;
+                }
+            }
+
+            // should always be full lit here
+            lowestY = currY;
+            break;
+        }
+
+        if (chunkY > lowestY) {
+            // we need to set this one to full
+            final SWMRNibbleArray nibble = this.getNibbleFromCache(chunkX, chunkY, chunkZ);
+            nibble.setNonNull();
+            nibble.setFull();
+            return;
+        }
+
+        if (extrude) {
+            // this nibble is going to depend solely on the skylight data above it
+            // find first non-null data above (there does exist one, as we just found it above)
+            for (int currY = chunkY + 1; currY <= this.maxLightSection; ++currY) {
+                final SWMRNibbleArray nibble = this.getNibbleFromCache(chunkX, currY, chunkZ);
+                if (nibble != null && !nibble.isNullNibbleUpdating()) {
+                    currNibble.setNonNull();
+                    currNibble.extrudeLower(nibble);
+                    break;
+                }
+            }
+        } else {
+            currNibble.setNonNull();
+        }
+    }
+
+    protected final void rewriteNibbleCacheForSkylight(final ChunkAccess chunk) {
+        for (int index = 0, max = this.nibbleCache.length; index < max; ++index) {
+            final SWMRNibbleArray nibble = this.nibbleCache[index];
+            if (nibble != null && nibble.isNullNibbleUpdating()) {
+                // stop propagation in these areas
+                this.nibbleCache[index] = null;
+                nibble.updateVisible();
+            }
+        }
+    }
+
+    // rets whether neighbours were init'd
+
+    protected final boolean checkNullSection(final int chunkX, final int chunkY, final int chunkZ,
+                                             final boolean extrudeInitialised) {
+        // null chunk sections may have nibble neighbours in the horizontal 1 radius that are
+        // non-null. Propagation to these neighbours is necessary.
+        // What makes this easy is we know none of these neighbours are non-empty (otherwise
+        // this nibble would be initialised). So, we don't have to initialise
+        // the neighbours in the full 1 radius, because there's no worry that any "paths"
+        // to the neighbours on this horizontal plane are blocked.
+        if (chunkY < this.minLightSection || chunkY > this.maxLightSection || this.nullPropagationCheckCache[chunkY - this.minLightSection]) {
+            return false;
+        }
+        this.nullPropagationCheckCache[chunkY - this.minLightSection] = true;
+
+        // check horizontal neighbours
+        boolean needInitNeighbours = false;
+        neighbour_search:
+        for (int dz = -1; dz <= 1; ++dz) {
+            for (int dx = -1; dx <= 1; ++dx) {
+                final SWMRNibbleArray nibble = this.getNibbleFromCache(dx + chunkX, chunkY, dz + chunkZ);
+                if (nibble != null && !nibble.isNullNibbleUpdating()) {
+                    needInitNeighbours = true;
+                    break neighbour_search;
+                }
+            }
+        }
+
+        if (needInitNeighbours) {
+            for (int dz = -1; dz <= 1; ++dz) {
+                for (int dx = -1; dx <= 1; ++dx) {
+                    this.initNibble(dx + chunkX, chunkY, dz + chunkZ, (dx | dz) == 0 ? extrudeInitialised : true, true);
+                }
+            }
+        }
+
+        return needInitNeighbours;
+    }
+
+    protected final int getLightLevelExtruded(final int worldX, final int worldY, final int worldZ) {
+        final int chunkX = worldX >> 4;
+        int chunkY = worldY >> 4;
+        final int chunkZ = worldZ >> 4;
+
+        SWMRNibbleArray nibble = this.getNibbleFromCache(chunkX, chunkY, chunkZ);
+        if (nibble != null) {
+            return nibble.getUpdating(worldX, worldY, worldZ);
+        }
+
+        for (;;) {
+            if (++chunkY > this.maxLightSection) {
+                return 15;
+            }
+
+            nibble = this.getNibbleFromCache(chunkX, chunkY, chunkZ);
+
+            if (nibble != null) {
+                return nibble.getUpdating(worldX, 0, worldZ);
+            }
+        }
+    }
+
+    @Override
+    protected boolean[] getEmptinessMap(final ChunkAccess chunk) {
+        return ((StarlightChunk)chunk).starlight$getSkyEmptinessMap();
+    }
+
+    @Override
+    protected void setEmptinessMap(final ChunkAccess chunk, final boolean[] to) {
+        ((StarlightChunk)chunk).starlight$setSkyEmptinessMap(to);
+    }
+
+    @Override
+    protected SWMRNibbleArray[] getNibblesOnChunk(final ChunkAccess chunk) {
+        return ((StarlightChunk)chunk).starlight$getSkyNibbles();
+    }
+
+    @Override
+    protected void setNibbles(final ChunkAccess chunk, final SWMRNibbleArray[] to) {
+        ((StarlightChunk)chunk).starlight$setSkyNibbles(to);
+    }
+
+    @Override
+    protected boolean canUseChunk(final ChunkAccess chunk) {
+        // can only use chunks for sky stuff if their sections have been init'd
+        return chunk.getPersistedStatus().isOrAfter(ChunkStatus.LIGHT) && (this.isClientSide || chunk.isLightCorrect());
+    }
+
+    @Override
+    protected void checkChunkEdges(final LightChunkGetter lightAccess, final ChunkAccess chunk, final int fromSection,
+                                   final int toSection) {
+        Arrays.fill(this.nullPropagationCheckCache, false);
+        this.rewriteNibbleCacheForSkylight(chunk);
+        final int chunkX = chunk.getPos().x;
+        final int chunkZ = chunk.getPos().z;
+        for (int y = toSection; y >= fromSection; --y) {
+            this.checkNullSection(chunkX, y, chunkZ, true);
+        }
+
+        super.checkChunkEdges(lightAccess, chunk, fromSection, toSection);
+    }
+
+    @Override
+    protected void checkChunkEdges(final LightChunkGetter lightAccess, final ChunkAccess chunk, final ShortCollection sections) {
+        Arrays.fill(this.nullPropagationCheckCache, false);
+        this.rewriteNibbleCacheForSkylight(chunk);
+        final int chunkX = chunk.getPos().x;
+        final int chunkZ = chunk.getPos().z;
+        for (final ShortIterator iterator = sections.iterator(); iterator.hasNext();) {
+            final int y = (int)iterator.nextShort();
+            this.checkNullSection(chunkX, y, chunkZ, true);
+        }
+
+        super.checkChunkEdges(lightAccess, chunk, sections);
+    }
+
+    @Override
+    protected void checkBlock(final LightChunkGetter lightAccess, final int worldX, final int worldY, final int worldZ) {
+        // blocks can change opacity
+        // blocks can change direction of propagation
+
+        // same logic applies from BlockStarLightEngine#checkBlock
+
+        final int encodeOffset = this.coordinateOffset;
+
+        final int currentLevel = this.getLightLevel(worldX, worldY, worldZ);
+
+        if (currentLevel == 15) {
+            // must re-propagate clobbered source
+            this.appendToIncreaseQueue(
+                    ((worldX + (worldZ << 6) + (worldY << (6 + 6)) + encodeOffset) & ((1L << (6 + 6 + 16)) - 1))
+                            | (currentLevel & 0xFL) << (6 + 6 + 16)
+                            | (((long)ALL_DIRECTIONS_BITSET) << (6 + 6 + 16 + 4))
+                            | FLAG_HAS_SIDED_TRANSPARENT_BLOCKS // don't know if the block is conditionally transparent
+            );
+        } else {
+            this.setLightLevel(worldX, worldY, worldZ, 0);
+        }
+
+        this.appendToDecreaseQueue(
+                ((worldX + (worldZ << 6) + (worldY << (6 + 6)) + encodeOffset) & ((1L << (6 + 6 + 16)) - 1))
+                        | (currentLevel & 0xFL) << (6 + 6 + 16)
+                        | (((long)ALL_DIRECTIONS_BITSET) << (6 + 6 + 16 + 4))
+        );
+    }
+
+    @Override
+    protected int calculateLightValue(final LightChunkGetter lightAccess, final int worldX, final int worldY, final int worldZ,
+                                      final int expect) {
+        if (expect == 15) {
+            return expect;
+        }
+
+        final int sectionOffset = this.chunkSectionIndexOffset;
+        final BlockState centerState = this.getBlockState(worldX, worldY, worldZ);
+
+        final BlockState conditionallyOpaqueState;
+        final int opacity = Math.max(1, centerState.getLightBlock());
+        if (((StarlightAbstractBlockState)centerState).starlight$isConditionallyFullOpaque()) {
+            conditionallyOpaqueState = centerState;
+        } else {
+            conditionallyOpaqueState = null;
+        }
+
+        int level = 0;
+
+        for (final AxisDirection direction : AXIS_DIRECTIONS) {
+            final int offX = worldX + direction.x;
+            final int offY = worldY + direction.y;
+            final int offZ = worldZ + direction.z;
+
+            final int sectionIndex = (offX >> 4) + 5 * (offZ >> 4) + (5 * 5) * (offY >> 4) + sectionOffset;
+
+            final int neighbourLevel = this.getLightLevel(sectionIndex, (offX & 15) | ((offZ & 15) << 4) | ((offY & 15) << 8));
+
+            if ((neighbourLevel - 1) <= level) {
+                // don't need to test transparency, we know it wont affect the result.
+                continue;
+            }
+
+            final BlockState neighbourState = this.getBlockState(offX, offY, offZ);
+
+            if (((StarlightAbstractBlockState)neighbourState).starlight$isConditionallyFullOpaque()) {
+                // here the block can be conditionally opaque (i.e light cannot propagate from it), so we need to test that
+                // we don't read the blockstate because most of the time this is false, so using the faster
+                // known transparency lookup results in a net win
+                final VoxelShape neighbourFace = neighbourState.getFaceOcclusionShape(direction.opposite.nms);
+                final VoxelShape thisFace = conditionallyOpaqueState == null ? Shapes.empty() : conditionallyOpaqueState.getFaceOcclusionShape(direction.nms);
+                if (Shapes.faceShapeOccludes(thisFace, neighbourFace)) {
+                    // not allowed to propagate
+                    continue;
+                }
+            }
+
+            final int calculated = neighbourLevel - opacity;
+            level = Math.max(calculated, level);
+            if (level > expect) {
+                return level;
+            }
+        }
+
+        return level;
+    }
+
+    @Override
+    protected void propagateBlockChanges(final LightChunkGetter lightAccess, final ChunkAccess atChunk, final Set<BlockPos> positions) {
+        this.rewriteNibbleCacheForSkylight(atChunk);
+        Arrays.fill(this.nullPropagationCheckCache, false);
+
+        final BlockGetter world = lightAccess.getLevel();
+        final int chunkX = atChunk.getPos().x;
+        final int chunkZ = atChunk.getPos().z;
+        final int heightMapOffset = chunkX * -16 + (chunkZ * (-16 * 16));
+
+        // setup heightmap for changes
+        for (final BlockPos pos : positions) {
+            final int index = pos.getX() + (pos.getZ() << 4) + heightMapOffset;
+            final int curr = this.heightMapBlockChange[index];
+            if (pos.getY() > curr) {
+                this.heightMapBlockChange[index] = pos.getY();
+            }
+        }
+
+        // note: light sets are delayed while processing skylight source changes due to how
+        // nibbles are initialised, as we want to avoid clobbering nibble values so what when
+        // below nibbles are initialised they aren't reading from partially modified nibbles
+
+        // now we can recalculate the sources for the changed columns
+        for (int index = 0; index < (16 * 16); ++index) {
+            final int maxY = this.heightMapBlockChange[index];
+            if (maxY == Integer.MIN_VALUE) {
+                // not changed
+                continue;
+            }
+            this.heightMapBlockChange[index] = Integer.MIN_VALUE; // restore default for next caller
+
+            final int columnX = (index & 15) | (chunkX << 4);
+            final int columnZ = (index >>> 4) | (chunkZ << 4);
+
+            // try and propagate from the above y
+            // delay light set until after processing all sources to setup
+            final int maxPropagationY = this.tryPropagateSkylight(world, columnX, maxY, columnZ, true, true);
+
+            // maxPropagationY is now the highest block that could not be propagated to
+
+            // remove all sources below that are 15
+            final long propagateDirection = AxisDirection.POSITIVE_Y.everythingButThisDirection;
+            final int encodeOffset = this.coordinateOffset;
+
+            if (this.getLightLevelExtruded(columnX, maxPropagationY, columnZ) == 15) {
+                // ensure section is checked
+                this.checkNullSection(columnX >> 4, maxPropagationY >> 4, columnZ >> 4, true);
+
+                for (int currY = maxPropagationY; currY >= (this.minLightSection << 4); --currY) {
+                    if ((currY & 15) == 15) {
+                        // ensure section is checked
+                        this.checkNullSection(columnX >> 4, (currY >> 4), columnZ >> 4, true);
+                    }
+
+                    // ensure section below is always checked
+                    final SWMRNibbleArray nibble = this.getNibbleFromCache(columnX >> 4, currY >> 4, columnZ >> 4);
+                    if (nibble == null) {
+                        // advance currY to the the top of the section below
+                        currY = (currY) & (~15);
+                        // note: this value ^ is actually 1 above the top, but the loop decrements by 1 so we actually
+                        // end up there
+                        continue;
+                    }
+
+                    if (nibble.getUpdating(columnX, currY, columnZ) != 15) {
+                        break;
+                    }
+
+                    // delay light set until after processing all sources to setup
+                    this.appendToDecreaseQueue(
+                            ((columnX + (columnZ << 6) + (currY << (6 + 6)) + encodeOffset) & ((1L << (6 + 6 + 16)) - 1))
+                                    | (15L << (6 + 6 + 16))
+                                    | (propagateDirection << (6 + 6 + 16 + 4))
+                                    // do not set transparent blocks for the same reason we don't in the checkBlock method
+                    );
+                }
+            }
+        }
+
+        // delayed light sets are processed here, and must be processed before checkBlock as checkBlock reads
+        // immediate light value
+        this.processDelayedIncreases();
+        this.processDelayedDecreases();
+
+        for (final BlockPos pos : positions) {
+            this.checkBlock(lightAccess, pos.getX(), pos.getY(), pos.getZ());
+        }
+
+        this.performLightDecrease(lightAccess);
+    }
+
+    protected final int[] heightMapGen = new int[32 * 32];
+
+    @Override
+    protected void lightChunk(final LightChunkGetter lightAccess, final ChunkAccess chunk, final boolean needsEdgeChecks) {
+        this.rewriteNibbleCacheForSkylight(chunk);
+        Arrays.fill(this.nullPropagationCheckCache, false);
+
+        final BlockGetter world = lightAccess.getLevel();
+        final ChunkPos chunkPos = chunk.getPos();
+        final int chunkX = chunkPos.x;
+        final int chunkZ = chunkPos.z;
+
+        final LevelChunkSection[] sections = chunk.getSections();
+
+        int highestNonEmptySection = this.maxSection;
+        while (highestNonEmptySection == (this.minSection - 1) ||
+                sections[highestNonEmptySection - this.minSection] == null || sections[highestNonEmptySection - this.minSection].hasOnlyAir()) {
+            this.checkNullSection(chunkX, highestNonEmptySection, chunkZ, false);
+            // try propagate FULL to neighbours
+
+            // check neighbours to see if we need to propagate into them
+            for (final AxisDirection direction : ONLY_HORIZONTAL_DIRECTIONS) {
+                final int neighbourX = chunkX + direction.x;
+                final int neighbourZ = chunkZ + direction.z;
+                final SWMRNibbleArray neighbourNibble = this.getNibbleFromCache(neighbourX, highestNonEmptySection, neighbourZ);
+                if (neighbourNibble == null) {
+                    // unloaded neighbour
+                    // most of the time we fall here
+                    continue;
+                }
+
+                // it looks like we need to propagate into the neighbour
+
+                final int incX;
+                final int incZ;
+                final int startX;
+                final int startZ;
+
+                if (direction.x != 0) {
+                    // x direction
+                    incX = 0;
+                    incZ = 1;
+
+                    if (direction.x < 0) {
+                        // negative
+                        startX = chunkX << 4;
+                    } else {
+                        startX = chunkX << 4 | 15;
+                    }
+                    startZ = chunkZ << 4;
+                } else {
+                    // z direction
+                    incX = 1;
+                    incZ = 0;
+
+                    if (direction.z < 0) {
+                        // negative
+                        startZ = chunkZ << 4;
+                    } else {
+                        startZ = chunkZ << 4 | 15;
+                    }
+                    startX = chunkX << 4;
+                }
+
+                final int encodeOffset = this.coordinateOffset;
+                final long propagateDirection = 1L << direction.ordinal(); // we only want to check in this direction
+
+                for (int currY = highestNonEmptySection << 4, maxY = currY | 15; currY <= maxY; ++currY) {
+                    for (int i = 0, currX = startX, currZ = startZ; i < 16; ++i, currX += incX, currZ += incZ) {
+                        this.appendToIncreaseQueue(
+                                ((currX + (currZ << 6) + (currY << (6 + 6)) + encodeOffset) & ((1L << (6 + 6 + 16)) - 1))
+                                        | (15L << (6 + 6 + 16)) // we know we're at full lit here
+                                        | (propagateDirection << (6 + 6 + 16 + 4))
+                                        // no transparent flag, we know for a fact there are no blocks here that could be directionally transparent (as the section is EMPTY)
+                        );
+                    }
+                }
+            }
+
+            if (highestNonEmptySection-- == (this.minSection - 1)) {
+                break;
+            }
+        }
+
+        if (highestNonEmptySection >= this.minSection) {
+            // fill out our other sources
+            final int minX = chunkPos.x << 4;
+            final int maxX = chunkPos.x << 4 | 15;
+            final int minZ = chunkPos.z << 4;
+            final int maxZ = chunkPos.z << 4 | 15;
+            final int startY = highestNonEmptySection << 4 | 15;
+            for (int currZ = minZ; currZ <= maxZ; ++currZ) {
+                for (int currX = minX; currX <= maxX; ++currX) {
+                    this.tryPropagateSkylight(world, currX, startY + 1, currZ, false, false);
+                }
+            }
+        } // else: apparently the chunk is empty
+
+        if (needsEdgeChecks) {
+            // not required to propagate here, but this will reduce the hit of the edge checks
+            this.performLightIncrease(lightAccess);
+
+            for (int y = highestNonEmptySection; y >= this.minLightSection; --y) {
+                this.checkNullSection(chunkX, y, chunkZ, false);
+            }
+            // no need to rewrite the nibble cache again
+            super.checkChunkEdges(lightAccess, chunk, this.minLightSection, highestNonEmptySection);
+        } else {
+            for (int y = highestNonEmptySection; y >= this.minLightSection; --y) {
+                this.checkNullSection(chunkX, y, chunkZ, false);
+            }
+            this.propagateNeighbourLevels(lightAccess, chunk, this.minLightSection, highestNonEmptySection);
+
+            this.performLightIncrease(lightAccess);
+        }
+    }
+
+    protected final void processDelayedIncreases() {
+        // copied from performLightIncrease
+        final long[] queue = this.increaseQueue;
+        final int decodeOffsetX = -this.encodeOffsetX;
+        final int decodeOffsetY = -this.encodeOffsetY;
+        final int decodeOffsetZ = -this.encodeOffsetZ;
+
+        for (int i = 0, len = this.increaseQueueInitialLength; i < len; ++i) {
+            final long queueValue = queue[i];
+
+            final int posX = ((int)queueValue & 63) + decodeOffsetX;
+            final int posZ = (((int)queueValue >>> 6) & 63) + decodeOffsetZ;
+            final int posY = (((int)queueValue >>> 12) & ((1 << 16) - 1)) + decodeOffsetY;
+            final int propagatedLightLevel = (int)((queueValue >>> (6 + 6 + 16)) & 0xF);
+
+            this.setLightLevel(posX, posY, posZ, propagatedLightLevel);
+        }
+    }
+
+    protected final void processDelayedDecreases() {
+        // copied from performLightDecrease
+        final long[] queue = this.decreaseQueue;
+        final int decodeOffsetX = -this.encodeOffsetX;
+        final int decodeOffsetY = -this.encodeOffsetY;
+        final int decodeOffsetZ = -this.encodeOffsetZ;
+
+        for (int i = 0, len = this.decreaseQueueInitialLength; i < len; ++i) {
+            final long queueValue = queue[i];
+
+            final int posX = ((int)queueValue & 63) + decodeOffsetX;
+            final int posZ = (((int)queueValue >>> 6) & 63) + decodeOffsetZ;
+            final int posY = (((int)queueValue >>> 12) & ((1 << 16) - 1)) + decodeOffsetY;
+
+            this.setLightLevel(posX, posY, posZ, 0);
+        }
+    }
+
+    // delaying the light set is useful for block changes since they need to worry about initialising nibblearrays
+    // while also queueing light at the same time (initialising nibblearrays might depend on nibbles above, so
+    // clobbering the light values will result in broken propagation)
+    protected final int tryPropagateSkylight(final BlockGetter world, final int worldX, int startY, final int worldZ,
+                                             final boolean extrudeInitialised, final boolean delayLightSet) {
+        final int encodeOffset = this.coordinateOffset;
+        final long propagateDirection = AxisDirection.POSITIVE_Y.everythingButThisDirection; // just don't check upwards.
+
+        if (this.getLightLevelExtruded(worldX, startY + 1, worldZ) != 15) {
+            return startY;
+        }
+
+        // ensure this section is always checked
+        this.checkNullSection(worldX >> 4, startY >> 4, worldZ >> 4, extrudeInitialised);
+
+        BlockState above = this.getBlockState(worldX, startY + 1, worldZ);
+
+        for (;startY >= (this.minLightSection << 4); --startY) {
+            if ((startY & 15) == 15) {
+                // ensure this section is always checked
+                this.checkNullSection(worldX >> 4, startY >> 4, worldZ >> 4, extrudeInitialised);
+            }
+            final BlockState current = this.getBlockState(worldX, startY, worldZ);
+
+            final VoxelShape fromShape;
+            if (((StarlightAbstractBlockState)above).starlight$isConditionallyFullOpaque()) {
+                fromShape = above.getFaceOcclusionShape(AxisDirection.NEGATIVE_Y.nms);
+                if (Shapes.faceShapeOccludes(Shapes.empty(), fromShape)) {
+                    // above wont let us propagate
+                    break;
+                }
+            } else {
+                fromShape = Shapes.empty();
+            }
+
+            // does light propagate from the top down?
+            long flags = 0L;
+            if (((StarlightAbstractBlockState)current).starlight$isConditionallyFullOpaque()) {
+                final VoxelShape cullingFace = current.getFaceOcclusionShape(AxisDirection.POSITIVE_Y.nms);
+
+                if (Shapes.faceShapeOccludes(fromShape, cullingFace)) {
+                    // can't propagate here, we're done on this column.
+                    break;
+                }
+                flags |= FLAG_HAS_SIDED_TRANSPARENT_BLOCKS;
+            }
+
+            final int opacity = current.getLightBlock();
+            if (opacity > 0) {
+                // let the queued value (if any) handle it from here.
+                break;
+            }
+
+            // light set delayed until we determine if this nibble section is null
+            this.appendToIncreaseQueue(
+                    ((worldX + (worldZ << 6) + (startY << (6 + 6)) + encodeOffset) & ((1L << (6 + 6 + 16)) - 1))
+                            | (15L << (6 + 6 + 16)) // we know we're at full lit here
+                            | (propagateDirection << (6 + 6 + 16 + 4))
+                            | flags
+            );
+
+            above = current;
+
+            if (this.getNibbleFromCache(worldX >> 4, startY >> 4, worldZ >> 4) == null) {
+                // we skip empty sections here, as this is just an easy way of making sure the above block
+                // can propagate through air.
+
+                // nothing can propagate in null sections, remove the queue entry for it
+                --this.increaseQueueInitialLength;
+
+                // advance currY to the the top of the section below
+                startY = (startY) & (~15);
+                // note: this value ^ is actually 1 above the top, but the loop decrements by 1 so we actually
+                // end up there
+
+                // make sure this is marked as AIR
+                above = AIR_BLOCK_STATE;
+            } else if (!delayLightSet) {
+                this.setLightLevel(worldX, startY, worldZ, 15);
+            }
+        }
+
+        return startY;
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/starlight/light/StarLightEngine.java b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/light/StarLightEngine.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/light/StarLightEngine.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.starlight.light;
+
+import ca.spottedleaf.concurrentutil.util.IntegerUtil;
+import ca.spottedleaf.moonrise.common.PlatformHooks;
+import ca.spottedleaf.moonrise.common.util.CoordinateUtils;
+import ca.spottedleaf.moonrise.common.util.WorldUtil;
+import ca.spottedleaf.moonrise.patches.starlight.blockstate.StarlightAbstractBlockState;
+import it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap;
+import it.unimi.dsi.fastutil.shorts.ShortCollection;
+import it.unimi.dsi.fastutil.shorts.ShortIterator;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.Direction;
+import net.minecraft.core.SectionPos;
+import net.minecraft.world.level.BlockGetter;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.LevelHeightAccessor;
+import net.minecraft.world.level.LightLayer;
+import net.minecraft.world.level.block.Blocks;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.LevelChunkSection;
+import net.minecraft.world.level.chunk.LightChunkGetter;
+import net.minecraft.world.phys.shapes.Shapes;
+import net.minecraft.world.phys.shapes.VoxelShape;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Set;
+import java.util.function.Consumer;
+import java.util.function.IntConsumer;
+
+public abstract class StarLightEngine {
+
+    protected static final BlockState AIR_BLOCK_STATE = Blocks.AIR.defaultBlockState();
+
+    protected static final AxisDirection[] DIRECTIONS = AxisDirection.values();
+    protected static final AxisDirection[] AXIS_DIRECTIONS = DIRECTIONS;
+    protected static final AxisDirection[] ONLY_HORIZONTAL_DIRECTIONS = new AxisDirection[] {
+            AxisDirection.POSITIVE_X, AxisDirection.NEGATIVE_X,
+            AxisDirection.POSITIVE_Z, AxisDirection.NEGATIVE_Z
+    };
+
+    protected static enum AxisDirection {
+
+        // Declaration order is important and relied upon. Do not change without modifying propagation code.
+        POSITIVE_X(1, 0, 0, Direction.EAST) , NEGATIVE_X(-1, 0, 0, Direction.WEST),
+        POSITIVE_Z(0, 0, 1, Direction.SOUTH), NEGATIVE_Z(0, 0, -1, Direction.NORTH),
+        POSITIVE_Y(0, 1, 0, Direction.UP)   , NEGATIVE_Y(0, -1, 0, Direction.DOWN);
+
+        static {
+            POSITIVE_X.opposite = NEGATIVE_X; NEGATIVE_X.opposite = POSITIVE_X;
+            POSITIVE_Z.opposite = NEGATIVE_Z; NEGATIVE_Z.opposite = POSITIVE_Z;
+            POSITIVE_Y.opposite = NEGATIVE_Y; NEGATIVE_Y.opposite = POSITIVE_Y;
+        }
+
+        protected AxisDirection opposite;
+
+        public final int x;
+        public final int y;
+        public final int z;
+        public final Direction nms;
+        public final long everythingButThisDirection;
+        public final long everythingButTheOppositeDirection;
+
+        AxisDirection(final int x, final int y, final int z, final Direction nms) {
+            this.x = x;
+            this.y = y;
+            this.z = z;
+            this.nms = nms;
+            this.everythingButThisDirection = (long)(ALL_DIRECTIONS_BITSET ^ (1 << this.ordinal()));
+            // positive is always even, negative is always odd. Flip the 1 bit to get the negative direction.
+            this.everythingButTheOppositeDirection = (long)(ALL_DIRECTIONS_BITSET ^ (1 << (this.ordinal() ^ 1)));
+        }
+
+        public AxisDirection getOpposite() {
+            return this.opposite;
+        }
+    }
+
+    // I'd like to thank https://www.seedofandromeda.com/blogs/29-fast-flood-fill-lighting-in-a-blocky-voxel-game-pt-1
+    // for explaining how light propagates via breadth-first search
+
+    // While the above is a good start to understanding the general idea of what the general principles are, it's not
+    // exactly how the vanilla light engine should behave for minecraft.
+
+    // similar to the above, except the chunk section indices vary from [-1, 1], or [0, 2]
+    // for the y chunk section it's from [minLightSection, maxLightSection] or [0, maxLightSection - minLightSection]
+    // index = x + (z * 5) + (y * 25)
+    // null index indicates the chunk section doesn't exist (empty or out of bounds)
+    protected final LevelChunkSection[] sectionCache;
+
+    // the exact same as above, except for storing fast access to SWMRNibbleArray
+    // for the y chunk section it's from [minLightSection, maxLightSection] or [0, maxLightSection - minLightSection]
+    // index = x + (z * 5) + (y * 25)
+    protected final SWMRNibbleArray[] nibbleCache;
+
+    // the exact same as above, except for storing fast access to nibbles to call change callbacks for
+    // for the y chunk section it's from [minLightSection, maxLightSection] or [0, maxLightSection - minLightSection]
+    // index = x + (z * 5) + (y * 25)
+    protected final boolean[] notifyUpdateCache;
+
+    // always initialsed during start of lighting.
+    // index = x + (z * 5)
+    protected final ChunkAccess[] chunkCache = new ChunkAccess[5 * 5];
+
+    // index = x + (z * 5)
+    protected final boolean[][] emptinessMapCache = new boolean[5 * 5][];
+
+    protected final BlockPos.MutableBlockPos lightEmissionPos = new BlockPos.MutableBlockPos();
+
+    protected int encodeOffsetX;
+    protected int encodeOffsetY;
+    protected int encodeOffsetZ;
+
+    protected int coordinateOffset;
+
+    protected int chunkOffsetX;
+    protected int chunkOffsetY;
+    protected int chunkOffsetZ;
+
+    protected int chunkIndexOffset;
+    protected int chunkSectionIndexOffset;
+
+    protected final boolean skylightPropagator;
+    protected final int emittedLightMask;
+    protected final boolean isClientSide;
+
+    protected final Level world;
+    protected final int minLightSection;
+    protected final int maxLightSection;
+    protected final int minSection;
+    protected final int maxSection;
+
+    protected StarLightEngine(final boolean skylightPropagator, final Level world) {
+        this.skylightPropagator = skylightPropagator;
+        this.emittedLightMask = skylightPropagator ? 0 : 0xF;
+        this.isClientSide = world.isClientSide;
+        this.world = world;
+        this.minLightSection = WorldUtil.getMinLightSection(world);
+        this.maxLightSection = WorldUtil.getMaxLightSection(world);
+        this.minSection = WorldUtil.getMinSection(world);
+        this.maxSection = WorldUtil.getMaxSection(world);
+
+        this.sectionCache = new LevelChunkSection[5 * 5 * ((this.maxLightSection - this.minLightSection + 1) + 2)]; // add two extra sections for buffer
+        this.nibbleCache = new SWMRNibbleArray[5 * 5 * ((this.maxLightSection - this.minLightSection + 1) + 2)]; // add two extra sections for buffer
+        this.notifyUpdateCache = new boolean[5 * 5 * ((this.maxLightSection - this.minLightSection + 1) + 2)]; // add two extra sections for buffer
+    }
+
+    protected final void setupEncodeOffset(final int centerX, final int centerY, final int centerZ) {
+        // 31 = center + encodeOffset
+        this.encodeOffsetX = 31 - centerX;
+        this.encodeOffsetY = (-(this.minLightSection - 1) << 4); // we want 0 to be the smallest encoded value
+        this.encodeOffsetZ = 31 - centerZ;
+
+        // coordinateIndex = x | (z << 6) | (y << 12)
+        this.coordinateOffset = this.encodeOffsetX + (this.encodeOffsetZ << 6) + (this.encodeOffsetY << 12);
+
+        // 2 = (centerX >> 4) + chunkOffset
+        this.chunkOffsetX = 2 - (centerX >> 4);
+        this.chunkOffsetY = -(this.minLightSection - 1); // lowest should be 0
+        this.chunkOffsetZ = 2 - (centerZ >> 4);
+
+        // chunk index = x + (5 * z)
+        this.chunkIndexOffset = this.chunkOffsetX + (5 * this.chunkOffsetZ);
+
+        // chunk section index = x + (5 * z) + ((5*5) * y)
+        this.chunkSectionIndexOffset = this.chunkIndexOffset + ((5 * 5) * this.chunkOffsetY);
+    }
+
+    protected final void setupCaches(final LightChunkGetter chunkProvider, final int centerX, final int centerY, final int centerZ,
+                                     final boolean relaxed, final boolean tryToLoadChunksFor2Radius) {
+        final int centerChunkX = centerX >> 4;
+        final int centerChunkY = centerY >> 4;
+        final int centerChunkZ = centerZ >> 4;
+
+        this.setupEncodeOffset(centerChunkX * 16 + 7, centerChunkY * 16 + 7, centerChunkZ * 16 + 7);
+
+        final int radius = tryToLoadChunksFor2Radius ? 2 : 1;
+
+        for (int dz = -radius; dz <= radius; ++dz) {
+            for (int dx = -radius; dx <= radius; ++dx) {
+                final int cx = centerChunkX + dx;
+                final int cz = centerChunkZ + dz;
+                final boolean isTwoRadius = Math.max(IntegerUtil.branchlessAbs(dx), IntegerUtil.branchlessAbs(dz)) == 2;
+                final ChunkAccess chunk = (ChunkAccess)chunkProvider.getChunkForLighting(cx, cz);
+
+                if (chunk == null) {
+                    if (relaxed | isTwoRadius) {
+                        continue;
+                    }
+                    throw new IllegalArgumentException("Trying to propagate light update before 1 radius neighbours ready");
+                }
+
+                if (!this.canUseChunk(chunk)) {
+                    continue;
+                }
+
+                this.setChunkInCache(cx, cz, chunk);
+                this.setEmptinessMapCache(cx, cz, this.getEmptinessMap(chunk));
+                if (!isTwoRadius) {
+                    this.setBlocksForChunkInCache(cx, cz, chunk.getSections());
+                    this.setNibblesForChunkInCache(cx, cz, this.getNibblesOnChunk(chunk));
+                }
+            }
+        }
+    }
+
+    protected final ChunkAccess getChunkInCache(final int chunkX, final int chunkZ) {
+        return this.chunkCache[chunkX + 5*chunkZ + this.chunkIndexOffset];
+    }
+
+    protected final void setChunkInCache(final int chunkX, final int chunkZ, final ChunkAccess chunk) {
+        this.chunkCache[chunkX + 5*chunkZ + this.chunkIndexOffset] = chunk;
+    }
+
+    protected final LevelChunkSection getChunkSection(final int chunkX, final int chunkY, final int chunkZ) {
+        return this.sectionCache[chunkX + 5*chunkZ + (5 * 5) * chunkY + this.chunkSectionIndexOffset];
+    }
+
+    protected final void setChunkSectionInCache(final int chunkX, final int chunkY, final int chunkZ, final LevelChunkSection section) {
+        this.sectionCache[chunkX + 5*chunkZ + 5*5*chunkY + this.chunkSectionIndexOffset] = section;
+    }
+
+    protected final void setBlocksForChunkInCache(final int chunkX, final int chunkZ, final LevelChunkSection[] sections) {
+        for (int cy = this.minLightSection; cy <= this.maxLightSection; ++cy) {
+            this.setChunkSectionInCache(chunkX, cy, chunkZ,
+                    sections == null ? null : (cy >= this.minSection && cy <= this.maxSection ? sections[cy - this.minSection] : null));
+        }
+    }
+
+    protected final SWMRNibbleArray getNibbleFromCache(final int chunkX, final int chunkY, final int chunkZ) {
+        return this.nibbleCache[chunkX + 5*chunkZ + (5 * 5) * chunkY + this.chunkSectionIndexOffset];
+    }
+
+    protected final SWMRNibbleArray[] getNibblesForChunkFromCache(final int chunkX, final int chunkZ) {
+        final SWMRNibbleArray[] ret = new SWMRNibbleArray[this.maxLightSection - this.minLightSection + 1];
+
+        for (int cy = this.minLightSection; cy <= this.maxLightSection; ++cy) {
+            ret[cy - this.minLightSection] = this.nibbleCache[chunkX + 5*chunkZ + (cy * (5 * 5)) + this.chunkSectionIndexOffset];
+        }
+
+        return ret;
+    }
+
+    protected final void setNibbleInCache(final int chunkX, final int chunkY, final int chunkZ, final SWMRNibbleArray nibble) {
+        this.nibbleCache[chunkX + 5*chunkZ + (5 * 5) * chunkY + this.chunkSectionIndexOffset] = nibble;
+    }
+
+    protected final void setNibblesForChunkInCache(final int chunkX, final int chunkZ, final SWMRNibbleArray[] nibbles) {
+        for (int cy = this.minLightSection; cy <= this.maxLightSection; ++cy) {
+            this.setNibbleInCache(chunkX, cy, chunkZ, nibbles == null ? null : nibbles[cy - this.minLightSection]);
+        }
+    }
+
+    protected final void updateVisible(final LightChunkGetter lightAccess) {
+        for (int index = 0, max = this.nibbleCache.length; index < max; ++index) {
+            final SWMRNibbleArray nibble = this.nibbleCache[index];
+            if (!this.notifyUpdateCache[index] && (nibble == null || !nibble.isDirty())) {
+                continue;
+            }
+
+            final int chunkX = (index % 5) - this.chunkOffsetX;
+            final int chunkZ = ((index / 5) % 5) - this.chunkOffsetZ;
+            final int ySections = this.maxSection - this.minSection + 1;
+            final int chunkY = ((index / (5*5)) % (ySections + 2 + 2)) - this.chunkOffsetY;
+            if ((nibble != null && nibble.updateVisible()) || this.notifyUpdateCache[index]) {
+                lightAccess.onLightUpdate(this.skylightPropagator ? LightLayer.SKY : LightLayer.BLOCK, SectionPos.of(chunkX, chunkY, chunkZ));
+            }
+        }
+    }
+
+    protected final void destroyCaches() {
+        Arrays.fill(this.sectionCache, null);
+        Arrays.fill(this.nibbleCache, null);
+        Arrays.fill(this.chunkCache, null);
+        Arrays.fill(this.emptinessMapCache, null);
+        if (this.isClientSide) {
+            Arrays.fill(this.notifyUpdateCache, false);
+        }
+    }
+
+    protected final BlockState getBlockState(final int worldX, final int worldY, final int worldZ) {
+        final LevelChunkSection section = this.sectionCache[(worldX >> 4) + 5 * (worldZ >> 4) + (5 * 5) * (worldY >> 4) + this.chunkSectionIndexOffset];
+
+        if (section != null) {
+            return section.hasOnlyAir() ? AIR_BLOCK_STATE : section.getBlockState(worldX & 15, worldY & 15, worldZ & 15);
+        }
+
+        return AIR_BLOCK_STATE;
+    }
+
+    protected final BlockState getBlockState(final int sectionIndex, final int localIndex) {
+        final LevelChunkSection section = this.sectionCache[sectionIndex];
+
+        if (section != null) {
+            return section.hasOnlyAir() ? AIR_BLOCK_STATE : section.states.get(localIndex);
+        }
+
+        return AIR_BLOCK_STATE;
+    }
+
+    protected final int getLightLevel(final int worldX, final int worldY, final int worldZ) {
+        final SWMRNibbleArray nibble = this.nibbleCache[(worldX >> 4) + 5 * (worldZ >> 4) + (5 * 5) * (worldY >> 4) + this.chunkSectionIndexOffset];
+
+        return nibble == null ? 0 : nibble.getUpdating((worldX & 15) | ((worldZ & 15) << 4) | ((worldY & 15) << 8));
+    }
+
+    protected final int getLightLevel(final int sectionIndex, final int localIndex) {
+        final SWMRNibbleArray nibble = this.nibbleCache[sectionIndex];
+
+        return nibble == null ? 0 : nibble.getUpdating(localIndex);
+    }
+
+    protected final void setLightLevel(final int worldX, final int worldY, final int worldZ, final int level) {
+        final int sectionIndex = (worldX >> 4) + 5 * (worldZ >> 4) + (5 * 5) * (worldY >> 4) + this.chunkSectionIndexOffset;
+        final SWMRNibbleArray nibble = this.nibbleCache[sectionIndex];
+
+        if (nibble != null) {
+            nibble.set((worldX & 15) | ((worldZ & 15) << 4) | ((worldY & 15) << 8), level);
+            if (this.isClientSide) {
+                int cx1 = (worldX - 1) >> 4;
+                int cx2 = (worldX + 1) >> 4;
+                int cy1 = (worldY - 1) >> 4;
+                int cy2 = (worldY + 1) >> 4;
+                int cz1 = (worldZ - 1) >> 4;
+                int cz2 = (worldZ + 1) >> 4;
+                for (int x = cx1; x <= cx2; ++x) {
+                    for (int y = cy1; y <= cy2; ++y) {
+                        for (int z = cz1; z <= cz2; ++z) {
+                            this.notifyUpdateCache[x + 5 * z + (5 * 5) * y + this.chunkSectionIndexOffset] = true;
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    protected final void postLightUpdate(final int worldX, final int worldY, final int worldZ) {
+        if (this.isClientSide) {
+            int cx1 = (worldX - 1) >> 4;
+            int cx2 = (worldX + 1) >> 4;
+            int cy1 = (worldY - 1) >> 4;
+            int cy2 = (worldY + 1) >> 4;
+            int cz1 = (worldZ - 1) >> 4;
+            int cz2 = (worldZ + 1) >> 4;
+            for (int x = cx1; x <= cx2; ++x) {
+                for (int y = cy1; y <= cy2; ++y) {
+                    for (int z = cz1; z <= cz2; ++z) {
+                        this.notifyUpdateCache[x + (5 * z) + (5 * 5 * y) + this.chunkSectionIndexOffset] = true;
+                    }
+                }
+            }
+        }
+    }
+
+    protected final void setLightLevel(final int sectionIndex, final int localIndex, final int worldX, final int worldY, final int worldZ, final int level) {
+        final SWMRNibbleArray nibble = this.nibbleCache[sectionIndex];
+
+        if (nibble != null) {
+            nibble.set(localIndex, level);
+            if (this.isClientSide) {
+                int cx1 = (worldX - 1) >> 4;
+                int cx2 = (worldX + 1) >> 4;
+                int cy1 = (worldY - 1) >> 4;
+                int cy2 = (worldY + 1) >> 4;
+                int cz1 = (worldZ - 1) >> 4;
+                int cz2 = (worldZ + 1) >> 4;
+                for (int x = cx1; x <= cx2; ++x) {
+                    for (int y = cy1; y <= cy2; ++y) {
+                        for (int z = cz1; z <= cz2; ++z) {
+                            this.notifyUpdateCache[x + (5 * z) + (5 * 5 * y) + this.chunkSectionIndexOffset] = true;
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    protected final boolean[] getEmptinessMap(final int chunkX, final int chunkZ) {
+        return this.emptinessMapCache[chunkX + 5*chunkZ + this.chunkIndexOffset];
+    }
+
+    protected final void setEmptinessMapCache(final int chunkX, final int chunkZ, final boolean[] emptinessMap) {
+        this.emptinessMapCache[chunkX + 5*chunkZ + this.chunkIndexOffset] = emptinessMap;
+    }
+
+    public static SWMRNibbleArray[] getFilledEmptyLight(final LevelHeightAccessor world) {
+        return getFilledEmptyLight(WorldUtil.getTotalLightSections(world));
+    }
+
+    private static SWMRNibbleArray[] getFilledEmptyLight(final int totalLightSections) {
+        final SWMRNibbleArray[] ret = new SWMRNibbleArray[totalLightSections];
+
+        for (int i = 0, len = ret.length; i < len; ++i) {
+            ret[i] = new SWMRNibbleArray(null, true);
+        }
+
+        return ret;
+    }
+
+    protected abstract boolean[] getEmptinessMap(final ChunkAccess chunk);
+
+    protected abstract void setEmptinessMap(final ChunkAccess chunk, final boolean[] to);
+
+    protected abstract SWMRNibbleArray[] getNibblesOnChunk(final ChunkAccess chunk);
+
+    protected abstract void setNibbles(final ChunkAccess chunk, final SWMRNibbleArray[] to);
+
+    protected abstract boolean canUseChunk(final ChunkAccess chunk);
+
+    public final void blocksChangedInChunk(final LightChunkGetter lightAccess, final int chunkX, final int chunkZ,
+                                           final Set<BlockPos> positions, final Boolean[] changedSections) {
+        this.setupCaches(lightAccess, chunkX * 16 + 7, 128, chunkZ * 16 + 7, true, true);
+        try {
+            final ChunkAccess chunk = this.getChunkInCache(chunkX, chunkZ);
+            if (chunk == null) {
+                return;
+            }
+            if (changedSections != null) {
+                final boolean[] ret = this.handleEmptySectionChanges(lightAccess, chunk, changedSections, false);
+                if (ret != null) {
+                    this.setEmptinessMap(chunk, ret);
+                }
+            }
+            if (!positions.isEmpty()) {
+                this.propagateBlockChanges(lightAccess, chunk, positions);
+            }
+            this.updateVisible(lightAccess);
+        } finally {
+            this.destroyCaches();
+        }
+    }
+
+    // subclasses should not initialise caches, as this will always be done by the super call
+    // subclasses should not invoke updateVisible, as this will always be done by the super call
+    protected abstract void propagateBlockChanges(final LightChunkGetter lightAccess, final ChunkAccess atChunk, final Set<BlockPos> positions);
+
+    protected abstract void checkBlock(final LightChunkGetter lightAccess, final int worldX, final int worldY, final int worldZ);
+
+    // if ret > expect, then the real value is at least ret (early returns if ret > expect, rather than calculating actual)
+    // if ret == expect, then expect is the correct light value for pos
+    // if ret < expect, then ret is the real light value
+    protected abstract int calculateLightValue(final LightChunkGetter lightAccess, final int worldX, final int worldY, final int worldZ,
+                                               final int expect);
+
+    protected final int[] chunkCheckDelayedUpdatesCenter = new int[16 * 16];
+    protected final int[] chunkCheckDelayedUpdatesNeighbour = new int[16 * 16];
+
+    protected void checkChunkEdge(final LightChunkGetter lightAccess, final ChunkAccess chunk,
+                                  final int chunkX, final int chunkY, final int chunkZ) {
+        final SWMRNibbleArray currNibble = this.getNibbleFromCache(chunkX, chunkY, chunkZ);
+        if (currNibble == null) {
+            return;
+        }
+
+        for (final AxisDirection direction : ONLY_HORIZONTAL_DIRECTIONS) {
+            final int neighbourOffX = direction.x;
+            final int neighbourOffZ = direction.z;
+
+            final SWMRNibbleArray neighbourNibble = this.getNibbleFromCache(chunkX + neighbourOffX,
+                    chunkY, chunkZ + neighbourOffZ);
+
+            if (neighbourNibble == null) {
+                continue;
+            }
+
+            if (!currNibble.isInitialisedUpdating() && !neighbourNibble.isInitialisedUpdating()) {
+                // both are zero, nothing to check.
+                continue;
+            }
+
+            // this chunk
+            final int incX;
+            final int incZ;
+            final int startX;
+            final int startZ;
+
+            if (neighbourOffX != 0) {
+                // x direction
+                incX = 0;
+                incZ = 1;
+
+                if (direction.x < 0) {
+                    // negative
+                    startX = chunkX << 4;
+                } else {
+                    startX = chunkX << 4 | 15;
+                }
+                startZ = chunkZ << 4;
+            } else {
+                // z direction
+                incX = 1;
+                incZ = 0;
+
+                if (neighbourOffZ < 0) {
+                    // negative
+                    startZ = chunkZ << 4;
+                } else {
+                    startZ = chunkZ << 4 | 15;
+                }
+                startX = chunkX << 4;
+            }
+
+            int centerDelayedChecks = 0;
+            int neighbourDelayedChecks = 0;
+            for (int currY = chunkY << 4, maxY = currY | 15; currY <= maxY; ++currY) {
+                for (int i = 0, currX = startX, currZ = startZ; i < 16; ++i, currX += incX, currZ += incZ) {
+                    final int neighbourX = currX + neighbourOffX;
+                    final int neighbourZ = currZ + neighbourOffZ;
+
+                    final int currentIndex = (currX & 15) |
+                            ((currZ & 15)) << 4 |
+                            ((currY & 15) << 8);
+                    final int currentLevel = currNibble.getUpdating(currentIndex);
+
+                    final int neighbourIndex =
+                            (neighbourX & 15) |
+                            ((neighbourZ & 15)) << 4 |
+                            ((currY & 15) << 8);
+                    final int neighbourLevel = neighbourNibble.getUpdating(neighbourIndex);
+
+                    // the checks are delayed because the checkBlock method clobbers light values - which then
+                    // affect later calculate light value operations. While they don't affect it in a behaviourly significant
+                    // way, they do have a negative performance impact due to simply queueing more values
+
+                    if (this.calculateLightValue(lightAccess, currX, currY, currZ, currentLevel) != currentLevel) {
+                        this.chunkCheckDelayedUpdatesCenter[centerDelayedChecks++] = currentIndex;
+                    }
+
+                    if (this.calculateLightValue(lightAccess, neighbourX, currY, neighbourZ, neighbourLevel) != neighbourLevel) {
+                        this.chunkCheckDelayedUpdatesNeighbour[neighbourDelayedChecks++] = neighbourIndex;
+                    }
+                }
+            }
+
+            final int currentChunkOffX = chunkX << 4;
+            final int currentChunkOffZ = chunkZ << 4;
+            final int neighbourChunkOffX = (chunkX + direction.x) << 4;
+            final int neighbourChunkOffZ = (chunkZ + direction.z) << 4;
+            final int chunkOffY = chunkY << 4;
+            for (int i = 0, len = Math.max(centerDelayedChecks, neighbourDelayedChecks); i < len; ++i) {
+                // try to queue neighbouring data together
+                // index = x | (z << 4) | (y << 8)
+                if (i < centerDelayedChecks) {
+                    final int value = this.chunkCheckDelayedUpdatesCenter[i];
+                    this.checkBlock(lightAccess, currentChunkOffX | (value & 15),
+                            chunkOffY | (value >>> 8),
+                            currentChunkOffZ | ((value >>> 4) & 0xF));
+                }
+                if (i < neighbourDelayedChecks) {
+                    final int value = this.chunkCheckDelayedUpdatesNeighbour[i];
+                    this.checkBlock(lightAccess, neighbourChunkOffX | (value & 15),
+                            chunkOffY | (value >>> 8),
+                            neighbourChunkOffZ | ((value >>> 4) & 0xF));
+                }
+            }
+        }
+    }
+
+    protected void checkChunkEdges(final LightChunkGetter lightAccess, final ChunkAccess chunk, final ShortCollection sections) {
+        final ChunkPos chunkPos = chunk.getPos();
+        final int chunkX = chunkPos.x;
+        final int chunkZ = chunkPos.z;
+
+        for (final ShortIterator iterator = sections.iterator(); iterator.hasNext();) {
+            this.checkChunkEdge(lightAccess, chunk, chunkX, iterator.nextShort(), chunkZ);
+        }
+
+        this.performLightDecrease(lightAccess);
+    }
+
+    // subclasses should not initialise caches, as this will always be done by the super call
+    // subclasses should not invoke updateVisible, as this will always be done by the super call
+    // verifies that light levels on this chunks edges are consistent with this chunk's neighbours
+    // edges. if they are not, they are decreased (effectively performing the logic in checkBlock).
+    // This does not resolve skylight source problems.
+    protected void checkChunkEdges(final LightChunkGetter lightAccess, final ChunkAccess chunk, final int fromSection, final int toSection) {
+        final ChunkPos chunkPos = chunk.getPos();
+        final int chunkX = chunkPos.x;
+        final int chunkZ = chunkPos.z;
+
+        for (int currSectionY = toSection; currSectionY >= fromSection; --currSectionY) {
+            this.checkChunkEdge(lightAccess, chunk, chunkX, currSectionY, chunkZ);
+        }
+
+        this.performLightDecrease(lightAccess);
+    }
+
+    // pulls light from neighbours, and adds them into the increase queue. does not actually propagate.
+    protected final void propagateNeighbourLevels(final LightChunkGetter lightAccess, final ChunkAccess chunk, final int fromSection, final int toSection) {
+        final ChunkPos chunkPos = chunk.getPos();
+        final int chunkX = chunkPos.x;
+        final int chunkZ = chunkPos.z;
+
+        for (int currSectionY = toSection; currSectionY >= fromSection; --currSectionY) {
+            final SWMRNibbleArray currNibble = this.getNibbleFromCache(chunkX, currSectionY, chunkZ);
+            if (currNibble == null) {
+                continue;
+            }
+            for (final AxisDirection direction : ONLY_HORIZONTAL_DIRECTIONS) {
+                final int neighbourOffX = direction.x;
+                final int neighbourOffZ = direction.z;
+
+                final SWMRNibbleArray neighbourNibble = this.getNibbleFromCache(chunkX + neighbourOffX,
+                        currSectionY, chunkZ + neighbourOffZ);
+
+                if (neighbourNibble == null || !neighbourNibble.isInitialisedUpdating()) {
+                    // can't pull from 0
+                    continue;
+                }
+
+                // neighbour chunk
+                final int incX;
+                final int incZ;
+                final int startX;
+                final int startZ;
+
+                if (neighbourOffX != 0) {
+                    // x direction
+                    incX = 0;
+                    incZ = 1;
+
+                    if (direction.x < 0) {
+                        // negative
+                        startX = (chunkX << 4) - 1;
+                    } else {
+                        startX = (chunkX << 4) + 16;
+                    }
+                    startZ = chunkZ << 4;
+                } else {
+                    // z direction
+                    incX = 1;
+                    incZ = 0;
+
+                    if (neighbourOffZ < 0) {
+                        // negative
+                        startZ = (chunkZ << 4) - 1;
+                    } else {
+                        startZ = (chunkZ << 4) + 16;
+                    }
+                    startX = chunkX << 4;
+                }
+
+                final long propagateDirection = 1L << direction.getOpposite().ordinal(); // we only want to check in this direction towards this chunk
+                final int encodeOffset = this.coordinateOffset;
+
+                for (int currY = currSectionY << 4, maxY = currY | 15; currY <= maxY; ++currY) {
+                    for (int i = 0, currX = startX, currZ = startZ; i < 16; ++i, currX += incX, currZ += incZ) {
+                        final int level = neighbourNibble.getUpdating(
+                                (currX & 15)
+                                        | ((currZ & 15) << 4)
+                                        | ((currY & 15) << 8)
+                        );
+
+                        if (level <= 1) {
+                            // nothing to propagate
+                            continue;
+                        }
+
+                        this.appendToIncreaseQueue(
+                                ((currX + (currZ << 6) + (currY << (6 + 6)) + encodeOffset) & ((1L << (6 + 6 + 16)) - 1))
+                                        | ((level & 0xFL) << (6 + 6 + 16))
+                                        | (propagateDirection << (6 + 6 + 16 + 4))
+                                        | FLAG_HAS_SIDED_TRANSPARENT_BLOCKS // don't know if the current block is transparent, must check.
+                        );
+                    }
+                }
+            }
+        }
+    }
+
+    public static Boolean[] getEmptySectionsForChunk(final ChunkAccess chunk) {
+        final LevelChunkSection[] sections = chunk.getSections();
+        final Boolean[] ret = new Boolean[sections.length];
+
+        for (int i = 0; i < sections.length; ++i) {
+            if (sections[i] == null || sections[i].hasOnlyAir()) {
+                ret[i] = Boolean.TRUE;
+            } else {
+                ret[i] = Boolean.FALSE;
+            }
+        }
+
+        return ret;
+    }
+
+    public final void forceHandleEmptySectionChanges(final LightChunkGetter lightAccess, final ChunkAccess chunk, final Boolean[] emptinessChanges) {
+        final int chunkX = chunk.getPos().x;
+        final int chunkZ = chunk.getPos().z;
+        this.setupCaches(lightAccess, chunkX * 16 + 7, 128, chunkZ * 16 + 7, true, true);
+        try {
+            // force current chunk into cache
+            this.setChunkInCache(chunkX, chunkZ, chunk);
+            this.setBlocksForChunkInCache(chunkX, chunkZ, chunk.getSections());
+            this.setNibblesForChunkInCache(chunkX, chunkZ, this.getNibblesOnChunk(chunk));
+            this.setEmptinessMapCache(chunkX, chunkZ, this.getEmptinessMap(chunk));
+
+            final boolean[] ret = this.handleEmptySectionChanges(lightAccess, chunk, emptinessChanges, false);
+            if (ret != null) {
+                this.setEmptinessMap(chunk, ret);
+            }
+            this.updateVisible(lightAccess);
+        } finally {
+            this.destroyCaches();
+        }
+    }
+
+    public final void handleEmptySectionChanges(final LightChunkGetter lightAccess, final int chunkX, final int chunkZ,
+                                                final Boolean[] emptinessChanges) {
+        this.setupCaches(lightAccess, chunkX * 16 + 7, 128, chunkZ * 16 + 7, true, true);
+        try {
+            final ChunkAccess chunk = this.getChunkInCache(chunkX, chunkZ);
+            if (chunk == null) {
+                return;
+            }
+            final boolean[] ret = this.handleEmptySectionChanges(lightAccess, chunk, emptinessChanges, false);
+            if (ret != null) {
+                this.setEmptinessMap(chunk, ret);
+            }
+            this.updateVisible(lightAccess);
+        } finally {
+            this.destroyCaches();
+        }
+    }
+
+    protected abstract void initNibble(final int chunkX, final int chunkY, final int chunkZ, final boolean extrude, final boolean initRemovedNibbles);
+
+    protected abstract void setNibbleNull(final int chunkX, final int chunkY, final int chunkZ);
+
+    // subclasses should not initialise caches, as this will always be done by the super call
+    // subclasses should not invoke updateVisible, as this will always be done by the super call
+    // subclasses are guaranteed that this is always called before a changed block set
+    // newChunk specifies whether the changes describe a "first load" of a chunk or changes to existing, already loaded chunks
+    // rets non-null when the emptiness map changed and needs to be updated
+    protected final boolean[] handleEmptySectionChanges(final LightChunkGetter lightAccess, final ChunkAccess chunk,
+                                                        final Boolean[] emptinessChanges, final boolean unlit) {
+        final Level world = (Level)lightAccess.getLevel();
+        final int chunkX = chunk.getPos().x;
+        final int chunkZ = chunk.getPos().z;
+
+        boolean[] chunkEmptinessMap = this.getEmptinessMap(chunkX, chunkZ);
+        boolean[] ret = null;
+        final boolean needsInit = unlit || chunkEmptinessMap == null;
+        if (needsInit) {
+            this.setEmptinessMapCache(chunkX, chunkZ, ret = chunkEmptinessMap = new boolean[WorldUtil.getTotalSections(world)]);
+        }
+
+        // update emptiness map
+        for (int sectionIndex = (emptinessChanges.length - 1); sectionIndex >= 0; --sectionIndex) {
+            Boolean valueBoxed = emptinessChanges[sectionIndex];
+            if (valueBoxed == null) {
+                if (!needsInit) {
+                    continue;
+                }
+                final LevelChunkSection section = this.getChunkSection(chunkX, sectionIndex + this.minSection, chunkZ);
+                emptinessChanges[sectionIndex] = valueBoxed = section == null || section.hasOnlyAir() ? Boolean.TRUE : Boolean.FALSE;
+            }
+            chunkEmptinessMap[sectionIndex] = valueBoxed.booleanValue();
+        }
+
+        // now init neighbour nibbles
+        for (int sectionIndex = (emptinessChanges.length - 1); sectionIndex >= 0; --sectionIndex) {
+            final Boolean valueBoxed = emptinessChanges[sectionIndex];
+            final int sectionY = sectionIndex + this.minSection;
+            if (valueBoxed == null) {
+                continue;
+            }
+
+            final boolean empty = valueBoxed.booleanValue();
+
+            if (empty) {
+                continue;
+            }
+
+            for (int dz = -1; dz <= 1; ++dz) {
+                for (int dx = -1; dx <= 1; ++dx) {
+                    // if we're not empty, we also need to initialise nibbles
+                    // note: if we're unlit, we absolutely do not want to extrude, as light data isn't set up
+                    final boolean extrude = (dx | dz) != 0 || !unlit;
+                    for (int dy = 1; dy >= -1; --dy) {
+                        this.initNibble(dx + chunkX, dy + sectionY, dz + chunkZ, extrude, false);
+                    }
+                }
+            }
+        }
+
+        // check for de-init and lazy-init
+        // lazy init is when chunks are being lit, so at the time they weren't loaded when their neighbours were running
+        // init checks.
+        for (int dz = -1; dz <= 1; ++dz) {
+            for (int dx = -1; dx <= 1; ++dx) {
+                // does this neighbour have 1 radius loaded?
+                boolean neighboursLoaded = true;
+                neighbour_loaded_search:
+                for (int dz2 = -1; dz2 <= 1; ++dz2) {
+                    for (int dx2 = -1; dx2 <= 1; ++dx2) {
+                        if (this.getEmptinessMap(dx + dx2 + chunkX, dz + dz2 + chunkZ) == null) {
+                            neighboursLoaded = false;
+                            break neighbour_loaded_search;
+                        }
+                    }
+                }
+
+                for (int sectionY = this.maxLightSection; sectionY >= this.minLightSection; --sectionY) {
+                    // check neighbours to see if we need to de-init this one
+                    boolean allEmpty = true;
+                    neighbour_search:
+                    for (int dy2 = -1; dy2 <= 1; ++dy2) {
+                        for (int dz2 = -1; dz2 <= 1; ++dz2) {
+                            for (int dx2 = -1; dx2 <= 1; ++dx2) {
+                                final int y = sectionY + dy2;
+                                if (y < this.minSection || y > this.maxSection) {
+                                    // empty
+                                    continue;
+                                }
+                                final boolean[] emptinessMap = this.getEmptinessMap(dx + dx2 + chunkX, dz + dz2 + chunkZ);
+                                if (emptinessMap != null) {
+                                    if (!emptinessMap[y - this.minSection]) {
+                                        allEmpty = false;
+                                        break neighbour_search;
+                                    }
+                                } else {
+                                    final LevelChunkSection section = this.getChunkSection(dx + dx2 + chunkX, y, dz + dz2 + chunkZ);
+                                    if (section != null && !section.hasOnlyAir()) {
+                                        allEmpty = false;
+                                        break neighbour_search;
+                                    }
+                                }
+                            }
+                        }
+                    }
+
+                    if (allEmpty & neighboursLoaded) {
+                        // can only de-init when neighbours are loaded
+                        // de-init is fine to delay, as de-init is just an optimisation - it's not required for lighting
+                        // to be correct
+
+                        // all were empty, so de-init
+                        this.setNibbleNull(dx + chunkX, sectionY, dz + chunkZ);
+                    } else if (!allEmpty) {
+                        // must init
+                        final boolean extrude = (dx | dz) != 0 || !unlit;
+                        this.initNibble(dx + chunkX, sectionY, dz + chunkZ, extrude, false);
+                    }
+                }
+            }
+        }
+
+        return ret;
+    }
+
+    public final void checkChunkEdges(final LightChunkGetter lightAccess, final int chunkX, final int chunkZ) {
+        this.setupCaches(lightAccess, chunkX * 16 + 7, 128, chunkZ * 16 + 7, true, false);
+        try {
+            final ChunkAccess chunk = this.getChunkInCache(chunkX, chunkZ);
+            if (chunk == null) {
+                return;
+            }
+            this.checkChunkEdges(lightAccess, chunk, this.minLightSection, this.maxLightSection);
+            this.updateVisible(lightAccess);
+        } finally {
+            this.destroyCaches();
+        }
+    }
+
+    public final void checkChunkEdges(final LightChunkGetter lightAccess, final int chunkX, final int chunkZ, final ShortCollection sections) {
+        this.setupCaches(lightAccess, chunkX * 16 + 7, 128, chunkZ * 16 + 7, true, false);
+        try {
+            final ChunkAccess chunk = this.getChunkInCache(chunkX, chunkZ);
+            if (chunk == null) {
+                return;
+            }
+            this.checkChunkEdges(lightAccess, chunk, sections);
+            this.updateVisible(lightAccess);
+        } finally {
+            this.destroyCaches();
+        }
+    }
+
+    // subclasses should not initialise caches, as this will always be done by the super call
+    // subclasses should not invoke updateVisible, as this will always be done by the super call
+    // needsEdgeChecks applies when possibly loading vanilla data, which means we need to validate the current
+    // chunks light values with respect to neighbours
+    // subclasses should note that the emptiness changes are propagated BEFORE this is called, so this function
+    // does not need to detect empty chunks itself (and it should do no handling for them either!)
+    protected abstract void lightChunk(final LightChunkGetter lightAccess, final ChunkAccess chunk, final boolean needsEdgeChecks);
+
+    public final void light(final LightChunkGetter lightAccess, final ChunkAccess chunk, final Boolean[] emptySections) {
+        final int chunkX = chunk.getPos().x;
+        final int chunkZ = chunk.getPos().z;
+        this.setupCaches(lightAccess, chunkX * 16 + 7, 128, chunkZ * 16 + 7, true, true);
+
+        try {
+            final SWMRNibbleArray[] nibbles = getFilledEmptyLight(this.maxLightSection - this.minLightSection + 1);
+            // force current chunk into cache
+            this.setChunkInCache(chunkX, chunkZ, chunk);
+            this.setBlocksForChunkInCache(chunkX, chunkZ, chunk.getSections());
+            this.setNibblesForChunkInCache(chunkX, chunkZ, nibbles);
+            this.setEmptinessMapCache(chunkX, chunkZ, this.getEmptinessMap(chunk));
+
+            final boolean[] ret = this.handleEmptySectionChanges(lightAccess, chunk, emptySections, true);
+            if (ret != null) {
+                this.setEmptinessMap(chunk, ret);
+            }
+            this.lightChunk(lightAccess, chunk, true);
+            this.setNibbles(chunk, nibbles);
+            this.updateVisible(lightAccess);
+        } finally {
+            this.destroyCaches();
+        }
+    }
+
+    public final void relightChunks(final LightChunkGetter lightAccess, final Set<ChunkPos> chunks,
+                                    final Consumer<ChunkPos> chunkLightCallback, final IntConsumer onComplete) {
+        // it's recommended for maximum performance that the set is ordered according to a BFS from the center of
+        // the region of chunks to relight
+        // it's required that tickets are added for each chunk to keep them loaded
+        final Long2ObjectOpenHashMap<SWMRNibbleArray[]> nibblesByChunk = new Long2ObjectOpenHashMap<>();
+        final Long2ObjectOpenHashMap<boolean[]> emptinessMapByChunk = new Long2ObjectOpenHashMap<>();
+
+        final int[] neighbourLightOrder = new int[] {
+                // d = 0
+                0, 0,
+                // d = 1
+                -1, 0,
+                0, -1,
+                1, 0,
+                0, 1,
+                // d = 2
+                -1, 1,
+                1, 1,
+                -1, -1,
+                1, -1,
+        };
+
+        int lightCalls = 0;
+
+        for (final ChunkPos chunkPos : chunks) {
+            final int chunkX = chunkPos.x;
+            final int chunkZ = chunkPos.z;
+            final ChunkAccess chunk = (ChunkAccess)lightAccess.getChunkForLighting(chunkX, chunkZ);
+            if (chunk == null || !this.canUseChunk(chunk)) {
+                throw new IllegalStateException();
+            }
+
+            for (int i = 0, len = neighbourLightOrder.length; i < len; i += 2) {
+                final int dx = neighbourLightOrder[i];
+                final int dz = neighbourLightOrder[i + 1];
+                final int neighbourX = dx + chunkX;
+                final int neighbourZ = dz + chunkZ;
+
+                final ChunkAccess neighbour = (ChunkAccess)lightAccess.getChunkForLighting(neighbourX, neighbourZ);
+                if (neighbour == null || !this.canUseChunk(neighbour)) {
+                    continue;
+                }
+
+                if (nibblesByChunk.get(CoordinateUtils.getChunkKey(neighbourX, neighbourZ)) != null) {
+                    // lit already called for neighbour, no need to light it now
+                    continue;
+                }
+
+                // light neighbour chunk
+                this.setupEncodeOffset(neighbourX * 16 + 7, 128, neighbourZ * 16 + 7);
+                try {
+                    // insert all neighbouring chunks for this neighbour that we have data for
+                    for (int dz2 = -1; dz2 <= 1; ++dz2) {
+                        for (int dx2 = -1; dx2 <= 1; ++dx2) {
+                            final int neighbourX2 = neighbourX + dx2;
+                            final int neighbourZ2 = neighbourZ + dz2;
+                            final long key = CoordinateUtils.getChunkKey(neighbourX2, neighbourZ2);
+                            final ChunkAccess neighbour2 = (ChunkAccess)lightAccess.getChunkForLighting(neighbourX2, neighbourZ2);
+                            if (neighbour2 == null || !this.canUseChunk(neighbour2)) {
+                                continue;
+                            }
+
+                            final SWMRNibbleArray[] nibbles = nibblesByChunk.get(key);
+                            if (nibbles == null) {
+                                // we haven't lit this chunk
+                                continue;
+                            }
+
+                            this.setChunkInCache(neighbourX2, neighbourZ2, neighbour2);
+                            this.setBlocksForChunkInCache(neighbourX2, neighbourZ2, neighbour2.getSections());
+                            this.setNibblesForChunkInCache(neighbourX2, neighbourZ2, nibbles);
+                            this.setEmptinessMapCache(neighbourX2, neighbourZ2, emptinessMapByChunk.get(key));
+                        }
+                    }
+
+                    final long key = CoordinateUtils.getChunkKey(neighbourX, neighbourZ);
+
+                    // now insert the neighbour chunk and light it
+                    final SWMRNibbleArray[] nibbles = getFilledEmptyLight(this.world);
+                    nibblesByChunk.put(key, nibbles);
+
+                    this.setChunkInCache(neighbourX, neighbourZ, neighbour);
+                    this.setBlocksForChunkInCache(neighbourX, neighbourZ, neighbour.getSections());
+                    this.setNibblesForChunkInCache(neighbourX, neighbourZ, nibbles);
+
+                    final boolean[] neighbourEmptiness = this.handleEmptySectionChanges(lightAccess, neighbour, getEmptySectionsForChunk(neighbour), true);
+                    emptinessMapByChunk.put(key, neighbourEmptiness);
+                    if (chunks.contains(new ChunkPos(neighbourX, neighbourZ))) {
+                        this.setEmptinessMap(neighbour, neighbourEmptiness);
+                    }
+
+                    this.lightChunk(lightAccess, neighbour, false);
+                } finally {
+                    this.destroyCaches();
+                }
+            }
+
+            // done lighting all neighbours, so the chunk is now fully lit
+
+            // make sure nibbles are fully updated before calling back
+            final SWMRNibbleArray[] nibbles = nibblesByChunk.get(CoordinateUtils.getChunkKey(chunkX, chunkZ));
+            for (final SWMRNibbleArray nibble : nibbles) {
+                nibble.updateVisible();
+            }
+
+            this.setNibbles(chunk, nibbles);
+
+            for (int y = this.minLightSection; y <= this.maxLightSection; ++y) {
+                lightAccess.onLightUpdate(this.skylightPropagator ? LightLayer.SKY : LightLayer.BLOCK, SectionPos.of(chunkX, y, chunkZ));
+            }
+
+            // now do callback
+            if (chunkLightCallback != null) {
+                chunkLightCallback.accept(chunkPos);
+            }
+            ++lightCalls;
+        }
+
+        if (onComplete != null) {
+            onComplete.accept(lightCalls);
+        }
+    }
+
+    // contains:
+    // lower (6 + 6 + 16) = 28 bits: encoded coordinate position (x | (z << 6) | (y << (6 + 6))))
+    // next 4 bits: propagated light level (0, 15]
+    // next 6 bits: propagation direction bitset
+    // next 24 bits: unused
+    // last 3 bits: state flags
+    // state flags:
+    // whether the increase propagator needs to write the propagated level to the position, used to avoid cascading light
+    // updates for block sources
+    protected static final long FLAG_WRITE_LEVEL = Long.MIN_VALUE >>> 2;
+    // whether the propagation needs to check if its current level is equal to the expected level
+    // used only in increase propagation
+    protected static final long FLAG_RECHECK_LEVEL = Long.MIN_VALUE >>> 1;
+    // whether the propagation needs to consider if its block is conditionally transparent
+    protected static final long FLAG_HAS_SIDED_TRANSPARENT_BLOCKS = Long.MIN_VALUE;
+
+    protected long[] increaseQueue = new long[16 * 16 * 16];
+    protected int increaseQueueInitialLength;
+    protected long[] decreaseQueue = new long[16 * 16 * 16];
+    protected int decreaseQueueInitialLength;
+
+    protected final long[] resizeIncreaseQueue() {
+        return this.increaseQueue = Arrays.copyOf(this.increaseQueue, this.increaseQueue.length * 2);
+    }
+
+    protected final long[] resizeDecreaseQueue() {
+        return this.decreaseQueue = Arrays.copyOf(this.decreaseQueue, this.decreaseQueue.length * 2);
+    }
+
+    protected final void appendToIncreaseQueue(final long value) {
+        final int idx = this.increaseQueueInitialLength++;
+        long[] queue = this.increaseQueue;
+        if (idx >= queue.length) {
+            queue = this.resizeIncreaseQueue();
+            queue[idx] = value;
+        } else {
+            queue[idx] = value;
+        }
+    }
+
+    protected final void appendToDecreaseQueue(final long value) {
+        final int idx = this.decreaseQueueInitialLength++;
+        long[] queue = this.decreaseQueue;
+        if (idx >= queue.length) {
+            queue = this.resizeDecreaseQueue();
+            queue[idx] = value;
+        } else {
+            queue[idx] = value;
+        }
+    }
+
+    protected static final AxisDirection[][] OLD_CHECK_DIRECTIONS = new AxisDirection[1 << 6][];
+    protected static final int ALL_DIRECTIONS_BITSET = (1 << 6) - 1;
+    static {
+        for (int i = 0; i < OLD_CHECK_DIRECTIONS.length; ++i) {
+            final List<AxisDirection> directions = new ArrayList<>();
+            for (int bitset = i, len = Integer.bitCount(i), index = 0; index < len; ++index, bitset ^= IntegerUtil.getTrailingBit(bitset)) {
+                directions.add(AXIS_DIRECTIONS[IntegerUtil.trailingZeros(bitset)]);
+            }
+            OLD_CHECK_DIRECTIONS[i] = directions.toArray(new AxisDirection[0]);
+        }
+    }
+
+    protected final void performLightIncrease(final LightChunkGetter lightAccess) {
+        final BlockGetter world = lightAccess.getLevel();
+        long[] queue = this.increaseQueue;
+        int queueReadIndex = 0;
+        int queueLength = this.increaseQueueInitialLength;
+        this.increaseQueueInitialLength = 0;
+        final int decodeOffsetX = -this.encodeOffsetX;
+        final int decodeOffsetY = -this.encodeOffsetY;
+        final int decodeOffsetZ = -this.encodeOffsetZ;
+        final int encodeOffset = this.coordinateOffset;
+        final int sectionOffset = this.chunkSectionIndexOffset;
+
+        while (queueReadIndex < queueLength) {
+            final long queueValue = queue[queueReadIndex++];
+
+            final int posX = ((int)queueValue & 63) + decodeOffsetX;
+            final int posZ = (((int)queueValue >>> 6) & 63) + decodeOffsetZ;
+            final int posY = (((int)queueValue >>> 12) & ((1 << 16) - 1)) + decodeOffsetY;
+            final int propagatedLightLevel = (int)((queueValue >>> (6 + 6 + 16)) & 0xFL);
+            final AxisDirection[] checkDirections = OLD_CHECK_DIRECTIONS[(int)((queueValue >>> (6 + 6 + 16 + 4)) & 63L)];
+
+            if ((queueValue & FLAG_RECHECK_LEVEL) != 0L) {
+                if (this.getLightLevel(posX, posY, posZ) != propagatedLightLevel) {
+                    // not at the level we expect, so something changed.
+                    continue;
+                }
+            } else if ((queueValue & FLAG_WRITE_LEVEL) != 0L) {
+                // these are used to restore block sources after a propagation decrease
+                this.setLightLevel(posX, posY, posZ, propagatedLightLevel);
+            }
+
+            if ((queueValue & FLAG_HAS_SIDED_TRANSPARENT_BLOCKS) == 0L) {
+                // we don't need to worry about our state here.
+                for (final AxisDirection propagate : checkDirections) {
+                    final int offX = posX + propagate.x;
+                    final int offY = posY + propagate.y;
+                    final int offZ = posZ + propagate.z;
+
+                    final int sectionIndex = (offX >> 4) + 5 * (offZ >> 4) + (5 * 5) * (offY >> 4) + sectionOffset;
+                    final int localIndex = (offX & 15) | ((offZ & 15) << 4) | ((offY & 15) << 8);
+
+                    final SWMRNibbleArray currentNibble = this.nibbleCache[sectionIndex];
+                    final int currentLevel;
+                    if (currentNibble == null || (currentLevel = currentNibble.getUpdating(localIndex)) >= (propagatedLightLevel - 1)) {
+                        continue; // already at the level we want or unloaded
+                    }
+
+                    final BlockState blockState = this.getBlockState(sectionIndex, localIndex);
+                    if (blockState == null) {
+                        continue;
+                    }
+                    long flags = 0;
+                    if (((StarlightAbstractBlockState)blockState).starlight$isConditionallyFullOpaque()) {
+                        final VoxelShape cullingFace = blockState.getFaceOcclusionShape(propagate.getOpposite().nms);
+
+                        if (Shapes.faceShapeOccludes(Shapes.empty(), cullingFace)) {
+                            continue;
+                        }
+                        flags |= FLAG_HAS_SIDED_TRANSPARENT_BLOCKS;
+                    }
+
+                    final int opacity = blockState.getLightBlock();
+                    final int targetLevel = propagatedLightLevel - Math.max(1, opacity);
+                    if (targetLevel <= currentLevel) {
+                        continue;
+                    }
+
+                    currentNibble.set(localIndex, targetLevel);
+                    this.postLightUpdate(offX, offY, offZ);
+
+                    if (targetLevel > 1) {
+                        if (queueLength >= queue.length) {
+                            queue = this.resizeIncreaseQueue();
+                        }
+                        queue[queueLength++] =
+                                ((offX + (offZ << 6) + (offY << 12) + encodeOffset) & ((1L << (6 + 6 + 16)) - 1))
+                                        | ((targetLevel & 0xFL) << (6 + 6 + 16))
+                                        | (propagate.everythingButTheOppositeDirection << (6 + 6 + 16 + 4))
+                                        | (flags);
+                    }
+                    continue;
+                }
+            } else {
+                // we actually need to worry about our state here
+                final BlockState fromBlock = this.getBlockState(posX, posY, posZ);
+                for (final AxisDirection propagate : checkDirections) {
+                    final int offX = posX + propagate.x;
+                    final int offY = posY + propagate.y;
+                    final int offZ = posZ + propagate.z;
+
+                    final VoxelShape fromShape = (((StarlightAbstractBlockState)fromBlock).starlight$isConditionallyFullOpaque()) ? fromBlock.getFaceOcclusionShape(propagate.nms) : Shapes.empty();
+
+                    if (fromShape != Shapes.empty() && Shapes.faceShapeOccludes(Shapes.empty(), fromShape)) {
+                        continue;
+                    }
+
+                    final int sectionIndex = (offX >> 4) + 5 * (offZ >> 4) + (5 * 5) * (offY >> 4) + sectionOffset;
+                    final int localIndex = (offX & 15) | ((offZ & 15) << 4) | ((offY & 15) << 8);
+
+                    final SWMRNibbleArray currentNibble = this.nibbleCache[sectionIndex];
+                    final int currentLevel;
+
+                    if (currentNibble == null || (currentLevel = currentNibble.getUpdating(localIndex)) >= (propagatedLightLevel - 1)) {
+                        continue; // already at the level we want
+                    }
+
+                    final BlockState blockState = this.getBlockState(sectionIndex, localIndex);
+                    if (blockState == null) {
+                        continue;
+                    }
+                    long flags = 0;
+                    if (((StarlightAbstractBlockState)blockState).starlight$isConditionallyFullOpaque()) {
+                        final VoxelShape cullingFace = blockState.getFaceOcclusionShape(propagate.getOpposite().nms);
+
+                        if (Shapes.faceShapeOccludes(fromShape, cullingFace)) {
+                            continue;
+                        }
+                        flags |= FLAG_HAS_SIDED_TRANSPARENT_BLOCKS;
+                    }
+
+                    final int opacity = blockState.getLightBlock();
+                    final int targetLevel = propagatedLightLevel - Math.max(1, opacity);
+                    if (targetLevel <= currentLevel) {
+                        continue;
+                    }
+
+                    currentNibble.set(localIndex, targetLevel);
+                    this.postLightUpdate(offX, offY, offZ);
+
+                    if (targetLevel > 1) {
+                        if (queueLength >= queue.length) {
+                            queue = this.resizeIncreaseQueue();
+                        }
+                        queue[queueLength++] =
+                                ((offX + (offZ << 6) + (offY << 12) + encodeOffset) & ((1L << (6 + 6 + 16)) - 1))
+                                        | ((targetLevel & 0xFL) << (6 + 6 + 16))
+                                        | (propagate.everythingButTheOppositeDirection << (6 + 6 + 16 + 4))
+                                        | (flags);
+                    }
+                    continue;
+                }
+            }
+        }
+    }
+
+    protected final void performLightDecrease(final LightChunkGetter lightAccess) {
+        final BlockGetter world = lightAccess.getLevel();
+        long[] queue = this.decreaseQueue;
+        long[] increaseQueue = this.increaseQueue;
+        int queueReadIndex = 0;
+        int queueLength = this.decreaseQueueInitialLength;
+        this.decreaseQueueInitialLength = 0;
+        int increaseQueueLength = this.increaseQueueInitialLength;
+        final int decodeOffsetX = -this.encodeOffsetX;
+        final int decodeOffsetY = -this.encodeOffsetY;
+        final int decodeOffsetZ = -this.encodeOffsetZ;
+        final int encodeOffset = this.coordinateOffset;
+        final int sectionOffset = this.chunkSectionIndexOffset;
+        final int emittedMask = this.emittedLightMask;
+
+        final PlatformHooks platformHooks = PlatformHooks.get();
+
+        while (queueReadIndex < queueLength) {
+            final long queueValue = queue[queueReadIndex++];
+
+            final int posX = ((int)queueValue & 63) + decodeOffsetX;
+            final int posZ = (((int)queueValue >>> 6) & 63) + decodeOffsetZ;
+            final int posY = (((int)queueValue >>> 12) & ((1 << 16) - 1)) + decodeOffsetY;
+            final int propagatedLightLevel = (int)((queueValue >>> (6 + 6 + 16)) & 0xF);
+            final AxisDirection[] checkDirections = OLD_CHECK_DIRECTIONS[(int)((queueValue >>> (6 + 6 + 16 + 4)) & 63)];
+
+            if ((queueValue & FLAG_HAS_SIDED_TRANSPARENT_BLOCKS) == 0L) {
+                // we don't need to worry about our state here.
+                for (final AxisDirection propagate : checkDirections) {
+                    final int offX = posX + propagate.x;
+                    final int offY = posY + propagate.y;
+                    final int offZ = posZ + propagate.z;
+
+                    final int sectionIndex = (offX >> 4) + 5 * (offZ >> 4) + (5 * 5) * (offY >> 4) + sectionOffset;
+                    final int localIndex = (offX & 15) | ((offZ & 15) << 4) | ((offY & 15) << 8);
+
+                    final SWMRNibbleArray currentNibble = this.nibbleCache[sectionIndex];
+                    final int lightLevel;
+
+                    if (currentNibble == null || (lightLevel = currentNibble.getUpdating(localIndex)) == 0) {
+                        // already at lowest (or unloaded), nothing we can do
+                        continue;
+                    }
+
+                    final BlockState blockState = this.getBlockState(sectionIndex, localIndex);
+                    if (blockState == null) {
+                        continue;
+                    }
+                    this.lightEmissionPos.set(offX, offY, offZ);
+                    long flags = 0;
+                    if (((StarlightAbstractBlockState)blockState).starlight$isConditionallyFullOpaque()) {
+                        final VoxelShape cullingFace = blockState.getFaceOcclusionShape(propagate.getOpposite().nms);
+
+                        if (Shapes.faceShapeOccludes(Shapes.empty(), cullingFace)) {
+                            continue;
+                        }
+                        flags |= FLAG_HAS_SIDED_TRANSPARENT_BLOCKS;
+                    }
+
+                    final int opacity = blockState.getLightBlock();
+                    final int targetLevel = Math.max(0, propagatedLightLevel - Math.max(1, opacity));
+                    if (lightLevel > targetLevel) {
+                        // it looks like another source propagated here, so re-propagate it
+                        if (increaseQueueLength >= increaseQueue.length) {
+                            increaseQueue = this.resizeIncreaseQueue();
+                        }
+                        increaseQueue[increaseQueueLength++] =
+                                ((offX + (offZ << 6) + (offY << 12) + encodeOffset) & ((1L << (6 + 6 + 16)) - 1))
+                                        | ((lightLevel & 0xFL) << (6 + 6 + 16))
+                                        | (((long)ALL_DIRECTIONS_BITSET) << (6 + 6 + 16 + 4))
+                                        | (FLAG_RECHECK_LEVEL | flags);
+                        continue;
+                    }
+                    final int emittedLight = (platformHooks.getLightEmission(blockState, world, this.lightEmissionPos)) & emittedMask;
+                    if (emittedLight != 0) {
+                        // re-propagate source
+                        // note: do not set recheck level, or else the propagation will fail
+                        if (increaseQueueLength >= increaseQueue.length) {
+                            increaseQueue = this.resizeIncreaseQueue();
+                        }
+                        increaseQueue[increaseQueueLength++] =
+                                ((offX + (offZ << 6) + (offY << 12) + encodeOffset) & ((1L << (6 + 6 + 16)) - 1))
+                                        | ((emittedLight & 0xFL) << (6 + 6 + 16))
+                                        | (((long)ALL_DIRECTIONS_BITSET) << (6 + 6 + 16 + 4))
+                                        | (flags | FLAG_WRITE_LEVEL);
+                    }
+
+                    currentNibble.set(localIndex, 0);
+                    this.postLightUpdate(offX, offY, offZ);
+
+                    if (targetLevel > 0) {
+                        if (queueLength >= queue.length) {
+                            queue = this.resizeDecreaseQueue();
+                        }
+                        queue[queueLength++] =
+                                ((offX + (offZ << 6) + (offY << 12) + encodeOffset) & ((1L << (6 + 6 + 16)) - 1))
+                                        | ((targetLevel & 0xFL) << (6 + 6 + 16))
+                                        | ((propagate.everythingButTheOppositeDirection) << (6 + 6 + 16 + 4))
+                                        | flags;
+                    }
+                    continue;
+                }
+            } else {
+                // we actually need to worry about our state here
+                final BlockState fromBlock = this.getBlockState(posX, posY, posZ);
+                for (final AxisDirection propagate : checkDirections) {
+                    final int offX = posX + propagate.x;
+                    final int offY = posY + propagate.y;
+                    final int offZ = posZ + propagate.z;
+
+                    final int sectionIndex = (offX >> 4) + 5 * (offZ >> 4) + (5 * 5) * (offY >> 4) + sectionOffset;
+                    final int localIndex = (offX & 15) | ((offZ & 15) << 4) | ((offY & 15) << 8);
+
+                    final VoxelShape fromShape = (((StarlightAbstractBlockState)fromBlock).starlight$isConditionallyFullOpaque()) ? fromBlock.getFaceOcclusionShape(propagate.nms) : Shapes.empty();
+
+                    if (fromShape != Shapes.empty() && Shapes.faceShapeOccludes(Shapes.empty(), fromShape)) {
+                        continue;
+                    }
+
+                    final SWMRNibbleArray currentNibble = this.nibbleCache[sectionIndex];
+                    final int lightLevel;
+
+                    if (currentNibble == null || (lightLevel = currentNibble.getUpdating(localIndex)) == 0) {
+                        // already at lowest (or unloaded), nothing we can do
+                        continue;
+                    }
+
+                    final BlockState blockState = this.getBlockState(sectionIndex, localIndex);
+                    if (blockState == null) {
+                        continue;
+                    }
+                    this.lightEmissionPos.set(offX, offY, offZ);
+                    long flags = 0;
+                    if (((StarlightAbstractBlockState)blockState).starlight$isConditionallyFullOpaque()) {
+                        final VoxelShape cullingFace = blockState.getFaceOcclusionShape(propagate.getOpposite().nms);
+
+                        if (Shapes.faceShapeOccludes(fromShape, cullingFace)) {
+                            continue;
+                        }
+                        flags |= FLAG_HAS_SIDED_TRANSPARENT_BLOCKS;
+                    }
+
+                    final int opacity = blockState.getLightBlock();
+                    final int targetLevel = Math.max(0, propagatedLightLevel - Math.max(1, opacity));
+                    if (lightLevel > targetLevel) {
+                        // it looks like another source propagated here, so re-propagate it
+                        if (increaseQueueLength >= increaseQueue.length) {
+                            increaseQueue = this.resizeIncreaseQueue();
+                        }
+                        increaseQueue[increaseQueueLength++] =
+                                ((offX + (offZ << 6) + (offY << 12) + encodeOffset) & ((1L << (6 + 6 + 16)) - 1))
+                                        | ((lightLevel & 0xFL) << (6 + 6 + 16))
+                                        | (((long)ALL_DIRECTIONS_BITSET) << (6 + 6 + 16 + 4))
+                                        | (FLAG_RECHECK_LEVEL | flags);
+                        continue;
+                    }
+                    final int emittedLight = (platformHooks.getLightEmission(blockState, world, this.lightEmissionPos)) & emittedMask;
+                    if (emittedLight != 0) {
+                        // re-propagate source
+                        // note: do not set recheck level, or else the propagation will fail
+                        if (increaseQueueLength >= increaseQueue.length) {
+                            increaseQueue = this.resizeIncreaseQueue();
+                        }
+                        increaseQueue[increaseQueueLength++] =
+                                ((offX + (offZ << 6) + (offY << 12) + encodeOffset) & ((1L << (6 + 6 + 16)) - 1))
+                                        | ((emittedLight & 0xFL) << (6 + 6 + 16))
+                                        | (((long)ALL_DIRECTIONS_BITSET) << (6 + 6 + 16 + 4))
+                                        | (flags | FLAG_WRITE_LEVEL);
+                    }
+
+                    currentNibble.set(localIndex, 0);
+                    this.postLightUpdate(offX, offY, offZ);
+
+                    if (targetLevel > 0) { // we actually need to propagate 0 just in case we find a neighbour...
+                        if (queueLength >= queue.length) {
+                            queue = this.resizeDecreaseQueue();
+                        }
+                        queue[queueLength++] =
+                                ((offX + (offZ << 6) + (offY << 12) + encodeOffset) & ((1L << (6 + 6 + 16)) - 1))
+                                        | ((targetLevel & 0xFL) << (6 + 6 + 16))
+                                        | ((propagate.everythingButTheOppositeDirection) << (6 + 6 + 16 + 4))
+                                        | flags;
+                    }
+                    continue;
+                }
+            }
+        }
+
+        // propagate sources we clobbered
+        this.increaseQueueInitialLength = increaseQueueLength;
+        this.performLightIncrease(lightAccess);
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/starlight/light/StarLightInterface.java b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/light/StarLightInterface.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/light/StarLightInterface.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.starlight.light;
+
+import ca.spottedleaf.concurrentutil.collection.MultiThreadedQueue;
+import ca.spottedleaf.concurrentutil.executor.PrioritisedExecutor;
+import ca.spottedleaf.concurrentutil.map.ConcurrentLong2ReferenceChainedHashTable;
+import ca.spottedleaf.concurrentutil.util.Priority;
+import ca.spottedleaf.moonrise.common.util.CoordinateUtils;
+import ca.spottedleaf.moonrise.common.util.WorldUtil;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemChunkStatus;
+import ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk;
+import it.unimi.dsi.fastutil.longs.Long2ObjectLinkedOpenHashMap;
+import it.unimi.dsi.fastutil.shorts.ShortCollection;
+import it.unimi.dsi.fastutil.shorts.ShortOpenHashSet;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.SectionPos;
+import net.minecraft.server.level.ChunkLevel;
+import net.minecraft.server.level.FullChunkStatus;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.TicketType;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.DataLayer;
+import net.minecraft.world.level.chunk.LightChunkGetter;
+import net.minecraft.world.level.chunk.status.ChunkStatus;
+import net.minecraft.world.level.lighting.LayerLightEventListener;
+import net.minecraft.world.level.lighting.LevelLightEngine;
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.BooleanSupplier;
+import java.util.function.Consumer;
+import java.util.function.IntConsumer;
+
+public final class StarLightInterface {
+
+    public static final TicketType<Long> CHUNK_WORK_TICKET = TicketType.create("starlight:chunk_work_ticket", Long::compareTo);
+    public static final int LIGHT_TICKET_LEVEL = ChunkLevel.byStatus(ChunkStatus.LIGHT);
+    // ticket level = ChunkLevel.byStatus(FullChunkStatus.FULL) - input
+    public static final int REGION_LIGHT_TICKET_LEVEL = ChunkLevel.byStatus(FullChunkStatus.FULL) - LIGHT_TICKET_LEVEL;
+
+    /**
+     * Can be {@code null}, indicating the light is all empty.
+     */
+    public final Level world;
+    public final LightChunkGetter lightAccess;
+
+    private final ArrayDeque<SkyStarLightEngine> cachedSkyPropagators;
+    private final ArrayDeque<BlockStarLightEngine> cachedBlockPropagators;
+
+    private final LightQueue lightQueue;
+
+    private final LayerLightEventListener skyReader;
+    private final LayerLightEventListener blockReader;
+    private final boolean isClientSide;
+
+    public final int minSection;
+    public final int maxSection;
+    public final int minLightSection;
+    public final int maxLightSection;
+
+    public final LevelLightEngine lightEngine;
+
+    private final boolean hasBlockLight;
+    private final boolean hasSkyLight;
+
+    public StarLightInterface(final LightChunkGetter lightAccess, final boolean hasSkyLight, final boolean hasBlockLight, final LevelLightEngine lightEngine) {
+        this.lightAccess = lightAccess;
+        this.world = lightAccess == null ? null : (Level)lightAccess.getLevel();
+        this.cachedSkyPropagators = hasSkyLight && lightAccess != null ? new ArrayDeque<>() : null;
+        this.cachedBlockPropagators = hasBlockLight && lightAccess != null ? new ArrayDeque<>() : null;
+        this.isClientSide = !(this.world instanceof ServerLevel);
+        if (this.world == null) {
+            this.minSection = -4;
+            this.maxSection = 19;
+            this.minLightSection = -5;
+            this.maxLightSection = 20;
+        } else {
+            this.minSection = WorldUtil.getMinSection(this.world);
+            this.maxSection = WorldUtil.getMaxSection(this.world);
+            this.minLightSection = WorldUtil.getMinLightSection(this.world);
+            this.maxLightSection = WorldUtil.getMaxLightSection(this.world);
+        }
+
+        if (this.world instanceof ServerLevel) {
+            this.lightQueue = new ServerLightQueue(this);
+        } else {
+            this.lightQueue = new ClientLightQueue(this);
+        }
+
+        this.lightEngine = lightEngine;
+        this.hasBlockLight = hasBlockLight;
+        this.hasSkyLight = hasSkyLight;
+        this.skyReader = !hasSkyLight ? LayerLightEventListener.DummyLightLayerEventListener.INSTANCE : new LayerLightEventListener() {
+            @Override
+            public void checkBlock(final BlockPos blockPos) {
+                StarLightInterface.this.lightEngine.checkBlock(blockPos.immutable());
+            }
+
+            @Override
+            public void propagateLightSources(final ChunkPos chunkPos) {
+                throw new UnsupportedOperationException();
+            }
+
+            @Override
+            public boolean hasLightWork() {
+                // not really correct...
+                return StarLightInterface.this.hasUpdates();
+            }
+
+            @Override
+            public int runLightUpdates() {
+                throw new UnsupportedOperationException();
+            }
+
+            @Override
+            public void setLightEnabled(final ChunkPos chunkPos, final boolean bl) {
+                throw new UnsupportedOperationException();
+            }
+
+            @Override
+            public DataLayer getDataLayerData(final SectionPos pos) {
+                final ChunkAccess chunk = StarLightInterface.this.getAnyChunkNow(pos.getX(), pos.getZ());
+                if (chunk == null || (!StarLightInterface.this.isClientSide && !chunk.isLightCorrect()) || !chunk.getPersistedStatus().isOrAfter(ChunkStatus.LIGHT)) {
+                    return null;
+                }
+
+                final int sectionY = pos.getY();
+
+                if (sectionY > StarLightInterface.this.maxLightSection || sectionY < StarLightInterface.this.minLightSection) {
+                    return null;
+                }
+
+                if (((StarlightChunk)chunk).starlight$getSkyEmptinessMap() == null) {
+                    return null;
+                }
+
+                return ((StarlightChunk)chunk).starlight$getSkyNibbles()[sectionY - StarLightInterface.this.minLightSection].toVanillaNibble();
+            }
+
+            @Override
+            public int getLightValue(final BlockPos blockPos) {
+                return StarLightInterface.this.getSkyLightValue(blockPos, StarLightInterface.this.getAnyChunkNow(blockPos.getX() >> 4, blockPos.getZ() >> 4));
+            }
+
+            @Override
+            public void updateSectionStatus(final SectionPos pos, final boolean notReady) {
+                StarLightInterface.this.sectionChange(pos, notReady);
+            }
+        };
+        this.blockReader = !hasBlockLight ? LayerLightEventListener.DummyLightLayerEventListener.INSTANCE : new LayerLightEventListener() {
+            @Override
+            public void checkBlock(final BlockPos blockPos) {
+                StarLightInterface.this.lightEngine.checkBlock(blockPos.immutable());
+            }
+
+            @Override
+            public void propagateLightSources(final ChunkPos chunkPos) {
+                throw new UnsupportedOperationException();
+            }
+
+            @Override
+            public boolean hasLightWork() {
+                // not really correct...
+                return StarLightInterface.this.hasUpdates();
+            }
+
+            @Override
+            public int runLightUpdates() {
+                throw new UnsupportedOperationException();
+            }
+
+            @Override
+            public void setLightEnabled(final ChunkPos chunkPos, final boolean bl) {
+                throw new UnsupportedOperationException();
+            }
+
+            @Override
+            public DataLayer getDataLayerData(final SectionPos pos) {
+                final ChunkAccess chunk = StarLightInterface.this.getAnyChunkNow(pos.getX(), pos.getZ());
+
+                if (chunk == null || pos.getY() < StarLightInterface.this.minLightSection || pos.getY() > StarLightInterface.this.maxLightSection) {
+                    return null;
+                }
+
+                return ((StarlightChunk)chunk).starlight$getBlockNibbles()[pos.getY() - StarLightInterface.this.minLightSection].toVanillaNibble();
+            }
+
+            @Override
+            public int getLightValue(final BlockPos blockPos) {
+                return StarLightInterface.this.getBlockLightValue(blockPos, StarLightInterface.this.getAnyChunkNow(blockPos.getX() >> 4, blockPos.getZ() >> 4));
+            }
+
+            @Override
+            public void updateSectionStatus(final SectionPos pos, final boolean notReady) {
+                StarLightInterface.this.sectionChange(pos, notReady);
+            }
+        };
+    }
+
+    public ClientLightQueue getClientLightQueue() {
+        if (this.lightQueue instanceof ClientLightQueue clientLightQueue) {
+            return clientLightQueue;
+        }
+        return null;
+    }
+
+    public ServerLightQueue getServerLightQueue() {
+        if (this.lightQueue instanceof ServerLightQueue serverLightQueue) {
+            return serverLightQueue;
+        }
+        return null;
+    }
+
+    public boolean hasSkyLight() {
+        return this.hasSkyLight;
+    }
+
+    public boolean hasBlockLight() {
+        return this.hasBlockLight;
+    }
+
+    public int getSkyLightValue(final BlockPos blockPos, final ChunkAccess chunk) {
+        if (!this.hasSkyLight) {
+            return 0;
+        }
+        final int x = blockPos.getX();
+        int y = blockPos.getY();
+        final int z = blockPos.getZ();
+
+        final int minSection = this.minSection;
+        final int maxSection = this.maxSection;
+        final int minLightSection = this.minLightSection;
+        final int maxLightSection = this.maxLightSection;
+
+        if (chunk == null || (!this.isClientSide && !chunk.isLightCorrect()) || !chunk.getPersistedStatus().isOrAfter(ChunkStatus.LIGHT)) {
+            return 15;
+        }
+
+        int sectionY = y >> 4;
+
+        if (sectionY > maxLightSection) {
+            return 15;
+        }
+
+        if (sectionY < minLightSection) {
+            sectionY = minLightSection;
+            y = sectionY << 4;
+        }
+
+        final SWMRNibbleArray[] nibbles = ((StarlightChunk)chunk).starlight$getSkyNibbles();
+        final SWMRNibbleArray immediate = nibbles[sectionY - minLightSection];
+
+        if (!immediate.isNullNibbleVisible()) {
+            return immediate.getVisible(x, y, z);
+        }
+
+        final boolean[] emptinessMap = ((StarlightChunk)chunk).starlight$getSkyEmptinessMap();
+
+        if (emptinessMap == null) {
+            return 15;
+        }
+
+        // are we above this chunk's lowest empty section?
+        int lowestY = minLightSection - 1;
+        for (int currY = maxSection; currY >= minSection; --currY) {
+            if (emptinessMap[currY - minSection]) {
+                continue;
+            }
+
+            // should always be full lit here
+            lowestY = currY;
+            break;
+        }
+
+        if (sectionY > lowestY) {
+            return 15;
+        }
+
+        // this nibble is going to depend solely on the skylight data above it
+        // find first non-null data above (there does exist one, as we just found it above)
+        for (int currY = sectionY + 1; currY <= maxLightSection; ++currY) {
+            final SWMRNibbleArray nibble = nibbles[currY - minLightSection];
+            if (!nibble.isNullNibbleVisible()) {
+                return nibble.getVisible(x, 0, z);
+            }
+        }
+
+        // should never reach here
+        return 15;
+    }
+
+    public int getBlockLightValue(final BlockPos blockPos, final ChunkAccess chunk) {
+        if (!this.hasBlockLight) {
+            return 0;
+        }
+        final int y = blockPos.getY();
+        final int cy = y >> 4;
+
+        final int minLightSection = this.minLightSection;
+        final int maxLightSection = this.maxLightSection;
+
+        if (cy < minLightSection || cy > maxLightSection) {
+            return 0;
+        }
+
+        if (chunk == null) {
+            return 0;
+        }
+
+        final SWMRNibbleArray nibble = ((StarlightChunk)chunk).starlight$getBlockNibbles()[cy - minLightSection];
+        return nibble.getVisible(blockPos.getX(), y, blockPos.getZ());
+    }
+
+    public int getRawBrightness(final BlockPos pos, final int ambientDarkness) {
+        final ChunkAccess chunk = this.getAnyChunkNow(pos.getX() >> 4, pos.getZ() >> 4);
+
+        final int sky = this.getSkyLightValue(pos, chunk) - ambientDarkness;
+        // Don't fetch the block light level if the skylight level is 15, since the value will never be higher.
+        if (sky == 15) {
+            return 15;
+        }
+        final int block = this.getBlockLightValue(pos, chunk);
+        return Math.max(sky, block);
+    }
+
+    public LayerLightEventListener getSkyReader() {
+        return this.skyReader;
+    }
+
+    public LayerLightEventListener getBlockReader() {
+        return this.blockReader;
+    }
+
+    public boolean isClientSide() {
+        return this.isClientSide;
+    }
+
+    public ChunkAccess getAnyChunkNow(final int chunkX, final int chunkZ) {
+        if (this.world == null) {
+            // empty world
+            return null;
+        }
+        return ((ChunkSystemLevel)this.world).moonrise$getAnyChunkIfLoaded(chunkX, chunkZ);
+    }
+
+    public boolean hasUpdates() {
+        return !this.lightQueue.isEmpty();
+    }
+
+    public Level getWorld() {
+        return this.world;
+    }
+
+    public LightChunkGetter getLightAccess() {
+        return this.lightAccess;
+    }
+
+    public SkyStarLightEngine getSkyLightEngine() {
+        if (this.cachedSkyPropagators == null) {
+            return null;
+        }
+        final SkyStarLightEngine ret;
+        synchronized (this.cachedSkyPropagators) {
+            ret = this.cachedSkyPropagators.pollFirst();
+        }
+
+        if (ret == null) {
+            return new SkyStarLightEngine(this.world);
+        }
+        return ret;
+    }
+
+    public void releaseSkyLightEngine(final SkyStarLightEngine engine) {
+        if (this.cachedSkyPropagators == null) {
+            return;
+        }
+        synchronized (this.cachedSkyPropagators) {
+            this.cachedSkyPropagators.addFirst(engine);
+        }
+    }
+
+    public BlockStarLightEngine getBlockLightEngine() {
+        if (this.cachedBlockPropagators == null) {
+            return null;
+        }
+        final BlockStarLightEngine ret;
+        synchronized (this.cachedBlockPropagators) {
+            ret = this.cachedBlockPropagators.pollFirst();
+        }
+
+        if (ret == null) {
+            return new BlockStarLightEngine(this.world);
+        }
+        return ret;
+    }
+
+    public void releaseBlockLightEngine(final BlockStarLightEngine engine) {
+        if (this.cachedBlockPropagators == null) {
+            return;
+        }
+        synchronized (this.cachedBlockPropagators) {
+            this.cachedBlockPropagators.addFirst(engine);
+        }
+    }
+
+    public LightQueue.ChunkTasks blockChange(final BlockPos pos) {
+        if (this.world == null || pos.getY() < WorldUtil.getMinBlockY(this.world) || pos.getY() > WorldUtil.getMaxBlockY(this.world)) { // empty world
+            return null;
+        }
+
+        return this.lightQueue.queueBlockChange(pos);
+    }
+
+    public LightQueue.ChunkTasks sectionChange(final SectionPos pos, final boolean newEmptyValue) {
+        if (this.world == null) { // empty world
+            return null;
+        }
+
+        return this.lightQueue.queueSectionChange(pos, newEmptyValue);
+    }
+
+    public void forceLoadInChunk(final ChunkAccess chunk, final Boolean[] emptySections) {
+        final SkyStarLightEngine skyEngine = this.getSkyLightEngine();
+        final BlockStarLightEngine blockEngine = this.getBlockLightEngine();
+
+        try {
+            if (skyEngine != null) {
+                skyEngine.forceHandleEmptySectionChanges(this.lightAccess, chunk, emptySections);
+            }
+            if (blockEngine != null) {
+                blockEngine.forceHandleEmptySectionChanges(this.lightAccess, chunk, emptySections);
+            }
+        } finally {
+            this.releaseSkyLightEngine(skyEngine);
+            this.releaseBlockLightEngine(blockEngine);
+        }
+    }
+
+    public void loadInChunk(final int chunkX, final int chunkZ, final Boolean[] emptySections) {
+        final SkyStarLightEngine skyEngine = this.getSkyLightEngine();
+        final BlockStarLightEngine blockEngine = this.getBlockLightEngine();
+
+        try {
+            if (skyEngine != null) {
+                skyEngine.handleEmptySectionChanges(this.lightAccess, chunkX, chunkZ, emptySections);
+            }
+            if (blockEngine != null) {
+                blockEngine.handleEmptySectionChanges(this.lightAccess, chunkX, chunkZ, emptySections);
+            }
+        } finally {
+            this.releaseSkyLightEngine(skyEngine);
+            this.releaseBlockLightEngine(blockEngine);
+        }
+    }
+
+    public void lightChunk(final ChunkAccess chunk, final Boolean[] emptySections) {
+        final SkyStarLightEngine skyEngine = this.getSkyLightEngine();
+        final BlockStarLightEngine blockEngine = this.getBlockLightEngine();
+
+        try {
+            if (skyEngine != null) {
+                skyEngine.light(this.lightAccess, chunk, emptySections);
+            }
+            if (blockEngine != null) {
+                blockEngine.light(this.lightAccess, chunk, emptySections);
+            }
+        } finally {
+            this.releaseSkyLightEngine(skyEngine);
+            this.releaseBlockLightEngine(blockEngine);
+        }
+    }
+
+    public void relightChunks(final Set<ChunkPos> chunks, final Consumer<ChunkPos> chunkLightCallback,
+                              final IntConsumer onComplete) {
+        final SkyStarLightEngine skyEngine = this.getSkyLightEngine();
+        final BlockStarLightEngine blockEngine = this.getBlockLightEngine();
+
+        try {
+            if (skyEngine != null) {
+                skyEngine.relightChunks(this.lightAccess, chunks, blockEngine == null ? chunkLightCallback : null,
+                        blockEngine == null ? onComplete : null);
+            }
+            if (blockEngine != null) {
+                blockEngine.relightChunks(this.lightAccess, chunks, chunkLightCallback, onComplete);
+            }
+        } finally {
+            this.releaseSkyLightEngine(skyEngine);
+            this.releaseBlockLightEngine(blockEngine);
+        }
+    }
+
+    public void checkChunkEdges(final int chunkX, final int chunkZ) {
+        this.checkSkyEdges(chunkX, chunkZ);
+        this.checkBlockEdges(chunkX, chunkZ);
+    }
+
+    public void checkSkyEdges(final int chunkX, final int chunkZ) {
+        final SkyStarLightEngine skyEngine = this.getSkyLightEngine();
+
+        try {
+            if (skyEngine != null) {
+                skyEngine.checkChunkEdges(this.lightAccess, chunkX, chunkZ);
+            }
+        } finally {
+            this.releaseSkyLightEngine(skyEngine);
+        }
+    }
+
+    public void checkBlockEdges(final int chunkX, final int chunkZ) {
+        final BlockStarLightEngine blockEngine = this.getBlockLightEngine();
+        try {
+            if (blockEngine != null) {
+                blockEngine.checkChunkEdges(this.lightAccess, chunkX, chunkZ);
+            }
+        } finally {
+            this.releaseBlockLightEngine(blockEngine);
+        }
+    }
+
+    public void propagateChanges() {
+        final LightQueue lightQueue = this.lightQueue;
+        if (lightQueue instanceof ClientLightQueue clientLightQueue) {
+            clientLightQueue.drainTasks();
+        } // else: invalid usage, although we won't throw because mods...
+    }
+
+    public static abstract class LightQueue {
+
+        protected final StarLightInterface lightInterface;
+
+        public LightQueue(final StarLightInterface lightInterface) {
+            this.lightInterface = lightInterface;
+        }
+
+        public abstract boolean isEmpty();
+
+        public abstract ChunkTasks queueBlockChange(final BlockPos pos);
+
+        public abstract ChunkTasks queueSectionChange(final SectionPos pos, final boolean newEmptyValue);
+
+        public abstract ChunkTasks queueChunkSkylightEdgeCheck(final SectionPos pos, final ShortCollection sections);
+
+        public abstract ChunkTasks queueChunkBlocklightEdgeCheck(final SectionPos pos, final ShortCollection sections);
+
+        public static abstract class ChunkTasks implements Runnable {
+
+            public final long chunkCoordinate;
+
+            protected final StarLightInterface lightEngine;
+            protected final LightQueue queue;
+            protected final MultiThreadedQueue<Runnable> onComplete = new MultiThreadedQueue<>();
+            protected final Set<BlockPos> changedPositions = new HashSet<>();
+            protected Boolean[] changedSectionSet;
+            protected ShortOpenHashSet queuedEdgeChecksSky;
+            protected ShortOpenHashSet queuedEdgeChecksBlock;
+            protected List<BooleanSupplier> lightTasks;
+
+            public ChunkTasks(final long chunkCoordinate, final StarLightInterface lightEngine, final LightQueue queue) {
+                this.chunkCoordinate = chunkCoordinate;
+                this.lightEngine = lightEngine;
+                this.queue = queue;
+            }
+
+            @Override
+            public abstract void run();
+
+            public void queueOrRunTask(final Runnable run) {
+                if (!this.onComplete.add(run)) {
+                    run.run();
+                }
+            }
+
+            protected void addChangedPosition(final BlockPos pos) {
+                this.changedPositions.add(pos.immutable());
+            }
+
+            protected void setChangedSection(final int y, final Boolean newEmptyValue) {
+                if (this.changedSectionSet == null) {
+                    this.changedSectionSet = new Boolean[this.lightEngine.maxSection - this.lightEngine.minSection + 1];
+                }
+                this.changedSectionSet[y - this.lightEngine.minSection] = newEmptyValue;
+            }
+
+            protected void addLightTask(final BooleanSupplier lightTask) {
+                if (this.lightTasks == null) {
+                    this.lightTasks = new ArrayList<>();
+                }
+                this.lightTasks.add(lightTask);
+            }
+
+            protected void addEdgeChecksSky(final ShortCollection values) {
+                if (this.queuedEdgeChecksSky == null) {
+                    this.queuedEdgeChecksSky = new ShortOpenHashSet(Math.max(8, values.size()));
+                }
+                this.queuedEdgeChecksSky.addAll(values);
+            }
+
+            protected void addEdgeChecksBlock(final ShortCollection values) {
+                if (this.queuedEdgeChecksBlock == null) {
+                    this.queuedEdgeChecksBlock = new ShortOpenHashSet(Math.max(8, values.size()));
+                }
+                this.queuedEdgeChecksBlock.addAll(values);
+            }
+
+            protected final void runTasks() {
+                boolean litChunk = false;
+                if (this.lightTasks != null) {
+                    for (final BooleanSupplier run : this.lightTasks) {
+                        if (run.getAsBoolean()) {
+                            litChunk = true;
+                            break;
+                        }
+                    }
+                }
+
+                if (!litChunk) {
+                    final SkyStarLightEngine skyEngine = this.lightEngine.getSkyLightEngine();
+                    final BlockStarLightEngine blockEngine = this.lightEngine.getBlockLightEngine();
+                    try {
+                        final long coordinate = this.chunkCoordinate;
+                        final int chunkX = CoordinateUtils.getChunkX(coordinate);
+                        final int chunkZ = CoordinateUtils.getChunkZ(coordinate);
+
+                        final Set<BlockPos> positions = this.changedPositions;
+                        final Boolean[] sectionChanges = this.changedSectionSet;
+
+                        if (skyEngine != null && (!positions.isEmpty() || sectionChanges != null)) {
+                            skyEngine.blocksChangedInChunk(this.lightEngine.getLightAccess(), chunkX, chunkZ, positions, sectionChanges);
+                        }
+                        if (blockEngine != null && (!positions.isEmpty() || sectionChanges != null)) {
+                            blockEngine.blocksChangedInChunk(this.lightEngine.getLightAccess(), chunkX, chunkZ, positions, sectionChanges);
+                        }
+
+                        if (skyEngine != null && this.queuedEdgeChecksSky != null) {
+                            skyEngine.checkChunkEdges(this.lightEngine.getLightAccess(), chunkX, chunkZ, this.queuedEdgeChecksSky);
+                        }
+                        if (blockEngine != null && this.queuedEdgeChecksBlock != null) {
+                            blockEngine.checkChunkEdges(this.lightEngine.getLightAccess(), chunkX, chunkZ, this.queuedEdgeChecksBlock);
+                        }
+                    } finally {
+                        this.lightEngine.releaseSkyLightEngine(skyEngine);
+                        this.lightEngine.releaseBlockLightEngine(blockEngine);
+                    }
+                }
+
+                Runnable run;
+                while ((run = this.onComplete.pollOrBlockAdds()) != null) {
+                    run.run();
+                }
+            }
+        }
+    }
+
+    public static final class ClientLightQueue extends LightQueue {
+
+        private final Long2ObjectLinkedOpenHashMap<ClientChunkTasks> chunkTasks = new Long2ObjectLinkedOpenHashMap<>();
+
+        public ClientLightQueue(final StarLightInterface lightInterface) {
+            super(lightInterface);
+        }
+
+        @Override
+        public synchronized boolean isEmpty() {
+            return this.chunkTasks.isEmpty();
+        }
+
+        // must hold synchronized lock on this object
+        private ClientChunkTasks getOrCreate(final long key) {
+            return this.chunkTasks.computeIfAbsent(key, (final long keyInMap) -> {
+                return new ClientChunkTasks(keyInMap, ClientLightQueue.this.lightInterface, ClientLightQueue.this);
+            });
+        }
+
+        @Override
+        public synchronized ClientChunkTasks queueBlockChange(final BlockPos pos) {
+            final ClientChunkTasks tasks = this.getOrCreate(CoordinateUtils.getChunkKey(pos));
+            tasks.addChangedPosition(pos);
+            return tasks;
+        }
+
+        @Override
+        public synchronized ClientChunkTasks queueSectionChange(final SectionPos pos, final boolean newEmptyValue) {
+            final ClientChunkTasks tasks = this.getOrCreate(CoordinateUtils.getChunkKey(pos));
+
+            tasks.setChangedSection(pos.getY(), Boolean.valueOf(newEmptyValue));
+
+            return tasks;
+        }
+
+        @Override
+        public synchronized ClientChunkTasks queueChunkSkylightEdgeCheck(final SectionPos pos, final ShortCollection sections) {
+            final ClientChunkTasks tasks = this.getOrCreate(CoordinateUtils.getChunkKey(pos));
+
+            tasks.addEdgeChecksSky(sections);
+
+            return tasks;
+        }
+
+        @Override
+        public synchronized ClientChunkTasks queueChunkBlocklightEdgeCheck(final SectionPos pos, final ShortCollection sections) {
+            final ClientChunkTasks tasks = this.getOrCreate(CoordinateUtils.getChunkKey(pos));
+
+            tasks.addEdgeChecksBlock(sections);
+
+            return tasks;
+        }
+
+        public synchronized ClientChunkTasks removeFirstTask() {
+            if (this.chunkTasks.isEmpty()) {
+                return null;
+            }
+            return this.chunkTasks.removeFirst();
+        }
+
+        public void drainTasks() {
+            ClientChunkTasks task;
+            while ((task = this.removeFirstTask()) != null) {
+                task.runTasks();
+            }
+        }
+
+        public static final class ClientChunkTasks extends ChunkTasks {
+
+            public ClientChunkTasks(final long chunkCoordinate, final StarLightInterface lightEngine, final ClientLightQueue queue) {
+                super(chunkCoordinate, lightEngine, queue);
+            }
+
+            @Override
+            public void run() {
+                this.runTasks();
+            }
+        }
+    }
+
+    public static final class ServerLightQueue extends LightQueue {
+
+        private final ConcurrentLong2ReferenceChainedHashTable<ServerChunkTasks> chunkTasks = new ConcurrentLong2ReferenceChainedHashTable<>();
+
+        public ServerLightQueue(final StarLightInterface lightInterface) {
+            super(lightInterface);
+        }
+
+        public void lowerPriority(final int chunkX, final int chunkZ, final Priority priority) {
+            final ServerChunkTasks task = this.chunkTasks.get(CoordinateUtils.getChunkKey(chunkX, chunkZ));
+            if (task != null) {
+                task.lowerPriority(priority);
+            }
+        }
+
+        public void setPriority(final int chunkX, final int chunkZ, final Priority priority) {
+            final ServerChunkTasks task = this.chunkTasks.get(CoordinateUtils.getChunkKey(chunkX, chunkZ));
+            if (task != null) {
+                task.setPriority(priority);
+            }
+        }
+
+        public void raisePriority(final int chunkX, final int chunkZ, final Priority priority) {
+            final ServerChunkTasks task = this.chunkTasks.get(CoordinateUtils.getChunkKey(chunkX, chunkZ));
+            if (task != null) {
+                task.raisePriority(priority);
+            }
+        }
+
+        public Priority getPriority(final int chunkX, final int chunkZ) {
+            final ServerChunkTasks task = this.chunkTasks.get(CoordinateUtils.getChunkKey(chunkX, chunkZ));
+            if (task != null) {
+                return task.getPriority();
+            }
+
+            return Priority.COMPLETING;
+        }
+
+        @Override
+        public boolean isEmpty() {
+            return this.chunkTasks.isEmpty();
+        }
+
+        @Override
+        public ServerChunkTasks queueBlockChange(final BlockPos pos) {
+            final ServerChunkTasks ret = this.chunkTasks.compute(CoordinateUtils.getChunkKey(pos), (final long keyInMap, ServerChunkTasks valueInMap) -> {
+                if (valueInMap == null) {
+                    valueInMap = new ServerChunkTasks(
+                            keyInMap, ServerLightQueue.this.lightInterface, ServerLightQueue.this
+                    );
+                }
+                valueInMap.addChangedPosition(pos);
+                return valueInMap;
+            });
+
+            ret.schedule();
+
+            return ret;
+        }
+
+        @Override
+        public ServerChunkTasks queueSectionChange(final SectionPos pos, final boolean newEmptyValue) {
+            final ServerChunkTasks ret = this.chunkTasks.compute(CoordinateUtils.getChunkKey(pos), (final long keyInMap, ServerChunkTasks valueInMap) -> {
+                if (valueInMap == null) {
+                    valueInMap = new ServerChunkTasks(
+                            keyInMap, ServerLightQueue.this.lightInterface, ServerLightQueue.this
+                    );
+                }
+
+                valueInMap.setChangedSection(pos.getY(), Boolean.valueOf(newEmptyValue));
+
+                return valueInMap;
+            });
+
+            ret.schedule();
+
+            return ret;
+        }
+
+        public ServerChunkTasks queueChunkLightTask(final ChunkPos pos, final BooleanSupplier lightTask, final Priority priority) {
+            final ServerChunkTasks ret = this.chunkTasks.compute(CoordinateUtils.getChunkKey(pos), (final long keyInMap, ServerChunkTasks valueInMap) -> {
+                if (valueInMap == null) {
+                    valueInMap = new ServerChunkTasks(
+                            keyInMap, ServerLightQueue.this.lightInterface, ServerLightQueue.this, priority
+                    );
+                }
+
+                valueInMap.addLightTask(lightTask);
+
+                return valueInMap;
+            });
+
+            ret.schedule();
+
+            return ret;
+        }
+
+        @Override
+        public ServerChunkTasks queueChunkSkylightEdgeCheck(final SectionPos pos, final ShortCollection sections) {
+            final ServerChunkTasks ret = this.chunkTasks.compute(CoordinateUtils.getChunkKey(pos), (final long keyInMap, ServerChunkTasks valueInMap) -> {
+                if (valueInMap == null) {
+                    valueInMap = new ServerChunkTasks(
+                            keyInMap, ServerLightQueue.this.lightInterface, ServerLightQueue.this
+                    );
+                }
+
+                valueInMap.addEdgeChecksSky(sections);
+
+                return valueInMap;
+            });
+
+            ret.schedule();
+
+            return ret;
+        }
+
+        @Override
+        public ServerChunkTasks queueChunkBlocklightEdgeCheck(final SectionPos pos, final ShortCollection sections) {
+            final ServerChunkTasks ret = this.chunkTasks.compute(CoordinateUtils.getChunkKey(pos), (final long keyInMap, ServerChunkTasks valueInMap) -> {
+                if (valueInMap == null) {
+                    valueInMap = new ServerChunkTasks(
+                            keyInMap, ServerLightQueue.this.lightInterface, ServerLightQueue.this
+                    );
+                }
+
+                valueInMap.addEdgeChecksBlock(sections);
+
+                return valueInMap;
+            });
+
+            ret.schedule();
+
+            return ret;
+        }
+
+        public static final class ServerChunkTasks extends ChunkTasks {
+
+            private final AtomicBoolean ticketAdded = new AtomicBoolean();
+            private final PrioritisedExecutor.PrioritisedTask task;
+
+            public ServerChunkTasks(final long chunkCoordinate, final StarLightInterface lightEngine,
+                                    final ServerLightQueue queue) {
+                this(chunkCoordinate, lightEngine, queue, Priority.NORMAL);
+            }
+
+            public ServerChunkTasks(final long chunkCoordinate, final StarLightInterface lightEngine,
+                                    final ServerLightQueue queue, final Priority priority) {
+                super(chunkCoordinate, lightEngine, queue);
+                this.task = ((ChunkSystemServerLevel)(ServerLevel)lightEngine.getWorld()).moonrise$getChunkTaskScheduler().radiusAwareScheduler.createTask(
+                        CoordinateUtils.getChunkX(chunkCoordinate), CoordinateUtils.getChunkZ(chunkCoordinate),
+                        ((ChunkSystemChunkStatus)ChunkStatus.LIGHT).moonrise$getWriteRadius(), this, priority
+                );
+            }
+
+            public boolean markTicketAdded() {
+                return !this.ticketAdded.get() && !this.ticketAdded.getAndSet(true);
+            }
+
+            public void schedule() {
+                this.task.queue();
+            }
+
+            public boolean cancel() {
+                return this.task.cancel();
+            }
+
+            public Priority getPriority() {
+                return this.task.getPriority();
+            }
+
+            public void lowerPriority(final Priority priority) {
+                this.task.lowerPriority(priority);
+            }
+
+            public void setPriority(final Priority priority) {
+                this.task.setPriority(priority);
+            }
+
+            public void raisePriority(final Priority priority) {
+                this.task.raisePriority(priority);
+            }
+
+            @Override
+            public void run() {
+                ((ServerLightQueue)this.queue).chunkTasks.remove(this.chunkCoordinate, this);
+
+                this.runTasks();
+            }
+        }
+    }
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/starlight/light/StarLightLightingProvider.java b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/light/StarLightLightingProvider.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/light/StarLightLightingProvider.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.starlight.light;
+
+import net.minecraft.core.SectionPos;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.LightLayer;
+import net.minecraft.world.level.chunk.DataLayer;
+import net.minecraft.world.level.chunk.LevelChunk;
+import java.util.Collection;
+import java.util.function.Consumer;
+import java.util.function.IntConsumer;
+
+public interface StarLightLightingProvider {
+
+    public StarLightInterface starlight$getLightEngine();
+
+    public void starlight$clientUpdateLight(final LightLayer lightType, final SectionPos pos,
+                                            final DataLayer nibble, final boolean trustEdges);
+
+    public void starlight$clientRemoveLightData(final ChunkPos chunkPos);
+
+    public void starlight$clientChunkLoad(final ChunkPos pos, final LevelChunk chunk);
+
+    public default int starlight$serverRelightChunks(final Collection<ChunkPos> chunks,
+                                                      final Consumer<ChunkPos> chunkLightCallback,
+                                                      final IntConsumer onComplete) throws UnsupportedOperationException {
+        throw new UnsupportedOperationException();
+    }
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/starlight/storage/StarlightSectionData.java b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/storage/StarlightSectionData.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/storage/StarlightSectionData.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.starlight.storage;
+
+public interface StarlightSectionData {
+
+    public int starlight$getBlockLightState();
+
+    public void starlight$setBlockLightState(final int state);
+
+    public int starlight$getSkyLightState();
+
+    public void starlight$setSkyLightState(final int state);
+
+}
diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/starlight/util/SaveUtil.java b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/util/SaveUtil.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/starlight/util/SaveUtil.java
@@ -0,0 +0,0 @@
+package ca.spottedleaf.moonrise.patches.starlight.util;
+
+import ca.spottedleaf.moonrise.common.util.WorldUtil;
+import ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk;
+import ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray;
+import ca.spottedleaf.moonrise.patches.starlight.light.StarLightEngine;
+import com.mojang.logging.LogUtils;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.ListTag;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.status.ChunkStatus;
+import org.slf4j.Logger;
+
+// note: keep in-sync with SerializableChunkDataMixin
+public final class SaveUtil {
+
+    private static final Logger LOGGER = LogUtils.getLogger();
+
+    public static final int STARLIGHT_LIGHT_VERSION = 9;
+
+    public static int getLightVersion() {
+        return STARLIGHT_LIGHT_VERSION;
+    }
+
+    public static final String BLOCKLIGHT_STATE_TAG = "starlight.blocklight_state";
+    public static final String SKYLIGHT_STATE_TAG = "starlight.skylight_state";
+    public static final String STARLIGHT_VERSION_TAG = "starlight.light_version";
+
+    public static void saveLightHook(final Level world, final ChunkAccess chunk, final CompoundTag nbt) {
+        try {
+            saveLightHookReal(world, chunk, nbt);
+        } catch (final Throwable ex) {
+            // failing to inject is not fatal so we catch anything here. if it fails, it will have correctly set lit to false
+            // for Vanilla to relight on load and it will not set our lit tag so we will relight on load
+            LOGGER.warn("Failed to inject light data into save data for chunk " + chunk.getPos() + ", chunk light will be recalculated on its next load", ex);
+        }
+    }
+
+    private static void saveLightHookReal(final Level world, final ChunkAccess chunk, final CompoundTag tag) {
+        if (tag == null) {
+            return;
+        }
+
+        final int minSection = WorldUtil.getMinLightSection(world);
+        final int maxSection = WorldUtil.getMaxLightSection(world);
+
+        SWMRNibbleArray[] blockNibbles = ((StarlightChunk)chunk).starlight$getBlockNibbles();
+        SWMRNibbleArray[] skyNibbles = ((StarlightChunk)chunk).starlight$getSkyNibbles();
+
+        boolean lit = chunk.isLightCorrect() || !(world instanceof ServerLevel);
+        // diff start - store our tag for whether light data is init'd
+        if (lit) {
+            tag.putBoolean("isLightOn", false);
+        }
+        // diff end - store our tag for whether light data is init'd
+        ChunkStatus status = ChunkStatus.byName(tag.getString("Status"));
+
+        CompoundTag[] sections = new CompoundTag[maxSection - minSection + 1];
+
+        ListTag sectionsStored = tag.getList("sections", 10);
+
+        for (int i = 0; i < sectionsStored.size(); ++i) {
+            CompoundTag sectionStored = sectionsStored.getCompound(i);
+            int k = sectionStored.getByte("Y");
+
+            // strip light data
+            sectionStored.remove("BlockLight");
+            sectionStored.remove("SkyLight");
+
+            if (!sectionStored.isEmpty()) {
+                sections[k - minSection] = sectionStored;
+            }
+        }
+
+        if (lit && status.isOrAfter(ChunkStatus.LIGHT)) {
+            for (int i = minSection; i <= maxSection; ++i) {
+                SWMRNibbleArray.SaveState blockNibble = blockNibbles[i - minSection].getSaveState();
+                SWMRNibbleArray.SaveState skyNibble = skyNibbles[i - minSection].getSaveState();
+                if (blockNibble != null || skyNibble != null) {
+                    CompoundTag section = sections[i - minSection];
+                    if (section == null) {
+                        section = new CompoundTag();
+                        section.putByte("Y", (byte)i);
+                        sections[i - minSection] = section;
+                    }
+
+                    // we store under the same key so mod programs editing nbt
+                    // can still read the data, hopefully.
+                    // however, for compatibility we store chunks as unlit so vanilla
+                    // is forced to re-light them if it encounters our data. It's too much of a burden
+                    // to try and maintain compatibility with a broken and inferior skylight management system.
+
+                    if (blockNibble != null) {
+                        if (blockNibble.data != null) {
+                            section.putByteArray("BlockLight", blockNibble.data);
+                        }
+                        section.putInt(BLOCKLIGHT_STATE_TAG, blockNibble.state);
+                    }
+
+                    if (skyNibble != null) {
+                        if (skyNibble.data != null) {
+                            section.putByteArray("SkyLight", skyNibble.data);
+                        }
+                        section.putInt(SKYLIGHT_STATE_TAG, skyNibble.state);
+                    }
+                }
+            }
+        }
+
+        // rewrite section list
+        sectionsStored.clear();
+        for (CompoundTag section : sections) {
+            if (section != null) {
+                sectionsStored.add(section);
+            }
+        }
+        tag.put("sections", sectionsStored);
+        if (lit) {
+            tag.putInt(STARLIGHT_VERSION_TAG, STARLIGHT_LIGHT_VERSION); // only mark as fully lit after we have successfully injected our data
+        }
+    }
+
+    public static void loadLightHook(final Level world, final ChunkPos pos, final CompoundTag tag, final ChunkAccess into) {
+        try {
+            loadLightHookReal(world, pos, tag, into);
+        } catch (final Throwable ex) {
+            // failing to inject is not fatal so we catch anything here. if it fails, then we simply relight. Not a problem, we get correct
+            // lighting in both cases.
+            LOGGER.warn("Failed to load light for chunk " + pos + ", light will be recalculated", ex);
+        }
+    }
+
+    private static void loadLightHookReal(final Level world, final ChunkPos pos, final CompoundTag tag, final ChunkAccess into) {
+        if (into == null) {
+            return;
+        }
+        final int minSection = WorldUtil.getMinLightSection(world);
+        final int maxSection = WorldUtil.getMaxLightSection(world);
+
+        into.setLightCorrect(false); // mark as unlit in case we fail parsing
+
+        SWMRNibbleArray[] blockNibbles = StarLightEngine.getFilledEmptyLight(world);
+        SWMRNibbleArray[] skyNibbles = StarLightEngine.getFilledEmptyLight(world);
+
+
+        // start copy from the original method
+        boolean lit = tag.get("isLightOn") != null && tag.getInt(STARLIGHT_VERSION_TAG) == STARLIGHT_LIGHT_VERSION;
+        boolean canReadSky = world.dimensionType().hasSkyLight();
+        ChunkStatus status = ChunkStatus.byName(tag.getString("Status"));
+        if (lit && status.isOrAfter(ChunkStatus.LIGHT)) { // diff - we add the status check here
+            ListTag sections = tag.getList("sections", 10);
+
+            for (int i = 0; i < sections.size(); ++i) {
+                CompoundTag sectionData = sections.getCompound(i);
+                int y = sectionData.getByte("Y");
+
+                if (sectionData.contains("BlockLight", 7)) {
+                    // this is where our diff is
+                    blockNibbles[y - minSection] = new SWMRNibbleArray(sectionData.getByteArray("BlockLight").clone(), sectionData.getInt(BLOCKLIGHT_STATE_TAG)); // clone for data safety
+                } else {
+                    blockNibbles[y - minSection] = new SWMRNibbleArray(null, sectionData.getInt(BLOCKLIGHT_STATE_TAG));
+                }
+
+                if (canReadSky) {
+                    if (sectionData.contains("SkyLight", 7)) {
+                        // we store under the same key so mod programs editing nbt
+                        // can still read the data, hopefully.
+                        // however, for compatibility we store chunks as unlit so vanilla
+                        // is forced to re-light them if it encounters our data. It's too much of a burden
+                        // to try and maintain compatibility with a broken and inferior skylight management system.
+                        skyNibbles[y - minSection] = new SWMRNibbleArray(sectionData.getByteArray("SkyLight").clone(), sectionData.getInt(SKYLIGHT_STATE_TAG)); // clone for data safety
+                    } else {
+                        skyNibbles[y - minSection] = new SWMRNibbleArray(null, sectionData.getInt(SKYLIGHT_STATE_TAG));
+                    }
+                }
+            }
+        }
+        // end copy from vanilla
+
+        ((StarlightChunk)into).starlight$setBlockNibbles(blockNibbles);
+        ((StarlightChunk)into).starlight$setSkyNibbles(skyNibbles);
+        into.setLightCorrect(lit); // now we set lit here, only after we've correctly parsed data
+    }
+
+    private SaveUtil() {}
+}
diff --git a/src/main/java/io/papermc/paper/FeatureHooks.java b/src/main/java/io/papermc/paper/FeatureHooks.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/io/papermc/paper/FeatureHooks.java
+++ b/src/main/java/io/papermc/paper/FeatureHooks.java
@@ -0,0 +0,0 @@
 package io.papermc.paper;
 
 import io.papermc.paper.command.PaperSubcommand;
+import io.papermc.paper.command.subcommands.ChunkDebugCommand;
+import io.papermc.paper.command.subcommands.FixLightCommand;
 import it.unimi.dsi.fastutil.longs.LongOpenHashSet;
 import it.unimi.dsi.fastutil.longs.LongSet;
 import it.unimi.dsi.fastutil.longs.LongSets;
@@ -0,0 +0,0 @@ import org.bukkit.World;
 public final class FeatureHooks {
 
     public static void initChunkTaskScheduler(final boolean useParallelGen) {
+        ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler.init(useParallelGen); // Paper - Chunk system
     }
 
     public static void registerPaperCommands(final Map<Set<String>, PaperSubcommand> commands) {
+        commands.put(Set.of("fixlight"), new FixLightCommand()); // Paper - rewrite chunk system
+        commands.put(Set.of("debug", "chunkinfo", "holderinfo"), new ChunkDebugCommand());  // Paper - rewrite chunk system
     }
 
     public static LevelChunkSection createSection(final Registry<Biome> biomeRegistry, final Level level, final ChunkPos chunkPos, final int chunkSection) {
diff --git a/src/main/java/io/papermc/paper/command/subcommands/ChunkDebugCommand.java b/src/main/java/io/papermc/paper/command/subcommands/ChunkDebugCommand.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/io/papermc/paper/command/subcommands/ChunkDebugCommand.java
@@ -0,0 +0,0 @@
+package io.papermc.paper.command.subcommands;
+
+import ca.spottedleaf.moonrise.common.util.JsonUtil;
+import ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler;
+import ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder;
+import io.papermc.paper.command.CommandUtil;
+import io.papermc.paper.command.PaperSubcommand;
+import java.io.File;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Locale;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import net.minecraft.world.level.chunk.ImposterProtoChunk;
+import net.minecraft.world.level.chunk.LevelChunk;
+import net.minecraft.world.level.chunk.ProtoChunk;
+import org.bukkit.Bukkit;
+import org.bukkit.command.CommandSender;
+import org.bukkit.craftbukkit.CraftWorld;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.checkerframework.framework.qual.DefaultQualifier;
+
+import static net.kyori.adventure.text.Component.text;
+import static net.kyori.adventure.text.format.NamedTextColor.BLUE;
+import static net.kyori.adventure.text.format.NamedTextColor.DARK_AQUA;
+import static net.kyori.adventure.text.format.NamedTextColor.GREEN;
+import static net.kyori.adventure.text.format.NamedTextColor.RED;
+
+@DefaultQualifier(NonNull.class)
+public final class ChunkDebugCommand implements PaperSubcommand {
+    @Override
+    public boolean execute(final CommandSender sender, final String subCommand, final String[] args) {
+        switch (subCommand) {
+            case "debug" -> this.doDebug(sender, args);
+            case "chunkinfo" -> this.doChunkInfo(sender, args);
+            case "holderinfo" -> this.doHolderInfo(sender, args);
+        }
+        return true;
+    }
+
+    @Override
+    public List<String> tabComplete(final CommandSender sender, final String subCommand, final String[] args) {
+        switch (subCommand) {
+            case "debug" -> {
+                if (args.length == 1) {
+                    return CommandUtil.getListMatchingLast(sender, args, "help", "chunks");
+                }
+            }
+            case "holderinfo" -> {
+                List<String> worldNames = new ArrayList<>();
+                worldNames.add("*");
+                for (org.bukkit.World world : Bukkit.getWorlds()) {
+                    worldNames.add(world.getName());
+                }
+                if (args.length == 1) {
+                    return CommandUtil.getListMatchingLast(sender, args, worldNames);
+                }
+            }
+            case "chunkinfo" -> {
+                List<String> worldNames = new ArrayList<>();
+                worldNames.add("*");
+                for (org.bukkit.World world : Bukkit.getWorlds()) {
+                    worldNames.add(world.getName());
+                }
+                if (args.length == 1) {
+                    return CommandUtil.getListMatchingLast(sender, args, worldNames);
+                }
+            }
+        }
+        return Collections.emptyList();
+    }
+
+    private void doChunkInfo(final CommandSender sender, final String[] args) {
+        List<org.bukkit.World> worlds;
+        if (args.length < 1 || args[0].equals("*")) {
+            worlds = Bukkit.getWorlds();
+        } else {
+            worlds = new ArrayList<>(args.length);
+            for (final String arg : args) {
+                org.bukkit.@Nullable World world = Bukkit.getWorld(arg);
+                if (world == null) {
+                    sender.sendMessage(text("World '" + arg + "' is invalid", RED));
+                    return;
+                }
+                worlds.add(world);
+            }
+        }
+
+        int accumulatedTotal = 0;
+        int accumulatedInactive = 0;
+        int accumulatedBorder = 0;
+        int accumulatedTicking = 0;
+        int accumulatedEntityTicking = 0;
+
+        for (final org.bukkit.World bukkitWorld : worlds) {
+            final ServerLevel world = ((CraftWorld) bukkitWorld).getHandle();
+
+            int total = 0;
+            int inactive = 0;
+            int full = 0;
+            int blockTicking = 0;
+            int entityTicking = 0;
+
+            for (final NewChunkHolder holder : ((ChunkSystemServerLevel)world).moonrise$getChunkTaskScheduler().chunkHolderManager.getChunkHolders()) {
+                final NewChunkHolder.ChunkCompletion completion = holder.getLastChunkCompletion();
+                final ChunkAccess chunk = completion == null ? null : completion.chunk();
+
+                if (!(chunk instanceof LevelChunk fullChunk)) {
+                    continue;
+                }
+
+                ++total;
+
+                switch (holder.getChunkStatus()) {
+                    case INACCESSIBLE: {
+                        ++inactive;
+                        break;
+                    }
+                    case FULL: {
+                        ++full;
+                        break;
+                    }
+                    case BLOCK_TICKING: {
+                        ++blockTicking;
+                        break;
+                    }
+                    case ENTITY_TICKING: {
+                        ++entityTicking;
+                        break;
+                    }
+                }
+            }
+
+            accumulatedTotal += total;
+            accumulatedInactive += inactive;
+            accumulatedBorder += full;
+            accumulatedTicking += blockTicking;
+            accumulatedEntityTicking += entityTicking;
+
+            sender.sendMessage(text().append(text("Chunks in ", BLUE), text(bukkitWorld.getName(), GREEN), text(":")));
+            sender.sendMessage(text().color(DARK_AQUA).append(
+                text("Total: ", BLUE), text(total),
+                text(" Inactive: ", BLUE), text(inactive),
+                text(" Full: ", BLUE), text(full),
+                text(" Block Ticking: ", BLUE), text(blockTicking),
+                text(" Entity Ticking: ", BLUE), text(entityTicking)
+            ));
+        }
+        if (worlds.size() > 1) {
+            sender.sendMessage(text().append(text("Chunks in ", BLUE), text("all listed worlds", GREEN), text(":", DARK_AQUA)));
+            sender.sendMessage(text().color(DARK_AQUA).append(
+                text("Total: ", BLUE), text(accumulatedTotal),
+                text(" Inactive: ", BLUE), text(accumulatedInactive),
+                text(" Full: ", BLUE), text(accumulatedBorder),
+                text(" Block Ticking: ", BLUE), text(accumulatedTicking),
+                text(" Entity Ticking: ", BLUE), text(accumulatedEntityTicking)
+            ));
+        }
+    }
+
+    private void doHolderInfo(final CommandSender sender, final String[] args) {
+        List<org.bukkit.World> worlds;
+        if (args.length < 1 || args[0].equals("*")) {
+            worlds = Bukkit.getWorlds();
+        } else {
+            worlds = new ArrayList<>(args.length);
+            for (final String arg : args) {
+                org.bukkit.@Nullable World world = Bukkit.getWorld(arg);
+                if (world == null) {
+                    sender.sendMessage(text("World '" + arg + "' is invalid", RED));
+                    return;
+                }
+                worlds.add(world);
+            }
+        }
+
+        int accumulatedTotal = 0;
+        int accumulatedCanUnload = 0;
+        int accumulatedNull = 0;
+        int accumulatedReadOnly = 0;
+        int accumulatedProtoChunk = 0;
+        int accumulatedFullChunk = 0;
+
+        for (final org.bukkit.World bukkitWorld : worlds) {
+            final ServerLevel world = ((CraftWorld) bukkitWorld).getHandle();
+
+            int total = 0;
+            int canUnload = 0;
+            int nullChunks = 0;
+            int readOnly = 0;
+            int protoChunk = 0;
+            int fullChunk = 0;
+
+            for (final NewChunkHolder holder : ((ChunkSystemServerLevel)world).moonrise$getChunkTaskScheduler().chunkHolderManager.getChunkHolders()) {
+                final NewChunkHolder.ChunkCompletion completion = holder.getLastChunkCompletion();
+                final ChunkAccess chunk = completion == null ? null : completion.chunk();
+
+                ++total;
+
+                if (chunk == null) {
+                    ++nullChunks;
+                } else if (chunk instanceof ImposterProtoChunk) {
+                    ++readOnly;
+                } else if (chunk instanceof ProtoChunk) {
+                    ++protoChunk;
+                } else if (chunk instanceof LevelChunk) {
+                    ++fullChunk;
+                }
+
+                if (holder.isSafeToUnload() == null) {
+                    ++canUnload;
+                }
+            }
+
+            accumulatedTotal += total;
+            accumulatedCanUnload += canUnload;
+            accumulatedNull += nullChunks;
+            accumulatedReadOnly += readOnly;
+            accumulatedProtoChunk += protoChunk;
+            accumulatedFullChunk += fullChunk;
+
+            sender.sendMessage(text().append(text("Chunks in ", BLUE), text(bukkitWorld.getName(), GREEN), text(":")));
+            sender.sendMessage(text().color(DARK_AQUA).append(
+                text("Total: ", BLUE), text(total),
+                text(" Unloadable: ", BLUE), text(canUnload),
+                text(" Null: ", BLUE), text(nullChunks),
+                text(" ReadOnly: ", BLUE), text(readOnly),
+                text(" Proto: ", BLUE), text(protoChunk),
+                text(" Full: ", BLUE), text(fullChunk)
+            ));
+        }
+        if (worlds.size() > 1) {
+            sender.sendMessage(text().append(text("Chunks in ", BLUE), text("all listed worlds", GREEN), text(":", DARK_AQUA)));
+            sender.sendMessage(text().color(DARK_AQUA).append(
+                text("Total: ", BLUE), text(accumulatedTotal),
+                text(" Unloadable: ", BLUE), text(accumulatedCanUnload),
+                text(" Null: ", BLUE), text(accumulatedNull),
+                text(" ReadOnly: ", BLUE), text(accumulatedReadOnly),
+                text(" Proto: ", BLUE), text(accumulatedProtoChunk),
+                text(" Full: ", BLUE), text(accumulatedFullChunk)
+            ));
+        }
+    }
+
+    private void doDebug(final CommandSender sender, final String[] args) {
+        if (args.length < 1) {
+            sender.sendMessage(text("Use /paper debug [chunks] help for more information on a specific command", RED));
+            return;
+        }
+
+        final String debugType = args[0].toLowerCase(Locale.ROOT);
+        switch (debugType) {
+            case "chunks" -> {
+                if (args.length >= 2 && args[1].toLowerCase(Locale.ROOT).equals("help")) {
+                    sender.sendMessage(text("Use /paper debug chunks to dump loaded chunk information to a file", RED));
+                    break;
+                }
+                final File file = ChunkTaskScheduler.getChunkDebugFile();
+                sender.sendMessage(text("Writing chunk information dump to " + file, GREEN));
+                try {
+                    JsonUtil.writeJson(ChunkTaskScheduler.debugAllWorlds(MinecraftServer.getServer()), file);
+                    sender.sendMessage(text("Successfully written chunk information!", GREEN));
+                } catch (Throwable thr) {
+                    MinecraftServer.LOGGER.warn("Failed to dump chunk information to file " + file.toString(), thr);
+                    sender.sendMessage(text("Failed to dump chunk information, see console", RED));
+                }
+            }
+            // "help" & default
+            default -> sender.sendMessage(text("Use /paper debug [chunks] help for more information on a specific command", RED));
+        }
+    }
+
+}
diff --git a/src/main/java/io/papermc/paper/command/subcommands/FixLightCommand.java b/src/main/java/io/papermc/paper/command/subcommands/FixLightCommand.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/io/papermc/paper/command/subcommands/FixLightCommand.java
@@ -0,0 +0,0 @@
+package io.papermc.paper.command.subcommands;
+
+import ca.spottedleaf.moonrise.patches.starlight.light.StarLightLightingProvider;
+import io.papermc.paper.command.PaperSubcommand;
+import io.papermc.paper.util.MCUtil;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.server.level.ThreadedLevelLightEngine;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.chunk.ChunkAccess;
+import org.bukkit.command.CommandSender;
+import org.bukkit.craftbukkit.entity.CraftPlayer;
+import org.bukkit.entity.Player;
+import org.checkerframework.checker.nullness.qual.NonNull;
+import org.checkerframework.checker.nullness.qual.Nullable;
+import org.checkerframework.framework.qual.DefaultQualifier;
+
+import java.text.DecimalFormat;
+
+import static net.kyori.adventure.text.Component.text;
+import static net.kyori.adventure.text.format.NamedTextColor.BLUE;
+import static net.kyori.adventure.text.format.NamedTextColor.DARK_AQUA;
+import static net.kyori.adventure.text.format.NamedTextColor.RED;
+
+@DefaultQualifier(NonNull.class)
+public final class FixLightCommand implements PaperSubcommand {
+
+    private static final ThreadLocal<DecimalFormat> ONE_DECIMAL_PLACES = ThreadLocal.withInitial(() -> {
+        return new DecimalFormat("#,##0.0");
+    });
+
+    @Override
+    public boolean execute(final CommandSender sender, final String subCommand, final String[] args) {
+        this.doFixLight(sender, args);
+        return true;
+    }
+
+    private void doFixLight(final CommandSender sender, final String[] args) {
+        if (!(sender instanceof Player)) {
+            sender.sendMessage(text("Only players can use this command", RED));
+            return;
+        }
+        @Nullable Runnable post = null;
+        int radius = 2;
+        if (args.length > 0) {
+            try {
+                final int parsed = Integer.parseInt(args[0]);
+                if (parsed < 0) {
+                    sender.sendMessage(text("Radius cannot be negative!", RED));
+                    return;
+                }
+                final int maxRadius = 32;
+                radius = Math.min(maxRadius, parsed);
+                if (radius != parsed) {
+                    post = () -> sender.sendMessage(text("Radius '" + parsed + "' was not in the required range [0, " + maxRadius + "], it was lowered to the maximum (" + maxRadius + " chunks).", RED));
+                }
+            } catch (final Exception e) {
+                sender.sendMessage(text("'" + args[0] + "' is not a valid number.", RED));
+                return;
+            }
+        }
+
+        CraftPlayer player = (CraftPlayer) sender;
+        ServerPlayer handle = player.getHandle();
+        ServerLevel world = (ServerLevel) handle.level();
+        ThreadedLevelLightEngine lightengine = world.getChunkSource().getLightEngine();
+        this.starlightFixLight(handle, world, lightengine, radius, post);
+    }
+
+    private void starlightFixLight(
+        final ServerPlayer sender,
+        final ServerLevel world,
+        final ThreadedLevelLightEngine lightengine,
+        final int radius,
+        final @Nullable Runnable done
+    ) {
+        final long start = System.nanoTime();
+        final java.util.LinkedHashSet<ChunkPos> chunks = new java.util.LinkedHashSet<>(MCUtil.getSpiralOutChunks(sender.blockPosition(), radius)); // getChunkCoordinates is actually just bad mappings, this function rets position as blockpos
+
+        final int[] pending = new int[1];
+        for (java.util.Iterator<ChunkPos> iterator = chunks.iterator(); iterator.hasNext(); ) {
+            final ChunkPos chunkPos = iterator.next();
+
+            final @Nullable ChunkAccess chunk = (ChunkAccess) world.getChunkSource().getChunkForLighting(chunkPos.x, chunkPos.z);
+            if (chunk == null || !chunk.isLightCorrect() || !chunk.getPersistedStatus().isOrAfter(net.minecraft.world.level.chunk.status.ChunkStatus.LIGHT)) {
+                // cannot relight this chunk
+                iterator.remove();
+                continue;
+            }
+
+            ++pending[0];
+        }
+
+        final int[] relitChunks = new int[1];
+        ((StarLightLightingProvider)lightengine).starlight$serverRelightChunks(chunks,
+            (final ChunkPos chunkPos) -> {
+                ++relitChunks[0];
+                sender.getBukkitEntity().sendMessage(text().color(DARK_AQUA).append(
+                    text("Relit chunk ", BLUE), text(chunkPos.toString()),
+                    text(", progress: ", BLUE), text(ONE_DECIMAL_PLACES.get().format(100.0 * (double) (relitChunks[0]) / (double) pending[0]) + "%")
+                ));
+            },
+            (final int totalRelit) -> {
+                final long end = System.nanoTime();
+                sender.getBukkitEntity().sendMessage(text().color(DARK_AQUA).append(
+                    text("Relit ", BLUE), text(totalRelit),
+                    text(" chunks. Took ", BLUE), text(ONE_DECIMAL_PLACES.get().format(1.0e-6 * (end - start)) + "ms")
+                ));
+                if (done != null) {
+                    done.run();
+                }
+            }
+        );
+        sender.getBukkitEntity().sendMessage(text().color(BLUE).append(text("Relighting "), text(pending[0], DARK_AQUA), text(" chunks")));
+    }
+}
diff --git a/src/main/java/io/papermc/paper/threadedregions/TickRegions.java b/src/main/java/io/papermc/paper/threadedregions/TickRegions.java
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
--- /dev/null
+++ b/src/main/java/io/papermc/paper/threadedregions/TickRegions.java
@@ -0,0 +0,0 @@
+package io.papermc.paper.threadedregions;
+
+// placeholder class for Folia
+public class TickRegions {
+
+    public static int getRegionChunkShift() {
+        return ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ThreadedTicketLevelPropagator.SECTION_SHIFT;
+    }
+
+}
diff --git a/src/main/java/net/minecraft/core/Direction.java b/src/main/java/net/minecraft/core/Direction.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/core/Direction.java
+++ b/src/main/java/net/minecraft/core/Direction.java
@@ -0,0 +0,0 @@ import org.joml.Quaternionf;
 import org.joml.Vector3f;
 import org.joml.Vector4f;
 
-public enum Direction implements StringRepresentable {
+public enum Direction implements StringRepresentable, ca.spottedleaf.moonrise.patches.collisions.util.CollisionDirection { // Paper - optimise collisions
     DOWN(0, 1, -1, "down", Direction.AxisDirection.NEGATIVE, Direction.Axis.Y, new Vec3i(0, -1, 0)),
     UP(1, 0, -1, "up", Direction.AxisDirection.POSITIVE, Direction.Axis.Y, new Vec3i(0, 1, 0)),
     NORTH(2, 3, 2, "north", Direction.AxisDirection.NEGATIVE, Direction.Axis.Z, new Vec3i(0, 0, -1)),
@@ -0,0 +0,0 @@ public enum Direction implements StringRepresentable {
     private final int adjY;
     private final int adjZ;
     // Paper end - Perf: Inline shift direction fields
+    // Paper start - optimise collisions
+    private static final int RANDOM_OFFSET = 2017601568;
+    private Direction opposite;
+    private Quaternionf rotation;
+    private int id;
+    private int stepX;
+    private int stepY;
+    private int stepZ;
+
+    private Quaternionf getRotationUncached() {
+        switch ((Direction)(Object)this) {
+            case DOWN: {
+                return new Quaternionf().rotationX(3.1415927F);
+            }
+            case UP: {
+                return new Quaternionf();
+            }
+            case NORTH: {
+                return new Quaternionf().rotationXYZ(1.5707964F, 0.0F, 3.1415927F);
+            }
+            case SOUTH: {
+                return new Quaternionf().rotationX(1.5707964F);
+            }
+            case WEST: {
+                return new Quaternionf().rotationXYZ(1.5707964F, 0.0F, 1.5707964F);
+            }
+            case EAST: {
+                return new Quaternionf().rotationXYZ(1.5707964F, 0.0F, -1.5707964F);
+            }
+            default: {
+                throw new IllegalStateException();
+            }
+        }
+    }
+
+    @Override
+    public final int moonrise$uniqueId() {
+        return this.id;
+    }
+    // Paper end - optimise collisions
 
     private Direction(
         final int id,
@@ -0,0 +0,0 @@ public enum Direction implements StringRepresentable {
     }
 
     public Quaternionf getRotation() {
-        return switch (this) {
-            case DOWN -> new Quaternionf().rotationX((float) Math.PI);
-            case UP -> new Quaternionf();
-            case NORTH -> new Quaternionf().rotationXYZ((float) (Math.PI / 2), 0.0F, (float) Math.PI);
-            case SOUTH -> new Quaternionf().rotationX((float) (Math.PI / 2));
-            case WEST -> new Quaternionf().rotationXYZ((float) (Math.PI / 2), 0.0F, (float) (Math.PI / 2));
-            case EAST -> new Quaternionf().rotationXYZ((float) (Math.PI / 2), 0.0F, (float) (-Math.PI / 2));
-        };
+        // Paper start - optimise collisions
+        try {
+            return (Quaternionf)this.rotation.clone();
+        } catch (final CloneNotSupportedException ex) {
+            throw new InternalError(ex);
+        }
+        // Paper end - optimise collisions
     }
 
     public int get3DDataValue() {
@@ -0,0 +0,0 @@ public enum Direction implements StringRepresentable {
     }
 
     public Direction getOpposite() {
-        return from3DDataValue(this.oppositeIndex);
+        return this.opposite; // Paper - optimise collisions
     }
 
     public Direction getClockWise(Direction.Axis axis) {
@@ -0,0 +0,0 @@ public enum Direction implements StringRepresentable {
             return this.faces.length;
         }
     }
+
+    // Paper start - optimise collisions
+    static {
+        for (final Direction direction : VALUES) {
+            ((Direction)(Object)direction).opposite = from3DDataValue(((Direction)(Object)direction).oppositeIndex);
+            ((Direction)(Object)direction).rotation = ((Direction)(Object)direction).getRotationUncached();
+            ((Direction)(Object)direction).id = it.unimi.dsi.fastutil.HashCommon.murmurHash3(it.unimi.dsi.fastutil.HashCommon.murmurHash3(direction.ordinal() + RANDOM_OFFSET) + RANDOM_OFFSET);
+            ((Direction)(Object)direction).stepX = ((Direction)(Object)direction).normal.getX();
+            ((Direction)(Object)direction).stepY = ((Direction)(Object)direction).normal.getY();
+            ((Direction)(Object)direction).stepZ = ((Direction)(Object)direction).normal.getZ();
+        }
+    }
+    // Paper end - optimise collisions
 }
diff --git a/src/main/java/net/minecraft/core/MappedRegistry.java b/src/main/java/net/minecraft/core/MappedRegistry.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/core/MappedRegistry.java
+++ b/src/main/java/net/minecraft/core/MappedRegistry.java
@@ -0,0 +0,0 @@ public class MappedRegistry<T> implements WritableRegistry<T> {
         return this.getTags();
     }
 
+    // Paper start - fluid method optimisations
+    private void injectFluidRegister(
+        final ResourceKey<?> resourceKey,
+        final T object
+    ) {
+        if (resourceKey.registryKey() == (Object)net.minecraft.core.registries.Registries.FLUID) {
+            for (final net.minecraft.world.level.material.FluidState possibleState : ((net.minecraft.world.level.material.Fluid)object).getStateDefinition().getPossibleStates()) {
+                ((ca.spottedleaf.moonrise.patches.fluid.FluidFluidState)(Object)possibleState).moonrise$initCaches();
+            }
+        }
+    }
+    // Paper end - fluid method optimisations
+
     public MappedRegistry(ResourceKey<? extends Registry<T>> key, Lifecycle lifecycle) {
         this(key, lifecycle, false);
     }
@@ -0,0 +0,0 @@ public class MappedRegistry<T> implements WritableRegistry<T> {
             this.toId.put(value, i);
             this.registrationInfos.put(key, info);
             this.registryLifecycle = this.registryLifecycle.add(info.lifecycle());
+            this.injectFluidRegister(key, value); // Paper - fluid method optimisations
             return reference;
         }
     }
diff --git a/src/main/java/net/minecraft/server/Main.java b/src/main/java/net/minecraft/server/Main.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/Main.java
+++ b/src/main/java/net/minecraft/server/Main.java
@@ -0,0 +0,0 @@ public class Main {
 
             convertable_conversionsession.saveDataTag(iregistrycustom_dimension, savedata);
             */
+            Class.forName(net.minecraft.world.entity.npc.VillagerTrades.class.getName()); // Paper - load this sync so it won't fail later async
             final DedicatedServer dedicatedserver = (DedicatedServer) MinecraftServer.spin((thread) -> {
                 DedicatedServer dedicatedserver1 = new DedicatedServer(optionset, worldLoader.get(), thread, convertable_conversionsession, resourcepackrepository, worldstem, dedicatedserversettings, DataFixers.getDataFixer(), services, LoggerChunkProgressListener::createFromGameruleRadius);
 
diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -0,0 +0,0 @@ import org.bukkit.event.server.ServerLoadEvent;
 // CraftBukkit end
 
 
-public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTask> implements ServerInfo, ChunkIOErrorReporter, CommandSource {
+public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTask> implements ServerInfo, ChunkIOErrorReporter, CommandSource, ca.spottedleaf.moonrise.patches.chunk_system.server.ChunkSystemMinecraftServer { // Paper - rewrite chunk system
 
     private static MinecraftServer SERVER; // Paper
     public static final Logger LOGGER = LogUtils.getLogger();
@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
     public static <S extends MinecraftServer> S spin(Function<Thread, S> serverFactory) {
         ca.spottedleaf.dataconverter.minecraft.datatypes.MCTypeRegistry.init(); // Paper - rewrite data converter system
         AtomicReference<S> atomicreference = new AtomicReference();
-        Thread thread = new Thread(() -> {
+        Thread thread = new ca.spottedleaf.moonrise.common.util.TickThread(() -> { // Paper - rewrite chunk system
             ((MinecraftServer) atomicreference.get()).runServer();
         }, "Server thread");
 
@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
         return s0;
     }
 
+    // Paper start - rewrite chunk system
+    private volatile Throwable chunkSystemCrash;
+
+    @Override
+    public final void moonrise$setChunkSystemCrash(final Throwable throwable) {
+        this.chunkSystemCrash = throwable;
+    }
+
+    private static final long CHUNK_TASK_QUEUE_BACKOFF_MIN_TIME = 25L * 1000L; // 25us
+    private static final long MAX_CHUNK_EXEC_TIME = 1000L; // 1us
+    private static final long TASK_EXECUTION_FAILURE_BACKOFF = 5L * 1000L; // 5us
+
+    private long lastMidTickExecute;
+    private long lastMidTickExecuteFailure;
+
+    private boolean tickMidTickTasks() {
+        // give all worlds a fair chance at by targeting them all.
+        // if we execute too many tasks, that's fine - we have logic to correctly handle overuse of allocated time.
+        boolean executed = false;
+        for (final ServerLevel world : this.getAllLevels()) {
+            long currTime = System.nanoTime();
+            if (currTime - ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)world).moonrise$getLastMidTickFailure() <= TASK_EXECUTION_FAILURE_BACKOFF) {
+                continue;
+            }
+            if (!world.getChunkSource().pollTask()) {
+                // we need to back off if this fails
+                ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)world).moonrise$setLastMidTickFailure(currTime);
+            } else {
+                executed = true;
+            }
+        }
+
+        return executed;
+    }
+
+    @Override
+    public final void moonrise$executeMidTickTasks() {
+        final long startTime = System.nanoTime();
+        if ((startTime - this.lastMidTickExecute) <= CHUNK_TASK_QUEUE_BACKOFF_MIN_TIME || (startTime - this.lastMidTickExecuteFailure) <= TASK_EXECUTION_FAILURE_BACKOFF) {
+            // it's shown to be bad to constantly hit the queue (chunk loads slow to a crawl), even if no tasks are executed.
+            // so, backoff to prevent this
+            return;
+        }
+
+        for (;;) {
+            final boolean moreTasks = this.tickMidTickTasks();
+            final long currTime = System.nanoTime();
+            final long diff = currTime - startTime;
+
+            if (!moreTasks || diff >= MAX_CHUNK_EXEC_TIME) {
+                if (!moreTasks) {
+                    this.lastMidTickExecuteFailure = currTime;
+                }
+
+                // note: negative values reduce the time
+                long overuse = diff - MAX_CHUNK_EXEC_TIME;
+                if (overuse >= (10L * 1000L * 1000L)) { // 10ms
+                    // make sure something like a GC or dumb plugin doesn't screw us over...
+                    overuse = 10L * 1000L * 1000L; // 10ms
+                }
+
+                final double overuseCount = (double)overuse/(double)MAX_CHUNK_EXEC_TIME;
+                final long extraSleep = (long)Math.round(overuseCount*CHUNK_TASK_QUEUE_BACKOFF_MIN_TIME);
+
+                this.lastMidTickExecute = currTime + extraSleep;
+                return;
+            }
+        }
+    }
+    // Paper end - rewrite chunk system
+
     public MinecraftServer(OptionSet options, WorldLoader.DataLoadContext worldLoader, Thread thread, LevelStorageSource.LevelStorageAccess convertable_conversionsession, PackRepository resourcepackrepository, WorldStem worldstem, Proxy proxy, DataFixer datafixer, Services services, ChunkProgressListenerFactory worldloadlistenerfactory) {
         super("Server");
         SERVER = this; // Paper - better singleton
@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
         this.forceDifficulty();
         for (ServerLevel worldserver : this.getAllLevels()) {
             this.prepareLevels(worldserver.getChunkSource().chunkMap.progressListener, worldserver);
-            worldserver.entityManager.tick(); // SPIGOT-6526: Load pending entities so they are available to the API
+            // Paper - rewrite chunk system
             this.server.getPluginManager().callEvent(new org.bukkit.event.world.WorldLoadEvent(worldserver.getWorld()));
         }
 
@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
     public abstract boolean shouldRconBroadcast();
 
     public boolean saveAllChunks(boolean suppressLogs, boolean flush, boolean force) {
+        // Paper start - add close param
+        return this.saveAllChunks(suppressLogs, flush, force, false);
+    }
+    public boolean saveAllChunks(boolean suppressLogs, boolean flush, boolean force, boolean close) {
+        // Paper end - add close param
         boolean flag3 = false;
 
         for (Iterator iterator = this.getAllLevels().iterator(); iterator.hasNext(); flag3 = true) {
@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
                 MinecraftServer.LOGGER.info("Saving chunks for level '{}'/{}", worldserver, worldserver.dimension().location());
             }
 
-            worldserver.save((ProgressListener) null, flush, worldserver.noSave && !force);
+            worldserver.save((ProgressListener) null, flush, worldserver.noSave && !force, close); // Paper - add close param
         }
 
         // CraftBukkit start - moved to WorldServer.save
@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
             }
         }
 
-        while (this.levels.values().stream().anyMatch((worldserver1) -> {
+        while (false && this.levels.values().stream().anyMatch((worldserver1) -> { // Paper - rewrite chunk system
             return worldserver1.getChunkSource().chunkMap.hasWork();
         })) {
             this.nextTickTimeNanos = Util.getNanos() + TimeUtil.NANOSECONDS_PER_MILLISECOND;
@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
             this.waitUntilNextTick();
         }
 
-        this.saveAllChunks(false, true, false);
-        iterator = this.getAllLevels().iterator();
-
-        while (iterator.hasNext()) {
-            worldserver = (ServerLevel) iterator.next();
-            if (worldserver != null) {
-                try {
-                    worldserver.close();
-                } catch (IOException ioexception) {
-                    MinecraftServer.LOGGER.error("Exception closing the level", ioexception);
-                }
-            }
-        }
+        this.saveAllChunks(false, true, true, true); // Paper - rewrite chunk system
 
         this.isSaving = false;
         this.resources.close();
@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
         }
         // Spigot end
 
+        // Paper start - rewrite chunk system
+        LOGGER.info("Waiting for I/O tasks to complete...");
+        ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.flush((MinecraftServer)(Object)this);
+        LOGGER.info("All I/O tasks to complete");
+        if ((Object)this instanceof DedicatedServer) {
+            ca.spottedleaf.moonrise.common.util.MoonriseCommon.haltExecutors();
+        }
+        // Paper end - rewrite chunk system
     }
 
     public String getLocalIp() {
@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
                         this.tickServer(flag ? () -> {
                             return false;
                         } : this::haveTime);
+                        // Paper start - rewrite chunk system
+                        final Throwable crash = this.chunkSystemCrash;
+                        if (crash != null) {
+                            this.chunkSystemCrash = null;
+                            throw new RuntimeException("Chunk system crash propagated to tick()", crash);
+                        }
+                        // Paper end - rewrite chunk system
                         this.tickFrame.end();
                         gameprofilerfiller.popPush("nextTickWait");
                         this.mayHaveDelayedTasks = true;
@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
 
     private boolean pollTaskInternal() {
         if (super.pollTask()) {
+            this.moonrise$executeMidTickTasks(); // Paper - rewrite chunk system
             return true;
         } else {
             boolean ret = false; // Paper - force execution of all worlds, do not just bias the first
@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
 
     }
 
+    // Paper start - rewrite chunk system
+    @Override
+    public boolean isSameThread() {
+        return ca.spottedleaf.moonrise.common.util.TickThread.isTickThread();
+    }
+    // Paper end - rewrite chunk system
+
     // CraftBukkit start
     public boolean isDebugging() {
         return false;
diff --git a/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java b/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java
+++ b/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java
@@ -0,0 +0,0 @@ public class DedicatedServer extends MinecraftServer implements ServerInterface
         return world.dimension() == net.minecraft.world.level.Level.NETHER ? this.getProperties().allowNether : true;
     }
 
+    private static final java.util.concurrent.atomic.AtomicInteger ASYNC_DEBUG_CHUNKS_COUNT = new java.util.concurrent.atomic.AtomicInteger(); // Paper - rewrite chunk system
+
     public void handleConsoleInput(String command, CommandSourceStack commandSource) {
+        // Paper start - rewrite chunk system
+        if (command.equalsIgnoreCase("paper debug chunks --async")) {
+            LOGGER.info("Scheduling async debug chunks");
+            Runnable run = () -> {
+                LOGGER.info("Async debug chunks executing");
+                ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler.dumpAllChunkLoadInfo(this, false);
+                CommandSender sender = MinecraftServer.getServer().console;
+                java.io.File file = ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler.getChunkDebugFile();
+                sender.sendMessage(net.kyori.adventure.text.Component.text("Writing chunk information dump to " + file, net.kyori.adventure.text.format.NamedTextColor.GREEN));
+                try {
+                    ca.spottedleaf.moonrise.common.util.JsonUtil.writeJson(ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler.debugAllWorlds(this), file);
+                    sender.sendMessage(net.kyori.adventure.text.Component.text("Successfully written chunk information!", net.kyori.adventure.text.format.NamedTextColor.GREEN));
+                } catch (Throwable thr) {
+                    MinecraftServer.LOGGER.warn("Failed to dump chunk information to file " + file.toString(), thr);
+                    sender.sendMessage(net.kyori.adventure.text.Component.text("Failed to dump chunk information, see console", net.kyori.adventure.text.format.NamedTextColor.RED));
+                }
+            };
+            Thread t = new Thread(run);
+            t.setName("Async debug thread #" + ASYNC_DEBUG_CHUNKS_COUNT.getAndIncrement());
+            t.setDaemon(true);
+            t.start();
+            return;
+        }
+        // Paper end - rewrite chunk system
         this.serverCommandQueue.add(new ConsoleInput(command, commandSource)); // Paper - Perf: use proper queue
     }
 
diff --git a/src/main/java/net/minecraft/server/level/ChunkHolder.java b/src/main/java/net/minecraft/server/level/ChunkHolder.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/level/ChunkHolder.java
+++ b/src/main/java/net/minecraft/server/level/ChunkHolder.java
@@ -0,0 +0,0 @@ import net.minecraft.world.level.lighting.LevelLightEngine;
 import net.minecraft.server.MinecraftServer;
 // CraftBukkit end
 
-public class ChunkHolder extends GenerationChunkHolder {
+public class ChunkHolder extends GenerationChunkHolder implements ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemChunkHolder { // Paper - rewrite chunk system
 
     public static final ChunkResult<LevelChunk> UNLOADED_LEVEL_CHUNK = ChunkResult.error("Unloaded level chunk");
     private static final CompletableFuture<ChunkResult<LevelChunk>> UNLOADED_LEVEL_CHUNK_FUTURE = CompletableFuture.completedFuture(ChunkHolder.UNLOADED_LEVEL_CHUNK);
     private final LevelHeightAccessor levelHeightAccessor;
-    private volatile CompletableFuture<ChunkResult<LevelChunk>> fullChunkFuture; private int fullChunkCreateCount; private volatile boolean isFullChunkReady; // Paper - cache chunk ticking stage
-    private volatile CompletableFuture<ChunkResult<LevelChunk>> tickingChunkFuture; private volatile boolean isTickingReady; // Paper - cache chunk ticking stage
-    private volatile CompletableFuture<ChunkResult<LevelChunk>> entityTickingChunkFuture; private volatile boolean isEntityTickingReady; // Paper - cache chunk ticking stage
-    public int oldTicketLevel;
-    private int ticketLevel;
-    private int queueLevel;
+    // Paper - rewrite chunk system
     private boolean hasChangedSections;
     private final ShortSet[] changedBlocksPerSection;
     private final BitSet blockChangedLightSectionFilter;
     private final BitSet skyChangedLightSectionFilter;
     private final LevelLightEngine lightEngine;
-    private final ChunkHolder.LevelChangeListener onLevelChange;
+    // Paper - rewrite chunk system
     public final ChunkHolder.PlayerProvider playerProvider;
-    private boolean wasAccessibleSinceLastSave;
-    private CompletableFuture<?> pendingFullStateConfirmation;
-    private CompletableFuture<?> sendSync;
-    private CompletableFuture<?> saveSync;
+    // Paper - rewrite chunk system
+
+    // Paper start - rewrite chunk system
+    private ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder newChunkHolder;
+
+    private static final ServerPlayer[] EMPTY_PLAYER_ARRAY = new ServerPlayer[0];
+    private final ca.spottedleaf.moonrise.common.list.ReferenceList<ServerPlayer> playersSentChunkTo = new ca.spottedleaf.moonrise.common.list.ReferenceList<>(EMPTY_PLAYER_ARRAY);
+
+    private ChunkMap getChunkMap() {
+        return (ChunkMap)this.playerProvider;
+    }
+
+    @Override
+    public final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder moonrise$getRealChunkHolder() {
+        return this.newChunkHolder;
+    }
+
+    @Override
+    public final void moonrise$setRealChunkHolder(final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder newChunkHolder) {
+        this.newChunkHolder = newChunkHolder;
+    }
+
+    @Override
+    public final void moonrise$addReceivedChunk(final ServerPlayer player) {
+        if (!this.playersSentChunkTo.add(player)) {
+            throw new IllegalStateException("Already sent chunk " + this.pos + " in world '" + ca.spottedleaf.moonrise.common.util.WorldUtil.getWorldName(this.getChunkMap().level) + "' to player " + player);
+        }
+    }
+
+    @Override
+    public final void moonrise$removeReceivedChunk(final ServerPlayer player) {
+        if (!this.playersSentChunkTo.remove(player)) {
+            throw new IllegalStateException("Already sent chunk " + this.pos + " in world '" + ca.spottedleaf.moonrise.common.util.WorldUtil.getWorldName(this.getChunkMap().level) + "' to player " + player);
+        }
+    }
+
+    @Override
+    public final boolean moonrise$hasChunkBeenSent() {
+        return this.playersSentChunkTo.size() != 0;
+    }
+
+    @Override
+    public final boolean moonrise$hasChunkBeenSent(final ServerPlayer to) {
+        return this.playersSentChunkTo.contains(to);
+    }
+
+    @Override
+    public final List<ServerPlayer> moonrise$getPlayers(final boolean onlyOnWatchDistanceEdge) {
+        final List<ServerPlayer> ret = new java.util.ArrayList<>();
+        final ServerPlayer[] raw = this.playersSentChunkTo.getRawDataUnchecked();
+        for (int i = 0, len = this.playersSentChunkTo.size(); i < len; ++i) {
+            final ServerPlayer player = raw[i];
+            if (onlyOnWatchDistanceEdge && !((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.getChunkMap().level).moonrise$getPlayerChunkLoader().isChunkSent(player, this.pos.x, this.pos.z, onlyOnWatchDistanceEdge)) {
+                continue;
+            }
+            ret.add(player);
+        }
+
+        return ret;
+    }
+
+    @Override
+    public final LevelChunk moonrise$getFullChunk() {
+        if (this.newChunkHolder.isFullChunkReady()) {
+            if (this.newChunkHolder.getCurrentChunk() instanceof LevelChunk levelChunk) {
+                return levelChunk;
+            } // else: race condition: chunk unload
+        }
+        return null;
+    }
+
+    private boolean isRadiusLoaded(final int radius) {
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkHolderManager manager = ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.getChunkMap().level).moonrise$getChunkTaskScheduler()
+            .chunkHolderManager;
+        final ChunkPos pos = this.pos;
+        final int chunkX = pos.x;
+        final int chunkZ = pos.z;
+        for (int dz = -radius; dz <= radius; ++dz) {
+            for (int dx = -radius; dx <= radius; ++dx) {
+                if ((dx | dz) == 0) {
+                    continue;
+                }
+
+                final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder holder = manager.getChunkHolder(dx + chunkX, dz + chunkZ);
+
+                if (holder == null || !holder.isFullChunkReady()) {
+                    return false;
+                }
+            }
+        }
+
+        return true;
+    }
+    // Paper end - rewrite chunk system
 
     public ChunkHolder(ChunkPos pos, int level, LevelHeightAccessor world, LevelLightEngine lightingProvider, ChunkHolder.LevelChangeListener levelUpdateListener, ChunkHolder.PlayerProvider playersWatchingChunkProvider) {
         super(pos);
-        this.fullChunkFuture = ChunkHolder.UNLOADED_LEVEL_CHUNK_FUTURE;
-        this.tickingChunkFuture = ChunkHolder.UNLOADED_LEVEL_CHUNK_FUTURE;
-        this.entityTickingChunkFuture = ChunkHolder.UNLOADED_LEVEL_CHUNK_FUTURE;
+        // Paper - rewrite chunk system
         this.blockChangedLightSectionFilter = new BitSet();
         this.skyChangedLightSectionFilter = new BitSet();
-        this.pendingFullStateConfirmation = CompletableFuture.completedFuture(null); // CraftBukkit - decompile error
-        this.sendSync = CompletableFuture.completedFuture(null); // CraftBukkit - decompile error
-        this.saveSync = CompletableFuture.completedFuture(null); // CraftBukkit - decompile error
+        // Paper - rewrite chunk system
         this.levelHeightAccessor = world;
         this.lightEngine = lightingProvider;
-        this.onLevelChange = levelUpdateListener;
+        // Paper - rewrite chunk system
         this.playerProvider = playersWatchingChunkProvider;
-        this.oldTicketLevel = ChunkLevel.MAX_LEVEL + 1;
-        this.ticketLevel = this.oldTicketLevel;
-        this.queueLevel = this.oldTicketLevel;
+        // Paper - rewrite chunk system
         this.setTicketLevel(level);
         this.changedBlocksPerSection = new ShortSet[world.getSectionsCount()];
     }
@@ -0,0 +0,0 @@ public class ChunkHolder extends GenerationChunkHolder {
     // CraftBukkit start
     public LevelChunk getFullChunkNow() {
         // Note: We use the oldTicketLevel for isLoaded checks.
-        if (!ChunkLevel.fullStatus(this.oldTicketLevel).isOrAfter(FullChunkStatus.FULL)) return null;
+        if (!this.newChunkHolder.isFullChunkReady()) return null; // Paper - rewrite chunk system
         return this.getFullChunkNowUnchecked();
     }
 
@@ -0,0 +0,0 @@ public class ChunkHolder extends GenerationChunkHolder {
     // CraftBukkit end
 
     public CompletableFuture<ChunkResult<LevelChunk>> getTickingChunkFuture() {
-        return this.tickingChunkFuture;
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public CompletableFuture<ChunkResult<LevelChunk>> getEntityTickingChunkFuture() {
-        return this.entityTickingChunkFuture;
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public CompletableFuture<ChunkResult<LevelChunk>> getFullChunkFuture() {
-        return this.fullChunkFuture;
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     @Nullable
     public final LevelChunk getTickingChunk() { // Paper - final for inline
-        return (LevelChunk) ((ChunkResult) this.getTickingChunkFuture().getNow(ChunkHolder.UNLOADED_LEVEL_CHUNK)).orElse(null); // CraftBukkit - decompile error
+        // Paper start - rewrite chunk system
+        if (this.newChunkHolder.isTickingReady()) {
+            if (this.newChunkHolder.getCurrentChunk() instanceof LevelChunk levelChunk) {
+                return levelChunk;
+            } // else: race condition: chunk unload
+        }
+        return null;
+        // Paper end - rewrite chunk system
     }
 
     @Nullable
     public LevelChunk getChunkToSend() {
-        return !this.sendSync.isDone() ? null : this.getTickingChunk();
+        // Paper start - rewrite chunk system
+        final LevelChunk ret = this.moonrise$getFullChunk();
+        if (ret != null && this.isRadiusLoaded(1)) {
+            return ret;
+        }
+        return null;
+        // Paper end - rewrite chunk system
     }
 
     public CompletableFuture<?> getSendSyncFuture() {
-        return this.sendSync;
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public void addSendDependency(CompletableFuture<?> postProcessingFuture) {
-        if (this.sendSync.isDone()) {
-            this.sendSync = postProcessingFuture;
-        } else {
-            this.sendSync = this.sendSync.thenCombine(postProcessingFuture, (object, object1) -> {
-                return null;
-            });
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
 
     }
 
     public CompletableFuture<?> getSaveSyncFuture() {
-        return this.saveSync;
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public boolean isReadyForSaving() {
-        return this.saveSync.isDone();
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     @Override
     protected void addSaveDependency(CompletableFuture<?> savingFuture) {
-        if (this.saveSync.isDone()) {
-            this.saveSync = savingFuture;
-        } else {
-            this.saveSync = this.saveSync.thenCombine(savingFuture, (object, object1) -> {
-                return null;
-            });
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
 
     }
 
     public boolean blockChanged(BlockPos pos) {
-        LevelChunk chunk = this.getTickingChunk();
+        LevelChunk chunk = this.playersSentChunkTo.size() == 0 ? null : this.getChunkToSend(); // Paper - rewrite chunk system
 
         if (chunk == null) {
             return false;
@@ -0,0 +0,0 @@ public class ChunkHolder extends GenerationChunkHolder {
             return false;
         } else {
             ichunkaccess.markUnsaved();
-            LevelChunk chunk = this.getTickingChunk();
+            LevelChunk chunk = this.playersSentChunkTo.size() == 0 ? null : this.getChunkToSend(); // Paper - rewrite chunk system
 
             if (chunk == null) {
                 return false;
@@ -0,0 +0,0 @@ public class ChunkHolder extends GenerationChunkHolder {
             List list;
 
             if (!this.skyChangedLightSectionFilter.isEmpty() || !this.blockChangedLightSectionFilter.isEmpty()) {
-                list = this.playerProvider.getPlayers(this.pos, true);
+                list = this.moonrise$getPlayers(true); // Paper - rewrite chunk system
                 if (!list.isEmpty()) {
                     ClientboundLightUpdatePacket packetplayoutlightupdate = new ClientboundLightUpdatePacket(chunk.getPos(), this.lightEngine, this.skyChangedLightSectionFilter, this.blockChangedLightSectionFilter);
 
@@ -0,0 +0,0 @@ public class ChunkHolder extends GenerationChunkHolder {
             }
 
             if (this.hasChangedSections) {
-                list = this.playerProvider.getPlayers(this.pos, false);
+                list = this.moonrise$getPlayers(false); // Paper - rewrite chunk system
 
                 for (int i = 0; i < this.changedBlocksPerSection.length; ++i) {
                     ShortSet shortset = this.changedBlocksPerSection[i];
@@ -0,0 +0,0 @@ public class ChunkHolder extends GenerationChunkHolder {
 
     @Override
     public int getTicketLevel() {
-        return this.ticketLevel;
+        return this.newChunkHolder.getTicketLevel(); // Paper - rewrite chunk system
     }
 
     @Override
     public int getQueueLevel() {
-        return this.queueLevel;
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     private void setQueueLevel(int level) {
-        this.queueLevel = level;
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public void setTicketLevel(int level) {
-        this.ticketLevel = level;
+        // Paper - rewrite chunk system
     }
 
     private void scheduleFullChunkPromotion(ChunkMap chunkLoadingManager, CompletableFuture<ChunkResult<LevelChunk>> chunkFuture, Executor executor, FullChunkStatus target) {
-        this.pendingFullStateConfirmation.cancel(false);
-        CompletableFuture<Void> completablefuture1 = new CompletableFuture();
-
-        completablefuture1.thenRunAsync(() -> {
-            chunkLoadingManager.onFullChunkStatusChange(this.pos, target);
-        }, executor);
-        this.pendingFullStateConfirmation = completablefuture1;
-        chunkFuture.thenAccept((chunkresult) -> {
-            chunkresult.ifSuccess((chunk) -> {
-                completablefuture1.complete(null); // CraftBukkit - decompile error
-            });
-        });
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     private void demoteFullChunk(ChunkMap chunkLoadingManager, FullChunkStatus target) {
-        this.pendingFullStateConfirmation.cancel(false);
-        chunkLoadingManager.onFullChunkStatusChange(this.pos, target);
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     // CraftBukkit start
     // ChunkUnloadEvent: Called before the chunk is unloaded: isChunkLoaded is still true and chunk can still be modified by plugins.
     // SPIGOT-7780: Moved out of updateFutures to call all chunk unload events before calling updateHighestAllowedStatus for all chunks
     protected void callEventIfUnloading(ChunkMap playerchunkmap) {
-        FullChunkStatus oldFullChunkStatus = ChunkLevel.fullStatus(this.oldTicketLevel);
-        FullChunkStatus newFullChunkStatus = ChunkLevel.fullStatus(this.ticketLevel);
-        boolean oldIsFull = oldFullChunkStatus.isOrAfter(FullChunkStatus.FULL);
-        boolean newIsFull = newFullChunkStatus.isOrAfter(FullChunkStatus.FULL);
-        if (oldIsFull && !newIsFull) {
-            this.getFullChunkFuture().thenAccept((either) -> {
-                LevelChunk chunk = (LevelChunk) either.orElse(null);
-                if (chunk != null) {
-                    playerchunkmap.callbackExecutor.execute(() -> {
-                        // Minecraft will apply the chunks tick lists to the world once the chunk got loaded, and then store the tick
-                        // lists again inside the chunk once the chunk becomes inaccessible and set the chunk's needsSaving flag.
-                        // These actions may however happen deferred, so we manually set the needsSaving flag already here.
-                        chunk.markUnsaved();
-                        chunk.unloadCallback();
-                    });
-                }
-            }).exceptionally((throwable) -> {
-                // ensure exceptions are printed, by default this is not the case
-                MinecraftServer.LOGGER.error("Failed to schedule unload callback for chunk " + ChunkHolder.this.pos, throwable);
-                return null;
-            });
-
-            // Run callback right away if the future was already done
-            playerchunkmap.callbackExecutor.run();
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
     // CraftBukkit end
 
     protected void updateFutures(ChunkMap chunkLoadingManager, Executor executor) {
-        FullChunkStatus fullchunkstatus = ChunkLevel.fullStatus(this.oldTicketLevel);
-        FullChunkStatus fullchunkstatus1 = ChunkLevel.fullStatus(this.ticketLevel);
-        boolean flag = fullchunkstatus.isOrAfter(FullChunkStatus.FULL);
-        boolean flag1 = fullchunkstatus1.isOrAfter(FullChunkStatus.FULL);
-
-        this.wasAccessibleSinceLastSave |= flag1;
-        if (!flag && flag1) {
-            int expectCreateCount = ++this.fullChunkCreateCount; // Paper
-            this.fullChunkFuture = chunkLoadingManager.prepareAccessibleChunk(this);
-            this.scheduleFullChunkPromotion(chunkLoadingManager, this.fullChunkFuture, executor, FullChunkStatus.FULL);
-            // Paper start - cache ticking ready status
-            this.fullChunkFuture.thenAccept(chunkResult -> {
-                chunkResult.ifSuccess(chunk -> {
-                    if (ChunkHolder.this.fullChunkCreateCount == expectCreateCount) {
-                        ChunkHolder.this.isFullChunkReady = true;
-                        ca.spottedleaf.moonrise.common.util.ChunkSystem.onChunkBorder(chunk, this);
-                    }
-                });
-            });
-            // Paper end - cache ticking ready status
-            this.addSaveDependency(this.fullChunkFuture);
-        }
-
-        if (flag && !flag1) {
-            // Paper start
-            if (this.isFullChunkReady) {
-                ca.spottedleaf.moonrise.common.util.ChunkSystem.onChunkNotBorder(this.fullChunkFuture.join().orElseThrow(IllegalStateException::new), this); // Paper
-            }
-            // Paper end
-            this.fullChunkFuture.complete(ChunkHolder.UNLOADED_LEVEL_CHUNK);
-            this.fullChunkFuture = ChunkHolder.UNLOADED_LEVEL_CHUNK_FUTURE;
-        }
-
-        boolean flag2 = fullchunkstatus.isOrAfter(FullChunkStatus.BLOCK_TICKING);
-        boolean flag3 = fullchunkstatus1.isOrAfter(FullChunkStatus.BLOCK_TICKING);
-
-        if (!flag2 && flag3) {
-            this.tickingChunkFuture = chunkLoadingManager.prepareTickingChunk(this);
-            this.scheduleFullChunkPromotion(chunkLoadingManager, this.tickingChunkFuture, executor, FullChunkStatus.BLOCK_TICKING);
-            // Paper start - cache ticking ready status
-            this.tickingChunkFuture.thenAccept(chunkResult -> {
-                chunkResult.ifSuccess(chunk -> {
-                    // note: Here is a very good place to add callbacks to logic waiting on this.
-                    ChunkHolder.this.isTickingReady = true;
-                    ca.spottedleaf.moonrise.common.util.ChunkSystem.onChunkTicking(chunk, this);
-                });
-            });
-            // Paper end
-            this.addSaveDependency(this.tickingChunkFuture);
-        }
-
-        if (flag2 && !flag3) {
-            // Paper start
-            if (this.isTickingReady) {
-                ca.spottedleaf.moonrise.common.util.ChunkSystem.onChunkNotTicking(this.tickingChunkFuture.join().orElseThrow(IllegalStateException::new), this); // Paper
-            }
-            // Paper end
-            this.tickingChunkFuture.complete(ChunkHolder.UNLOADED_LEVEL_CHUNK); this.isTickingReady = false; // Paper - cache chunk ticking stage
-            this.tickingChunkFuture = ChunkHolder.UNLOADED_LEVEL_CHUNK_FUTURE;
-        }
-
-        boolean flag4 = fullchunkstatus.isOrAfter(FullChunkStatus.ENTITY_TICKING);
-        boolean flag5 = fullchunkstatus1.isOrAfter(FullChunkStatus.ENTITY_TICKING);
-
-        if (!flag4 && flag5) {
-            if (this.entityTickingChunkFuture != ChunkHolder.UNLOADED_LEVEL_CHUNK_FUTURE) {
-                throw (IllegalStateException) Util.pauseInIde(new IllegalStateException());
-            }
-
-            this.entityTickingChunkFuture = chunkLoadingManager.prepareEntityTickingChunk(this);
-            this.scheduleFullChunkPromotion(chunkLoadingManager, this.entityTickingChunkFuture, executor, FullChunkStatus.ENTITY_TICKING);
-            // Paper start - cache ticking ready status
-            this.entityTickingChunkFuture.thenAccept(chunkResult -> {
-                chunkResult.ifSuccess(chunk -> {
-                    ChunkHolder.this.isEntityTickingReady = true;
-                    ca.spottedleaf.moonrise.common.util.ChunkSystem.onChunkEntityTicking(chunk, this);
-                });
-            });
-            // Paper end
-            this.addSaveDependency(this.entityTickingChunkFuture);
-        }
-
-        if (flag4 && !flag5) {
-            // Paper start
-            if (this.isEntityTickingReady) {
-                ca.spottedleaf.moonrise.common.util.ChunkSystem.onChunkNotEntityTicking(this.entityTickingChunkFuture.join().orElseThrow(IllegalStateException::new), this);
-            }
-            // Paper end
-            this.entityTickingChunkFuture.complete(ChunkHolder.UNLOADED_LEVEL_CHUNK); this.isEntityTickingReady = false; // Paper - cache chunk ticking stage
-            this.entityTickingChunkFuture = ChunkHolder.UNLOADED_LEVEL_CHUNK_FUTURE;
-        }
-
-        if (!fullchunkstatus1.isOrAfter(fullchunkstatus)) {
-            this.demoteFullChunk(chunkLoadingManager, fullchunkstatus1);
-        }
-
-        this.onLevelChange.onLevelChange(this.pos, this::getQueueLevel, this.ticketLevel, this::setQueueLevel);
-        this.oldTicketLevel = this.ticketLevel;
-        // CraftBukkit start
-        // ChunkLoadEvent: Called after the chunk is loaded: isChunkLoaded returns true and chunk is ready to be modified by plugins.
-        if (!fullchunkstatus.isOrAfter(FullChunkStatus.FULL) && fullchunkstatus1.isOrAfter(FullChunkStatus.FULL)) {
-            this.getFullChunkFuture().thenAccept((either) -> {
-                LevelChunk chunk = (LevelChunk) either.orElse(null);
-                if (chunk != null) {
-                    chunkLoadingManager.callbackExecutor.execute(() -> {
-                        chunk.loadCallback();
-                    });
-                }
-            }).exceptionally((throwable) -> {
-                // ensure exceptions are printed, by default this is not the case
-                MinecraftServer.LOGGER.error("Failed to schedule load callback for chunk " + ChunkHolder.this.pos, throwable);
-                return null;
-            });
-
-            // Run callback right away if the future was already done
-            chunkLoadingManager.callbackExecutor.run();
-        }
-        // CraftBukkit end
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public boolean wasAccessibleSinceLastSave() {
-        return this.wasAccessibleSinceLastSave;
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public void refreshAccessibility() {
-        this.wasAccessibleSinceLastSave = ChunkLevel.fullStatus(this.ticketLevel).isOrAfter(FullChunkStatus.FULL);
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     @FunctionalInterface
diff --git a/src/main/java/net/minecraft/server/level/ChunkLevel.java b/src/main/java/net/minecraft/server/level/ChunkLevel.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/level/ChunkLevel.java
+++ b/src/main/java/net/minecraft/server/level/ChunkLevel.java
@@ -0,0 +0,0 @@ import net.minecraft.world.level.chunk.status.ChunkStep;
 import org.jetbrains.annotations.Contract;
 
 public class ChunkLevel {
-    private static final int FULL_CHUNK_LEVEL = 33;
-    private static final int BLOCK_TICKING_LEVEL = 32;
+    public static final int FULL_CHUNK_LEVEL = 33;
+    public static final int BLOCK_TICKING_LEVEL = 32;
     public static final int ENTITY_TICKING_LEVEL = 31;
     private static final ChunkStep FULL_CHUNK_STEP = ChunkPyramid.GENERATION_PYRAMID.getStepTo(ChunkStatus.FULL);
     public static final int RADIUS_AROUND_FULL_CHUNK = FULL_CHUNK_STEP.accumulatedDependencies().getRadius();
diff --git a/src/main/java/net/minecraft/server/level/ChunkMap.java b/src/main/java/net/minecraft/server/level/ChunkMap.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/level/ChunkMap.java
+++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
@@ -0,0 +0,0 @@ import org.slf4j.Logger;
 import org.bukkit.craftbukkit.generator.CustomChunkGenerator;
 // CraftBukkit end
 
-public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider, GeneratingChunkMap {
+public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider, GeneratingChunkMap, ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemChunkMap { // Paper - rewrite chunk system
 
     private static final ChunkResult<List<ChunkAccess>> UNLOADED_CHUNK_LIST_RESULT = ChunkResult.error("Unloaded chunks found in range");
     private static final CompletableFuture<ChunkResult<List<ChunkAccess>>> UNLOADED_CHUNK_LIST_FUTURE = CompletableFuture.completedFuture(ChunkMap.UNLOADED_CHUNK_LIST_RESULT);
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
     public static final int MIN_VIEW_DISTANCE = 2;
     public static final int MAX_VIEW_DISTANCE = 32;
     public static final int FORCED_TICKET_LEVEL = ChunkLevel.byStatus(FullChunkStatus.ENTITY_TICKING);
-    public final Long2ObjectLinkedOpenHashMap<ChunkHolder> updatingChunkMap = new Long2ObjectLinkedOpenHashMap();
-    public volatile Long2ObjectLinkedOpenHashMap<ChunkHolder> visibleChunkMap;
-    private final Long2ObjectLinkedOpenHashMap<ChunkHolder> pendingUnloads;
-    private final List<ChunkGenerationTask> pendingGenerationTasks;
+    // Paper - rewrite chunk system
     public final ServerLevel level;
     private final ThreadedLevelLightEngine lightEngine;
     private final BlockableEventLoop<Runnable> mainThreadExecutor;
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
     private final PoiManager poiManager;
     public final LongSet toDrop;
     private boolean modified;
-    private final ChunkTaskDispatcher worldgenTaskDispatcher;
-    private final ChunkTaskDispatcher lightTaskDispatcher;
+    // Paper - rewrite chunk system
     public final ChunkProgressListener progressListener;
     private final ChunkStatusUpdateListener chunkStatusListener;
     public final ChunkMap.ChunkDistanceManager distanceManager;
-    private final AtomicInteger tickingGenerated;
+    public final AtomicInteger tickingGenerated; // Paper - public
     private final String storageName;
     private final PlayerMap playerMap;
     public final Int2ObjectMap<ChunkMap.TrackedEntity> entityMap;
     private final Long2ByteMap chunkTypeCache;
-    private final Long2LongMap nextChunkSaveTime;
-    private final LongSet chunksToEagerlySave;
-    private final Queue<Runnable> unloadQueue;
-    private final AtomicInteger activeChunkWrites;
+    // Paper - rewrite chunk system
     public int serverViewDistance;
-    private final WorldGenContext worldGenContext;
+    public final WorldGenContext worldGenContext; // Paper - public
 
     // CraftBukkit start - recursion-safe executor for Chunk loadCallback() and unloadCallback()
     public final CallbackExecutor callbackExecutor = new CallbackExecutor();
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
 
     // Paper start
     public final ChunkHolder getUnloadingChunkHolder(int chunkX, int chunkZ) {
-        return this.pendingUnloads.get(ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkKey(chunkX, chunkZ));
+        return null; // Paper - rewrite chunk system
     }
     // Paper end
+    // Paper start - rewrite chunk system
+    @Override
+    public final void moonrise$writeFinishCallback(final ChunkPos pos) throws IOException {
+        // see ChunkStorage#write
+        this.handleLegacyStructureIndex(pos);
+    }
+    // Paper end - rewrite chunk system
 
     public ChunkMap(ServerLevel world, LevelStorageSource.LevelStorageAccess session, DataFixer dataFixer, StructureTemplateManager structureTemplateManager, Executor executor, BlockableEventLoop<Runnable> mainThreadExecutor, LightChunkGetter chunkProvider, ChunkGenerator chunkGenerator, ChunkProgressListener worldGenerationProgressListener, ChunkStatusUpdateListener chunkStatusChangeListener, Supplier<DimensionDataStorage> persistentStateManagerFactory, int viewDistance, boolean dsync) {
         super(new RegionStorageInfo(session.getLevelId(), world.dimension(), "chunk"), session.getDimensionPath(world.dimension()).resolve("region"), dataFixer, dsync);
-        this.visibleChunkMap = this.updatingChunkMap.clone();
-        this.pendingUnloads = new Long2ObjectLinkedOpenHashMap();
-        this.pendingGenerationTasks = new ArrayList();
+        // Paper - rewrite chunk system
         this.toDrop = new LongOpenHashSet();
         this.tickingGenerated = new AtomicInteger();
         this.playerMap = new PlayerMap();
         this.entityMap = new Int2ObjectOpenHashMap();
         this.chunkTypeCache = new Long2ByteOpenHashMap();
-        this.nextChunkSaveTime = new Long2LongOpenHashMap();
-        this.chunksToEagerlySave = new LongLinkedOpenHashSet();
-        this.unloadQueue = Queues.newConcurrentLinkedQueue();
-        this.activeChunkWrites = new AtomicInteger();
+        // Paper - rewrite chunk system
         Path path = session.getDimensionPath(world.dimension());
 
         this.storageName = path.getFileName().toString();
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         this.chunkStatusListener = chunkStatusChangeListener;
         ConsecutiveExecutor consecutiveexecutor1 = new ConsecutiveExecutor(executor, "light");
 
-        this.worldgenTaskDispatcher = new ChunkTaskDispatcher(consecutiveexecutor, executor);
-        this.lightTaskDispatcher = new ChunkTaskDispatcher(consecutiveexecutor1, executor);
-        this.lightEngine = new ThreadedLevelLightEngine(chunkProvider, this, this.level.dimensionType().hasSkyLight(), consecutiveexecutor1, this.lightTaskDispatcher);
+        this.lightEngine = new ThreadedLevelLightEngine(chunkProvider, this, this.level.dimensionType().hasSkyLight(), consecutiveexecutor1, null); // Paper - rewrite chunk system
         this.distanceManager = new ChunkMap.ChunkDistanceManager(executor, mainThreadExecutor);
         this.overworldDataStorage = persistentStateManagerFactory;
         this.poiManager = new PoiManager(new RegionStorageInfo(session.getLevelId(), world.dimension(), "poi"), path.resolve("poi"), dataFixer, dsync, iregistrycustom, world.getServer(), world);
         this.setServerViewDistance(viewDistance);
-        this.worldGenContext = new WorldGenContext(world, chunkGenerator, structureTemplateManager, this.lightEngine, mainThreadExecutor, this::setChunkUnsaved);
+        this.worldGenContext = new WorldGenContext(world, chunkGenerator, structureTemplateManager, this.lightEngine, null, this::setChunkUnsaved); // Paper - rewrite chunk system
     }
 
     private void setChunkUnsaved(ChunkPos pos) {
-        this.chunksToEagerlySave.add(pos.toLong());
+        // Paper - rewrite chunk system
     }
 
     // Paper start
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
     }
 
     boolean isChunkTracked(ServerPlayer player, int chunkX, int chunkZ) {
-        return player.getChunkTrackingView().contains(chunkX, chunkZ) && !player.connection.chunkSender.isPending(ChunkPos.asLong(chunkX, chunkZ));
+        return ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getPlayerChunkLoader().isChunkSent(player, chunkX, chunkZ); // Paper - rewrite chunk system
     }
 
     private boolean isChunkOnTrackedBorder(ServerPlayer player, int chunkX, int chunkZ) {
-        if (!this.isChunkTracked(player, chunkX, chunkZ)) {
-            return false;
-        } else {
-            for (int k = -1; k <= 1; ++k) {
-                for (int l = -1; l <= 1; ++l) {
-                    if ((k != 0 || l != 0) && !this.isChunkTracked(player, chunkX + k, chunkZ + l)) {
-                        return true;
-                    }
-                }
-            }
-
-            return false;
-        }
+        return ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getPlayerChunkLoader().isChunkSent(player, chunkX, chunkZ, true); // Paper - rewrite chunk system
     }
 
     protected ThreadedLevelLightEngine getLightEngine() {
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
 
     @Nullable
     protected ChunkHolder getUpdatingChunkIfPresent(long pos) {
-        return (ChunkHolder) this.updatingChunkMap.get(pos);
+        // Paper start - rewrite chunk system
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder holder = ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getChunkTaskScheduler().chunkHolderManager.getChunkHolder(pos);
+        return holder == null ? null : holder.vanillaChunkHolder;
+        // Paper end - rewrite chunk system
     }
 
     @Nullable
     public ChunkHolder getVisibleChunkIfPresent(long pos) {
-        return (ChunkHolder) this.visibleChunkMap.get(pos);
+        // Paper start - rewrite chunk system
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder holder = ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getChunkTaskScheduler().chunkHolderManager.getChunkHolder(pos);
+        return holder == null ? null : holder.vanillaChunkHolder;
+        // Paper end - rewrite chunk system
     }
 
     protected IntSupplier getChunkQueueLevel(long pos) {
-        return () -> {
-            ChunkHolder playerchunk = this.getVisibleChunkIfPresent(pos);
-
-            return playerchunk == null ? ChunkTaskPriorityQueue.PRIORITY_LEVEL_COUNT - 1 : Math.min(playerchunk.getQueueLevel(), ChunkTaskPriorityQueue.PRIORITY_LEVEL_COUNT - 1);
-        };
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public String getChunkDebugData(ChunkPos chunkPos) {
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
     }
 
     private CompletableFuture<ChunkResult<List<ChunkAccess>>> getChunkRangeFuture(ChunkHolder centerChunk, int margin, IntFunction<ChunkStatus> distanceToStatus) {
-        if (margin == 0) {
-            ChunkStatus chunkstatus = (ChunkStatus) distanceToStatus.apply(0);
-
-            return centerChunk.scheduleChunkGenerationTask(chunkstatus, this).thenApply((chunkresult) -> {
-                return chunkresult.map(List::of);
-            });
-        } else {
-            int j = Mth.square(margin * 2 + 1);
-            List<CompletableFuture<ChunkResult<ChunkAccess>>> list = new ArrayList(j);
-            ChunkPos chunkcoordintpair = centerChunk.getPos();
-
-            for (int k = -margin; k <= margin; ++k) {
-                for (int l = -margin; l <= margin; ++l) {
-                    int i1 = Math.max(Math.abs(l), Math.abs(k));
-                    long j1 = ChunkPos.asLong(chunkcoordintpair.x + l, chunkcoordintpair.z + k);
-                    ChunkHolder playerchunk1 = this.getUpdatingChunkIfPresent(j1);
-
-                    if (playerchunk1 == null) {
-                        return ChunkMap.UNLOADED_CHUNK_LIST_FUTURE;
-                    }
-
-                    ChunkStatus chunkstatus1 = (ChunkStatus) distanceToStatus.apply(i1);
-
-                    list.add(playerchunk1.scheduleChunkGenerationTask(chunkstatus1, this));
-                }
-            }
-
-            return Util.sequence(list).thenApply((list1) -> {
-                List<ChunkAccess> list2 = new ArrayList(list1.size());
-                Iterator iterator = list1.iterator();
-
-                while (iterator.hasNext()) {
-                    ChunkResult<ChunkAccess> chunkresult = (ChunkResult) iterator.next();
-
-                    if (chunkresult == null) {
-                        throw this.debugFuturesAndCreateReportedException(new IllegalStateException("At least one of the chunk futures were null"), "n/a");
-                    }
-
-                    ChunkAccess ichunkaccess = (ChunkAccess) chunkresult.orElse(null); // CraftBukkit - decompile error
-
-                    if (ichunkaccess == null) {
-                        return ChunkMap.UNLOADED_CHUNK_LIST_RESULT;
-                    }
-
-                    list2.add(ichunkaccess);
-                }
-
-                return ChunkResult.of(list2);
-            });
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public ReportedException debugFuturesAndCreateReportedException(IllegalStateException exception, String details) {
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
     }
 
     public CompletableFuture<ChunkResult<LevelChunk>> prepareEntityTickingChunk(ChunkHolder holder) {
-        return this.getChunkRangeFuture(holder, 2, (i) -> {
-            return ChunkStatus.FULL;
-        }).thenApply((chunkresult) -> {
-            return chunkresult.map((list) -> {
-                return (LevelChunk) list.get(list.size() / 2);
-            });
-        });
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     @Nullable
     ChunkHolder updateChunkScheduling(long pos, int level, @Nullable ChunkHolder holder, int k) {
-        if (!ChunkLevel.isLoaded(k) && !ChunkLevel.isLoaded(level)) {
-            return holder;
-        } else {
-            if (holder != null) {
-                holder.setTicketLevel(level);
-            }
-
-            if (holder != null) {
-                if (!ChunkLevel.isLoaded(level)) {
-                    this.toDrop.add(pos);
-                } else {
-                    this.toDrop.remove(pos);
-                }
-            }
-
-            if (ChunkLevel.isLoaded(level) && holder == null) {
-                holder = (ChunkHolder) this.pendingUnloads.remove(pos);
-                if (holder != null) {
-                    holder.setTicketLevel(level);
-                } else {
-                    holder = new ChunkHolder(new ChunkPos(pos), level, this.level, this.lightEngine, this::onLevelChange, this);
-                    // Paper start
-                    ca.spottedleaf.moonrise.common.util.ChunkSystem.onChunkHolderCreate(this.level, holder);
-                    // Paper end
-                }
-
-                this.updatingChunkMap.put(pos, holder);
-                this.modified = true;
-            }
-
-            return holder;
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     private void onLevelChange(ChunkPos pos, IntSupplier levelGetter, int targetLevel, IntConsumer levelSetter) {
-        this.worldgenTaskDispatcher.onLevelChange(pos, levelGetter, targetLevel, levelSetter);
-        this.lightTaskDispatcher.onLevelChange(pos, levelGetter, targetLevel, levelSetter);
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     @Override
     public void close() throws IOException {
-        try {
-            this.worldgenTaskDispatcher.close();
-            this.lightTaskDispatcher.close();
-            this.poiManager.close();
-        } finally {
-            super.close();
-        }
+        throw new UnsupportedOperationException("Use ServerChunkCache#close"); // Paper - rewrite chunk system
 
     }
 
     protected void saveAllChunks(boolean flush) {
-        if (flush) {
-            List<ChunkHolder> list = ca.spottedleaf.moonrise.common.util.ChunkSystem.getVisibleChunkHolders(this.level).stream().filter(ChunkHolder::wasAccessibleSinceLastSave).peek(ChunkHolder::refreshAccessibility).toList(); // Paper
-            MutableBoolean mutableboolean = new MutableBoolean();
-
-            do {
-                mutableboolean.setFalse();
-                list.stream().map((playerchunk) -> {
-                    BlockableEventLoop iasynctaskhandler = this.mainThreadExecutor;
-
-                    Objects.requireNonNull(playerchunk);
-                    iasynctaskhandler.managedBlock(playerchunk::isReadyForSaving);
-                    return playerchunk.getLatestChunk();
-                }).filter((ichunkaccess) -> {
-                    return ichunkaccess instanceof ImposterProtoChunk || ichunkaccess instanceof LevelChunk;
-                }).filter(this::save).forEach((ichunkaccess) -> {
-                    mutableboolean.setTrue();
-                });
-            } while (mutableboolean.isTrue());
-
-            this.poiManager.flushAll();
-            this.processUnloads(() -> {
-                return true;
-            });
-            this.flushWorker();
-        } else {
-            this.nextChunkSaveTime.clear();
-            long i = Util.getMillis();
-            Iterator<ChunkHolder> objectiterator = ca.spottedleaf.moonrise.common.util.ChunkSystem.getVisibleChunkHolders(this.level).iterator(); // Paper
-
-            while (objectiterator.hasNext()) {
-                ChunkHolder playerchunk = (ChunkHolder) objectiterator.next();
-
-                this.saveChunkIfNeeded(playerchunk, i);
-            }
-        }
+        // Paper start - rewrite chunk system
+        ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getChunkTaskScheduler().chunkHolderManager.saveAllChunks(
+            flush, false, false
+        );
+        // Paper end - rewrite chunk system
 
     }
 
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
     }
 
     public boolean hasWork() {
-        return this.lightEngine.hasLightWork() || !this.pendingUnloads.isEmpty() || ca.spottedleaf.moonrise.common.util.ChunkSystem.hasAnyChunkHolders(this.level) || !this.updatingChunkMap.isEmpty() || this.poiManager.hasWork() || !this.toDrop.isEmpty() || !this.unloadQueue.isEmpty() || this.worldgenTaskDispatcher.hasWork() || this.lightTaskDispatcher.hasWork() || this.distanceManager.hasTickets();
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     private void processUnloads(BooleanSupplier shouldKeepTicking) {
-        for (LongIterator longiterator = this.toDrop.iterator(); longiterator.hasNext(); longiterator.remove()) {
-            long i = longiterator.nextLong();
-            ChunkHolder playerchunk = (ChunkHolder) this.updatingChunkMap.get(i);
-
-            if (playerchunk != null) {
-                this.updatingChunkMap.remove(i);
-                this.pendingUnloads.put(i, playerchunk);
-                this.modified = true;
-                this.scheduleUnload(i, playerchunk);
-            }
-        }
-
-        int j = Math.max(0, this.unloadQueue.size() - 2000);
-
-        Runnable runnable;
-
-        while ((j > 0 || shouldKeepTicking.getAsBoolean()) && (runnable = (Runnable) this.unloadQueue.poll()) != null) {
-            --j;
-            runnable.run();
-        }
-
-        this.saveChunksEagerly(shouldKeepTicking);
+        ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getChunkTaskScheduler().chunkHolderManager.processUnloads(); // Paper - rewrite chunk system
+        ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getChunkTaskScheduler().chunkHolderManager.autoSave(); // Paper - rewrite chunk system
     }
 
     private void saveChunksEagerly(BooleanSupplier shouldKeepTicking) {
-        long i = Util.getMillis();
-        int j = 0;
-        LongIterator longiterator = this.chunksToEagerlySave.iterator();
-
-        while (j < 20 && this.activeChunkWrites.get() < 128 && shouldKeepTicking.getAsBoolean() && longiterator.hasNext()) {
-            long k = longiterator.nextLong();
-            ChunkHolder playerchunk = (ChunkHolder) this.visibleChunkMap.get(k);
-            ChunkAccess ichunkaccess = playerchunk != null ? playerchunk.getLatestChunk() : null;
-
-            if (ichunkaccess != null && ichunkaccess.isUnsaved()) {
-                if (this.saveChunkIfNeeded(playerchunk, i)) {
-                    ++j;
-                    longiterator.remove();
-                }
-            } else {
-                longiterator.remove();
-            }
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
 
     }
 
     private void scheduleUnload(long pos, ChunkHolder chunk) {
-        CompletableFuture<?> completablefuture = chunk.getSaveSyncFuture();
-        Runnable runnable = () -> {
-            CompletableFuture<?> completablefuture1 = chunk.getSaveSyncFuture();
-
-            if (completablefuture1 != completablefuture) {
-                this.scheduleUnload(pos, chunk);
-            } else {
-                ChunkAccess ichunkaccess = chunk.getLatestChunk();
-                // Paper start
-                boolean removed;
-                if ((removed = this.pendingUnloads.remove(pos, chunk)) && ichunkaccess != null) {
-                    ca.spottedleaf.moonrise.common.util.ChunkSystem.onChunkHolderDelete(this.level, chunk);
-                    // Paper end
-                    LevelChunk chunk1;
-
-                    if (ichunkaccess instanceof LevelChunk) {
-                        chunk1 = (LevelChunk) ichunkaccess;
-                        chunk1.setLoaded(false);
-                    }
-
-                    this.save(ichunkaccess);
-                    if (ichunkaccess instanceof LevelChunk) {
-                        chunk1 = (LevelChunk) ichunkaccess;
-                        this.level.unload(chunk1);
-                    }
-
-                    this.lightEngine.updateChunkStatus(ichunkaccess.getPos());
-                    this.lightEngine.tryScheduleUpdate();
-                    this.progressListener.onStatusChange(ichunkaccess.getPos(), (ChunkStatus) null);
-                    this.nextChunkSaveTime.remove(ichunkaccess.getPos().toLong());
-                } else if (removed) { // Paper start
-                    ca.spottedleaf.moonrise.common.util.ChunkSystem.onChunkHolderDelete(this.level, chunk);
-                } // Paper end
-
-            }
-        };
-        Queue queue = this.unloadQueue;
-
-        Objects.requireNonNull(this.unloadQueue);
-        completablefuture.thenRunAsync(runnable, queue::add).whenComplete((ovoid, throwable) -> {
-            if (throwable != null) {
-                ChunkMap.LOGGER.error("Failed to save chunk {}", chunk.getPos(), throwable);
-            }
-
-        });
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     protected boolean promoteChunkMap() {
-        if (!this.modified) {
-            return false;
-        } else {
-            this.visibleChunkMap = this.updatingChunkMap.clone();
-            this.modified = false;
-            return true;
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     private CompletableFuture<ChunkAccess> scheduleChunkLoad(ChunkPos pos) {
-        CompletableFuture<Optional<SerializableChunkData>> completablefuture = this.readChunk(pos).thenApplyAsync((optional) -> {
-            return optional.map((nbttagcompound) -> {
-                SerializableChunkData serializablechunkdata = SerializableChunkData.parse(this.level, this.level.registryAccess(), nbttagcompound);
-
-                if (serializablechunkdata == null) {
-                    ChunkMap.LOGGER.error("Chunk file at {} is missing level data, skipping", pos);
-                }
-
-                return serializablechunkdata;
-            });
-        }, Util.backgroundExecutor().forName("parseChunk"));
-        CompletableFuture<?> completablefuture1 = this.poiManager.prefetch(pos);
-
-        return completablefuture.thenCombine(completablefuture1, (optional, object) -> {
-            return optional;
-        }).thenApplyAsync((optional) -> {
-            Profiler.get().incrementCounter("chunkLoad");
-            if (optional.isPresent()) {
-                ProtoChunk protochunk = ((SerializableChunkData) optional.get()).read(this.level, this.poiManager, this.storageInfo(), pos);
-
-                this.markPosition(pos, protochunk.getPersistedStatus().getChunkType());
-                return protochunk;
-            } else {
-                return this.createEmptyChunk(pos);
-            }
-        }, this.mainThreadExecutor).exceptionallyAsync((throwable) -> {
-            return this.handleChunkLoadFailure(throwable, pos);
-        }, this.mainThreadExecutor);
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     private ChunkAccess handleChunkLoadFailure(Throwable throwable, ChunkPos chunkPos) {
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
 
     @Override
     public GenerationChunkHolder acquireGeneration(long pos) {
-        ChunkHolder playerchunk = (ChunkHolder) this.updatingChunkMap.get(pos);
-
-        playerchunk.increaseGenerationRefCount();
-        return playerchunk;
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     @Override
     public void releaseGeneration(GenerationChunkHolder chunkHolder) {
-        chunkHolder.decreaseGenerationRefCount();
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     @Override
     public CompletableFuture<ChunkAccess> applyStep(GenerationChunkHolder chunkHolder, ChunkStep step, StaticCache2D<GenerationChunkHolder> chunks) {
-        ChunkPos chunkcoordintpair = chunkHolder.getPos();
-
-        if (step.targetStatus() == ChunkStatus.EMPTY) {
-            return this.scheduleChunkLoad(chunkcoordintpair);
-        } else {
-            try {
-                GenerationChunkHolder generationchunkholder1 = (GenerationChunkHolder) chunks.get(chunkcoordintpair.x, chunkcoordintpair.z);
-                ChunkAccess ichunkaccess = generationchunkholder1.getChunkIfPresentUnchecked(step.targetStatus().getParent());
-
-                if (ichunkaccess == null) {
-                    throw new IllegalStateException("Parent chunk missing");
-                } else {
-                    CompletableFuture<ChunkAccess> completablefuture = step.apply(this.worldGenContext, chunks, ichunkaccess);
-
-                    this.progressListener.onStatusChange(chunkcoordintpair, step.targetStatus());
-                    return completablefuture;
-                }
-            } catch (Exception exception) {
-                exception.getStackTrace();
-                CrashReport crashreport = CrashReport.forThrowable(exception, "Exception generating new chunk");
-                CrashReportCategory crashreportsystemdetails = crashreport.addCategory("Chunk to be generated");
-
-                crashreportsystemdetails.setDetail("Status being generated", () -> {
-                    return step.targetStatus().getName();
-                });
-                crashreportsystemdetails.setDetail("Location", (Object) String.format(Locale.ROOT, "%d,%d", chunkcoordintpair.x, chunkcoordintpair.z));
-                crashreportsystemdetails.setDetail("Position hash", (Object) ChunkPos.asLong(chunkcoordintpair.x, chunkcoordintpair.z));
-                crashreportsystemdetails.setDetail("Generator", (Object) this.generator());
-                this.mainThreadExecutor.execute(() -> {
-                    throw new ReportedException(crashreport);
-                });
-                throw new ReportedException(crashreport);
-            }
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     @Override
     public ChunkGenerationTask scheduleGenerationTask(ChunkStatus requestedStatus, ChunkPos pos) {
-        ChunkGenerationTask chunkgenerationtask = ChunkGenerationTask.create(this, requestedStatus, pos);
-
-        this.pendingGenerationTasks.add(chunkgenerationtask);
-        return chunkgenerationtask;
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     private void runGenerationTask(ChunkGenerationTask loader) {
-        GenerationChunkHolder generationchunkholder = loader.getCenter();
-        ChunkTaskDispatcher chunktaskdispatcher = this.worldgenTaskDispatcher;
-        Runnable runnable = () -> {
-            CompletableFuture<?> completablefuture = loader.runUntilWait();
-
-            if (completablefuture != null) {
-                completablefuture.thenRun(() -> {
-                    this.runGenerationTask(loader);
-                });
-            }
-        };
-        long i = generationchunkholder.getPos().toLong();
-
-        Objects.requireNonNull(generationchunkholder);
-        chunktaskdispatcher.submit(runnable, i, generationchunkholder::getQueueLevel);
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     @Override
     public void runGenerationTasks() {
-        this.pendingGenerationTasks.forEach(this::runGenerationTask);
-        this.pendingGenerationTasks.clear();
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public CompletableFuture<ChunkResult<LevelChunk>> prepareTickingChunk(ChunkHolder holder) {
-        CompletableFuture<ChunkResult<List<ChunkAccess>>> completablefuture = this.getChunkRangeFuture(holder, 1, (i) -> {
-            return ChunkStatus.FULL;
-        });
-        CompletableFuture<ChunkResult<LevelChunk>> completablefuture1 = completablefuture.thenApplyAsync((chunkresult) -> {
-            return chunkresult.map((list) -> {
-                LevelChunk chunk = (LevelChunk) list.get(list.size() / 2);
-
-                chunk.postProcessGeneration(this.level);
-                this.level.startTickingChunk(chunk);
-                CompletableFuture<?> completablefuture2 = holder.getSendSyncFuture();
-
-                if (completablefuture2.isDone()) {
-                    this.onChunkReadyToSend(holder, chunk);
-                } else {
-                    completablefuture2.thenAcceptAsync((object) -> {
-                        this.onChunkReadyToSend(holder, chunk);
-                    }, this.mainThreadExecutor);
-                }
-
-                return chunk;
-            });
-        }, this.mainThreadExecutor);
-
-        completablefuture1.handle((chunkresult, throwable) -> {
-            this.tickingGenerated.getAndIncrement();
-            return null;
-        });
-        return completablefuture1;
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     private void onChunkReadyToSend(ChunkHolder chunkHolder, LevelChunk chunk) {
-        ChunkPos chunkcoordintpair = chunk.getPos();
-        Iterator iterator = this.playerMap.getAllPlayers().iterator();
-
-        while (iterator.hasNext()) {
-            ServerPlayer entityplayer = (ServerPlayer) iterator.next();
-
-            if (entityplayer.getChunkTrackingView().contains(chunkcoordintpair)) {
-                ChunkMap.markChunkPendingToSend(entityplayer, chunk);
-            }
-        }
-
-        this.level.getChunkSource().onChunkReadyToSend(chunkHolder);
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public CompletableFuture<ChunkResult<LevelChunk>> prepareAccessibleChunk(ChunkHolder holder) {
-        return this.getChunkRangeFuture(holder, 1, ChunkLevel::getStatusAroundFullChunk).thenApply((chunkresult) -> {
-            return chunkresult.map((list) -> {
-                return (LevelChunk) list.get(list.size() / 2);
-            });
-        });
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public int getTickingGenerated() {
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
     }
 
     private boolean saveChunkIfNeeded(ChunkHolder chunkHolder, long currentTime) {
-        if (chunkHolder.wasAccessibleSinceLastSave() && chunkHolder.isReadyForSaving()) {
-            ChunkAccess ichunkaccess = chunkHolder.getLatestChunk();
-
-            if (!(ichunkaccess instanceof ImposterProtoChunk) && !(ichunkaccess instanceof LevelChunk)) {
-                return false;
-            } else if (!ichunkaccess.isUnsaved()) {
-                return false;
-            } else {
-                long j = ichunkaccess.getPos().toLong();
-                long k = this.nextChunkSaveTime.getOrDefault(j, -1L);
-
-                if (currentTime < k) {
-                    return false;
-                } else {
-                    boolean flag = this.save(ichunkaccess);
-
-                    chunkHolder.refreshAccessibility();
-                    if (flag) {
-                        this.nextChunkSaveTime.put(j, currentTime + 10000L);
-                    }
-
-                    return flag;
-                }
-            }
-        } else {
-            return false;
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public boolean save(ChunkAccess chunk) {
-        this.poiManager.flush(chunk.getPos());
-        if (!chunk.tryMarkSaved()) {
-            return false;
-        } else {
-            ChunkPos chunkcoordintpair = chunk.getPos();
-
-            try {
-                ChunkStatus chunkstatus = chunk.getPersistedStatus();
-
-                if (chunkstatus.getChunkType() != ChunkType.LEVELCHUNK) {
-                    if (this.isExistingChunkFull(chunkcoordintpair)) {
-                        return false;
-                    }
-
-                    if (chunkstatus == ChunkStatus.EMPTY && chunk.getAllStarts().values().stream().noneMatch(StructureStart::isValid)) {
-                        return false;
-                    }
-                }
-
-                Profiler.get().incrementCounter("chunkSave");
-                this.activeChunkWrites.incrementAndGet();
-                SerializableChunkData serializablechunkdata = SerializableChunkData.copyOf(this.level, chunk);
-
-                Objects.requireNonNull(serializablechunkdata);
-                CompletableFuture<CompoundTag> completablefuture = CompletableFuture.supplyAsync(serializablechunkdata::write, Util.backgroundExecutor());
-
-                Objects.requireNonNull(completablefuture);
-                this.write(chunkcoordintpair, completablefuture::join).handle((ovoid, throwable) -> {
-                    if (throwable != null) {
-                        this.level.getServer().reportChunkSaveFailure(throwable, this.storageInfo(), chunkcoordintpair);
-                    }
-
-                    this.activeChunkWrites.decrementAndGet();
-                    return null;
-                });
-                this.markPosition(chunkcoordintpair, chunkstatus.getChunkType());
-                return true;
-            } catch (Exception exception) {
-                this.level.getServer().reportChunkSaveFailure(exception, this.storageInfo(), chunkcoordintpair);
-                return false;
-            }
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     private boolean isExistingChunkFull(ChunkPos pos) {
-        byte b0 = this.chunkTypeCache.get(pos.toLong());
-
-        if (b0 != 0) {
-            return b0 == 1;
-        } else {
-            CompoundTag nbttagcompound;
-
-            try {
-                nbttagcompound = (CompoundTag) ((Optional) this.readChunk(pos).join()).orElse((Object) null);
-                if (nbttagcompound == null) {
-                    this.markPositionReplaceable(pos);
-                    return false;
-                }
-            } catch (Exception exception) {
-                ChunkMap.LOGGER.error("Failed to read chunk {}", pos, exception);
-                this.markPositionReplaceable(pos);
-                return false;
-            }
-
-            ChunkType chunktype = SerializableChunkData.getChunkTypeFromTag(nbttagcompound);
-
-            return this.markPosition(pos, chunktype) == 1;
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public void setServerViewDistance(int watchDistance) { // Paper - public
-        int j = Mth.clamp(watchDistance, 2, 32);
-
-        if (j != this.serverViewDistance) {
-            this.serverViewDistance = j;
-            this.distanceManager.updatePlayerTickets(this.serverViewDistance);
-            Iterator iterator = this.playerMap.getAllPlayers().iterator();
-
-            while (iterator.hasNext()) {
-                ServerPlayer entityplayer = (ServerPlayer) iterator.next();
-
-                this.updateChunkTracking(entityplayer);
-            }
+        // Paper start - rewrite chunk system
+        final int clamped = Mth.clamp(watchDistance, 2, ca.spottedleaf.moonrise.common.util.MoonriseConstants.MAX_VIEW_DISTANCE);
+        if (clamped == this.serverViewDistance) {
+            return;
         }
 
+        this.serverViewDistance = clamped;
+        ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getPlayerChunkLoader().setLoadDistance(this.serverViewDistance + 1);
+        // Paper end - rewrite chunk system
     }
 
     public int getPlayerViewDistance(ServerPlayer player) { // Paper - public
-        return Mth.clamp(player.requestedViewDistance(), 2, this.serverViewDistance);
+        return ca.spottedleaf.moonrise.common.util.ChunkSystem.getSendViewDistance(player); // Paper - rewrite chunk system
     }
 
     private void markChunkPendingToSend(ServerPlayer player, ChunkPos pos) {
-        LevelChunk chunk = this.getChunkToSend(pos.toLong());
-
-        if (chunk != null) {
-            ChunkMap.markChunkPendingToSend(player, chunk);
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
 
     }
 
     private static void markChunkPendingToSend(ServerPlayer player, LevelChunk chunk) {
-        player.connection.chunkSender.markChunkPendingToSend(chunk);
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     private static void dropChunk(ServerPlayer player, ChunkPos pos) {
-        player.connection.chunkSender.dropChunk(player, pos);
+        // Paper - rewrite chunk system
+    }
+
+    // Paper start - rewrite chunk system
+    @Override
+    public CompletableFuture<Optional<CompoundTag>> read(final ChunkPos pos) {
+        final CompletableFuture<Optional<CompoundTag>> ret = new CompletableFuture<>();
+
+        ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.loadDataAsync(
+            this.level, pos.x, pos.z, ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionFileType.CHUNK_DATA,
+            (final CompoundTag data, final Throwable thr) -> {
+                if (thr != null) {
+                    ret.completeExceptionally(thr);
+                } else {
+                    ret.complete(Optional.ofNullable(data));
+                }
+            }, false
+        );
+
+        return ret;
+    }
+
+    @Override
+    public CompletableFuture<Void> write(final ChunkPos pos, final Supplier<CompoundTag> tag) {
+        ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.scheduleSave(
+            this.level, pos.x, pos.z, tag.get(),
+            ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionFileType.CHUNK_DATA
+        );
+        return null;
     }
 
+    @Override
+    public void flushWorker() {
+        ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.flush(this.level);
+    }
+    // Paper end - rewrite chunk system
+
     @Nullable
     public LevelChunk getChunkToSend(long pos) {
         ChunkHolder playerchunk = this.getVisibleChunkIfPresent(pos);
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
     }
 
     // CraftBukkit start
-    private CompoundTag upgradeChunkTag(CompoundTag nbttagcompound, ChunkPos chunkcoordintpair) {
+    public CompoundTag upgradeChunkTag(CompoundTag nbttagcompound, ChunkPos chunkcoordintpair) { // Paper - public
         return this.upgradeChunkTag(this.level.getTypeKey(), this.overworldDataStorage, nbttagcompound, this.generator().getTypeNameForDataFixer(), chunkcoordintpair, this.level);
         // CraftBukkit end
     }
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
 
         while (longiterator.hasNext()) {
             long i = longiterator.nextLong();
-            ChunkHolder playerchunk = (ChunkHolder) this.visibleChunkMap.get(i);
+            ChunkHolder playerchunk = (ChunkHolder) this.getVisibleChunkIfPresent(i); // Paper - rewrite chunk system
 
             if (playerchunk != null && this.anyPlayerCloseEnoughForSpawningInternal(playerchunk.getPos())) {
                 callback.accept(playerchunk);
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
     }
 
     boolean anyPlayerCloseEnoughForSpawning(ChunkPos chunkcoordintpair, boolean reducedRange) {
-        return !this.distanceManager.hasPlayersNearby(chunkcoordintpair.toLong()) ? false : this.anyPlayerCloseEnoughForSpawningInternal(chunkcoordintpair, reducedRange);
+        return this.anyPlayerCloseEnoughForSpawningInternal(chunkcoordintpair, reducedRange); // Paper - chunk tick iteration optimisation
         // Spigot end
     }
 
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
     private boolean anyPlayerCloseEnoughForSpawningInternal(ChunkPos chunkcoordintpair, boolean reducedRange) {
         double blockRange; // Paper - use from event
         // Spigot end
-        Iterator iterator = this.playerMap.getAllPlayers().iterator();
-
-        ServerPlayer entityplayer;
+        // Paper start - chunk tick iteration optimisation
+        final ca.spottedleaf.moonrise.common.list.ReferenceList<ServerPlayer> players = ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getNearbyPlayers().getPlayers(
+            chunkcoordintpair, ca.spottedleaf.moonrise.common.misc.NearbyPlayers.NearbyMapType.SPAWN_RANGE
+        );
+        if (players == null) {
+            return false;
+        }
 
-        do {
-            if (!iterator.hasNext()) {
-                return false;
-            }
+        final ServerPlayer[] raw = players.getRawDataUnchecked();
+        final int len = players.size();
 
-            entityplayer = (ServerPlayer) iterator.next();
+        Objects.checkFromIndexSize(0, len, raw.length);
+        for (int i = 0; i < len; ++i) {
+            final ServerPlayer entityplayer = raw[i];
             // Paper start - PlayerNaturallySpawnCreaturesEvent
             com.destroystokyo.paper.event.entity.PlayerNaturallySpawnCreaturesEvent event;
             blockRange = 16384.0D;
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
                 blockRange = (double) ((event.getSpawnRadius() << 4) * (event.getSpawnRadius() << 4));
             }
             // Paper end - PlayerNaturallySpawnCreaturesEvent
-        } while (!this.playerIsCloseEnoughForSpawning(entityplayer, chunkcoordintpair, blockRange)); // Spigot
+            if (this.playerIsCloseEnoughForSpawning(entityplayer, chunkcoordintpair, blockRange)) {
+                return true;
+            }
+        }
 
-        return true;
+        return false;
+        // Paper end - chunk tick iteration optimisation
     }
 
     public List<ServerPlayer> getPlayersCloseForSpawning(ChunkPos pos) {
-        long i = pos.toLong();
+        // Paper start - chunk tick iteration optimisation
+        final ca.spottedleaf.moonrise.common.list.ReferenceList<ServerPlayer> players = ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getNearbyPlayers().getPlayers(
+            pos, ca.spottedleaf.moonrise.common.misc.NearbyPlayers.NearbyMapType.SPAWN_RANGE
+        );
+        if (players == null) {
+            return new ArrayList<>();
+        }
 
-        if (!this.distanceManager.hasPlayersNearby(i)) {
-            return List.of();
-        } else {
-            Builder<ServerPlayer> builder = ImmutableList.builder();
-            Iterator iterator = this.playerMap.getAllPlayers().iterator();
+        List<ServerPlayer> ret = null;
 
-            while (iterator.hasNext()) {
-                ServerPlayer entityplayer = (ServerPlayer) iterator.next();
+        final ServerPlayer[] raw = players.getRawDataUnchecked();
+        final int len = players.size();
 
-                if (this.playerIsCloseEnoughForSpawning(entityplayer, pos, 16384.0D)) { // Spigot
-                    builder.add(entityplayer);
+        Objects.checkFromIndexSize(0, len, raw.length);
+        for (int i = 0; i < len; ++i) {
+            final ServerPlayer player = raw[i];
+            if (this.playerIsCloseEnoughForSpawning(player, pos, 16384.0D)) { // Spigot
+                if (ret == null) {
+                    ret = new ArrayList<>(len - i);
+                    ret.add(player);
+                } else {
+                    ret.add(player);
                 }
             }
-
-            return builder.build();
         }
+
+        return ret == null ? new ArrayList<>() : ret;
+        // Paper end - chunk tick iteration optimisation
     }
 
-    private boolean playerIsCloseEnoughForSpawning(ServerPlayer entityplayer, ChunkPos chunkcoordintpair, double range) { // Spigot
+    public boolean playerIsCloseEnoughForSpawning(ServerPlayer entityplayer, ChunkPos chunkcoordintpair, double range) { // Spigot // Paper - chunk tick iteration optimisation - public
         if (entityplayer.isSpectator()) {
             return false;
         } else {
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
             this.updatePlayerPos(player);
             if (!flag1) {
                 this.distanceManager.addPlayer(SectionPos.of((EntityAccess) player), player);
+                ((ca.spottedleaf.moonrise.patches.chunk_tick_iteration.ChunkTickDistanceManager)this.distanceManager).moonrise$addPlayer(player, SectionPos.of(player)); // Paper - chunk tick iteration optimisation
             }
 
             player.setChunkTrackingView(ChunkTrackingView.EMPTY);
-            this.updateChunkTracking(player);
+            ca.spottedleaf.moonrise.common.util.ChunkSystem.addPlayerToDistanceMaps(this.level, player); // Paper - rewrite chunk system
         } else {
             SectionPos sectionposition = player.getLastSectionPos();
 
             this.playerMap.removePlayer(player);
             if (!flag2) {
                 this.distanceManager.removePlayer(sectionposition, player);
+                ((ca.spottedleaf.moonrise.patches.chunk_tick_iteration.ChunkTickDistanceManager)this.distanceManager).moonrise$removePlayer(player, SectionPos.of(player)); // Paper - chunk tick iteration optimisation
             }
 
-            this.applyChunkTrackingView(player, ChunkTrackingView.EMPTY);
+            ca.spottedleaf.moonrise.common.util.ChunkSystem.removePlayerFromDistanceMaps(this.level, player); // Paper - rewrite chunk system
         }
 
     }
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
     }
 
     public void move(ServerPlayer player) {
-        ObjectIterator objectiterator = this.entityMap.values().iterator();
-
-        while (objectiterator.hasNext()) {
-            ChunkMap.TrackedEntity playerchunkmap_entitytracker = (ChunkMap.TrackedEntity) objectiterator.next();
-
-            if (playerchunkmap_entitytracker.entity == player) {
-                playerchunkmap_entitytracker.updatePlayers(this.level.players());
-            } else {
-                playerchunkmap_entitytracker.updatePlayer(player);
-            }
-        }
+        // Paper - optimise entity tracker
 
         SectionPos sectionposition = player.getLastSectionPos();
         SectionPos sectionposition1 = SectionPos.of((EntityAccess) player);
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
 
         if (flag2 || flag != flag1) {
             this.updatePlayerPos(player);
+            ((ca.spottedleaf.moonrise.patches.chunk_tick_iteration.ChunkTickDistanceManager)this.distanceManager).moonrise$updatePlayer(player, sectionposition, sectionposition1, flag, flag1); // Paper - chunk tick iteration optimisation
             if (!flag) {
                 this.distanceManager.removePlayer(sectionposition, player);
             }
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
                 this.playerMap.unIgnorePlayer(player);
             }
 
-            this.updateChunkTracking(player);
+            // Paper - rewrite chunk system
         }
 
+        ca.spottedleaf.moonrise.common.util.ChunkSystem.updateMaps(this.level, player); // Paper - rewrite chunk system
     }
 
     private void updateChunkTracking(ServerPlayer player) {
-        ChunkPos chunkcoordintpair = player.chunkPosition();
-        int i = this.getPlayerViewDistance(player);
-        ChunkTrackingView chunktrackingview = player.getChunkTrackingView();
-
-        if (chunktrackingview instanceof ChunkTrackingView.Positioned chunktrackingview_a) {
-            if (chunktrackingview_a.center().equals(chunkcoordintpair) && chunktrackingview_a.viewDistance() == i) {
-                return;
-            }
-        }
-
-        this.applyChunkTrackingView(player, ChunkTrackingView.of(chunkcoordintpair, i));
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     private void applyChunkTrackingView(ServerPlayer player, ChunkTrackingView chunkFilter) {
-        if (player.level() == this.level) {
-            ChunkTrackingView chunktrackingview1 = player.getChunkTrackingView();
-
-            if (chunkFilter instanceof ChunkTrackingView.Positioned) {
-                label15:
-                {
-                    ChunkTrackingView.Positioned chunktrackingview_a = (ChunkTrackingView.Positioned) chunkFilter;
-
-                    if (chunktrackingview1 instanceof ChunkTrackingView.Positioned) {
-                        ChunkTrackingView.Positioned chunktrackingview_a1 = (ChunkTrackingView.Positioned) chunktrackingview1;
-
-                        if (chunktrackingview_a1.center().equals(chunktrackingview_a.center())) {
-                            break label15;
-                        }
-                    }
-
-                    player.connection.send(new ClientboundSetChunkCacheCenterPacket(chunktrackingview_a.center().x, chunktrackingview_a.center().z));
-                }
-            }
-
-            ChunkTrackingView.difference(chunktrackingview1, chunkFilter, (chunkcoordintpair) -> {
-                this.markChunkPendingToSend(player, chunkcoordintpair);
-            }, (chunkcoordintpair) -> {
-                ChunkMap.dropChunk(player, chunkcoordintpair);
-            });
-            player.setChunkTrackingView(chunkFilter);
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     @Override
     public List<ServerPlayer> getPlayers(ChunkPos chunkPos, boolean onlyOnWatchDistanceEdge) {
-        Set<ServerPlayer> set = this.playerMap.getAllPlayers();
-        Builder<ServerPlayer> builder = ImmutableList.builder();
-        Iterator iterator = set.iterator();
-
-        while (iterator.hasNext()) {
-            ServerPlayer entityplayer = (ServerPlayer) iterator.next();
-
-            if (onlyOnWatchDistanceEdge && this.isChunkOnTrackedBorder(entityplayer, chunkPos.x, chunkPos.z) || !onlyOnWatchDistanceEdge && this.isChunkTracked(entityplayer, chunkPos.x, chunkPos.z)) {
-                builder.add(entityplayer);
-            }
+        // Paper start - rewrite chunk system
+        final ChunkHolder holder = this.getVisibleChunkIfPresent(chunkPos.toLong());
+        if (holder == null) {
+            return new ArrayList<>();
+        } else {
+            return ((ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemChunkHolder)holder).moonrise$getPlayers(onlyOnWatchDistanceEdge);
         }
-
-        return builder.build();
+        // Paper end - rewrite chunk system
     }
 
     public void addEntity(Entity entity) {
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
                     ChunkMap.TrackedEntity playerchunkmap_entitytracker = new ChunkMap.TrackedEntity(entity, i, j, entitytypes.trackDeltas());
 
                     this.entityMap.put(entity.getId(), playerchunkmap_entitytracker);
+                    // Paper start - optimise entity tracker
+                    if (((ca.spottedleaf.moonrise.patches.entity_tracker.EntityTrackerEntity)entity).moonrise$getTrackedEntity() != null) {
+                        throw new IllegalStateException("Entity is already tracked");
+                    }
+                    ((ca.spottedleaf.moonrise.patches.entity_tracker.EntityTrackerEntity)entity).moonrise$setTrackedEntity(playerchunkmap_entitytracker);
+                    // Paper end - optimise entity tracker
                     playerchunkmap_entitytracker.updatePlayers(this.level.players());
                     if (entity instanceof ServerPlayer) {
                         ServerPlayer entityplayer = (ServerPlayer) entity;
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
             playerchunkmap_entitytracker1.broadcastRemoved();
         }
 
+        ((ca.spottedleaf.moonrise.patches.entity_tracker.EntityTrackerEntity)entity).moonrise$setTrackedEntity(null); // Paper - optimise entity tracker
     }
 
-    protected void tick() {
-        Iterator iterator = this.playerMap.getAllPlayers().iterator();
+    // Paper start - optimise entity tracker
+    private void newTrackerTick() {
+        final ca.spottedleaf.moonrise.patches.chunk_system.level.entity.server.ServerEntityLookup entityLookup = (ca.spottedleaf.moonrise.patches.chunk_system.level.entity.server.ServerEntityLookup)((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getEntityLookup();;
 
-        while (iterator.hasNext()) {
-            ServerPlayer entityplayer = (ServerPlayer) iterator.next();
+        final ca.spottedleaf.moonrise.common.list.ReferenceList<net.minecraft.world.entity.Entity> trackerEntities = entityLookup.trackerEntities;
+        final Entity[] trackerEntitiesRaw = trackerEntities.getRawDataUnchecked();
+        for (int i = 0, len = trackerEntities.size(); i < len; ++i) {
+            final Entity entity = trackerEntitiesRaw[i];
+            final ChunkMap.TrackedEntity tracker = ((ca.spottedleaf.moonrise.patches.entity_tracker.EntityTrackerEntity)entity).moonrise$getTrackedEntity();
+            if (tracker == null) {
+                continue;
+            }
+            ((ca.spottedleaf.moonrise.patches.entity_tracker.EntityTrackerTrackedEntity)tracker).moonrise$tick(((ca.spottedleaf.moonrise.patches.chunk_system.entity.ChunkSystemEntity)entity).moonrise$getChunkData().nearbyPlayers);
+            if (((ca.spottedleaf.moonrise.patches.entity_tracker.EntityTrackerTrackedEntity)tracker).moonrise$hasPlayers()
+                || ((ca.spottedleaf.moonrise.patches.chunk_system.entity.ChunkSystemEntity)entity).moonrise$getChunkStatus().isOrAfter(FullChunkStatus.ENTITY_TICKING)) {
+                tracker.serverEntity.sendChanges();
+            }
+        }
+    }
+    // Paper end - optimise entity tracker
 
-            this.updateChunkTracking(entityplayer);
+    protected void tick() {
+        // Paper start - optimise entity tracker
+        if (true) {
+            this.newTrackerTick();
+            return;
         }
+        // Paper end - optimise entity tracker
+        // Paper - rewrite chunk system
 
         List<ServerPlayer> list = Lists.newArrayList();
         List<ServerPlayer> list1 = this.level.players();
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
     }
 
     public void waitForLightBeforeSending(ChunkPos centerPos, int radius) {
-        int j = radius + 1;
-
-        ChunkPos.rangeClosed(centerPos, j).forEach((chunkcoordintpair1) -> {
-            ChunkHolder playerchunk = this.getVisibleChunkIfPresent(chunkcoordintpair1.toLong());
-
-            if (playerchunk != null) {
-                playerchunk.addSendDependency(this.lightEngine.waitForPendingTasks(chunkcoordintpair1.x, chunkcoordintpair1.z));
-            }
-
-        });
+        // Paper - rewrite chunk system
     }
 
-    public class ChunkDistanceManager extends DistanceManager { // Paper - public
+    public class ChunkDistanceManager extends DistanceManager implements ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemDistanceManager { // Paper - public // Paper - rewrite chunk system
 
         protected ChunkDistanceManager(final Executor workerExecutor, final Executor mainThreadExecutor) {
             super(workerExecutor, mainThreadExecutor);
         }
 
+        // Paper start - rewrite chunk system
+        @Override
+        public final ChunkMap moonrise$getChunkMap() {
+            return ChunkMap.this;
+        }
+        // Paper end - rewrite chunk system
+
         @Override
         protected boolean isChunkToRemove(long pos) {
-            return ChunkMap.this.toDrop.contains(pos);
+            throw new UnsupportedOperationException(); // Paper - rewrite chunk system
         }
 
         @Nullable
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         }
     }
 
-    public class TrackedEntity {
+    public class TrackedEntity implements ca.spottedleaf.moonrise.patches.entity_tracker.EntityTrackerTrackedEntity { // Paper - optimise entity tracker
 
         public final ServerEntity serverEntity;
         final Entity entity;
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         SectionPos lastSectionPos;
         public final Set<ServerPlayerConnection> seenBy = new it.unimi.dsi.fastutil.objects.ReferenceOpenHashSet<>(); // Paper - Perf: optimise map impl
 
+        // Paper start - optimise entity tracker
+        private long lastChunkUpdate = -1L;
+        private ca.spottedleaf.moonrise.common.misc.NearbyPlayers.TrackedChunk lastTrackedChunk;
+
+        @Override
+        public final void moonrise$tick(final ca.spottedleaf.moonrise.common.misc.NearbyPlayers.TrackedChunk chunk) {
+            if (chunk == null) {
+                this.moonrise$clearPlayers();
+                return;
+            }
+
+            final ca.spottedleaf.moonrise.common.list.ReferenceList<ServerPlayer> players = chunk.getPlayers(ca.spottedleaf.moonrise.common.misc.NearbyPlayers.NearbyMapType.VIEW_DISTANCE);
+
+            if (players == null) {
+                this.moonrise$clearPlayers();
+                return;
+            }
+
+            final long lastChunkUpdate = this.lastChunkUpdate;
+            final long currChunkUpdate = chunk.getUpdateCount();
+            final ca.spottedleaf.moonrise.common.misc.NearbyPlayers.TrackedChunk lastTrackedChunk = this.lastTrackedChunk;
+            this.lastChunkUpdate = currChunkUpdate;
+            this.lastTrackedChunk = chunk;
+
+            final ServerPlayer[] playersRaw = players.getRawDataUnchecked();
+
+            for (int i = 0, len = players.size(); i < len; ++i) {
+                final ServerPlayer player = playersRaw[i];
+                this.updatePlayer(player);
+            }
+
+            if (lastChunkUpdate != currChunkUpdate || lastTrackedChunk != chunk) {
+                // need to purge any players possible not in the chunk list
+                for (final ServerPlayerConnection conn : new java.util.ArrayList<>(this.seenBy)) {
+                    final ServerPlayer player = conn.getPlayer();
+                    if (!players.contains(player)) {
+                        this.removePlayer(player);
+                    }
+                }
+            }
+        }
+
+        @Override
+        public final void moonrise$removeNonTickThreadPlayers() {
+            boolean foundToRemove = false;
+            for (final ServerPlayerConnection conn : this.seenBy) {
+                if (!ca.spottedleaf.moonrise.common.util.TickThread.isTickThreadFor(conn.getPlayer())) {
+                    foundToRemove = true;
+                    break;
+                }
+            }
+
+            if (!foundToRemove) {
+                return;
+            }
+
+            for (final ServerPlayerConnection conn : new java.util.ArrayList<>(this.seenBy)) {
+                ServerPlayer player = conn.getPlayer();
+                if (!ca.spottedleaf.moonrise.common.util.TickThread.isTickThreadFor(player)) {
+                    this.removePlayer(player);
+                }
+            }
+        }
+
+        @Override
+        public final void moonrise$clearPlayers() {
+            this.lastChunkUpdate = -1;
+            this.lastTrackedChunk = null;
+            if (this.seenBy.isEmpty()) {
+                return;
+            }
+            for (final ServerPlayerConnection conn : new java.util.ArrayList<>(this.seenBy)) {
+                ServerPlayer player = conn.getPlayer();
+                this.removePlayer(player);
+            }
+        }
+
+        @Override
+        public final boolean moonrise$hasPlayers() {
+            return !this.seenBy.isEmpty();
+        }
+        // Paper end - optimise entity tracker
+
         public TrackedEntity(final Entity entity, final int i, final int j, final boolean flag) {
             this.serverEntity = new ServerEntity(ChunkMap.this.level, entity, j, flag, this::broadcast, this.seenBy); // CraftBukkit
             this.entity = entity;
@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         }
 
         private int getEffectiveRange() {
-            int i = this.range;
-            Iterator iterator = this.entity.getIndirectPassengers().iterator();
+            // Paper start - optimise entity tracker
+            final Entity entity = this.entity;
+            int range = this.range;
 
-            while (iterator.hasNext()) {
-                Entity entity = (Entity) iterator.next();
-                int j = entity.getType().clientTrackingRange() * 16;
-                j = org.spigotmc.TrackingRange.getEntityTrackingRange(entity, j); // Paper
+            if (entity.getPassengers() == ImmutableList.<Entity>of()) {
+                return this.scaledRange(range);
+            }
 
-                if (j > i) {
-                    i = j;
-                }
+            // note: we change to List
+            final List<Entity> passengers = (List<Entity>)entity.getIndirectPassengers();
+            for (int i = 0, len = passengers.size(); i < len; ++i) {
+                final Entity passenger = passengers.get(i);
+                // note: max should be branchless
+                range = Math.max(range, ca.spottedleaf.moonrise.common.PlatformHooks.get().modifyEntityTrackingRange(passenger, passenger.getType().clientTrackingRange() << 4));
             }
 
-            return this.scaledRange(i);
+            return this.scaledRange(range);
+            // Paper end - optimise entity tracker
         }
 
         public void updatePlayers(List<ServerPlayer> players) {
diff --git a/src/main/java/net/minecraft/server/level/DistanceManager.java b/src/main/java/net/minecraft/server/level/DistanceManager.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/level/DistanceManager.java
+++ b/src/main/java/net/minecraft/server/level/DistanceManager.java
@@ -0,0 +0,0 @@ import net.minecraft.world.level.ChunkPos;
 import net.minecraft.world.level.chunk.LevelChunk;
 import org.slf4j.Logger;
 
-public abstract class DistanceManager {
+public abstract class DistanceManager implements ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemDistanceManager, ca.spottedleaf.moonrise.patches.chunk_tick_iteration.ChunkTickDistanceManager { // Paper - rewrite chunk system // Paper - chunk tick iteration optimisation
 
     static final Logger LOGGER = LogUtils.getLogger();
     static final int PLAYER_TICKET_LEVEL = ChunkLevel.byStatus(FullChunkStatus.ENTITY_TICKING);
     private static final int INITIAL_TICKET_LIST_CAPACITY = 4;
     final Long2ObjectMap<ObjectSet<ServerPlayer>> playersPerChunk = new Long2ObjectOpenHashMap();
-    public final Long2ObjectOpenHashMap<SortedArraySet<Ticket<?>>> tickets = new Long2ObjectOpenHashMap();
-    private final DistanceManager.ChunkTicketTracker ticketTracker = new DistanceManager.ChunkTicketTracker();
-    private final DistanceManager.FixedPlayerDistanceChunkTracker naturalSpawnChunkCounter = new DistanceManager.FixedPlayerDistanceChunkTracker(8);
-    private final TickingTracker tickingTicketsTracker = new TickingTracker();
-    private final DistanceManager.PlayerTicketTracker playerTicketManager = new DistanceManager.PlayerTicketTracker(32);
-    final Set<ChunkHolder> chunksToUpdateFutures = new ReferenceOpenHashSet();
-    final ThrottlingChunkTaskDispatcher ticketDispatcher;
-    final LongSet ticketsToRelease = new LongOpenHashSet();
-    final Executor mainThreadExecutor;
+    // Paper - rewrite chunk system
+    // Paper - chunk tick iteration optimisation
+    // Paper - rewrite chunk system
     private long ticketTickCounter;
-    public int simulationDistance = 10;
+    // Paper - rewrite chunk system
 
     protected DistanceManager(Executor workerExecutor, Executor mainThreadExecutor) {
         TaskScheduler<Runnable> taskscheduler = TaskScheduler.wrapExecutor("player ticket throttler", mainThreadExecutor);
 
-        this.ticketDispatcher = new ThrottlingChunkTaskDispatcher(taskscheduler, workerExecutor, 4);
-        this.mainThreadExecutor = mainThreadExecutor;
+        // Paper - rewrite chunk system
     }
 
-    protected void purgeStaleTickets() {
-        ++this.ticketTickCounter;
-        ObjectIterator<Entry<SortedArraySet<Ticket<?>>>> objectiterator = this.tickets.long2ObjectEntrySet().fastIterator();
-
-        while (objectiterator.hasNext()) {
-            Entry<SortedArraySet<Ticket<?>>> entry = (Entry) objectiterator.next();
-            Iterator<Ticket<?>> iterator = ((SortedArraySet) entry.getValue()).iterator();
-            boolean flag = false;
-
-            while (iterator.hasNext()) {
-                Ticket<?> ticket = (Ticket) iterator.next();
+    // Paper start - rewrite chunk system
+    @Override
+    public final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkHolderManager moonrise$getChunkHolderManager() {
+        return ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.moonrise$getChunkMap().level).moonrise$getChunkTaskScheduler().chunkHolderManager;
+    }
+    // Paper end - rewrite chunk system
+    // Paper start - chunk tick iteration optimisation
+    private final ca.spottedleaf.moonrise.common.misc.PositionCountingAreaMap<ServerPlayer> spawnChunkTracker = new ca.spottedleaf.moonrise.common.misc.PositionCountingAreaMap<>();
 
-                if (ticket.timedOut(this.ticketTickCounter)) {
-                    iterator.remove();
-                    flag = true;
-                    this.tickingTicketsTracker.removeTicket(entry.getLongKey(), ticket);
-                }
-            }
+    @Override
+    public final void moonrise$addPlayer(final ServerPlayer player, final SectionPos pos) {
+        this.spawnChunkTracker.add(player, pos.x(), pos.z(), ca.spottedleaf.moonrise.patches.chunk_tick_iteration.ChunkTickConstants.PLAYER_SPAWN_TRACK_RANGE);
+    }
 
-            if (flag) {
-                this.ticketTracker.update(entry.getLongKey(), DistanceManager.getTicketLevelAt((SortedArraySet) entry.getValue()), false);
-            }
+    @Override
+    public final void moonrise$removePlayer(final ServerPlayer player, final SectionPos pos) {
+        this.spawnChunkTracker.remove(player);
+    }
 
-            if (((SortedArraySet) entry.getValue()).isEmpty()) {
-                objectiterator.remove();
-            }
+    @Override
+    public final void moonrise$updatePlayer(final ServerPlayer player,
+                                            final SectionPos oldPos, final SectionPos newPos,
+                                            final boolean oldIgnore, final boolean newIgnore) {
+        if (newIgnore) {
+            this.spawnChunkTracker.remove(player);
+        } else {
+            this.spawnChunkTracker.addOrUpdate(player, newPos.x(), newPos.z(), ca.spottedleaf.moonrise.patches.chunk_tick_iteration.ChunkTickConstants.PLAYER_SPAWN_TRACK_RANGE);
         }
+    }
+    // Paper end - chunk tick iteration optimisation
+
+    protected void purgeStaleTickets() {
+        this.moonrise$getChunkHolderManager().tick(); // Paper - rewrite chunk system
 
     }
 
@@ -0,0 +0,0 @@ public abstract class DistanceManager {
     protected abstract ChunkHolder updateChunkScheduling(long pos, int level, @Nullable ChunkHolder holder, int k);
 
     public boolean runAllUpdates(ChunkMap chunkLoadingManager) {
-        this.naturalSpawnChunkCounter.runAllUpdates();
-        this.tickingTicketsTracker.runAllUpdates();
-        this.playerTicketManager.runAllUpdates();
-        int i = Integer.MAX_VALUE - this.ticketTracker.runDistanceUpdates(Integer.MAX_VALUE);
-        boolean flag = i != 0;
-
-        if (flag) {
-            ;
-        }
-
-        if (!this.chunksToUpdateFutures.isEmpty()) {
-            Iterator iterator = this.chunksToUpdateFutures.iterator();
-
-            ChunkHolder playerchunk;
-
-            // CraftBukkit start - SPIGOT-7780: Call chunk unload events before updateHighestAllowedStatus
-            while (iterator.hasNext()) {
-                playerchunk = (ChunkHolder) iterator.next();
-                playerchunk.callEventIfUnloading(chunkLoadingManager);
-            }
-
-            iterator = this.chunksToUpdateFutures.iterator();
-            // CraftBukkit end
-
-            while (iterator.hasNext()) {
-                playerchunk = (ChunkHolder) iterator.next();
-                playerchunk.updateHighestAllowedStatus(chunkLoadingManager);
-            }
-
-            iterator = this.chunksToUpdateFutures.iterator();
-
-            while (iterator.hasNext()) {
-                playerchunk = (ChunkHolder) iterator.next();
-                playerchunk.updateFutures(chunkLoadingManager, this.mainThreadExecutor);
-            }
-
-            this.chunksToUpdateFutures.clear();
-            return true;
-        } else {
-            if (!this.ticketsToRelease.isEmpty()) {
-                LongIterator longiterator = this.ticketsToRelease.iterator();
-
-                while (longiterator.hasNext()) {
-                    long j = longiterator.nextLong();
-
-                    if (this.getTickets(j).stream().anyMatch((ticket) -> {
-                        return ticket.getType() == TicketType.PLAYER;
-                    })) {
-                        ChunkHolder playerchunk1 = chunkLoadingManager.getUpdatingChunkIfPresent(j);
-
-                        if (playerchunk1 == null) {
-                            throw new IllegalStateException();
-                        }
-
-                        CompletableFuture<ChunkResult<LevelChunk>> completablefuture = playerchunk1.getEntityTickingChunkFuture();
-
-                        completablefuture.thenAccept((chunkresult) -> {
-                            this.mainThreadExecutor.execute(() -> {
-                                this.ticketDispatcher.release(j, () -> {
-                                }, false);
-                            });
-                        });
-                    }
-                }
-
-                this.ticketsToRelease.clear();
-            }
-
-            return flag;
-        }
+        return this.moonrise$getChunkHolderManager().processTicketUpdates(); // Paper - rewrite chunk system
     }
 
     boolean addTicket(long i, Ticket<?> ticket) { // CraftBukkit - void -> boolean
-        SortedArraySet<Ticket<?>> arraysetsorted = this.getTickets(i);
-        int j = DistanceManager.getTicketLevelAt(arraysetsorted);
-        Ticket<?> ticket1 = (Ticket) arraysetsorted.addOrGet(ticket);
-
-        ticket1.setCreatedTick(this.ticketTickCounter);
-        if (ticket.getTicketLevel() < j) {
-            this.ticketTracker.update(i, ticket.getTicketLevel(), true);
-        }
-
-        return ticket == ticket1; // CraftBukkit
+        return this.moonrise$getChunkHolderManager().addTicketAtLevel((TicketType)ticket.getType(), i, ticket.getTicketLevel(), ticket.key); // Paper - rewrite chunk system
     }
 
     boolean removeTicket(long i, Ticket<?> ticket) { // CraftBukkit - void -> boolean
-        SortedArraySet<Ticket<?>> arraysetsorted = this.getTickets(i);
-
-        boolean removed = false; // CraftBukkit
-        if (arraysetsorted.remove(ticket)) {
-            removed = true; // CraftBukkit
-        }
-
-        if (arraysetsorted.isEmpty()) {
-            this.tickets.remove(i);
-        }
-
-        this.ticketTracker.update(i, DistanceManager.getTicketLevelAt(arraysetsorted), false);
-        return removed; // CraftBukkit
+        return this.moonrise$getChunkHolderManager().removeTicketAtLevel((TicketType)ticket.getType(), i, ticket.getTicketLevel(), ticket.key); // Paper - rewrite chunk system
     }
 
     public <T> void addTicket(TicketType<T> type, ChunkPos pos, int level, T argument) {
@@ -0,0 +0,0 @@ public abstract class DistanceManager {
     }
 
     public <T> boolean addRegionTicketAtDistance(TicketType<T> tickettype, ChunkPos chunkcoordintpair, int i, T t0) {
-        // CraftBukkit end
-        Ticket<T> ticket = new Ticket<>(tickettype, ChunkLevel.byStatus(FullChunkStatus.FULL) - i, t0);
-        long j = chunkcoordintpair.toLong();
-
-        boolean added = this.addTicket(j, ticket); // CraftBukkit
-        this.tickingTicketsTracker.addTicket(j, ticket);
-        return added; // CraftBukkit
+        return this.moonrise$getChunkHolderManager().addTicketAtLevel(tickettype, chunkcoordintpair, ChunkLevel.byStatus(FullChunkStatus.FULL) - i, t0); // Paper - rewrite chunk system
     }
 
     public <T> void removeRegionTicket(TicketType<T> type, ChunkPos pos, int radius, T argument) {
@@ -0,0 +0,0 @@ public abstract class DistanceManager {
     }
 
     public <T> boolean removeRegionTicketAtDistance(TicketType<T> tickettype, ChunkPos chunkcoordintpair, int i, T t0) {
-        // CraftBukkit end
-        Ticket<T> ticket = new Ticket<>(tickettype, ChunkLevel.byStatus(FullChunkStatus.FULL) - i, t0);
-        long j = chunkcoordintpair.toLong();
-
-        boolean removed = this.removeTicket(j, ticket); // CraftBukkit
-        this.tickingTicketsTracker.removeTicket(j, ticket);
-        return removed; // CraftBukkit
+        return this.moonrise$getChunkHolderManager().removeTicketAtLevel(tickettype, chunkcoordintpair, ChunkLevel.byStatus(FullChunkStatus.FULL) - i, t0); // Paper - rewrite chunk system
     }
 
     private SortedArraySet<Ticket<?>> getTickets(long position) {
-        return (SortedArraySet) this.tickets.computeIfAbsent(position, (j) -> {
-            return SortedArraySet.create(4);
-        });
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     protected void updateChunkForced(ChunkPos pos, boolean forced) {
-        Ticket<ChunkPos> ticket = new Ticket<>(TicketType.FORCED, ChunkMap.FORCED_TICKET_LEVEL, pos);
-        long i = pos.toLong();
-
+        // Paper start - rewrite chunk system
         if (forced) {
-            this.addTicket(i, ticket);
-            this.tickingTicketsTracker.addTicket(i, ticket);
+            this.moonrise$getChunkHolderManager().addTicketAtLevel(TicketType.FORCED, pos, ChunkMap.FORCED_TICKET_LEVEL, pos);
         } else {
-            this.removeTicket(i, ticket);
-            this.tickingTicketsTracker.removeTicket(i, ticket);
+            this.moonrise$getChunkHolderManager().removeTicketAtLevel(TicketType.FORCED, pos, ChunkMap.FORCED_TICKET_LEVEL, pos);
         }
+        // Paper end - rewrite chunk system
 
     }
 
@@ -0,0 +0,0 @@ public abstract class DistanceManager {
         ((ObjectSet) this.playersPerChunk.computeIfAbsent(i, (j) -> {
             return new ObjectOpenHashSet();
         })).add(player);
-        this.naturalSpawnChunkCounter.update(i, 0, true);
-        this.playerTicketManager.update(i, 0, true);
-        this.tickingTicketsTracker.addTicket(TicketType.PLAYER, chunkcoordintpair, this.getPlayerTicketLevel(), chunkcoordintpair);
+        // Paper - chunk tick iteration optimisation
+        // Paper - rewrite chunk system
     }
 
     public void removePlayer(SectionPos pos, ServerPlayer player) {
@@ -0,0 +0,0 @@ public abstract class DistanceManager {
         if (objectset != null) objectset.remove(player); // Paper - some state corruption happens here, don't crash, clean up gracefully
         if (objectset == null || objectset.isEmpty()) { // Paper
             this.playersPerChunk.remove(i);
-            this.naturalSpawnChunkCounter.update(i, Integer.MAX_VALUE, false);
-            this.playerTicketManager.update(i, Integer.MAX_VALUE, false);
-            this.tickingTicketsTracker.removeTicket(TicketType.PLAYER, chunkcoordintpair, this.getPlayerTicketLevel(), chunkcoordintpair);
+            // Paper - chunk tick iteration optimisation
+            // Paper - rewrite chunk system
         }
 
     }
 
     private int getPlayerTicketLevel() {
-        return Math.max(0, ChunkLevel.byStatus(FullChunkStatus.ENTITY_TICKING) - this.simulationDistance);
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public boolean inEntityTickingRange(long chunkPos) {
-        return ChunkLevel.isEntityTicking(this.tickingTicketsTracker.getLevel(chunkPos));
+        // Paper start - rewrite chunk system
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder chunkHolder = this.moonrise$getChunkHolderManager().getChunkHolder(chunkPos);
+        return chunkHolder != null && chunkHolder.isEntityTickingReady();
+        // Paper end - rewrite chunk system
     }
 
     public boolean inBlockTickingRange(long chunkPos) {
-        return ChunkLevel.isBlockTicking(this.tickingTicketsTracker.getLevel(chunkPos));
+        // Paper start - rewrite chunk system
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder chunkHolder = this.moonrise$getChunkHolderManager().getChunkHolder(chunkPos);
+        return chunkHolder != null && chunkHolder.isTickingReady();
+        // Paper end - rewrite chunk system
     }
 
     protected String getTicketDebugString(long pos) {
-        SortedArraySet<Ticket<?>> arraysetsorted = (SortedArraySet) this.tickets.get(pos);
-
-        return arraysetsorted != null && !arraysetsorted.isEmpty() ? ((Ticket) arraysetsorted.first()).toString() : "no_ticket";
+        return this.moonrise$getChunkHolderManager().getTicketDebugString(pos); // Paper - rewrite chunk system
     }
 
     protected void updatePlayerTickets(int viewDistance) {
-        this.playerTicketManager.updateViewDistance(viewDistance);
+        this.moonrise$getChunkMap().setServerViewDistance(viewDistance); // Paper - rewrite chunk system
     }
 
     public void updateSimulationDistance(int simulationDistance) {
-        if (simulationDistance != this.simulationDistance) {
-            this.simulationDistance = simulationDistance;
-            this.tickingTicketsTracker.replacePlayerTicketsLevel(this.getPlayerTicketLevel());
-        }
+        // Paper start - rewrite chunk system
+        // note: vanilla does not clamp to 0, but we do simply because we need a min of 0
+        final int clamped = net.minecraft.util.Mth.clamp(simulationDistance, 0, ca.spottedleaf.moonrise.common.util.MoonriseConstants.MAX_VIEW_DISTANCE);
 
+        ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.moonrise$getChunkMap().level).moonrise$getPlayerChunkLoader().setTickDistance(clamped);
+        // Paper end - rewrite chunk system
     }
 
     public int getNaturalSpawnChunkCount() {
-        this.naturalSpawnChunkCounter.runAllUpdates();
-        return this.naturalSpawnChunkCounter.chunks.size();
+        return this.spawnChunkTracker.getTotalPositions(); // Paper - chunk tick iteration optimisation
     }
 
     public boolean hasPlayersNearby(long chunkPos) {
-        this.naturalSpawnChunkCounter.runAllUpdates();
-        return this.naturalSpawnChunkCounter.chunks.containsKey(chunkPos);
+        return this.spawnChunkTracker.hasObjectsNear(ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkX(chunkPos), ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkZ(chunkPos)); // Paper - chunk tick iteration optimisation
     }
 
     public LongIterator getSpawnCandidateChunks() {
-        this.naturalSpawnChunkCounter.runAllUpdates();
-        return this.naturalSpawnChunkCounter.chunks.keySet().iterator();
+        return this.spawnChunkTracker.getPositions().iterator(); // Paper - chunk tick iteration optimisation
     }
 
     public String getDebugStatus() {
-        return this.ticketDispatcher.getDebugStatus();
+        return "No DistanceManager stats available"; // Paper - rewrite chunk system
     }
 
     private void dumpTickets(String path) {
-        try {
-            FileOutputStream fileoutputstream = new FileOutputStream(new File(path));
-
-            try {
-                ObjectIterator objectiterator = this.tickets.long2ObjectEntrySet().iterator();
-
-                while (objectiterator.hasNext()) {
-                    Entry<SortedArraySet<Ticket<?>>> entry = (Entry) objectiterator.next();
-                    ChunkPos chunkcoordintpair = new ChunkPos(entry.getLongKey());
-                    Iterator iterator = ((SortedArraySet) entry.getValue()).iterator();
-
-                    while (iterator.hasNext()) {
-                        Ticket<?> ticket = (Ticket) iterator.next();
-
-                        fileoutputstream.write((chunkcoordintpair.x + "\t" + chunkcoordintpair.z + "\t" + String.valueOf(ticket.getType()) + "\t" + ticket.getTicketLevel() + "\t\n").getBytes(StandardCharsets.UTF_8));
-                    }
-                }
-            } catch (Throwable throwable) {
-                try {
-                    fileoutputstream.close();
-                } catch (Throwable throwable1) {
-                    throwable.addSuppressed(throwable1);
-                }
-
-                throw throwable;
-            }
-
-            fileoutputstream.close();
-        } catch (IOException ioexception) {
-            DistanceManager.LOGGER.error("Failed to dump tickets to {}", path, ioexception);
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
 
     }
 
     @VisibleForTesting
     TickingTracker tickingTracker() {
-        return this.tickingTicketsTracker;
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public LongSet getTickingChunks() {
-        return this.tickingTicketsTracker.getTickingChunks();
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public void removeTicketsOnClosing() {
-        ImmutableSet<TicketType<?>> immutableset = ImmutableSet.of(TicketType.UNKNOWN, TicketType.POST_TELEPORT, TicketType.FUTURE_AWAIT); // Paper - add additional tickets to preserve
-        ObjectIterator<Entry<SortedArraySet<Ticket<?>>>> objectiterator = this.tickets.long2ObjectEntrySet().fastIterator();
-
-        while (objectiterator.hasNext()) {
-            Entry<SortedArraySet<Ticket<?>>> entry = (Entry) objectiterator.next();
-            Iterator<Ticket<?>> iterator = ((SortedArraySet) entry.getValue()).iterator();
-            boolean flag = false;
-
-            while (iterator.hasNext()) {
-                Ticket<?> ticket = (Ticket) iterator.next();
-
-                if (!immutableset.contains(ticket.getType())) {
-                    iterator.remove();
-                    flag = true;
-                    this.tickingTicketsTracker.removeTicket(entry.getLongKey(), ticket);
-                }
-            }
-
-            if (flag) {
-                this.ticketTracker.update(entry.getLongKey(), DistanceManager.getTicketLevelAt((SortedArraySet) entry.getValue()), false);
-            }
-
-            if (((SortedArraySet) entry.getValue()).isEmpty()) {
-                objectiterator.remove();
-            }
-        }
+        // Paper - rewrite chunk system
 
     }
 
     public boolean hasTickets() {
-        return !this.tickets.isEmpty();
+        throw new UnsupportedOperationException();  // Paper - rewrite chunk system
     }
 
     // CraftBukkit start
     public <T> void removeAllTicketsFor(TicketType<T> ticketType, int ticketLevel, T ticketIdentifier) {
-        Ticket<T> target = new Ticket<>(ticketType, ticketLevel, ticketIdentifier);
-
-        for (java.util.Iterator<Entry<SortedArraySet<Ticket<?>>>> iterator = this.tickets.long2ObjectEntrySet().fastIterator(); iterator.hasNext();) {
-            Entry<SortedArraySet<Ticket<?>>> entry = iterator.next();
-            SortedArraySet<Ticket<?>> tickets = entry.getValue();
-            if (tickets.remove(target)) {
-                // copied from removeTicket
-                this.ticketTracker.update(entry.getLongKey(), DistanceManager.getTicketLevelAt(tickets), false);
-
-                // can't use entry after it's removed
-                if (tickets.isEmpty()) {
-                    iterator.remove();
-                }
-            }
-        }
+        this.moonrise$getChunkHolderManager().removeAllTicketsFor(ticketType, ticketLevel, ticketIdentifier); // Paper - rewrite chunk system
     }
     // CraftBukkit end
 
+    /*  // Paper - rewrite chunk system
     private class ChunkTicketTracker extends ChunkTracker {
 
         private static final int MAX_LEVEL = ChunkLevel.MAX_LEVEL + 1;
@@ -0,0 +0,0 @@ public abstract class DistanceManager {
         public int runDistanceUpdates(int distance) {
             return this.runUpdates(distance);
         }
-    }
+    }*/  // Paper - rewrite chunk system
 
     private class FixedPlayerDistanceChunkTracker extends ChunkTracker {
 
@@ -0,0 +0,0 @@ public abstract class DistanceManager {
         }
     }
 
+    /*  // Paper - rewrite chunk system
     private class PlayerTicketTracker extends DistanceManager.FixedPlayerDistanceChunkTracker {
 
         private int viewDistance = 0;
@@ -0,0 +0,0 @@ public abstract class DistanceManager {
         private boolean haveTicketFor(int distance) {
             return distance <= this.viewDistance;
         }
-    }
+    }*/  // Paper - rewrite chunk system
 }
diff --git a/src/main/java/net/minecraft/server/level/GenerationChunkHolder.java b/src/main/java/net/minecraft/server/level/GenerationChunkHolder.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/level/GenerationChunkHolder.java
+++ b/src/main/java/net/minecraft/server/level/GenerationChunkHolder.java
@@ -0,0 +0,0 @@ public abstract class GenerationChunkHolder {
     public static final ChunkResult<ChunkAccess> UNLOADED_CHUNK = ChunkResult.error("Unloaded chunk");
     public static final CompletableFuture<ChunkResult<ChunkAccess>> UNLOADED_CHUNK_FUTURE = CompletableFuture.completedFuture(UNLOADED_CHUNK);
     protected final ChunkPos pos;
-    @Nullable
-    private volatile ChunkStatus highestAllowedStatus;
-    private final AtomicReference<ChunkStatus> startedWork = new AtomicReference<>();
-    private final AtomicReferenceArray<CompletableFuture<ChunkResult<ChunkAccess>>> futures = new AtomicReferenceArray<>(CHUNK_STATUSES.size());
-    private final AtomicReference<ChunkGenerationTask> task = new AtomicReference<>();
-    private final AtomicInteger generationRefCount = new AtomicInteger();
-    private volatile CompletableFuture<Void> generationSaveSyncFuture = CompletableFuture.completedFuture(null);
+    // Paper - rewrite chunk system
 
     public GenerationChunkHolder(ChunkPos pos) {
         this.pos = pos;
@@ -0,0 +0,0 @@ public abstract class GenerationChunkHolder {
     }
 
     public CompletableFuture<ChunkResult<ChunkAccess>> scheduleChunkGenerationTask(ChunkStatus requestedStatus, ChunkMap chunkLoadingManager) {
-        if (this.isStatusDisallowed(requestedStatus)) {
-            return UNLOADED_CHUNK_FUTURE;
-        } else {
-            CompletableFuture<ChunkResult<ChunkAccess>> completableFuture = this.getOrCreateFuture(requestedStatus);
-            if (completableFuture.isDone()) {
-                return completableFuture;
-            } else {
-                ChunkGenerationTask chunkGenerationTask = this.task.get();
-                if (chunkGenerationTask == null || requestedStatus.isAfter(chunkGenerationTask.targetStatus)) {
-                    this.rescheduleChunkTask(chunkLoadingManager, requestedStatus);
-                }
-
-                return completableFuture;
-            }
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     CompletableFuture<ChunkResult<ChunkAccess>> applyStep(ChunkStep step, GeneratingChunkMap chunkLoadingManager, StaticCache2D<GenerationChunkHolder> chunks) {
-        if (this.isStatusDisallowed(step.targetStatus())) {
-            return UNLOADED_CHUNK_FUTURE;
-        } else {
-            return this.acquireStatusBump(step.targetStatus()) ? chunkLoadingManager.applyStep(this, step, chunks).handle((chunk, throwable) -> {
-                if (throwable != null) {
-                    CrashReport crashReport = CrashReport.forThrowable(throwable, "Exception chunk generation/loading");
-                    MinecraftServer.setFatalException(new ReportedException(crashReport));
-                } else {
-                    this.completeFuture(step.targetStatus(), chunk);
-                }
-
-                return ChunkResult.of(chunk);
-            }) : this.getOrCreateFuture(step.targetStatus());
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     protected void updateHighestAllowedStatus(ChunkMap chunkLoadingManager) {
-        ChunkStatus chunkStatus = this.highestAllowedStatus;
-        ChunkStatus chunkStatus2 = ChunkLevel.generationStatus(this.getTicketLevel());
-        this.highestAllowedStatus = chunkStatus2;
-        boolean bl = chunkStatus != null && (chunkStatus2 == null || chunkStatus2.isBefore(chunkStatus));
-        if (bl) {
-            this.failAndClearPendingFuturesBetween(chunkStatus2, chunkStatus);
-            if (this.task.get() != null) {
-                this.rescheduleChunkTask(chunkLoadingManager, this.findHighestStatusWithPendingFuture(chunkStatus2));
-            }
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public void replaceProtoChunk(ImposterProtoChunk chunk) {
-        CompletableFuture<ChunkResult<ChunkAccess>> completableFuture = CompletableFuture.completedFuture(ChunkResult.of(chunk));
-
-        for (int i = 0; i < this.futures.length() - 1; i++) {
-            CompletableFuture<ChunkResult<ChunkAccess>> completableFuture2 = this.futures.get(i);
-            Objects.requireNonNull(completableFuture2);
-            ChunkAccess chunkAccess = completableFuture2.getNow(NOT_DONE_YET).orElse(null);
-            if (!(chunkAccess instanceof ProtoChunk)) {
-                throw new IllegalStateException("Trying to replace a ProtoChunk, but found " + chunkAccess);
-            }
-
-            if (!this.futures.compareAndSet(i, completableFuture2, completableFuture)) {
-                throw new IllegalStateException("Future changed by other thread while trying to replace it");
-            }
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     void removeTask(ChunkGenerationTask loader) {
-        this.task.compareAndSet(loader, null);
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     private void rescheduleChunkTask(ChunkMap chunkLoadingManager, @Nullable ChunkStatus requestedStatus) {
-        ChunkGenerationTask chunkGenerationTask;
-        if (requestedStatus != null) {
-            chunkGenerationTask = chunkLoadingManager.scheduleGenerationTask(requestedStatus, this.getPos());
-        } else {
-            chunkGenerationTask = null;
-        }
-
-        ChunkGenerationTask chunkGenerationTask3 = this.task.getAndSet(chunkGenerationTask);
-        if (chunkGenerationTask3 != null) {
-            chunkGenerationTask3.markForCancellation();
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     private CompletableFuture<ChunkResult<ChunkAccess>> getOrCreateFuture(ChunkStatus status) {
-        if (this.isStatusDisallowed(status)) {
-            return UNLOADED_CHUNK_FUTURE;
-        } else {
-            int i = status.getIndex();
-            CompletableFuture<ChunkResult<ChunkAccess>> completableFuture = this.futures.get(i);
-
-            while (completableFuture == null) {
-                CompletableFuture<ChunkResult<ChunkAccess>> completableFuture2 = new CompletableFuture<>();
-                completableFuture = this.futures.compareAndExchange(i, null, completableFuture2);
-                if (completableFuture == null) {
-                    if (this.isStatusDisallowed(status)) {
-                        this.failAndClearPendingFuture(i, completableFuture2);
-                        return UNLOADED_CHUNK_FUTURE;
-                    }
-
-                    return completableFuture2;
-                }
-            }
-
-            return completableFuture;
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     private void failAndClearPendingFuturesBetween(@Nullable ChunkStatus from, ChunkStatus to) {
-        int i = from == null ? 0 : from.getIndex() + 1;
-        int j = to.getIndex();
-
-        for (int k = i; k <= j; k++) {
-            CompletableFuture<ChunkResult<ChunkAccess>> completableFuture = this.futures.get(k);
-            if (completableFuture != null) {
-                this.failAndClearPendingFuture(k, completableFuture);
-            }
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     private void failAndClearPendingFuture(int statusIndex, CompletableFuture<ChunkResult<ChunkAccess>> previousFuture) {
-        if (previousFuture.complete(UNLOADED_CHUNK) && !this.futures.compareAndSet(statusIndex, previousFuture, null)) {
-            throw new IllegalStateException("Nothing else should replace the future here");
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     private void completeFuture(ChunkStatus status, ChunkAccess chunk) {
-        ChunkResult<ChunkAccess> chunkResult = ChunkResult.of(chunk);
-        int i = status.getIndex();
-
-        while (true) {
-            CompletableFuture<ChunkResult<ChunkAccess>> completableFuture = this.futures.get(i);
-            if (completableFuture == null) {
-                if (this.futures.compareAndSet(i, null, CompletableFuture.completedFuture(chunkResult))) {
-                    return;
-                }
-            } else {
-                if (completableFuture.complete(chunkResult)) {
-                    return;
-                }
-
-                if (completableFuture.getNow(NOT_DONE_YET).isSuccess()) {
-                    throw new IllegalStateException("Trying to complete a future but found it to be completed successfully already");
-                }
-
-                Thread.yield();
-            }
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     @Nullable
     private ChunkStatus findHighestStatusWithPendingFuture(@Nullable ChunkStatus checkUpperBound) {
-        if (checkUpperBound == null) {
-            return null;
-        } else {
-            ChunkStatus chunkStatus = checkUpperBound;
-
-            for (ChunkStatus chunkStatus2 = this.startedWork.get();
-                chunkStatus2 == null || chunkStatus.isAfter(chunkStatus2);
-                chunkStatus = chunkStatus.getParent()
-            ) {
-                if (this.futures.get(chunkStatus.getIndex()) != null) {
-                    return chunkStatus;
-                }
-
-                if (chunkStatus == ChunkStatus.EMPTY) {
-                    break;
-                }
-            }
-
-            return null;
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     private boolean acquireStatusBump(ChunkStatus nextStatus) {
-        ChunkStatus chunkStatus = nextStatus == ChunkStatus.EMPTY ? null : nextStatus.getParent();
-        ChunkStatus chunkStatus2 = this.startedWork.compareAndExchange(chunkStatus, nextStatus);
-        if (chunkStatus2 == chunkStatus) {
-            return true;
-        } else if (chunkStatus2 != null && !nextStatus.isAfter(chunkStatus2)) {
-            return false;
-        } else {
-            throw new IllegalStateException("Unexpected last startedWork status: " + chunkStatus2 + " while trying to start: " + nextStatus);
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     private boolean isStatusDisallowed(ChunkStatus status) {
-        ChunkStatus chunkStatus = this.highestAllowedStatus;
-        return chunkStatus == null || status.isAfter(chunkStatus);
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     protected abstract void addSaveDependency(CompletableFuture<?> savingFuture);
 
     public void increaseGenerationRefCount() {
-        if (this.generationRefCount.getAndIncrement() == 0) {
-            this.generationSaveSyncFuture = new CompletableFuture<>();
-            this.addSaveDependency(this.generationSaveSyncFuture);
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public void decreaseGenerationRefCount() {
-        CompletableFuture<Void> completableFuture = this.generationSaveSyncFuture;
-        int i = this.generationRefCount.decrementAndGet();
-        if (i == 0) {
-            completableFuture.complete(null);
-        }
-
-        if (i < 0) {
-            throw new IllegalStateException("More releases than claims. Count: " + i);
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     @Nullable
     public ChunkAccess getChunkIfPresentUnchecked(ChunkStatus requestedStatus) {
-        CompletableFuture<ChunkResult<ChunkAccess>> completableFuture = this.futures.get(requestedStatus.getIndex());
-        return completableFuture == null ? null : completableFuture.getNow(NOT_DONE_YET).orElse(null);
+        // Paper start - rewrite chunk system
+        return ((ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemChunkHolder)(Object)this).moonrise$getRealChunkHolder().getChunkIfPresentUnchecked(requestedStatus);
+        // Paper end - rewrite chunk system
     }
 
     @Nullable
     public ChunkAccess getChunkIfPresent(ChunkStatus requestedStatus) {
-        return this.isStatusDisallowed(requestedStatus) ? null : this.getChunkIfPresentUnchecked(requestedStatus);
+        // Paper start - rewrite chunk system
+        return ((ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemChunkHolder)(Object)this).moonrise$getRealChunkHolder().getChunkIfPresent(requestedStatus);
+        // Paper end - rewrite chunk system
     }
 
     @Nullable
     public ChunkAccess getLatestChunk() {
-        ChunkStatus chunkStatus = this.startedWork.get();
-        if (chunkStatus == null) {
-            return null;
-        } else {
-            ChunkAccess chunkAccess = this.getChunkIfPresentUnchecked(chunkStatus);
-            return chunkAccess != null ? chunkAccess : this.getChunkIfPresentUnchecked(chunkStatus.getParent());
-        }
+        // Paper start - rewrite chunk system
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder.ChunkCompletion lastCompletion = ((ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemChunkHolder)(Object)this).moonrise$getRealChunkHolder().getLastChunkCompletion();
+        return lastCompletion == null ? null : lastCompletion.chunk();
+        // Paper end - rewrite chunk system
     }
 
     @Nullable
     public ChunkStatus getPersistedStatus() {
-        CompletableFuture<ChunkResult<ChunkAccess>> completableFuture = this.futures.get(ChunkStatus.EMPTY.getIndex());
-        ChunkAccess chunkAccess = completableFuture == null ? null : completableFuture.getNow(NOT_DONE_YET).orElse(null);
-        return chunkAccess == null ? null : chunkAccess.getPersistedStatus();
+        // Paper start - rewrite chunk system
+        final ChunkAccess chunk = this.getLatestChunk();
+        return chunk == null ? null : chunk.getPersistedStatus();
+        // Paper end - rewrite chunk system
     }
 
     public ChunkPos getPos() {
@@ -0,0 +0,0 @@ public abstract class GenerationChunkHolder {
     }
 
     public FullChunkStatus getFullStatus() {
-        return ChunkLevel.fullStatus(this.getTicketLevel());
+        return ((ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemChunkHolder)(Object)this).moonrise$getRealChunkHolder().getChunkStatus(); // Paper - rewrite chunk system
     }
 
     public abstract int getTicketLevel();
@@ -0,0 +0,0 @@ public abstract class GenerationChunkHolder {
 
     @VisibleForDebug
     public List<Pair<ChunkStatus, CompletableFuture<ChunkResult<ChunkAccess>>>> getAllFutures() {
-        List<Pair<ChunkStatus, CompletableFuture<ChunkResult<ChunkAccess>>>> list = new ArrayList<>();
-
-        for (int i = 0; i < CHUNK_STATUSES.size(); i++) {
-            list.add(Pair.of(CHUNK_STATUSES.get(i), this.futures.get(i)));
-        }
-
-        return list;
+        throw new UnsupportedOperationException();  // Paper - rewrite chunk system
     }
 
     @Nullable
     @VisibleForDebug
     public ChunkStatus getLatestStatus() {
-        for (int i = CHUNK_STATUSES.size() - 1; i >= 0; i--) {
-            ChunkStatus chunkStatus = CHUNK_STATUSES.get(i);
-            ChunkAccess chunkAccess = this.getChunkIfPresentUnchecked(chunkStatus);
-            if (chunkAccess != null) {
-                return chunkStatus;
-            }
-        }
-
-        return null;
+        // Paper start - rewrite chunk system
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder.ChunkCompletion lastCompletion = ((ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemChunkHolder)(Object)this).moonrise$getRealChunkHolder().getLastChunkCompletion();
+        return lastCompletion == null ? null : lastCompletion.genStatus();
+        // Paper end - rewrite chunk system
     }
 }
diff --git a/src/main/java/net/minecraft/server/level/ServerChunkCache.java b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
+++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
@@ -0,0 +0,0 @@ import net.minecraft.world.level.storage.DimensionDataStorage;
 import net.minecraft.world.level.storage.LevelStorageSource;
 import org.slf4j.Logger;
 
-public class ServerChunkCache extends ChunkSource {
+public class ServerChunkCache extends ChunkSource implements ca.spottedleaf.moonrise.patches.chunk_system.world.ChunkSystemServerChunkCache { // Paper - rewrite chunk system
 
     private static final Logger LOGGER = LogUtils.getLogger();
     private final DistanceManager distanceManager;
@@ -0,0 +0,0 @@ public class ServerChunkCache extends ChunkSource {
     }
     long chunkFutureAwaitCounter;
     // Paper end
+    // Paper start - rewrite chunk system
+
+    @Override
+    public final void moonrise$setFullChunk(final int chunkX, final int chunkZ, final LevelChunk chunk) {
+        final long key = ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkKey(chunkX, chunkZ);
+        if (chunk == null) {
+            this.fullChunks.remove(key);
+        } else {
+            this.fullChunks.put(key, chunk);
+        }
+    }
+
+    @Override
+    public final LevelChunk moonrise$getFullChunkIfLoaded(final int chunkX, final int chunkZ) {
+        return this.fullChunks.get(ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkKey(chunkX, chunkZ));
+    }
+
+    private ChunkAccess syncLoad(final int chunkX, final int chunkZ, final ChunkStatus toStatus) {
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler chunkTaskScheduler = ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getChunkTaskScheduler();
+        final CompletableFuture<ChunkAccess> completable = new CompletableFuture<>();
+        chunkTaskScheduler.scheduleChunkLoad(
+            chunkX, chunkZ, toStatus, true, ca.spottedleaf.concurrentutil.util.Priority.BLOCKING,
+            completable::complete
+        );
+
+        if (!completable.isDone() && chunkTaskScheduler.hasShutdown()) {
+            throw new IllegalStateException(
+                "Chunk system has shut down, cannot process chunk requests in world '" + ca.spottedleaf.moonrise.common.util.WorldUtil.getWorldName(this.level) + "' at "
+                    + "(" + chunkX + "," + chunkZ + ") status: " + toStatus
+            );
+        }
+
+        if (ca.spottedleaf.moonrise.common.util.TickThread.isTickThreadFor(this.level, chunkX, chunkZ)) {
+            ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler.pushChunkWait(this.level, chunkX, chunkZ);
+            this.mainThreadProcessor.managedBlock(completable::isDone);
+            ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler.popChunkWait();
+        }
+
+        final ChunkAccess ret = completable.join();
+        if (ret == null) {
+            throw new IllegalStateException("Chunk not loaded when requested");
+        }
+
+        return ret;
+    }
+
+    private ChunkAccess getChunkFallback(final int chunkX, final int chunkZ, final ChunkStatus toStatus,
+                                         final boolean load) {
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler chunkTaskScheduler = ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getChunkTaskScheduler();
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkHolderManager chunkHolderManager = chunkTaskScheduler.chunkHolderManager;
+
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder currentChunk = chunkHolderManager.getChunkHolder(ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkKey(chunkX, chunkZ));
+
+        final ChunkAccess ifPresent = currentChunk == null ? null : currentChunk.getChunkIfPresent(toStatus);
+
+        if (ifPresent != null && (toStatus != ChunkStatus.FULL || currentChunk.isFullChunkReady())) {
+            return ifPresent;
+        }
+
+        final ca.spottedleaf.moonrise.common.PlatformHooks platformHooks = ca.spottedleaf.moonrise.common.PlatformHooks.get();
+
+        if (platformHooks.hasCurrentlyLoadingChunk() && currentChunk != null) {
+            final ChunkAccess loading = platformHooks.getCurrentlyLoadingChunk(currentChunk.vanillaChunkHolder);
+            if (loading != null && ca.spottedleaf.moonrise.common.util.TickThread.isTickThread()) {
+                return loading;
+            }
+        }
+
+        return load ? this.syncLoad(chunkX, chunkZ, toStatus) : null;
+    }
+    // Paper end - rewrite chunk system
+    // Paper start - chunk tick iteration optimisations
+    private final ca.spottedleaf.moonrise.common.util.SimpleThreadUnsafeRandom shuffleRandom = new ca.spottedleaf.moonrise.common.util.SimpleThreadUnsafeRandom(0L);
+    private boolean isChunkNearPlayer(final ChunkMap chunkMap, final ChunkPos chunkPos, final LevelChunk levelChunk) {
+        final ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkData chunkData = ((ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemChunkHolder)((ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemLevelChunk)levelChunk).moonrise$getChunkAndHolder().holder())
+            .moonrise$getRealChunkHolder().holderData;
+        final ca.spottedleaf.moonrise.common.misc.NearbyPlayers.TrackedChunk nearbyPlayers = chunkData.nearbyPlayers;
+        if (nearbyPlayers == null) {
+            return false;
+        }
+
+        final ca.spottedleaf.moonrise.common.list.ReferenceList<ServerPlayer> players = nearbyPlayers.getPlayers(ca.spottedleaf.moonrise.common.misc.NearbyPlayers.NearbyMapType.SPAWN_RANGE);
+
+        if (players == null) {
+            return false;
+        }
+
+        final ServerPlayer[] raw = players.getRawDataUnchecked();
+        final int len = players.size();
+
+        Objects.checkFromIndexSize(0, len, raw.length);
+        for (int i = 0; i < len; ++i) {
+            if (chunkMap.playerIsCloseEnoughForSpawning(raw[i], chunkPos, 16384.0D)) { // Spigot (reducedRange = false)
+                return true;
+            }
+        }
+
+        return false;
+    }
+    // Paper end - chunk tick iteration optimisations
+
 
     public ServerChunkCache(ServerLevel world, LevelStorageSource.LevelStorageAccess session, DataFixer dataFixer, StructureTemplateManager structureTemplateManager, Executor workerExecutor, ChunkGenerator chunkGenerator, int viewDistance, int simulationDistance, boolean dsync, ChunkProgressListener worldGenerationProgressListener, ChunkStatusUpdateListener chunkStatusChangeListener, Supplier<DimensionDataStorage> persistentStateManagerFactory) {
         this.level = world;
@@ -0,0 +0,0 @@ public class ServerChunkCache extends ChunkSource {
     }
     // CraftBukkit end
     // Paper start
-    public void addLoadedChunk(LevelChunk chunk) {
-        this.fullChunks.put(chunk.coordinateKey, chunk);
-    }
-
-    public void removeLoadedChunk(LevelChunk chunk) {
-        this.fullChunks.remove(chunk.coordinateKey);
-    }
+    // Paper - rewrite chunk system
 
     @Nullable
     public ChunkAccess getChunkAtImmediately(int x, int z) {
@@ -0,0 +0,0 @@ public class ServerChunkCache extends ChunkSource {
     @Nullable
     @Override
     public ChunkAccess getChunk(int x, int z, ChunkStatus leastStatus, boolean create) {
-        if (Thread.currentThread() != this.mainThread) {
-            return (ChunkAccess) CompletableFuture.supplyAsync(() -> {
-                return this.getChunk(x, z, leastStatus, create);
-            }, this.mainThreadProcessor).join();
-        } else {
-            // Paper start - Perf: Optimise getChunkAt calls for loaded chunks
-            LevelChunk ifLoaded = this.getChunkAtIfLoadedMainThread(x, z);
-            if (ifLoaded != null) {
-                return ifLoaded;
-            }
-            // Paper end - Perf: Optimise getChunkAt calls for loaded chunks
-            ProfilerFiller gameprofilerfiller = Profiler.get();
+        // Paper start - rewrite chunk system
+        if (leastStatus == ChunkStatus.FULL) {
+            final LevelChunk ret = this.fullChunks.get(ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkKey(x, z));
 
-            gameprofilerfiller.incrementCounter("getChunk");
-            long k = ChunkPos.asLong(x, z);
-
-            for (int l = 0; l < 4; ++l) {
-                if (k == this.lastChunkPos[l] && leastStatus == this.lastChunkStatus[l]) {
-                    ChunkAccess ichunkaccess = this.lastChunk[l];
-
-                    if (ichunkaccess != null) { // CraftBukkit - the chunk can become accessible in the meantime TODO for non-null chunks it might also make sense to check that the chunk's state hasn't changed in the meantime
-                        return ichunkaccess;
-                    }
-                }
+            if (ret != null) {
+                return ret;
             }
 
-            gameprofilerfiller.incrementCounter("getChunkCacheMiss");
-            CompletableFuture<ChunkResult<ChunkAccess>> completablefuture = this.getChunkFutureMainThread(x, z, leastStatus, create);
-            ServerChunkCache.MainThreadExecutor chunkproviderserver_b = this.mainThreadProcessor;
-
-            Objects.requireNonNull(completablefuture);
-            chunkproviderserver_b.managedBlock(completablefuture::isDone);
-            // com.destroystokyo.paper.io.SyncLoadFinder.logSyncLoad(this.level, x, z); // Paper - Add debug for sync chunk loads
-            ChunkResult<ChunkAccess> chunkresult = (ChunkResult) completablefuture.join();
-            ChunkAccess ichunkaccess1 = (ChunkAccess) chunkresult.orElse(null); // CraftBukkit - decompile error
-
-            if (ichunkaccess1 == null && create) {
-                throw (IllegalStateException) Util.pauseInIde(new IllegalStateException("Chunk not there when requested: " + chunkresult.getError()));
-            } else {
-                this.storeInCache(k, ichunkaccess1, leastStatus);
-                return ichunkaccess1;
-            }
+            return create ? this.getChunkFallback(x, z, leastStatus, create) : null;
         }
+
+        return this.getChunkFallback(x, z, leastStatus, create);
+        // Paper end - rewrite chunk system
     }
 
     @Nullable
     @Override
     public LevelChunk getChunkNow(int chunkX, int chunkZ) {
-        if (Thread.currentThread() != this.mainThread) {
-            return null;
-        } else {
-            return this.getChunkAtIfLoadedMainThread(chunkX, chunkZ); // Paper - Perf: Optimise getChunkAt calls for loaded chunks
+        // Paper start - rewrite chunk system
+        final LevelChunk ret = this.fullChunks.get(ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkKey(chunkX, chunkZ));
+        if (!ca.spottedleaf.moonrise.common.PlatformHooks.get().hasCurrentlyLoadingChunk()) {
+            return ret;
+        }
+
+        if (ret != null || !ca.spottedleaf.moonrise.common.util.TickThread.isTickThread()) {
+            return ret;
+        }
+
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder holder = ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getChunkTaskScheduler()
+            .chunkHolderManager.getChunkHolder(chunkX, chunkZ);
+        if (holder == null) {
+            return ret;
         }
+
+        return ca.spottedleaf.moonrise.common.PlatformHooks.get().getCurrentlyLoadingChunk(holder.vanillaChunkHolder);
+        // Paper end - rewrite chunk system
     }
 
     private void clearCache() {
@@ -0,0 +0,0 @@ public class ServerChunkCache extends ChunkSource {
     }
 
     private CompletableFuture<ChunkResult<ChunkAccess>> getChunkFutureMainThread(int chunkX, int chunkZ, ChunkStatus leastStatus, boolean create) {
-        ChunkPos chunkcoordintpair = new ChunkPos(chunkX, chunkZ);
-        long k = chunkcoordintpair.toLong();
-        int l = ChunkLevel.byStatus(leastStatus);
-        ChunkHolder playerchunk = this.getVisibleChunkIfPresent(k);
-
-        // CraftBukkit start - don't add new ticket for currently unloading chunk
-        boolean currentlyUnloading = false;
-        if (playerchunk != null) {
-            FullChunkStatus oldChunkState = ChunkLevel.fullStatus(playerchunk.oldTicketLevel);
-            FullChunkStatus currentChunkState = ChunkLevel.fullStatus(playerchunk.getTicketLevel());
-            currentlyUnloading = (oldChunkState.isOrAfter(FullChunkStatus.FULL) && !currentChunkState.isOrAfter(FullChunkStatus.FULL));
-        }
-        if (create && !currentlyUnloading) {
-            // CraftBukkit end
-            this.distanceManager.addTicket(TicketType.UNKNOWN, chunkcoordintpair, l, chunkcoordintpair);
-            if (this.chunkAbsent(playerchunk, l)) {
-                ProfilerFiller gameprofilerfiller = Profiler.get();
-
-                gameprofilerfiller.push("chunkLoad");
-                this.runDistanceManagerUpdates();
-                playerchunk = this.getVisibleChunkIfPresent(k);
-                gameprofilerfiller.pop();
-                if (this.chunkAbsent(playerchunk, l)) {
-                    throw (IllegalStateException) Util.pauseInIde(new IllegalStateException("No chunk holder after ticket has been added"));
-                }
-            }
+        // Paper start - rewrite chunk system
+        ca.spottedleaf.moonrise.common.util.TickThread.ensureTickThread(this.level, chunkX, chunkZ, "Scheduling chunk load off-main");
+
+        final int minLevel = ChunkLevel.byStatus(leastStatus);
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder chunkHolder = ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getChunkTaskScheduler().chunkHolderManager.getChunkHolder(chunkX, chunkZ);
+
+        final boolean needsFullScheduling = leastStatus == ChunkStatus.FULL && (chunkHolder == null || !chunkHolder.getChunkStatus().isOrAfter(FullChunkStatus.FULL));
+
+        if ((chunkHolder == null || chunkHolder.getTicketLevel() > minLevel || needsFullScheduling) && !create) {
+            return ChunkHolder.UNLOADED_CHUNK_FUTURE;
         }
 
-        return this.chunkAbsent(playerchunk, l) ? GenerationChunkHolder.UNLOADED_CHUNK_FUTURE : playerchunk.scheduleChunkGenerationTask(leastStatus, this.chunkMap);
-    }
+        final ChunkAccess ifPresent = chunkHolder == null ? null : chunkHolder.getChunkIfPresent(leastStatus);
+        if (needsFullScheduling || ifPresent == null) {
+            // schedule
+            final CompletableFuture<ChunkResult<ChunkAccess>> ret = new CompletableFuture<>();
+            final Consumer<ChunkAccess> complete = (ChunkAccess chunk) -> {
+                if (chunk == null) {
+                    ret.complete(ChunkHolder.UNLOADED_CHUNK);
+                } else {
+                    ret.complete(ChunkResult.of(chunk));
+                }
+            };
 
-    private boolean chunkAbsent(@Nullable ChunkHolder holder, int maxLevel) {
-        return holder == null || holder.oldTicketLevel > maxLevel; // CraftBukkit using oldTicketLevel for isLoaded checks
+            ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getChunkTaskScheduler().scheduleChunkLoad(
+                chunkX, chunkZ, leastStatus, true,
+                ca.spottedleaf.concurrentutil.util.Priority.HIGHER,
+                complete
+            );
+
+            return ret;
+        } else {
+            // can return now
+            return CompletableFuture.completedFuture(ChunkResult.of(ifPresent));
+        }
+        // Paper end - rewrite chunk system
     }
 
     @Override
     public boolean hasChunk(int x, int z) {
-        ChunkHolder playerchunk = this.getVisibleChunkIfPresent((new ChunkPos(x, z)).toLong());
-        int k = ChunkLevel.byStatus(ChunkStatus.FULL);
-
-        return !this.chunkAbsent(playerchunk, k);
+        return this.getChunkNow(x, z) != null; // Paper - rewrite chunk system
     }
 
     @Nullable
     @Override
     public LightChunk getChunkForLighting(int chunkX, int chunkZ) {
-        long k = ChunkPos.asLong(chunkX, chunkZ);
-        ChunkHolder playerchunk = this.getVisibleChunkIfPresent(k);
-
-        return playerchunk == null ? null : playerchunk.getChunkIfPresentUnchecked(ChunkStatus.INITIALIZE_LIGHT.getParent());
+        // Paper start - rewrite chunk system
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder newChunkHolder = ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getChunkTaskScheduler().chunkHolderManager.getChunkHolder(chunkX, chunkZ);
+        if (newChunkHolder == null) {
+            return null;
+        }
+        return newChunkHolder.getChunkIfPresentUnchecked(ChunkStatus.INITIALIZE_LIGHT.getParent());
+        // Paper end - rewrite chunk system
     }
 
     @Override
@@ -0,0 +0,0 @@ public class ServerChunkCache extends ChunkSource {
     }
 
     public boolean runDistanceManagerUpdates() { // Paper - public
-        boolean flag = this.distanceManager.runAllUpdates(this.chunkMap);
-        boolean flag1 = this.chunkMap.promoteChunkMap();
-
-        this.chunkMap.runGenerationTasks();
-        if (!flag && !flag1) {
-            return false;
-        } else {
-            this.clearCache();
-            return true;
-        }
+        return ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getChunkTaskScheduler().chunkHolderManager.processTicketUpdates(); // Paper - rewrite chunk system
     }
 
     public boolean isPositionTicking(long pos) {
-        if (!this.level.shouldTickBlocksAt(pos)) {
-            return false;
-        } else {
-            ChunkHolder playerchunk = this.getVisibleChunkIfPresent(pos);
-
-            return playerchunk == null ? false : ((ChunkResult) playerchunk.getTickingChunkFuture().getNow(ChunkHolder.UNLOADED_LEVEL_CHUNK)).isSuccess();
-        }
+        // Paper start - rewrite chunk system
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder newChunkHolder = ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getChunkTaskScheduler().chunkHolderManager.getChunkHolder(pos);
+        return newChunkHolder != null && newChunkHolder.isTickingReady();
+        // Paper end - rewrite chunk system
     }
 
     public void save(boolean flush) {
-        this.runDistanceManagerUpdates();
+        // Paper - rewrite chunk system
         this.chunkMap.saveAllChunks(flush);
     }
 
@@ -0,0 +0,0 @@ public class ServerChunkCache extends ChunkSource {
     }
 
     public void close(boolean save) throws IOException {
-        if (save) {
-            this.save(true);
-        }
         // CraftBukkit end
+        // Paper - rewrite chunk system
         this.dataStorage.close();
-        this.lightEngine.close();
-        this.chunkMap.close();
+        ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getChunkTaskScheduler().chunkHolderManager.close(save, true); // Paper - rewrite chunk system
     }
 
     // CraftBukkit start - modelled on below
     public void purgeUnload() {
+        if (true) return; // Paper - rewrite chunk system
         ProfilerFiller gameprofilerfiller = Profiler.get();
 
         gameprofilerfiller.push("purge");
@@ -0,0 +0,0 @@ public class ServerChunkCache extends ChunkSource {
         this.runDistanceManagerUpdates();
         gameprofilerfiller.popPush("chunks");
         if (tickChunks) {
+            ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getPlayerChunkLoader().tick(); // Paper - rewrite chunk system
             this.tickChunks();
             this.chunkMap.tick();
         }
@@ -0,0 +0,0 @@ public class ServerChunkCache extends ChunkSource {
                     gameprofilerfiller.push("filteringTickingChunks");
                     this.collectTickingChunks(list);
                     gameprofilerfiller.popPush("shuffleChunks");
-                    Util.shuffle(list, this.level.random);
+                    // Paper start - chunk tick iteration optimisation
+                    this.shuffleRandom.setSeed(this.level.random.nextLong());
+                    Util.shuffle(list, this.shuffleRandom);
+                    // Paper end - chunk tick iteration optimisation
                     this.tickChunks(gameprofilerfiller, j, list);
                     gameprofilerfiller.pop();
                 } finally {
@@ -0,0 +0,0 @@ public class ServerChunkCache extends ChunkSource {
 
         while (iterator.hasNext()) {
             ChunkHolder playerchunk = (ChunkHolder) iterator.next();
-            LevelChunk chunk = playerchunk.getTickingChunk();
+            LevelChunk chunk = playerchunk.getChunkToSend(); // Paper - rewrite chunk system
 
             if (chunk != null) {
                 playerchunk.broadcastChanges(chunk);
@@ -0,0 +0,0 @@ public class ServerChunkCache extends ChunkSource {
     }
 
     private void collectTickingChunks(List<LevelChunk> chunks) {
-        this.chunkMap.forEachSpawnCandidateChunk((playerchunk) -> {
-            LevelChunk chunk = playerchunk.getTickingChunk();
+        // Paper start - chunk tick iteration optimisation
+        final ca.spottedleaf.moonrise.common.list.ReferenceList<net.minecraft.server.level.ServerChunkCache.ChunkAndHolder> tickingChunks =
+            ((ca.spottedleaf.moonrise.patches.chunk_tick_iteration.ChunkTickServerLevel)this.level).moonrise$getPlayerTickingChunks();
+
+        final ServerChunkCache.ChunkAndHolder[] raw = tickingChunks.getRawDataUnchecked();
+        final int size = tickingChunks.size();
 
-            if (chunk != null && this.level.isNaturalSpawningAllowed(playerchunk.getPos())) {
-                chunks.add(chunk);
+        final ChunkMap chunkMap = this.chunkMap;
+
+        for (int i = 0; i < size; ++i) {
+            final ServerChunkCache.ChunkAndHolder chunkAndHolder = raw[i];
+            final LevelChunk levelChunk = chunkAndHolder.chunk();
+
+            if (!this.isChunkNearPlayer(chunkMap, levelChunk.getPos(), levelChunk)) {
+                continue;
             }
 
-        });
+            chunks.add(levelChunk);
+        }
+        // Paper end - chunk tick iteration optimisation
     }
 
     private void tickChunks(ProfilerFiller profiler, long timeDelta, List<LevelChunk> chunks) {
@@ -0,0 +0,0 @@ public class ServerChunkCache extends ChunkSource {
                 NaturalSpawner.spawnForChunk(this.level, chunk, spawnercreature_d, list1);
             }
 
-            if (this.level.shouldTickBlocksAt(chunkcoordintpair.toLong())) {
+            if (true) { // Paper - rewrite chunk system
                 this.level.tickChunk(chunk, k);
             }
         }
@@ -0,0 +0,0 @@ public class ServerChunkCache extends ChunkSource {
     }
 
     private void getFullChunk(long pos, Consumer<LevelChunk> chunkConsumer) {
-        ChunkHolder playerchunk = this.getVisibleChunkIfPresent(pos);
-
-        if (playerchunk != null) {
-            ((ChunkResult) playerchunk.getFullChunkFuture().getNow(ChunkHolder.UNLOADED_LEVEL_CHUNK)).ifSuccess(chunkConsumer);
+        // Paper start - rewrite chunk system
+        // note: bypass currentlyLoaded from getChunkNow
+        final LevelChunk fullChunk = this.fullChunks.get(pos);
+        if (fullChunk != null) {
+            chunkConsumer.accept(fullChunk);
         }
+        // Paper end - rewrite chunk system
 
     }
 
@@ -0,0 +0,0 @@ public class ServerChunkCache extends ChunkSource {
         this.chunkMap.setServerViewDistance(watchDistance);
     }
 
+    // Paper start - rewrite chunk system
+    public void setSendViewDistance(int viewDistance) {
+        ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getPlayerChunkLoader().setSendDistance(viewDistance);
+    }
+    // Paper end - rewrite chunk system
+
     public void setSimulationDistance(int simulationDistance) {
         this.distanceManager.updateSimulationDistance(simulationDistance);
     }
@@ -0,0 +0,0 @@ public class ServerChunkCache extends ChunkSource {
         @Override
         // CraftBukkit start - process pending Chunk loadCallback() and unloadCallback() after each run task
         public boolean pollTask() {
-        try {
-            if (ServerChunkCache.this.runDistanceManagerUpdates()) {
+            // Paper start - rewrite chunk system
+            final ServerChunkCache serverChunkCache = ServerChunkCache.this;
+            if (serverChunkCache.runDistanceManagerUpdates()) {
                 return true;
             } else {
-                ServerChunkCache.this.lightEngine.tryScheduleUpdate();
-                return super.pollTask();
+                return super.pollTask() | ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)serverChunkCache.level).moonrise$getChunkTaskScheduler().executeMainThreadTask();
             }
-        } finally {
-            ServerChunkCache.this.chunkMap.callbackExecutor.run();
-        }
+            // Paper end - rewrite chunk system
         // CraftBukkit end
         }
     }
 
-    private static record ChunkAndHolder(LevelChunk chunk, ChunkHolder holder) {
+    public static record ChunkAndHolder(LevelChunk chunk, ChunkHolder holder) { // Paper - rewrite chunk system - public
 
     }
 }
diff --git a/src/main/java/net/minecraft/server/level/ServerEntity.java b/src/main/java/net/minecraft/server/level/ServerEntity.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/level/ServerEntity.java
+++ b/src/main/java/net/minecraft/server/level/ServerEntity.java
@@ -0,0 +0,0 @@ public class ServerEntity {
     }
 
     public void sendChanges() {
+        // Paper start - optimise collisions
+        if (((ca.spottedleaf.moonrise.patches.chunk_system.entity.ChunkSystemEntity)this.entity).moonrise$isHardColliding()) {
+            this.teleportDelay = 9999;
+        }
+        // Paper end - optimise collisions
         List<Entity> list = this.entity.getPassengers();
 
         if (!list.equals(this.lastPassengers)) {
diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
+++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
@@ -0,0 +0,0 @@ import org.bukkit.event.weather.LightningStrikeEvent;
 import org.bukkit.event.world.TimeSkipEvent;
 // CraftBukkit end
 
-public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLevel {
+public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLevel, ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel, ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevelReader, ca.spottedleaf.moonrise.patches.chunk_tick_iteration.ChunkTickServerLevel {  // Paper - rewrite chunk system // Paper - chunk tick iteration
 
     public static final BlockPos END_SPAWN_POINT = new BlockPos(100, 50, 0);
     public static final IntProvider RAIN_DELAY = UniformInt.of(12000, 180000);
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
     public final PrimaryLevelData serverLevelData; // CraftBukkit - type
     private int lastSpawnChunkRadius;
     final EntityTickList entityTickList = new EntityTickList();
-    public final PersistentEntitySectionManager<Entity> entityManager;
+    // Paper - rewrite chunk system
     private final GameEventDispatcher gameEventDispatcher;
     public boolean noSave;
     private final SleepStatus sleepStatus;
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
 
     public final void loadChunksForMoveAsync(AABB axisalignedbb, ca.spottedleaf.concurrentutil.util.Priority priority,
                                              java.util.function.Consumer<List<net.minecraft.world.level.chunk.ChunkAccess>> onLoad) {
-        if (Thread.currentThread() != this.thread) {
-            this.getChunkSource().mainThreadProcessor.execute(() -> {
-                this.loadChunksForMoveAsync(axisalignedbb, priority, onLoad);
-            });
-            return;
-        }
+        // Paper - rewrite chunk system
         int minBlockX = Mth.floor(axisalignedbb.minX - 1.0E-7D) - 3;
         int minBlockZ = Mth.floor(axisalignedbb.minZ - 1.0E-7D) - 3;
 
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
     public final void loadChunks(int minChunkX, int minChunkZ, int maxChunkX, int maxChunkZ,
                                  ca.spottedleaf.concurrentutil.util.Priority priority,
                                  java.util.function.Consumer<List<net.minecraft.world.level.chunk.ChunkAccess>> onLoad) {
-        List<net.minecraft.world.level.chunk.ChunkAccess> ret = new java.util.ArrayList<>();
-        it.unimi.dsi.fastutil.ints.IntArrayList ticketLevels = new it.unimi.dsi.fastutil.ints.IntArrayList();
-        ServerChunkCache chunkProvider = this.getChunkSource();
+        this.moonrise$loadChunksAsync(minChunkX, maxChunkX, minChunkZ, maxChunkZ, priority, onLoad); // Paper - rewrite chunk system
+    }
+    // Paper end
+
+    // Paper start - optimise getPlayerByUUID
+    @Nullable
+    @Override
+    public Player getPlayerByUUID(UUID uuid) {
+        final Player player = this.getServer().getPlayerList().getPlayer(uuid);
+        return player != null && player.level() == this ? player : null;
+    }
+    // Paper end - optimise getPlayerByUUID
+    // Paper start - rewrite chunk system
+    private final ca.spottedleaf.moonrise.patches.chunk_system.player.RegionizedPlayerChunkLoader.ViewDistanceHolder viewDistanceHolder = new ca.spottedleaf.moonrise.patches.chunk_system.player.RegionizedPlayerChunkLoader.ViewDistanceHolder();
+    private final ca.spottedleaf.moonrise.patches.chunk_system.player.RegionizedPlayerChunkLoader chunkLoader = new ca.spottedleaf.moonrise.patches.chunk_system.player.RegionizedPlayerChunkLoader((ServerLevel)(Object)this);
+    private final ca.spottedleaf.moonrise.patches.chunk_system.io.datacontroller.EntityDataController entityDataController;
+    private final ca.spottedleaf.moonrise.patches.chunk_system.io.datacontroller.PoiDataController poiDataController;
+    private final ca.spottedleaf.moonrise.patches.chunk_system.io.datacontroller.ChunkDataController chunkDataController;
+    private final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler chunkTaskScheduler;
+    private long lastMidTickFailure;
+    private long tickedBlocksOrFluids;
+    private final ca.spottedleaf.moonrise.common.misc.NearbyPlayers nearbyPlayers = new ca.spottedleaf.moonrise.common.misc.NearbyPlayers((ServerLevel)(Object)this);
+    private static final ServerChunkCache.ChunkAndHolder[] EMPTY_CHUNK_AND_HOLDERS = new ServerChunkCache.ChunkAndHolder[0];
+    private final ca.spottedleaf.moonrise.common.list.ReferenceList<net.minecraft.server.level.ServerChunkCache.ChunkAndHolder> loadedChunks = new ca.spottedleaf.moonrise.common.list.ReferenceList<>(EMPTY_CHUNK_AND_HOLDERS);
+    private final ca.spottedleaf.moonrise.common.list.ReferenceList<net.minecraft.server.level.ServerChunkCache.ChunkAndHolder> tickingChunks = new ca.spottedleaf.moonrise.common.list.ReferenceList<>(EMPTY_CHUNK_AND_HOLDERS);
+    private final ca.spottedleaf.moonrise.common.list.ReferenceList<net.minecraft.server.level.ServerChunkCache.ChunkAndHolder> entityTickingChunks = new ca.spottedleaf.moonrise.common.list.ReferenceList<>(EMPTY_CHUNK_AND_HOLDERS);
+
+    @Override
+    public final LevelChunk moonrise$getFullChunkIfLoaded(final int chunkX, final int chunkZ) {
+        return this.chunkSource.getChunkNow(chunkX, chunkZ);
+    }
+
+    @Override
+    public final ChunkAccess moonrise$getAnyChunkIfLoaded(final int chunkX, final int chunkZ) {
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder newChunkHolder = this.moonrise$getChunkTaskScheduler().chunkHolderManager.getChunkHolder(ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkKey(chunkX, chunkZ));
+        if (newChunkHolder == null) {
+            return null;
+        }
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder.ChunkCompletion lastCompletion = newChunkHolder.getLastChunkCompletion();
+        return lastCompletion == null ? null : lastCompletion.chunk();
+    }
 
-        int requiredChunks = (maxChunkX - minChunkX + 1) * (maxChunkZ - minChunkZ + 1);
-        int[] loadedChunks = new int[1];
+    @Override
+    public final ChunkAccess moonrise$getSpecificChunkIfLoaded(final int chunkX, final int chunkZ, final net.minecraft.world.level.chunk.status.ChunkStatus leastStatus) {
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder newChunkHolder = this.moonrise$getChunkTaskScheduler().chunkHolderManager.getChunkHolder(chunkX, chunkZ);
+        if (newChunkHolder == null) {
+            return null;
+        }
+        return newChunkHolder.getChunkIfPresentUnchecked(leastStatus);
+    }
+
+    @Override
+    public final void moonrise$midTickTasks() {
+        ((ca.spottedleaf.moonrise.patches.chunk_system.server.ChunkSystemMinecraftServer)this.server).moonrise$executeMidTickTasks();
+    }
+
+    @Override
+    public final ChunkAccess moonrise$syncLoadNonFull(final int chunkX, final int chunkZ, final net.minecraft.world.level.chunk.status.ChunkStatus status) {
+        return this.moonrise$getChunkTaskScheduler().syncLoadNonFull(chunkX, chunkZ, status);
+    }
 
-        Long holderIdentifier = Long.valueOf(chunkProvider.chunkFutureAwaitCounter++);
+    @Override
+    public final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler moonrise$getChunkTaskScheduler() {
+        return this.chunkTaskScheduler;
+    }
 
-        java.util.function.Consumer<net.minecraft.world.level.chunk.ChunkAccess> consumer = (net.minecraft.world.level.chunk.ChunkAccess chunk) -> {
+    @Override
+    public final ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController  moonrise$getChunkDataController() {
+        return this.chunkDataController;
+    }
+
+    @Override
+    public final ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController moonrise$getPoiChunkDataController() {
+        return this.poiDataController;
+    }
+
+    @Override
+    public final ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController moonrise$getEntityChunkDataController() {
+        return this.entityDataController;
+    }
+
+    @Override
+    public final int moonrise$getRegionChunkShift() {
+        return io.papermc.paper.threadedregions.TickRegions.getRegionChunkShift();
+    }
+
+    @Override
+    public final ca.spottedleaf.moonrise.patches.chunk_system.player.RegionizedPlayerChunkLoader moonrise$getPlayerChunkLoader() {
+        return this.chunkLoader;
+    }
+
+    @Override
+    public final void moonrise$loadChunksAsync(final BlockPos pos, final int radiusBlocks,
+                                               final ca.spottedleaf.concurrentutil.util.Priority priority,
+                                               final java.util.function.Consumer<java.util.List<net.minecraft.world.level.chunk.ChunkAccess>> onLoad) {
+        this.moonrise$loadChunksAsync(
+            (pos.getX() - radiusBlocks) >> 4,
+            (pos.getX() + radiusBlocks) >> 4,
+            (pos.getZ() - radiusBlocks) >> 4,
+            (pos.getZ() + radiusBlocks) >> 4,
+            priority, onLoad
+        );
+    }
+
+    @Override
+    public final void moonrise$loadChunksAsync(final BlockPos pos, final int radiusBlocks,
+                                               final net.minecraft.world.level.chunk.status.ChunkStatus chunkStatus, final ca.spottedleaf.concurrentutil.util.Priority priority,
+                                               final java.util.function.Consumer<java.util.List<net.minecraft.world.level.chunk.ChunkAccess>> onLoad) {
+        this.moonrise$loadChunksAsync(
+            (pos.getX() - radiusBlocks) >> 4,
+            (pos.getX() + radiusBlocks) >> 4,
+            (pos.getZ() - radiusBlocks) >> 4,
+            (pos.getZ() + radiusBlocks) >> 4,
+            chunkStatus, priority, onLoad
+        );
+    }
+
+    @Override
+    public final void moonrise$loadChunksAsync(final int minChunkX, final int maxChunkX, final int minChunkZ, final int maxChunkZ,
+                                               final ca.spottedleaf.concurrentutil.util.Priority priority,
+                                               final java.util.function.Consumer<java.util.List<net.minecraft.world.level.chunk.ChunkAccess>> onLoad) {
+        this.moonrise$loadChunksAsync(minChunkX, maxChunkX, minChunkZ, maxChunkZ, net.minecraft.world.level.chunk.status.ChunkStatus.FULL, priority, onLoad);
+    }
+
+    @Override
+    public final void moonrise$loadChunksAsync(final int minChunkX, final int maxChunkX, final int minChunkZ, final int maxChunkZ,
+                                               final net.minecraft.world.level.chunk.status.ChunkStatus chunkStatus, final ca.spottedleaf.concurrentutil.util.Priority priority,
+                                               final java.util.function.Consumer<java.util.List<net.minecraft.world.level.chunk.ChunkAccess>> onLoad) {
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler chunkTaskScheduler = this.moonrise$getChunkTaskScheduler();
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkHolderManager chunkHolderManager = chunkTaskScheduler.chunkHolderManager;
+
+        final int requiredChunks = (maxChunkX - minChunkX + 1) * (maxChunkZ - minChunkZ + 1);
+        final java.util.concurrent.atomic.AtomicInteger loadedChunks = new java.util.concurrent.atomic.AtomicInteger();
+        final Long holderIdentifier = ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler.getNextChunkLoadId();
+        final int ticketLevel = ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler.getTicketLevel(chunkStatus);
+
+        final List<ChunkAccess> ret = new ArrayList<>(requiredChunks);
+
+        final java.util.function.Consumer<net.minecraft.world.level.chunk.ChunkAccess> consumer = (final ChunkAccess chunk) -> {
             if (chunk != null) {
-                int ticketLevel = Math.max(33, chunkProvider.chunkMap.getUpdatingChunkIfPresent(chunk.getPos().toLong()).getTicketLevel());
-                ret.add(chunk);
-                ticketLevels.add(ticketLevel);
-                chunkProvider.addTicketAtLevel(TicketType.FUTURE_AWAIT, chunk.getPos(), ticketLevel, holderIdentifier);
+                synchronized (ret) {
+                    ret.add(chunk);
+                }
+                chunkHolderManager.addTicketAtLevel(ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler.CHUNK_LOAD, chunk.getPos(), ticketLevel, holderIdentifier);
             }
-            if (++loadedChunks[0] == requiredChunks) {
+            if (loadedChunks.incrementAndGet() == requiredChunks) {
                 try {
                     onLoad.accept(java.util.Collections.unmodifiableList(ret));
                 } finally {
                     for (int i = 0, len = ret.size(); i < len; ++i) {
-                        ChunkPos chunkPos = ret.get(i).getPos();
-                        int ticketLevel = ticketLevels.getInt(i);
+                        final ChunkPos chunkPos = ret.get(i).getPos();
 
-                        chunkProvider.addTicketAtLevel(TicketType.UNKNOWN, chunkPos, ticketLevel, chunkPos);
-                        chunkProvider.removeTicketAtLevel(TicketType.FUTURE_AWAIT, chunkPos, ticketLevel, holderIdentifier);
+                        chunkHolderManager.removeTicketAtLevel(ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler.CHUNK_LOAD, chunkPos, ticketLevel, holderIdentifier);
                     }
                 }
             }
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
 
         for (int cx = minChunkX; cx <= maxChunkX; ++cx) {
             for (int cz = minChunkZ; cz <= maxChunkZ; ++cz) {
-                ca.spottedleaf.moonrise.common.util.ChunkSystem.scheduleChunkLoad(
-                    this, cx, cz, net.minecraft.world.level.chunk.status.ChunkStatus.FULL, true, priority, consumer
-                );
+                chunkTaskScheduler.scheduleChunkLoad(cx, cz, chunkStatus, true, priority, consumer);
             }
         }
     }
-    // Paper end
 
-    // Paper start - optimise getPlayerByUUID
-    @Nullable
     @Override
-    public Player getPlayerByUUID(UUID uuid) {
-        final Player player = this.getServer().getPlayerList().getPlayer(uuid);
-        return player != null && player.level() == this ? player : null;
+    public final ca.spottedleaf.moonrise.patches.chunk_system.player.RegionizedPlayerChunkLoader.ViewDistanceHolder moonrise$getViewDistanceHolder() {
+        return this.viewDistanceHolder;
     }
-    // Paper end - optimise getPlayerByUUID
+
+    @Override
+    public final long moonrise$getLastMidTickFailure() {
+        return this.lastMidTickFailure;
+    }
+
+    @Override
+    public final void moonrise$setLastMidTickFailure(final long time) {
+        this.lastMidTickFailure = time;
+    }
+
+    @Override
+    public final ca.spottedleaf.moonrise.common.misc.NearbyPlayers moonrise$getNearbyPlayers() {
+        return this.nearbyPlayers;
+    }
+
+    @Override
+    public final ca.spottedleaf.moonrise.common.list.ReferenceList<net.minecraft.server.level.ServerChunkCache.ChunkAndHolder> moonrise$getLoadedChunks() {
+        return this.loadedChunks;
+    }
+
+    @Override
+    public final ca.spottedleaf.moonrise.common.list.ReferenceList<net.minecraft.server.level.ServerChunkCache.ChunkAndHolder> moonrise$getTickingChunks() {
+        return this.tickingChunks;
+    }
+
+    @Override
+    public final ca.spottedleaf.moonrise.common.list.ReferenceList<net.minecraft.server.level.ServerChunkCache.ChunkAndHolder> moonrise$getEntityTickingChunks() {
+        return this.entityTickingChunks;
+    }
+
+    @Override
+    public final boolean moonrise$areChunksLoaded(final int fromX, final int fromZ, final int toX, final int toZ) {
+        final ServerChunkCache chunkSource = this.chunkSource;
+
+        for (int currZ = fromZ; currZ <= toZ; ++currZ) {
+            for (int currX = fromX; currX <= toX; ++currX) {
+                if (!chunkSource.hasChunk(currX, currZ)) {
+                    return false;
+                }
+            }
+        }
+
+        return true;
+    }
+    // Paper end - rewrite chunk system
+    // Paper start - chunk tick iteration
+    private static final ServerChunkCache.ChunkAndHolder[] EMPTY_PLAYER_CHUNK_HOLDERS = new ServerChunkCache.ChunkAndHolder[0];
+    private final ca.spottedleaf.moonrise.common.list.ReferenceList<net.minecraft.server.level.ServerChunkCache.ChunkAndHolder> playerTickingChunks = new ca.spottedleaf.moonrise.common.list.ReferenceList<>(EMPTY_PLAYER_CHUNK_HOLDERS);
+    private final it.unimi.dsi.fastutil.longs.Long2IntOpenHashMap playerTickingRequests = new it.unimi.dsi.fastutil.longs.Long2IntOpenHashMap();
+
+    @Override
+    public final ca.spottedleaf.moonrise.common.list.ReferenceList<net.minecraft.server.level.ServerChunkCache.ChunkAndHolder> moonrise$getPlayerTickingChunks() {
+        return this.playerTickingChunks;
+    }
+
+    @Override
+    public final void moonrise$markChunkForPlayerTicking(final LevelChunk chunk) {
+        final ChunkPos pos = chunk.getPos();
+        if (!this.playerTickingRequests.containsKey(ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkKey(pos))) {
+            return;
+        }
+
+        this.playerTickingChunks.add(((ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemLevelChunk)chunk).moonrise$getChunkAndHolder());
+    }
+
+    @Override
+    public final void moonrise$removeChunkForPlayerTicking(final LevelChunk chunk) {
+        this.playerTickingChunks.remove(((ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemLevelChunk)chunk).moonrise$getChunkAndHolder());
+    }
+
+    @Override
+    public final void moonrise$addPlayerTickingRequest(final int chunkX, final int chunkZ) {
+        ca.spottedleaf.moonrise.common.util.TickThread.ensureTickThread((ServerLevel)(Object)this, chunkX, chunkZ, "Cannot add ticking request async");
+
+        final long chunkKey = ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkKey(chunkX, chunkZ);
+
+        if (this.playerTickingRequests.addTo(chunkKey, 1) != 0) {
+            // already added
+            return;
+        }
+
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder chunkHolder = ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)(ServerLevel)(Object)this).moonrise$getChunkTaskScheduler()
+            .chunkHolderManager.getChunkHolder(chunkKey);
+
+        if (chunkHolder == null || !chunkHolder.isTickingReady()) {
+            return;
+        }
+
+        this.playerTickingChunks.add(
+            ((ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemLevelChunk)(LevelChunk)chunkHolder.getCurrentChunk()).moonrise$getChunkAndHolder()
+        );
+    }
+
+    @Override
+    public final void moonrise$removePlayerTickingRequest(final int chunkX, final int chunkZ) {
+        ca.spottedleaf.moonrise.common.util.TickThread.ensureTickThread((ServerLevel)(Object)this, chunkX, chunkZ, "Cannot remove ticking request async");
+
+        final long chunkKey = ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkKey(chunkX, chunkZ);
+        final int val = this.playerTickingRequests.addTo(chunkKey, -1);
+
+        if (val <= 0) {
+            throw new IllegalStateException("Negative counter");
+        }
+
+        if (val != 1) {
+            // still has at least one request
+            return;
+        }
+
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder chunkHolder = ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)(ServerLevel)(Object)this).moonrise$getChunkTaskScheduler()
+            .chunkHolderManager.getChunkHolder(chunkKey);
+
+        if (chunkHolder == null || !chunkHolder.isTickingReady()) {
+            return;
+        }
+
+        this.playerTickingChunks.remove(
+            ((ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemLevelChunk)(LevelChunk)chunkHolder.getCurrentChunk()).moonrise$getChunkAndHolder()
+        );
+    }
+    // Paper end - chunk tick iteration
 
     // Add env and gen to constructor, IWorldDataServer -> WorldDataServer
     public ServerLevel(MinecraftServer minecraftserver, Executor executor, LevelStorageSource.LevelStorageAccess convertable_conversionsession, PrimaryLevelData iworlddataserver, ResourceKey<Level> resourcekey, LevelStem worlddimension, ChunkProgressListener worldloadlistener, boolean flag, long i, List<CustomSpawner> list, boolean flag1, @Nullable RandomSequences randomsequences, org.bukkit.World.Environment env, org.bukkit.generator.ChunkGenerator gen, org.bukkit.generator.BiomeProvider biomeProvider) {
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
         DataFixer datafixer = minecraftserver.getFixerUpper();
         EntityPersistentStorage<Entity> entitypersistentstorage = new EntityStorage(new SimpleRegionStorage(new RegionStorageInfo(convertable_conversionsession.getLevelId(), resourcekey, "entities"), convertable_conversionsession.getDimensionPath(resourcekey).resolve("entities"), datafixer, flag2, DataFixTypes.ENTITY_CHUNK), this, minecraftserver);
 
-        this.entityManager = new PersistentEntitySectionManager<>(Entity.class, new ServerLevel.EntityCallbacks(), entitypersistentstorage);
+        // Paper - rewrite chunk system
         StructureTemplateManager structuretemplatemanager = minecraftserver.getStructureManager();
         int j = this.spigotConfig.viewDistance; // Spigot
         int k = this.spigotConfig.simulationDistance; // Spigot
-        PersistentEntitySectionManager persistententitysectionmanager = this.entityManager;
+        // Paper - rewrite chunk system
 
-        Objects.requireNonNull(this.entityManager);
-        this.chunkSource = new ServerChunkCache(this, convertable_conversionsession, datafixer, structuretemplatemanager, executor, chunkgenerator, j, k, flag2, worldloadlistener, persistententitysectionmanager::updateChunkStatus, () -> {
+        this.chunkSource = new ServerChunkCache(this, convertable_conversionsession, datafixer, structuretemplatemanager, executor, chunkgenerator, j, k, flag2, worldloadlistener, null, () -> { // Paper - rewrite chunk system
             return minecraftserver.overworld().getDataStorage();
         });
         this.chunkSource.getGeneratorState().ensureStructuresGenerated();
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
         this.randomSequences = (RandomSequences) Objects.requireNonNullElseGet(randomsequences, () -> {
             return (RandomSequences) this.getDataStorage().computeIfAbsent(RandomSequences.factory(l), "random_sequences");
         });
+        // Paper start - rewrite chunk system
+        this.moonrise$setEntityLookup(new ca.spottedleaf.moonrise.patches.chunk_system.level.entity.server.ServerEntityLookup((ServerLevel)(Object)this, ((ServerLevel)(Object)this).new EntityCallbacks()));
+        this.chunkTaskScheduler = new ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler((ServerLevel)(Object)this);
+        this.entityDataController = new ca.spottedleaf.moonrise.patches.chunk_system.io.datacontroller.EntityDataController(
+            new ca.spottedleaf.moonrise.patches.chunk_system.io.datacontroller.EntityDataController.EntityRegionFileStorage(
+                new RegionStorageInfo(convertable_conversionsession.getLevelId(), resourcekey, "entities"),
+                convertable_conversionsession.getDimensionPath(resourcekey).resolve("entities"),
+                minecraftserver.forceSynchronousWrites()
+            ),
+            this.chunkTaskScheduler
+        );
+        this.poiDataController = new ca.spottedleaf.moonrise.patches.chunk_system.io.datacontroller.PoiDataController((ServerLevel)(Object)this, this.chunkTaskScheduler);
+        this.chunkDataController = new ca.spottedleaf.moonrise.patches.chunk_system.io.datacontroller.ChunkDataController((ServerLevel)(Object)this, this.chunkTaskScheduler);
+        // Paper end - rewrite chunk system
         this.getCraftServer().addWorld(this.getWorld()); // CraftBukkit
     }
 
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
                         gameprofilerfiller.push("checkDespawn");
                         entity.checkDespawn();
                         gameprofilerfiller.pop();
-                        if (entity instanceof ServerPlayer || this.chunkSource.chunkMap.getDistanceManager().inEntityTickingRange(entity.chunkPosition().toLong())) {
+                        if (true) { // Paper - rewrite chunk system
                             Entity entity1 = entity.getVehicle();
 
                             if (entity1 != null) {
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
         }
 
         gameprofilerfiller.push("entityManagement");
-        this.entityManager.tick();
+        // Paper - rewrite chunk system
         gameprofilerfiller.pop();
     }
 
     @Override
     public boolean shouldTickBlocksAt(long chunkPos) {
-        return this.chunkSource.chunkMap.getDistanceManager().inBlockTickingRange(chunkPos);
+        // Paper start - rewrite chunk system
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder holder = this.moonrise$getChunkTaskScheduler().chunkHolderManager.getChunkHolder(chunkPos);
+        return holder != null && holder.isTickingReady();
+        // Paper end - rewrite chunk system
     }
 
     protected void tickTime() {
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
         });
     }
 
+    // Paper start - optimise random ticking
+    private final ca.spottedleaf.moonrise.common.util.SimpleThreadUnsafeRandom simpleRandom = new ca.spottedleaf.moonrise.common.util.SimpleThreadUnsafeRandom(net.minecraft.world.level.levelgen.RandomSupport.generateUniqueSeed());
+
+    private void optimiseRandomTick(final LevelChunk chunk, final int tickSpeed) {
+        final LevelChunkSection[] sections = chunk.getSections();
+        final int minSection = ca.spottedleaf.moonrise.common.util.WorldUtil.getMinSection((ServerLevel)(Object)this);
+        final ca.spottedleaf.moonrise.common.util.SimpleThreadUnsafeRandom simpleRandom = this.simpleRandom;
+        final boolean doubleTickFluids = !ca.spottedleaf.moonrise.common.PlatformHooks.get().configFixMC224294();
+
+        final ChunkPos cpos = chunk.getPos();
+        final int offsetX = cpos.x << 4;
+        final int offsetZ = cpos.z << 4;
+
+        for (int sectionIndex = 0, sectionsLen = sections.length; sectionIndex < sectionsLen; sectionIndex++) {
+            final int offsetY = (sectionIndex + minSection) << 4;
+            final LevelChunkSection section = sections[sectionIndex];
+            final net.minecraft.world.level.chunk.PalettedContainer<net.minecraft.world.level.block.state.BlockState> states = section.states;
+            if (!section.isRandomlyTickingBlocks()) {
+                continue;
+            }
+
+            final ca.spottedleaf.moonrise.common.list.ShortList tickList = ((ca.spottedleaf.moonrise.patches.block_counting.BlockCountingChunkSection)section).moonrise$getTickingBlockList();
+
+            for (int i = 0; i < tickSpeed; ++i) {
+                final int tickingBlocks = tickList.size();
+                final int index = simpleRandom.nextInt() & ((16 * 16 * 16) - 1);
+
+                if (index >= tickingBlocks) {
+                    // most of the time we fall here
+                    continue;
+                }
+
+                final int location = (int)tickList.getRaw(index) & 0xFFFF;
+                final BlockState state = states.get(location);
+
+                // do not use a mutable pos, as some random tick implementations store the input without calling immutable()!
+                final BlockPos pos = new BlockPos((location & 15) | offsetX, ((location >>> (4 + 4)) & 15) | offsetY, ((location >>> 4) & 15) | offsetZ);
+
+                state.randomTick((ServerLevel)(Object)this, pos, simpleRandom);
+                if (doubleTickFluids) {
+                    final FluidState fluidState = state.getFluidState();
+                    if (fluidState.isRandomlyTicking()) {
+                        fluidState.randomTick((ServerLevel)(Object)this, pos, simpleRandom);
+                    }
+                }
+            }
+        }
+
+        return;
+    }
+    // Paper end - optimise random ticking
+
     public void tickChunk(LevelChunk chunk, int randomTickSpeed) {
+        final ca.spottedleaf.moonrise.common.util.SimpleThreadUnsafeRandom simpleRandom = this.simpleRandom; // Paper - optimise random ticking
         ChunkPos chunkcoordintpair = chunk.getPos();
         boolean flag = this.isRaining();
         int j = chunkcoordintpair.getMinBlockX();
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
         ProfilerFiller gameprofilerfiller = Profiler.get();
 
         gameprofilerfiller.push("thunder");
-        if (!this.paperConfig().environment.disableThunder && flag && this.isThundering() && this.spigotConfig.thunderChance > 0 && this.random.nextInt(this.spigotConfig.thunderChance) == 0) { // Spigot // Paper - Option to disable thunder
+        if (!this.paperConfig().environment.disableThunder && flag && this.isThundering() && this.spigotConfig.thunderChance > 0 && simpleRandom.nextInt(this.spigotConfig.thunderChance) == 0) { // Spigot // Paper - Option to disable thunder // Paper - optimise random ticking
             BlockPos blockposition = this.findLightningTargetAround(this.getBlockRandomPos(j, 0, k, 15));
 
             if (this.isRainingAt(blockposition)) {
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
 
         if (!this.paperConfig().environment.disableIceAndSnow) { // Paper - Option to disable ice and snow
         for (int l = 0; l < randomTickSpeed; ++l) {
-            if (this.random.nextInt(48) == 0) {
+            if (simpleRandom.nextInt(48) == 0) { // Paper - optimise random ticking
                 this.tickPrecipitation(this.getBlockRandomPos(j, 0, k, 15));
             }
         }
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
 
         gameprofilerfiller.popPush("tickBlocks");
         if (randomTickSpeed > 0) {
-            LevelChunkSection[] achunksection = chunk.getSections();
-
-            for (int i1 = 0; i1 < achunksection.length; ++i1) {
-                LevelChunkSection chunksection = achunksection[i1];
-
-                if (chunksection.isRandomlyTicking()) {
-                    int j1 = chunk.getSectionYFromSectionIndex(i1);
-                    int k1 = SectionPos.sectionToBlockCoord(j1);
-
-                    for (int l1 = 0; l1 < randomTickSpeed; ++l1) {
-                        BlockPos blockposition1 = this.getBlockRandomPos(j, k1, k, 15);
-
-                        gameprofilerfiller.push("randomTick");
-                        BlockState iblockdata = chunksection.getBlockState(blockposition1.getX() - j, blockposition1.getY() - k1, blockposition1.getZ() - k);
-
-                        if (iblockdata.isRandomlyTicking()) {
-                            iblockdata.randomTick(this, blockposition1, this.random);
-                        }
-
-                        FluidState fluid = iblockdata.getFluidState();
-
-                        if (fluid.isRandomlyTicking()) {
-                            fluid.randomTick(this, blockposition1, this.random);
-                        }
-
-                        gameprofilerfiller.pop();
-                    }
-                }
-            }
+            this.optimiseRandomTick(chunk, randomTickSpeed); // Paper - optimise random ticking
         }
 
         gameprofilerfiller.pop();
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
         if (fluid1.is(fluid)) {
             fluid1.tick(this, pos, iblockdata);
         }
+        // Paper start - rewrite chunk system
+        if ((++this.tickedBlocksOrFluids & 7L) != 0L) {
+            ((ca.spottedleaf.moonrise.patches.chunk_system.server.ChunkSystemMinecraftServer)this.server).moonrise$executeMidTickTasks();
+        }
+        // Paper end - rewrite chunk system
 
     }
 
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
         if (iblockdata.is(block)) {
             iblockdata.tick(this, pos, this.random);
         }
+        // Paper start - rewrite chunk system
+        if ((++this.tickedBlocksOrFluids & 7L) != 0L) {
+            ((ca.spottedleaf.moonrise.patches.chunk_system.server.ChunkSystemMinecraftServer)this.server).moonrise$executeMidTickTasks();
+        }
+        // Paper end - rewrite chunk system
 
     }
 
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
     }
 
     public void save(@Nullable ProgressListener progressListener, boolean flush, boolean savingDisabled) {
+        // Paper start - add close param
+        this.save(progressListener, flush, savingDisabled, false);
+    }
+    public void save(@Nullable ProgressListener progressListener, boolean flush, boolean savingDisabled, boolean close) {
+        // Paper end - add close param
         ServerChunkCache chunkproviderserver = this.getChunkSource();
 
         if (!savingDisabled) {
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
                 progressListener.progressStage(Component.translatable("menu.savingChunks"));
             }
 
-            chunkproviderserver.save(flush);
-            if (flush) {
-                this.entityManager.saveAll();
-            } else {
-                this.entityManager.autoSave();
-            }
+            if (!close) { chunkproviderserver.save(flush); } // Paper - add close param
+            // Paper - rewrite chunk system
 
         }
+        // Paper start - add close param
+        if (close) {
+            try {
+                chunkproviderserver.close(!savingDisabled);
+            } catch (IOException never) {
+                throw new RuntimeException(never);
+            }
+        }
+        // Paper end - add close param
 
         // CraftBukkit start - moved from MinecraftServer.saveChunks
         ServerLevel worldserver1 = this;
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
             this.removePlayerImmediately((ServerPlayer) entity, Entity.RemovalReason.DISCARDED);
         }
 
-        this.entityManager.addNewEntity(player);
+        this.moonrise$getEntityLookup().addNewEntity(player); // Paper - rewrite chunk system
     }
 
     // CraftBukkit start
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
             }
             // CraftBukkit end
 
-            return this.entityManager.addNewEntity(entity);
+            return this.moonrise$getEntityLookup().addNewEntity(entity); // Paper - rewrite chunk system
         }
     }
 
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
 
     public boolean tryAddFreshEntityWithPassengers(Entity entity, org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason reason) {
         // CraftBukkit end
-        Stream<UUID> stream = entity.getSelfAndPassengers().map(Entity::getUUID); // CraftBukkit - decompile error
-        PersistentEntitySectionManager persistententitysectionmanager = this.entityManager;
-
-        Objects.requireNonNull(this.entityManager);
-        if (stream.anyMatch(persistententitysectionmanager::isLoaded)) {
+        if (entity.getSelfAndPassengers().map(Entity::getUUID).anyMatch(this.moonrise$getEntityLookup()::hasEntity)) { // Paper - rewrite chunk system
             return false;
         } else {
             this.addFreshEntityWithPassengers(entity, reason); // CraftBukkit
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
                 }
             }
 
-            bufferedwriter.write(String.format(Locale.ROOT, "entities: %s\n", this.entityManager.gatherStats()));
+            bufferedwriter.write(String.format(Locale.ROOT, "entities: %s\n", this.moonrise$getEntityLookup().getDebugInfo())); // Paper - rewrite chunk system
             bufferedwriter.write(String.format(Locale.ROOT, "block_entity_tickers: %d\n", this.blockEntityTickers.size()));
             bufferedwriter.write(String.format(Locale.ROOT, "block_ticks: %d\n", this.getBlockTicks().count()));
             bufferedwriter.write(String.format(Locale.ROOT, "fluid_ticks: %d\n", this.getFluidTicks().count()));
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
         BufferedWriter bufferedwriter2 = Files.newBufferedWriter(path1);
 
         try {
-            playerchunkmap.dumpChunks(bufferedwriter2);
+            //playerchunkmap.dumpChunks(bufferedwriter2); // Paper - rewrite chunk system
         } catch (Throwable throwable4) {
             if (bufferedwriter2 != null) {
                 try {
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
         BufferedWriter bufferedwriter3 = Files.newBufferedWriter(path2);
 
         try {
-            this.entityManager.dumpSections(bufferedwriter3);
+            //this.entityManager.dumpSections(bufferedwriter3); // Paper - rewrite chunk system
         } catch (Throwable throwable6) {
             if (bufferedwriter3 != null) {
                 try {
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
 
     @VisibleForTesting
     public String getWatchdogStats() {
-        return String.format(Locale.ROOT, "players: %s, entities: %s [%s], block_entities: %d [%s], block_ticks: %d, fluid_ticks: %d, chunk_source: %s", this.players.size(), this.entityManager.gatherStats(), ServerLevel.getTypeCount(this.entityManager.getEntityGetter().getAll(), (entity) -> {
+        return String.format(Locale.ROOT, "players: %s, entities: %s [%s], block_entities: %d [%s], block_ticks: %d, fluid_ticks: %d, chunk_source: %s", this.players.size(), this.moonrise$getEntityLookup().getDebugInfo(), ServerLevel.getTypeCount(this.moonrise$getEntityLookup().getAll(), (entity) -> { // Paper - rewrite chunk system
             return BuiltInRegistries.ENTITY_TYPE.getKey(entity.getType()).toString();
         }), this.blockEntityTickers.size(), ServerLevel.getTypeCount(this.blockEntityTickers, TickingBlockEntity::getType), this.getBlockTicks().count(), this.getFluidTicks().count(), this.gatherChunkSourceStats());
     }
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
     @Override
     public LevelEntityGetter<Entity> getEntities() {
         org.spigotmc.AsyncCatcher.catchOp("Chunk getEntities call"); // Spigot
-        return this.entityManager.getEntityGetter();
+        return this.moonrise$getEntityLookup(); // Paper - rewrite chunk system
     }
 
     public void addLegacyChunkEntities(Stream<Entity> entities) {
-        this.entityManager.addLegacyChunkEntities(entities);
+        // Paper start - add chunkpos param
+        this.addLegacyChunkEntities(entities, null);
+    }
+    public void addLegacyChunkEntities(Stream<Entity> entities, ChunkPos chunkPos) {
+        // Paper end - add chunkpos param
+        this.moonrise$getEntityLookup().addLegacyChunkEntities(entities.toList(), chunkPos); // Paper - rewrite chunk system
     }
 
     public void addWorldGenChunkEntities(Stream<Entity> entities) {
-        this.entityManager.addWorldGenChunkEntities(entities);
+        // Paper start - add chunkpos param
+        this.addWorldGenChunkEntities(entities, null);
+    }
+    public void addWorldGenChunkEntities(Stream<Entity> entities, ChunkPos chunkPos) {
+        // Paper end - add chunkpos param
+        this.moonrise$getEntityLookup().addWorldGenChunkEntities(entities.toList(), chunkPos); // Paper - rewrite chunk system
     }
 
     public void startTickingChunk(LevelChunk chunk) {
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
     @Override
     public void close() throws IOException {
         super.close();
-        this.entityManager.close();
+        // Paper - rewrite chunk system
     }
 
     @Override
     public String gatherChunkSourceStats() {
         String s = this.chunkSource.gatherStats();
 
-        return "Chunks[S] W: " + s + " E: " + this.entityManager.gatherStats();
+        return "Chunks[S] W: " + s + " E: " + this.moonrise$getEntityLookup().getDebugInfo(); // Paper - rewrite chunk system
     }
 
     public boolean areEntitiesLoaded(long chunkPos) {
-        return this.entityManager.areEntitiesLoaded(chunkPos);
+        return this.moonrise$getAnyChunkIfLoaded(ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkX(chunkPos), ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkZ(chunkPos)) != null; // Paper - rewrite chunk system
     }
 
     private boolean isPositionTickingWithEntitiesLoaded(long chunkPos) {
-        return this.areEntitiesLoaded(chunkPos) && this.chunkSource.isPositionTicking(chunkPos);
+        // Paper start - rewrite chunk system
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder chunkHolder = this.moonrise$getChunkTaskScheduler().chunkHolderManager.getChunkHolder(chunkPos);
+        // isTicking implies the chunk is loaded, and the chunk is loaded now implies the entities are loaded
+        return chunkHolder != null && chunkHolder.isTickingReady();
+        // Paper end - rewrite chunk system
     }
 
     public boolean isPositionEntityTicking(BlockPos pos) {
-        return this.entityManager.canPositionTick(pos) && this.chunkSource.chunkMap.getDistanceManager().inEntityTickingRange(ChunkPos.asLong(pos));
+        // Paper start - rewrite chunk system
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder chunkHolder = this.moonrise$getChunkTaskScheduler().chunkHolderManager.getChunkHolder(ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkKey(pos));
+        return chunkHolder != null && chunkHolder.isEntityTickingReady();
+        // Paper end - rewrite chunk system
     }
 
     public boolean isNaturalSpawningAllowed(BlockPos pos) {
-        return this.entityManager.canPositionTick(pos);
+        // Paper start - rewrite chunk system
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder chunkHolder = this.moonrise$getChunkTaskScheduler().chunkHolderManager.getChunkHolder(ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkKey(pos));
+        return chunkHolder != null && chunkHolder.isEntityTickingReady();
+        // Paper end - rewrite chunk system
     }
 
     public boolean isNaturalSpawningAllowed(ChunkPos pos) {
-        return this.entityManager.canPositionTick(pos);
+        // Paper start - rewrite chunk system
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder chunkHolder = this.moonrise$getChunkTaskScheduler().chunkHolderManager.getChunkHolder(ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkKey(pos));
+        return chunkHolder != null && chunkHolder.isEntityTickingReady();
+        // Paper end - rewrite chunk system
     }
 
     @Override
@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
         CrashReportCategory crashreportsystemdetails = super.fillReportDetails(report);
 
         crashreportsystemdetails.setDetail("Loaded entity count", () -> {
-            return String.valueOf(this.entityManager.count());
+            return String.valueOf(this.moonrise$getEntityLookup().getEntityCount()); // Paper - rewrite chunk system
         });
         return crashreportsystemdetails;
     }
diff --git a/src/main/java/net/minecraft/server/level/ServerPlayer.java b/src/main/java/net/minecraft/server/level/ServerPlayer.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/level/ServerPlayer.java
+++ b/src/main/java/net/minecraft/server/level/ServerPlayer.java
@@ -0,0 +0,0 @@ import org.bukkit.event.player.PlayerTeleportEvent.TeleportCause;
 import org.bukkit.inventory.MainHand;
 // CraftBukkit end
 
-public class ServerPlayer extends net.minecraft.world.entity.player.Player {
+public class ServerPlayer extends net.minecraft.world.entity.player.Player implements ca.spottedleaf.moonrise.patches.chunk_system.player.ChunkSystemServerPlayer { // Paper - rewrite chunk system
 
     private static final Logger LOGGER = LogUtils.getLogger();
     private static final int NEUTRAL_MOB_DEATH_NOTIFICATION_RADII_XZ = 32;
@@ -0,0 +0,0 @@ public class ServerPlayer extends net.minecraft.world.entity.player.Player {
     public @Nullable String clientBrandName = null; // Paper - Brand support
     public org.bukkit.event.player.PlayerQuitEvent.QuitReason quitReason = null; // Paper - Add API for quit reason; there are a lot of changes to do if we change all methods leading to the event
 
+    // Paper start - rewrite chunk system
+    private ca.spottedleaf.moonrise.patches.chunk_system.player.RegionizedPlayerChunkLoader.PlayerChunkLoaderData chunkLoader;
+    private final ca.spottedleaf.moonrise.patches.chunk_system.player.RegionizedPlayerChunkLoader.ViewDistanceHolder viewDistanceHolder = new ca.spottedleaf.moonrise.patches.chunk_system.player.RegionizedPlayerChunkLoader.ViewDistanceHolder();
+
+    @Override
+    public final boolean moonrise$isRealPlayer() {
+        return this.isRealPlayer;
+    }
+
+    @Override
+    public final void moonrise$setRealPlayer(final boolean real) {
+        this.isRealPlayer = real;
+    }
+
+    @Override
+    public final ca.spottedleaf.moonrise.patches.chunk_system.player.RegionizedPlayerChunkLoader.PlayerChunkLoaderData moonrise$getChunkLoader() {
+        return this.chunkLoader;
+    }
+
+    @Override
+    public final void moonrise$setChunkLoader(final ca.spottedleaf.moonrise.patches.chunk_system.player.RegionizedPlayerChunkLoader.PlayerChunkLoaderData loader) {
+        this.chunkLoader = loader;
+    }
+
+    @Override
+    public final ca.spottedleaf.moonrise.patches.chunk_system.player.RegionizedPlayerChunkLoader.ViewDistanceHolder moonrise$getViewDistanceHolder() {
+        return this.viewDistanceHolder;
+    }
+    // Paper end - rewrite chunk system
+
     public ServerPlayer(MinecraftServer server, ServerLevel world, GameProfile profile, ClientInformation clientOptions) {
         super(world, world.getSharedSpawnPos(), world.getSharedSpawnAngle(), profile);
         this.chatVisibility = ChatVisiblity.FULL;
diff --git a/src/main/java/net/minecraft/server/level/ThreadedLevelLightEngine.java b/src/main/java/net/minecraft/server/level/ThreadedLevelLightEngine.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/level/ThreadedLevelLightEngine.java
+++ b/src/main/java/net/minecraft/server/level/ThreadedLevelLightEngine.java
@@ -0,0 +0,0 @@ import net.minecraft.world.level.chunk.LightChunkGetter;
 import net.minecraft.world.level.lighting.LevelLightEngine;
 import org.slf4j.Logger;
 
-public class ThreadedLevelLightEngine extends LevelLightEngine implements AutoCloseable {
+public class ThreadedLevelLightEngine extends LevelLightEngine implements AutoCloseable, ca.spottedleaf.moonrise.patches.starlight.light.StarLightLightingProvider { // Paper - rewrite chunk system
     public static final int DEFAULT_BATCH_SIZE = 1000;
     private static final Logger LOGGER = LogUtils.getLogger();
-    private final ConsecutiveExecutor consecutiveExecutor;
-    private final ObjectList<Pair<ThreadedLevelLightEngine.TaskType, Runnable>> lightTasks = new ObjectArrayList<>();
+    // Paper - rewrite chunk sytem
     private final ChunkMap chunkMap;
-    private final ChunkTaskDispatcher taskDispatcher;
+    // Paper - rewrite chunk sytem
     private final int taskPerBatch = 1000;
-    private final AtomicBoolean scheduled = new AtomicBoolean();
+    // Paper - rewrite chunk sytem
+
+    // Paper start - rewrite chunk system
+    private final java.util.concurrent.atomic.AtomicLong chunkWorkCounter = new java.util.concurrent.atomic.AtomicLong();
+    private void queueTaskForSection(final int chunkX, final int chunkY, final int chunkZ,
+                                     final java.util.function.Supplier<ca.spottedleaf.moonrise.patches.starlight.light.StarLightInterface.LightQueue.ChunkTasks> supplier) {
+        final ServerLevel world = (ServerLevel)this.starlight$getLightEngine().getWorld();
+
+        final ChunkAccess center = this.starlight$getLightEngine().getAnyChunkNow(chunkX, chunkZ);
+        if (center == null || !center.getPersistedStatus().isOrAfter(net.minecraft.world.level.chunk.status.ChunkStatus.LIGHT)) {
+            // do not accept updates in unlit chunks, unless we might be generating a chunk
+            return;
+        }
+
+        final ca.spottedleaf.moonrise.patches.starlight.light.StarLightInterface.ServerLightQueue.ServerChunkTasks scheduledTask = (ca.spottedleaf.moonrise.patches.starlight.light.StarLightInterface.ServerLightQueue.ServerChunkTasks)supplier.get();
+
+        if (scheduledTask == null) {
+            // not scheduled
+            return;
+        }
+
+        if (!scheduledTask.markTicketAdded()) {
+            // ticket already added
+            return;
+        }
+
+        final Long ticketId = Long.valueOf(this.chunkWorkCounter.getAndIncrement());
+        final ChunkPos pos = new ChunkPos(chunkX, chunkZ);
+        world.getChunkSource().addRegionTicket(ca.spottedleaf.moonrise.patches.starlight.light.StarLightInterface.CHUNK_WORK_TICKET, pos, ca.spottedleaf.moonrise.patches.starlight.light.StarLightInterface.REGION_LIGHT_TICKET_LEVEL, ticketId);
+
+        scheduledTask.queueOrRunTask(() -> {
+            world.getChunkSource().removeRegionTicket(ca.spottedleaf.moonrise.patches.starlight.light.StarLightInterface.CHUNK_WORK_TICKET, pos, ca.spottedleaf.moonrise.patches.starlight.light.StarLightInterface.REGION_LIGHT_TICKET_LEVEL, ticketId);
+        });
+    }
+
+    @Override
+    public final int starlight$serverRelightChunks(final java.util.Collection<net.minecraft.world.level.ChunkPos> chunks0,
+                                                   final java.util.function.Consumer<net.minecraft.world.level.ChunkPos> chunkLightCallback,
+                                                   final java.util.function.IntConsumer onComplete) {
+        final java.util.Set<net.minecraft.world.level.ChunkPos> chunks = new java.util.LinkedHashSet<>(chunks0);
+        final java.util.Map<net.minecraft.world.level.ChunkPos, Long> ticketIds = new java.util.HashMap<>();
+        final ServerLevel world = (ServerLevel)this.starlight$getLightEngine().getWorld();
+
+        for (final java.util.Iterator<net.minecraft.world.level.ChunkPos> iterator = chunks.iterator(); iterator.hasNext();) {
+            final ChunkPos pos = iterator.next();
+
+            final Long id = ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler.getNextChunkRelightId();
+            world.getChunkSource().addRegionTicket(ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler.CHUNK_RELIGHT, pos, ca.spottedleaf.moonrise.patches.starlight.light.StarLightInterface.REGION_LIGHT_TICKET_LEVEL, id);
+            ticketIds.put(pos, id);
+
+            final ChunkAccess chunk = (ChunkAccess)world.getChunkSource().getChunkForLighting(pos.x, pos.z);
+            if (chunk == null || !chunk.isLightCorrect() || !chunk.getPersistedStatus().isOrAfter(net.minecraft.world.level.chunk.status.ChunkStatus.LIGHT)) {
+                // cannot relight this chunk
+                iterator.remove();
+                ticketIds.remove(pos);
+                world.getChunkSource().removeRegionTicket(ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler.CHUNK_RELIGHT, pos, ca.spottedleaf.moonrise.patches.starlight.light.StarLightInterface.REGION_LIGHT_TICKET_LEVEL, id);
+                continue;
+            }
+        }
+
+        ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)world).moonrise$getChunkTaskScheduler().radiusAwareScheduler.queueInfiniteRadiusTask(() -> {
+            ThreadedLevelLightEngine.this.starlight$getLightEngine().relightChunks(
+                chunks,
+                (final ChunkPos pos) -> {
+                    if (chunkLightCallback != null) {
+                        chunkLightCallback.accept(pos);
+                    }
+
+                    ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)world).moonrise$getChunkTaskScheduler().scheduleChunkTask(pos.x, pos.z, () -> {
+                        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.NewChunkHolder chunkHolder = ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)world).moonrise$getChunkTaskScheduler().chunkHolderManager.getChunkHolder(
+                            pos.x, pos.z
+                        );
+
+                        if (chunkHolder == null) {
+                            return;
+                        }
+
+                        final java.util.List<ServerPlayer> players = ((ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemChunkHolder)chunkHolder.vanillaChunkHolder).moonrise$getPlayers(false);
+
+                        if (players.isEmpty()) {
+                            return;
+                        }
+
+                        final net.minecraft.network.protocol.Packet<?> relightPacket = new net.minecraft.network.protocol.game.ClientboundLightUpdatePacket(
+                            pos, (ThreadedLevelLightEngine)(Object)ThreadedLevelLightEngine.this,
+                            null, null
+                        );
+
+                        for (final ServerPlayer player : players) {
+                            final net.minecraft.server.network.ServerGamePacketListenerImpl conn = player.connection;
+                            if (conn != null) {
+                                conn.send(relightPacket);
+                            }
+                        }
+                    });
+                },
+                (final int relight) -> {
+                    if (onComplete != null) {
+                        onComplete.accept(relight);
+                    }
+
+                    for (final java.util.Map.Entry<ChunkPos, Long> entry : ticketIds.entrySet()) {
+                        world.getChunkSource().removeRegionTicket(
+                            ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler.CHUNK_RELIGHT, entry.getKey(),
+                            ca.spottedleaf.moonrise.patches.starlight.light.StarLightInterface.REGION_LIGHT_TICKET_LEVEL, entry.getValue()
+                        );
+                    }
+                }
+            );
+        });
+
+        return chunks.size();
+    }
+    // Paper end - rewrite chunk system
 
     public ThreadedLevelLightEngine(
         LightChunkGetter chunkProvider, ChunkMap chunkLoadingManager, boolean hasBlockLight, ConsecutiveExecutor processor, ChunkTaskDispatcher executor
     ) {
         super(chunkProvider, true, hasBlockLight);
         this.chunkMap = chunkLoadingManager;
-        this.taskDispatcher = executor;
-        this.consecutiveExecutor = processor;
+        // Paper - rewrite chunk sytem
     }
 
     @Override
@@ -0,0 +0,0 @@ public class ThreadedLevelLightEngine extends LevelLightEngine implements AutoCl
 
     @Override
     public void checkBlock(BlockPos pos) {
-        BlockPos blockPos = pos.immutable();
-        this.addTask(
-            SectionPos.blockToSectionCoord(pos.getX()),
-            SectionPos.blockToSectionCoord(pos.getZ()),
-            ThreadedLevelLightEngine.TaskType.PRE_UPDATE,
-            Util.name(() -> super.checkBlock(blockPos), () -> "checkBlock " + blockPos)
-        );
+        // Paper start - rewrite chunk system
+        final BlockPos posCopy = pos.immutable();
+        this.queueTaskForSection(posCopy.getX() >> 4, posCopy.getY() >> 4, posCopy.getZ() >> 4, () -> {
+            return ThreadedLevelLightEngine.this.starlight$getLightEngine().blockChange(posCopy);
+        });
+        // Paper end - rewrite chunk system
     }
 
     protected void updateChunkStatus(ChunkPos pos) {
-        this.addTask(pos.x, pos.z, () -> 0, ThreadedLevelLightEngine.TaskType.PRE_UPDATE, Util.name(() -> {
-            super.retainData(pos, false);
-            super.setLightEnabled(pos, false);
-
-            for (int i = this.getMinLightSection(); i < this.getMaxLightSection(); i++) {
-                super.queueSectionData(LightLayer.BLOCK, SectionPos.of(pos, i), null);
-                super.queueSectionData(LightLayer.SKY, SectionPos.of(pos, i), null);
-            }
-
-            for (int j = this.levelHeightAccessor.getMinSectionY(); j <= this.levelHeightAccessor.getMaxSectionY(); j++) {
-                super.updateSectionStatus(SectionPos.of(pos, j), true);
-            }
-        }, () -> "updateChunkStatus " + pos + " true"));
+        // Paper - rewrite chunk system
     }
 
     @Override
     public void updateSectionStatus(SectionPos pos, boolean notReady) {
-        this.addTask(
-            pos.x(),
-            pos.z(),
-            () -> 0,
-            ThreadedLevelLightEngine.TaskType.PRE_UPDATE,
-            Util.name(() -> super.updateSectionStatus(pos, notReady), () -> "updateSectionStatus " + pos + " " + notReady)
-        );
+        // Paper start - rewrite chunk system
+        this.queueTaskForSection(pos.getX(), pos.getY(), pos.getZ(), () -> {
+            return ThreadedLevelLightEngine.this.starlight$getLightEngine().sectionChange(pos, notReady);
+        });
+        // Paper end - rewrite chunk system
     }
 
     @Override
     public void propagateLightSources(ChunkPos chunkPos) {
-        this.addTask(
-            chunkPos.x,
-            chunkPos.z,
-            ThreadedLevelLightEngine.TaskType.PRE_UPDATE,
-            Util.name(() -> super.propagateLightSources(chunkPos), () -> "propagateLight " + chunkPos)
-        );
+        // Paper - rewrite chunk system
     }
 
     @Override
     public void setLightEnabled(ChunkPos pos, boolean retainData) {
-        this.addTask(
-            pos.x,
-            pos.z,
-            ThreadedLevelLightEngine.TaskType.PRE_UPDATE,
-            Util.name(() -> super.setLightEnabled(pos, retainData), () -> "enableLight " + pos + " " + retainData)
-        );
+        // Paper start - rewrite chunk system
     }
 
     @Override
     public void queueSectionData(LightLayer lightType, SectionPos pos, @Nullable DataLayer nibbles) {
-        this.addTask(
-            pos.x(),
-            pos.z(),
-            () -> 0,
-            ThreadedLevelLightEngine.TaskType.PRE_UPDATE,
-            Util.name(() -> super.queueSectionData(lightType, pos, nibbles), () -> "queueData " + pos)
-        );
+        // Paper start - rewrite chunk system
     }
 
     private void addTask(int x, int z, ThreadedLevelLightEngine.TaskType stage, Runnable task) {
-        this.addTask(x, z, this.chunkMap.getChunkQueueLevel(ChunkPos.asLong(x, z)), stage, task);
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     private void addTask(int x, int z, IntSupplier completedLevelSupplier, ThreadedLevelLightEngine.TaskType stage, Runnable task) {
-        this.taskDispatcher.submit(() -> {
-            this.lightTasks.add(Pair.of(stage, task));
-            if (this.lightTasks.size() >= 1000) {
-                this.runUpdate();
-            }
-        }, ChunkPos.asLong(x, z), completedLevelSupplier);
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     @Override
     public void retainData(ChunkPos pos, boolean retainData) {
-        this.addTask(
-            pos.x, pos.z, () -> 0, ThreadedLevelLightEngine.TaskType.PRE_UPDATE, Util.name(() -> super.retainData(pos, retainData), () -> "retainData " + pos)
-        );
+        // Paper start - rewrite chunk system
     }
 
     public CompletableFuture<ChunkAccess> initializeLight(ChunkAccess chunk, boolean bl) {
-        ChunkPos chunkPos = chunk.getPos();
-        this.addTask(chunkPos.x, chunkPos.z, ThreadedLevelLightEngine.TaskType.PRE_UPDATE, Util.name(() -> {
-            LevelChunkSection[] levelChunkSections = chunk.getSections();
-
-            for (int i = 0; i < chunk.getSectionsCount(); i++) {
-                LevelChunkSection levelChunkSection = levelChunkSections[i];
-                if (!levelChunkSection.hasOnlyAir()) {
-                    int j = this.levelHeightAccessor.getSectionYFromSectionIndex(i);
-                    super.updateSectionStatus(SectionPos.of(chunkPos, j), false);
-                }
-            }
-        }, () -> "initializeLight: " + chunkPos));
-        return CompletableFuture.supplyAsync(() -> {
-            super.setLightEnabled(chunkPos, bl);
-            super.retainData(chunkPos, false);
-            return chunk;
-        }, task -> this.addTask(chunkPos.x, chunkPos.z, ThreadedLevelLightEngine.TaskType.POST_UPDATE, task));
+        return CompletableFuture.completedFuture(chunk); // Paper start - rewrite chunk system
     }
 
     public CompletableFuture<ChunkAccess> lightChunk(ChunkAccess chunk, boolean excludeBlocks) {
-        ChunkPos chunkPos = chunk.getPos();
-        chunk.setLightCorrect(false);
-        this.addTask(chunkPos.x, chunkPos.z, ThreadedLevelLightEngine.TaskType.PRE_UPDATE, Util.name(() -> {
-            if (!excludeBlocks) {
-                super.propagateLightSources(chunkPos);
-            }
-        }, () -> "lightChunk " + chunkPos + " " + excludeBlocks));
-        return CompletableFuture.supplyAsync(() -> {
-            chunk.setLightCorrect(true);
-            return chunk;
-        }, task -> this.addTask(chunkPos.x, chunkPos.z, ThreadedLevelLightEngine.TaskType.POST_UPDATE, task));
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public void tryScheduleUpdate() {
-        if ((!this.lightTasks.isEmpty() || super.hasLightWork()) && this.scheduled.compareAndSet(false, true)) {
-            this.consecutiveExecutor.schedule(() -> {
-                this.runUpdate();
-                this.scheduled.set(false);
-            });
-        }
+        // Paper - rewrite chunk system
     }
 
     private void runUpdate() {
-        int i = Math.min(this.lightTasks.size(), 1000);
-        ObjectListIterator<Pair<ThreadedLevelLightEngine.TaskType, Runnable>> objectListIterator = this.lightTasks.iterator();
-
-        int j;
-        for (j = 0; objectListIterator.hasNext() && j < i; j++) {
-            Pair<ThreadedLevelLightEngine.TaskType, Runnable> pair = objectListIterator.next();
-            if (pair.getFirst() == ThreadedLevelLightEngine.TaskType.PRE_UPDATE) {
-                pair.getSecond().run();
-            }
-        }
-
-        objectListIterator.back(j);
-        super.runLightUpdates();
-
-        for (int var5 = 0; objectListIterator.hasNext() && var5 < i; var5++) {
-            Pair<ThreadedLevelLightEngine.TaskType, Runnable> pair2 = objectListIterator.next();
-            if (pair2.getFirst() == ThreadedLevelLightEngine.TaskType.POST_UPDATE) {
-                pair2.getSecond().run();
-            }
-
-            objectListIterator.remove();
-        }
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public CompletableFuture<?> waitForPendingTasks(int x, int z) {
-        return CompletableFuture.runAsync(() -> {
-        }, callback -> this.addTask(x, z, ThreadedLevelLightEngine.TaskType.POST_UPDATE, callback));
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     static enum TaskType {
diff --git a/src/main/java/net/minecraft/server/level/Ticket.java b/src/main/java/net/minecraft/server/level/Ticket.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/level/Ticket.java
+++ b/src/main/java/net/minecraft/server/level/Ticket.java
@@ -0,0 +0,0 @@ package net.minecraft.server.level;
 
 import java.util.Objects;
 
-public final class Ticket<T> implements Comparable<Ticket<?>> {
+public final class Ticket<T> implements Comparable<Ticket<?>>, ca.spottedleaf.moonrise.patches.chunk_system.ticket.ChunkSystemTicket<T> { // Paper - rewrite chunk system
     private final TicketType<T> type;
     private final int ticketLevel;
     public final T key;
-    private long createdTick;
+    // Paper start - rewrite chunk system
+    private long removeDelay;
 
-    protected Ticket(TicketType<T> type, int level, T argument) {
+    @Override
+    public final long moonrise$getRemoveDelay() {
+        return this.removeDelay;
+    }
+
+    @Override
+    public final void moonrise$setRemoveDelay(final long removeDelay) {
+        this.removeDelay = removeDelay;
+    }
+    // Paper end - rewerite chunk system
+
+    public Ticket(TicketType<T> type, int level, T argument) { // Paper - public
         this.type = type;
         this.ticketLevel = level;
         this.key = argument;
@@ -0,0 +0,0 @@ public final class Ticket<T> implements Comparable<Ticket<?>> {
 
     @Override
     public String toString() {
-        return "Ticket[" + this.type + " " + this.ticketLevel + " (" + this.key + ")] at " + this.createdTick;
+        return "Ticket[" + this.type + " " + this.ticketLevel + " (" + this.key + ")] to die in " + this.removeDelay; // Paper - rewrite chunk system
     }
 
     public TicketType<T> getType() {
@@ -0,0 +0,0 @@ public final class Ticket<T> implements Comparable<Ticket<?>> {
     }
 
     protected void setCreatedTick(long tickCreated) {
-        this.createdTick = tickCreated;
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     protected boolean timedOut(long currentTick) {
-        long l = this.type.timeout();
-        return l != 0L && currentTick - this.createdTick > l;
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 }
diff --git a/src/main/java/net/minecraft/server/level/WorldGenRegion.java b/src/main/java/net/minecraft/server/level/WorldGenRegion.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/level/WorldGenRegion.java
+++ b/src/main/java/net/minecraft/server/level/WorldGenRegion.java
@@ -0,0 +0,0 @@ public class WorldGenRegion implements WorldGenLevel {
     private final AtomicLong subTickCount = new AtomicLong();
     private static final ResourceLocation WORLDGEN_REGION_RANDOM = ResourceLocation.withDefaultNamespace("worldgen_region_random");
 
+    // Paper start - rewrite chunk system
+    /**
+     * During feature generation, light data is not initialised and will always return 15 in Starlight. Vanilla
+     * can possibly return 0 if partially initialised, which allows some mushroom blocks to generate.
+     * In general, the brightness value from the light engine should not be used until the chunk is ready. To emulate
+     * Vanilla behavior better, we return 0 as the brightness during world gen unless the target chunk is finished
+     * lighting.
+     */
+    @Override
+    public int getBrightness(final net.minecraft.world.level.LightLayer lightLayer, final BlockPos blockPos) {
+        final ChunkAccess chunk = this.getChunk(blockPos.getX() >> 4, blockPos.getZ() >> 4);
+        if (!chunk.isLightCorrect()) {
+            return 0;
+        }
+        return this.getLightEngine().getLayerListener(lightLayer).getLightValue(blockPos);
+    }
+
+    /**
+     * See above
+     */
+    @Override
+    public int getRawBrightness(final BlockPos blockPos, final int subtract) {
+        final ChunkAccess chunk = this.getChunk(blockPos.getX() >> 4, blockPos.getZ() >> 4);
+        if (!chunk.isLightCorrect()) {
+            return 0;
+        }
+        return this.getLightEngine().getRawBrightness(blockPos, subtract);
+    }
+    // Paper end - rewrite chunk system
+
     public WorldGenRegion(ServerLevel world, StaticCache2D<GenerationChunkHolder> chunks, ChunkStep generationStep, ChunkAccess centerPos) {
         this.generatingStep = generationStep;
         this.cache = chunks;
diff --git a/src/main/java/net/minecraft/server/players/PlayerList.java b/src/main/java/net/minecraft/server/players/PlayerList.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/players/PlayerList.java
+++ b/src/main/java/net/minecraft/server/players/PlayerList.java
@@ -0,0 +0,0 @@ public abstract class PlayerList {
 
     public void setViewDistance(int viewDistance) {
         this.viewDistance = viewDistance;
-        this.broadcastAll(new ClientboundSetChunkCacheRadiusPacket(viewDistance));
+        //this.broadcastAll(new ClientboundSetChunkCacheRadiusPacket(viewDistance)); // Paper - rewrite chunk system
         Iterator iterator = this.server.getAllLevels().iterator();
 
         while (iterator.hasNext()) {
@@ -0,0 +0,0 @@ public abstract class PlayerList {
 
     public void setSimulationDistance(int simulationDistance) {
         this.simulationDistance = simulationDistance;
-        this.broadcastAll(new ClientboundSetSimulationDistancePacket(simulationDistance));
+        //this.broadcastAll(new ClientboundSetSimulationDistancePacket(simulationDistance)); // Paper - rewrite chunk system
         Iterator iterator = this.server.getAllLevels().iterator();
 
         while (iterator.hasNext()) {
diff --git a/src/main/java/net/minecraft/util/BitStorage.java b/src/main/java/net/minecraft/util/BitStorage.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/util/BitStorage.java
+++ b/src/main/java/net/minecraft/util/BitStorage.java
@@ -0,0 +0,0 @@ package net.minecraft.util;
 
 import java.util.function.IntConsumer;
 
-public interface BitStorage {
+public interface BitStorage extends ca.spottedleaf.moonrise.patches.block_counting.BlockCountingBitStorage { // Paper - block counting
     int getAndSet(int index, int value);
 
     void set(int index, int value);
@@ -0,0 +0,0 @@ public interface BitStorage {
     void unpack(int[] out);
 
     BitStorage copy();
+
+    // Paper start - block counting
+    // provide default impl in case mods implement this...
+    @Override
+    public default it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap<it.unimi.dsi.fastutil.shorts.ShortArrayList> moonrise$countEntries() {
+        final it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap<it.unimi.dsi.fastutil.shorts.ShortArrayList> ret = new it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap<>();
+
+        final int size = this.getSize();
+        for (int index = 0; index < size; ++index) {
+            final int paletteIdx = this.get(index);
+            ret.computeIfAbsent(paletteIdx, (final int key) -> {
+                return new it.unimi.dsi.fastutil.shorts.ShortArrayList();
+            }).add((short)index);
+        }
+
+        return ret;
+    }
+    // Paper end - block counting
 }
diff --git a/src/main/java/net/minecraft/util/CrudeIncrementalIntIdentityHashBiMap.java b/src/main/java/net/minecraft/util/CrudeIncrementalIntIdentityHashBiMap.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/util/CrudeIncrementalIntIdentityHashBiMap.java
+++ b/src/main/java/net/minecraft/util/CrudeIncrementalIntIdentityHashBiMap.java
@@ -0,0 +0,0 @@ import java.util.Iterator;
 import javax.annotation.Nullable;
 import net.minecraft.core.IdMap;
 
-public class CrudeIncrementalIntIdentityHashBiMap<K> implements IdMap<K> {
+public class CrudeIncrementalIntIdentityHashBiMap<K> implements IdMap<K>, ca.spottedleaf.moonrise.patches.fast_palette.FastPalette<K> { // Paper - optimise palette reads
     private static final int NOT_FOUND = -1;
     private static final Object EMPTY_SLOT = null;
     private static final float LOADFACTOR = 0.8F;
@@ -0,0 +0,0 @@ public class CrudeIncrementalIntIdentityHashBiMap<K> implements IdMap<K> {
     private int nextId;
     private int size;
 
+    // Paper start - optimise palette reads
+    private ca.spottedleaf.moonrise.patches.fast_palette.FastPaletteData<K> reference;
+
+    @Override
+    public final K[] moonrise$getRawPalette(final ca.spottedleaf.moonrise.patches.fast_palette.FastPaletteData<K> src) {
+        this.reference = src;
+        return this.byId;
+    }
+    // Paper end - optimise palette reads
+
     private CrudeIncrementalIntIdentityHashBiMap(int size) {
         this.keys = (K[])(new Object[size]);
         this.values = new int[size];
@@ -0,0 +0,0 @@ public class CrudeIncrementalIntIdentityHashBiMap<K> implements IdMap<K> {
         this.byId = crudeIncrementalIntIdentityHashBiMap.byId;
         this.nextId = crudeIncrementalIntIdentityHashBiMap.nextId;
         this.size = crudeIncrementalIntIdentityHashBiMap.size;
+        // Paper start - optimise palette reads
+        final ca.spottedleaf.moonrise.patches.fast_palette.FastPaletteData<K> ref = this.reference;
+        if (ref != null) {
+            ref.moonrise$setPalette(this.byId);
+        }
+        // Paper end - optimise palette reads
     }
 
     public void addMapping(K value, int id) {
diff --git a/src/main/java/net/minecraft/util/SimpleBitStorage.java b/src/main/java/net/minecraft/util/SimpleBitStorage.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/util/SimpleBitStorage.java
+++ b/src/main/java/net/minecraft/util/SimpleBitStorage.java
@@ -0,0 +0,0 @@ public class SimpleBitStorage implements BitStorage {
     private final int divideAdd; private final long divideAddUnsigned; // Paper - Perf: Optimize SimpleBitStorage
     private final int divideShift;
 
+    // Paper start - optimise bitstorage read/write operations
+    private static final int[] BETTER_MAGIC = new int[33];
+    static {
+        // 20 bits of precision
+        // since index is always [0, 4095] (i.e 12 bits), multiplication by a magic value here (20 bits)
+        // fits exactly in an int and allows us to use integer arithmetic
+        for (int bits = 1; bits < BETTER_MAGIC.length; ++bits) {
+            BETTER_MAGIC[bits] = (int)ca.spottedleaf.concurrentutil.util.IntegerUtil.getUnsignedDivisorMagic(64L / bits, 20);
+        }
+    }
+    private final int magic;
+    private final int mulBits;
+    // Paper end - optimise bitstorage read/write operations
+
     public SimpleBitStorage(int elementBits, int size, int[] data) {
         this(elementBits, size);
         int i = 0;
@@ -0,0 +0,0 @@ public class SimpleBitStorage implements BitStorage {
         } else {
             this.data = new long[j];
         }
+        // Paper start - optimise bitstorage read/write operations
+        this.magic = BETTER_MAGIC[this.bits];
+        this.mulBits = (64 / this.bits) * this.bits;
+        if (this.size > 4096) {
+            throw new IllegalStateException("Size > 4096 not supported");
+        }
+        // Paper end - optimise bitstorage read/write operations
     }
 
     private int cellIndex(int index) {
@@ -0,0 +0,0 @@ public class SimpleBitStorage implements BitStorage {
     public final int getAndSet(int index, int value) { // Paper - Perf: Optimize SimpleBitStorage
         //Validate.inclusiveBetween(0L, (long)(this.size - 1), (long)index); // Paper - Perf: Optimize SimpleBitStorage
         //Validate.inclusiveBetween(0L, this.mask, (long)value); // Paper - Perf: Optimize SimpleBitStorage
-        int i = this.cellIndex(index);
-        long l = this.data[i];
-        int j = (index - i * this.valuesPerLong) * this.bits;
-        int k = (int)(l >> j & this.mask);
-        this.data[i] = l & ~(this.mask << j) | ((long)value & this.mask) << j;
-        return k;
+        // Paper start - optimise bitstorage read/write operations
+        final int full = this.magic * index; // 20 bits of magic + 12 bits of index = barely int
+        final int divQ = full >>> 20;
+        final int divR = (full & 0xFFFFF) * this.mulBits >>> 20;
+
+        final long[] dataArray = this.data;
+
+        final long data = dataArray[divQ];
+        final long mask = this.mask;
+
+        final long write = data & ~(mask << divR) | ((long)value & mask) << divR;
+
+        dataArray[divQ] = write;
+
+        return (int)(data >>> divR & mask);
+        // Paper end - optimise bitstorage read/write operations
     }
 
     @Override
     public final void set(int index, int value) { // Paper - Perf: Optimize SimpleBitStorage
         //Validate.inclusiveBetween(0L, (long)(this.size - 1), (long)index); // Paper - Perf: Optimize SimpleBitStorage
         //Validate.inclusiveBetween(0L, this.mask, (long)value); // Paper - Perf: Optimize SimpleBitStorage
-        int i = this.cellIndex(index);
-        long l = this.data[i];
-        int j = (index - i * this.valuesPerLong) * this.bits;
-        this.data[i] = l & ~(this.mask << j) | ((long)value & this.mask) << j;
+        // Paper start - optimise bitstorage read/write operations
+        final int full = this.magic * index; // 20 bits of magic + 12 bits of index = barely int
+        final int divQ = full >>> 20;
+        final int divR = (full & 0xFFFFF) * this.mulBits >>> 20;
+
+        final long[] dataArray = this.data;
+
+        final long data = dataArray[divQ];
+        final long mask = this.mask;
+
+        final long write = data & ~(mask << divR) | ((long)value & mask) << divR;
+
+        dataArray[divQ] = write;
+        // Paper end - optimise bitstorage read/write operations
     }
 
     @Override
     public final int get(int index) { // Paper - Perf: Optimize SimpleBitStorage
         //Validate.inclusiveBetween(0L, (long)(this.size - 1), (long)index); // Paper - Perf: Optimize SimpleBitStorage
-        int i = this.cellIndex(index);
-        long l = this.data[i];
-        int j = (index - i * this.valuesPerLong) * this.bits;
-        return (int)(l >> j & this.mask);
+        // Paper start - optimise bitstorage read/write operations
+        final int full = this.magic * index; // 20 bits of magic + 12 bits of index = barely int
+        final int divQ = full >>> 20;
+        final int divR = (full & 0xFFFFF) * this.mulBits >>> 20;
+
+        return (int)(this.data[divQ] >>> divR & this.mask);
+        // Paper end - optimise bitstorage read/write operations
     }
 
     @Override
@@ -0,0 +0,0 @@ public class SimpleBitStorage implements BitStorage {
         return new SimpleBitStorage(this.bits, this.size, (long[])this.data.clone());
     }
 
+    // Paper start - block counting
+    @Override
+    public final it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap<it.unimi.dsi.fastutil.shorts.ShortArrayList> moonrise$countEntries() {
+        final int valuesPerLong = this.valuesPerLong;
+        final int bits = this.bits;
+        final long mask = (1L << bits) - 1L;
+        final int size = this.size;
+
+        if (bits <= 6) {
+            final it.unimi.dsi.fastutil.shorts.ShortArrayList[] byId = new it.unimi.dsi.fastutil.shorts.ShortArrayList[1 << bits];
+            final it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap<it.unimi.dsi.fastutil.shorts.ShortArrayList> ret = new it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap<>(1 << bits);
+
+            int index = 0;
+
+            for (long value : this.data) {
+                int li = 0;
+                do {
+                    final int paletteIdx = (int)(value & mask);
+                    value >>= bits;
+                    ++li;
+
+                    final it.unimi.dsi.fastutil.shorts.ShortArrayList coords = byId[paletteIdx];
+                    if (coords != null) {
+                        coords.add((short)index++);
+                        continue;
+                    } else {
+                        final it.unimi.dsi.fastutil.shorts.ShortArrayList newCoords = new it.unimi.dsi.fastutil.shorts.ShortArrayList(64);
+                        byId[paletteIdx] = newCoords;
+                        newCoords.add((short)index++);
+                        ret.put(paletteIdx, newCoords);
+                        continue;
+                    }
+                } while (li < valuesPerLong && index < size);
+            }
+
+            return ret;
+        } else {
+            final it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap<it.unimi.dsi.fastutil.shorts.ShortArrayList> ret = new it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap<>(
+                1 << 6
+            );
+
+            int index = 0;
+
+            for (long value : this.data) {
+                int li = 0;
+                do {
+                    final int paletteIdx = (int)(value & mask);
+                    value >>= bits;
+                    ++li;
+
+                    ret.computeIfAbsent(paletteIdx, (final int key) -> {
+                        return new it.unimi.dsi.fastutil.shorts.ShortArrayList(64);
+                    }).add((short)index++);
+                } while (li < valuesPerLong && index < size);
+            }
+
+            return ret;
+        }
+    }
+    // Paper end - block counting
+
     public static class InitializationException extends RuntimeException {
         InitializationException(String message) {
             super(message);
diff --git a/src/main/java/net/minecraft/util/SortedArraySet.java b/src/main/java/net/minecraft/util/SortedArraySet.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/util/SortedArraySet.java
+++ b/src/main/java/net/minecraft/util/SortedArraySet.java
@@ -0,0 +0,0 @@ import java.util.Iterator;
 import java.util.NoSuchElementException;
 import javax.annotation.Nullable;
 
-public class SortedArraySet<T> extends AbstractSet<T> {
+public class SortedArraySet<T> extends AbstractSet<T> implements ca.spottedleaf.moonrise.patches.chunk_system.util.ChunkSystemSortedArraySet<T> { // Paper - rewrite chunk system
     private static final int DEFAULT_INITIAL_CAPACITY = 10;
     private final Comparator<T> comparator;
     T[] contents;
     int size;
 
+    // Paper start - rewrite chunk system
+    @Override
+    public final boolean removeIf(final java.util.function.Predicate<? super T> filter) {
+        // prev. impl used an iterator, which could be n^2 and creates garbage
+        int i = 0;
+        final int len = this.size;
+        final T[] backingArray = this.contents;
+
+        for (;;) {
+            if (i >= len) {
+                return false;
+            }
+            if (!filter.test(backingArray[i])) {
+                ++i;
+                continue;
+            }
+            break;
+        }
+
+        // we only want to write back to backingArray if we really need to
+
+        int lastIndex = i; // this is where new elements are shifted to
+
+        for (; i < len; ++i) {
+            final T curr = backingArray[i];
+            if (!filter.test(curr)) { // if test throws we're screwed
+                backingArray[lastIndex++] = curr;
+            }
+        }
+
+        // cleanup end
+        Arrays.fill(backingArray, lastIndex, len, null);
+        this.size = lastIndex;
+        return true;
+    }
+
+    @Override
+    public final T moonrise$replace(final T object) {
+        final int index = this.findIndex(object);
+        if (index >= 0) {
+            final T old = this.contents[index];
+            this.contents[index] = object;
+            return old;
+        } else {
+            this.addInternal(object, getInsertionPosition(index));
+            return object;
+        }
+    }
+
+    @Override
+    public final T moonrise$removeAndGet(final T object) {
+        int i = this.findIndex(object);
+        if (i >= 0) {
+            final T ret = this.contents[i];
+            this.removeInternal(i);
+            return ret;
+        } else {
+            return null;
+        }
+    }
+
+    @Override
+    public final SortedArraySet<T> moonrise$copy() {
+        final SortedArraySet<T> ret = SortedArraySet.create(this.comparator, 0);
+
+        ret.size = this.size;
+        ret.contents = Arrays.copyOf(this.contents, this.size);
+
+        return ret;
+    }
+
+    @Override
+    public Object[] moonrise$copyBackingArray() {
+        return this.contents.clone();
+    }
+    // Paper end - rewrite chunk system
+
     private SortedArraySet(int initialCapacity, Comparator<T> comparator) {
         this.comparator = comparator;
         if (initialCapacity < 0) {
diff --git a/src/main/java/net/minecraft/util/ZeroBitStorage.java b/src/main/java/net/minecraft/util/ZeroBitStorage.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/util/ZeroBitStorage.java
+++ b/src/main/java/net/minecraft/util/ZeroBitStorage.java
@@ -0,0 +0,0 @@ public class ZeroBitStorage implements BitStorage {
     public BitStorage copy() {
         return this;
     }
+
+    // Paper start - block counting
+    @Override
+    public final it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap<it.unimi.dsi.fastutil.shorts.ShortArrayList> moonrise$countEntries() {
+        final int size = this.size;
+
+        final short[] raw = new short[size];
+        for (int i = 0; i < size; ++i) {
+            raw[i] = (short)i;
+        }
+
+        final it.unimi.dsi.fastutil.shorts.ShortArrayList coordinates = it.unimi.dsi.fastutil.shorts.ShortArrayList.wrap(raw, size);
+
+        final it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap<it.unimi.dsi.fastutil.shorts.ShortArrayList> ret = new it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap<>(1);
+        ret.put(0, coordinates);
+        return ret;
+    }
+    // Paper end - block counting
 }
diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -0,0 +0,0 @@ import org.bukkit.event.player.PlayerTeleportEvent;
 import org.bukkit.plugin.PluginManager;
 // CraftBukkit end
 
-public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess, ScoreHolder {
+public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess, ScoreHolder, ca.spottedleaf.moonrise.patches.chunk_system.entity.ChunkSystemEntity, ca.spottedleaf.moonrise.patches.entity_tracker.EntityTrackerEntity {  // Paper - rewrite chunk system // Paper - optimise entity tracker
 
     // CraftBukkit start
     private static final int CURRENT_LEVEL = 2;
@@ -0,0 +0,0 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
 
     // Paper start - Share random for entities to make them more random
     public static RandomSource SHARED_RANDOM = new RandomRandomSource();
-    private static final class RandomRandomSource extends java.util.Random implements net.minecraft.world.level.levelgen.BitRandomSource {
+    // Paper start - replace random
+    private static final class RandomRandomSource extends ca.spottedleaf.moonrise.common.util.ThreadUnsafeRandom {
+        public RandomRandomSource() {
+            this(net.minecraft.world.level.levelgen.RandomSupport.generateUniqueSeed());
+        }
+
+        public RandomRandomSource(long seed) {
+            super(seed);
+        }
+
+        // Paper end - replace random
         private boolean locked = false;
 
         @Override
@@ -0,0 +0,0 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
             }
         }
 
-        @Override
-        public RandomSource fork() {
-            return new net.minecraft.world.level.levelgen.LegacyRandomSource(this.nextLong());
-        }
-
-        @Override
-        public net.minecraft.world.level.levelgen.PositionalRandomFactory forkPositional() {
-            return new net.minecraft.world.level.levelgen.LegacyRandomSource.LegacyPositionalRandomFactory(this.nextLong());
-        }
-
-        // these below are added to fix reobf issues that I don't wanna deal with right now
-        @Override
-        public int next(int bits) {
-            return super.next(bits);
-        }
-
-        @Override
-        public int nextInt(int origin, int bound) {
-            return net.minecraft.world.level.levelgen.BitRandomSource.super.nextInt(origin, bound);
-        }
-
-        @Override
-        public long nextLong() {
-            return net.minecraft.world.level.levelgen.BitRandomSource.super.nextLong();
-        }
-
-        @Override
-        public int nextInt() {
-            return net.minecraft.world.level.levelgen.BitRandomSource.super.nextInt();
-        }
-
-        @Override
-        public int nextInt(int bound) {
-            return net.minecraft.world.level.levelgen.BitRandomSource.super.nextInt(bound);
-        }
-
-        @Override
-        public boolean nextBoolean() {
-            return net.minecraft.world.level.levelgen.BitRandomSource.super.nextBoolean();
-        }
-
-        @Override
-        public float nextFloat() {
-            return net.minecraft.world.level.levelgen.BitRandomSource.super.nextFloat();
-        }
-
-        @Override
-        public double nextDouble() {
-            return net.minecraft.world.level.levelgen.BitRandomSource.super.nextDouble();
-        }
-
-        @Override
-        public double nextGaussian() {
-            return super.nextGaussian();
-        }
+        // Paper - replace random
     }
     // Paper end - Share random for entities to make them more random
     public org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason spawnReason; // Paper - Entity#getEntitySpawnReason
@@ -0,0 +0,0 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
         return this.dimensions.makeBoundingBox(x, y, z);
     }
     // Paper end
+    // Paper start - rewrite chunk system
+    private final boolean isHardColliding = this.moonrise$isHardCollidingUncached();
+    private net.minecraft.server.level.FullChunkStatus chunkStatus;
+    private ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkData chunkData;
+    private int sectionX = Integer.MIN_VALUE;
+    private int sectionY = Integer.MIN_VALUE;
+    private int sectionZ = Integer.MIN_VALUE;
+    private boolean updatingSectionStatus;
+
+    @Override
+    public final boolean moonrise$isHardColliding() {
+        return this.isHardColliding;
+    }
+
+    @Override
+    public final net.minecraft.server.level.FullChunkStatus moonrise$getChunkStatus() {
+        return this.chunkStatus;
+    }
+
+    @Override
+    public final void moonrise$setChunkStatus(final net.minecraft.server.level.FullChunkStatus status) {
+        this.chunkStatus = status;
+    }
+
+    @Override
+    public final ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkData moonrise$getChunkData() {
+        return this.chunkData;
+    }
+
+    @Override
+    public final void moonrise$setChunkData(final ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkData chunkData) {
+        this.chunkData = chunkData;
+    }
+
+    @Override
+    public final int moonrise$getSectionX() {
+        return this.sectionX;
+    }
+
+    @Override
+    public final void moonrise$setSectionX(final int x) {
+        this.sectionX = x;
+    }
+
+    @Override
+    public final int moonrise$getSectionY() {
+        return this.sectionY;
+    }
+
+    @Override
+    public final void moonrise$setSectionY(final int y) {
+        this.sectionY = y;
+    }
+
+    @Override
+    public final int moonrise$getSectionZ() {
+        return this.sectionZ;
+    }
+
+    @Override
+    public final void moonrise$setSectionZ(final int z) {
+        this.sectionZ = z;
+    }
+
+    @Override
+    public final boolean moonrise$isUpdatingSectionStatus() {
+        return this.updatingSectionStatus;
+    }
+
+    @Override
+    public final void moonrise$setUpdatingSectionStatus(final boolean to) {
+        this.updatingSectionStatus = to;
+    }
+
+    @Override
+    public final boolean moonrise$hasAnyPlayerPassengers() {
+        if (this.passengers.isEmpty()) {
+            return false;
+        }
+        return this.getIndirectPassengersStream().anyMatch((entity) -> entity instanceof Player);
+    }
+    // Paper end - rewrite chunk system
+    // Paper start - optimise collisions
+    private static float[] calculateStepHeights(final AABB box, final List<VoxelShape> voxels, final List<AABB> aabbs, final float stepHeight,
+                                                final float collidedY) {
+        final FloatArraySet ret = new FloatArraySet();
+
+        for (int i = 0, len = voxels.size(); i < len; ++i) {
+            final VoxelShape shape = voxels.get(i);
+
+            final double[] yCoords = ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)shape).moonrise$rootCoordinatesY();
+            final double yOffset = ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)shape).moonrise$offsetY();
+
+            for (final double yUnoffset : yCoords) {
+                final double y = yUnoffset + yOffset;
+
+                final float step = (float)(y - box.minY);
+
+                if (step > stepHeight) {
+                    break;
+                }
+
+                if (step < 0.0f || !(step != collidedY)) {
+                    continue;
+                }
+
+                ret.add(step);
+            }
+        }
+
+        for (int i = 0, len = aabbs.size(); i < len; ++i) {
+            final AABB shape = aabbs.get(i);
+
+            final float step1 = (float)(shape.minY - box.minY);
+            final float step2 = (float)(shape.maxY - box.minY);
+
+            if (!(step1 < 0.0f) && step1 != collidedY && !(step1 > stepHeight)) {
+                ret.add(step1);
+            }
+
+            if (!(step2 < 0.0f) && step2 != collidedY && !(step2 > stepHeight)) {
+                ret.add(step2);
+            }
+        }
+
+        final float[] steps = ret.toFloatArray();
+        FloatArrays.unstableSort(steps);
+        return steps;
+    }
+    // Paper end - optimise collisions
+    // Paper start - optimise entity tracker
+    private net.minecraft.server.level.ChunkMap.TrackedEntity trackedEntity;
+
+    @Override
+    public final net.minecraft.server.level.ChunkMap.TrackedEntity moonrise$getTrackedEntity() {
+        return this.trackedEntity;
+    }
+
+    @Override
+    public final void moonrise$setTrackedEntity(final net.minecraft.server.level.ChunkMap.TrackedEntity trackedEntity) {
+        this.trackedEntity = trackedEntity;
+    }
+
+    private static void collectIndirectPassengers(final List<Entity> into, final List<Entity> from) {
+        for (final Entity passenger : from) {
+            into.add(passenger);
+            collectIndirectPassengers(into, ((Entity)(Object)passenger).passengers);
+        }
+    }
+    // Paper end - optimise entity tracker
 
     public Entity(EntityType<?> type, Level world) {
         this.id = Entity.ENTITY_COUNTER.incrementAndGet();
@@ -0,0 +0,0 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
     }
 
     private Vec3 collide(Vec3 movement) {
-        AABB axisalignedbb = this.getBoundingBox();
-        List<VoxelShape> list = this.level().getEntityCollisions(this, axisalignedbb.expandTowards(movement));
-        Vec3 vec3d1 = movement.lengthSqr() == 0.0D ? movement : Entity.collideBoundingBox(this, movement, axisalignedbb, this.level(), list);
-        boolean flag = movement.x != vec3d1.x;
-        boolean flag1 = movement.y != vec3d1.y;
-        boolean flag2 = movement.z != vec3d1.z;
-        boolean flag3 = flag1 && movement.y < 0.0D;
-
-        if (this.maxUpStep() > 0.0F && (flag3 || this.onGround()) && (flag || flag2)) {
-            AABB axisalignedbb1 = flag3 ? axisalignedbb.move(0.0D, vec3d1.y, 0.0D) : axisalignedbb;
-            AABB axisalignedbb2 = axisalignedbb1.expandTowards(movement.x, (double) this.maxUpStep(), movement.z);
-
-            if (!flag3) {
-                axisalignedbb2 = axisalignedbb2.expandTowards(0.0D, -9.999999747378752E-6D, 0.0D);
-            }
+        // Paper start - optimise collisions
+        final boolean xZero = movement.x == 0.0;
+        final boolean yZero = movement.y == 0.0;
+        final boolean zZero = movement.z == 0.0;
+        if (xZero & yZero & zZero) {
+            return movement;
+        }
+
+        final AABB currentBox = this.getBoundingBox();
+
+        final List<VoxelShape> potentialCollisionsVoxel = new ArrayList<>();
+        final List<AABB> potentialCollisionsBB = new ArrayList<>();
 
-            List<VoxelShape> list1 = Entity.collectColliders(this, this.level, list, axisalignedbb2);
-            float f = (float) vec3d1.y;
-            float[] afloat = Entity.collectCandidateStepUpHeights(axisalignedbb1, list1, this.maxUpStep(), f);
-            float[] afloat1 = afloat;
-            int i = afloat.length;
+        final AABB initialCollisionBox;
+        if (xZero & zZero) {
+            // note: xZero & zZero -> collision on x/z == 0 -> no step height calculation
+            // this specifically optimises entities standing still
+            initialCollisionBox = movement.y < 0.0 ?
+                ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.cutDownwards(currentBox, movement.y) : ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.cutUpwards(currentBox, movement.y);
+        } else {
+            initialCollisionBox = currentBox.expandTowards(movement);
+        }
 
-            for (int j = 0; j < i; ++j) {
-                float f1 = afloat1[j];
-                Vec3 vec3d2 = Entity.collideWithShapes(new Vec3(movement.x, (double) f1, movement.z), axisalignedbb1, list1);
+        final List<AABB> entityAABBs = new ArrayList<>();
+        ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.getEntityHardCollisions(
+            this.level, (Entity)(Object)this, initialCollisionBox, entityAABBs, 0, null
+        );
 
-                if (vec3d2.horizontalDistanceSqr() > vec3d1.horizontalDistanceSqr()) {
-                    double d0 = axisalignedbb.minY - axisalignedbb1.minY;
+        ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.getCollisionsForBlocksOrWorldBorder(
+            this.level, (Entity)(Object)this, initialCollisionBox, potentialCollisionsVoxel, potentialCollisionsBB,
+            ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_FLAG_CHECK_BORDER, null
+        );
+        potentialCollisionsBB.addAll(entityAABBs);
+        final Vec3 collided = ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.performCollisions(movement, currentBox, potentialCollisionsVoxel, potentialCollisionsBB);
 
-                    return vec3d2.add(0.0D, -d0, 0.0D);
-                }
+        final boolean collidedX = collided.x != movement.x;
+        final boolean collidedY = collided.y != movement.y;
+        final boolean collidedZ = collided.z != movement.z;
+
+        final boolean collidedDownwards = collidedY && movement.y < 0.0;
+
+        final double stepHeight;
+
+        if ((!collidedDownwards && !this.onGround) || (!collidedX && !collidedZ) || (stepHeight = (double)this.maxUpStep()) <= 0.0) {
+            return collided;
+        }
+
+        final AABB collidedYBox = collidedDownwards ? currentBox.move(0.0, collided.y, 0.0) : currentBox;
+        AABB stepRetrievalBox = collidedYBox.expandTowards(movement.x, stepHeight, movement.z);
+        if (!collidedDownwards) {
+            stepRetrievalBox = stepRetrievalBox.expandTowards(0.0, (double)-1.0E-5F, 0.0);
+        }
+
+        final List<VoxelShape> stepVoxels = new ArrayList<>();
+        final List<AABB> stepAABBs = entityAABBs;
+
+        ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.getCollisionsForBlocksOrWorldBorder(
+            this.level, (Entity)(Object)this, stepRetrievalBox, stepVoxels, stepAABBs,
+            ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_FLAG_CHECK_BORDER, null
+        );
+
+        for (final float step : calculateStepHeights(collidedYBox, stepVoxels, stepAABBs, (float)stepHeight, (float)collided.y)) {
+            final Vec3 stepResult = ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.performCollisions(new Vec3(movement.x, (double)step, movement.z), collidedYBox, stepVoxels, stepAABBs);
+            if (stepResult.horizontalDistanceSqr() > collided.horizontalDistanceSqr()) {
+                return stepResult.add(0.0, collidedYBox.minY - currentBox.minY, 0.0);
             }
         }
 
-        return vec3d1;
+        return collided;
+        // Paper end - optimise collisions
     }
 
     private static float[] collectCandidateStepUpHeights(AABB collisionBox, List<VoxelShape> collisions, float f, float stepHeight) {
@@ -0,0 +0,0 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
     }
 
     public boolean isInWall() {
+        // Paper start - optimise collisions
         if (this.noPhysics) {
             return false;
-        } else {
-            float f = this.dimensions.width() * 0.8F;
-            AABB axisalignedbb = AABB.ofSize(this.getEyePosition(), (double) f, 1.0E-6D, (double) f);
+        }
 
-            return BlockPos.betweenClosedStream(axisalignedbb).anyMatch((blockposition) -> {
-                BlockState iblockdata = this.level().getBlockState(blockposition);
+        final double reducedWith = (double)(this.dimensions.width() * 0.8F);
+        final AABB boundingBox = AABB.ofSize(this.getEyePosition(), reducedWith, 1.0E-6D, reducedWith);
+        final Level world = this.level;
 
-                return !iblockdata.isAir() && iblockdata.isSuffocating(this.level(), blockposition) && Shapes.joinIsNotEmpty(iblockdata.getCollisionShape(this.level(), blockposition).move((double) blockposition.getX(), (double) blockposition.getY(), (double) blockposition.getZ()), Shapes.create(axisalignedbb), BooleanOp.AND);
-            });
+        if (ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.isEmpty(boundingBox)) {
+            return false;
         }
+
+        final int minBlockX = Mth.floor(boundingBox.minX);
+        final int minBlockY = Mth.floor(boundingBox.minY);
+        final int minBlockZ = Mth.floor(boundingBox.minZ);
+
+        final int maxBlockX = Mth.floor(boundingBox.maxX);
+        final int maxBlockY = Mth.floor(boundingBox.maxY);
+        final int maxBlockZ = Mth.floor(boundingBox.maxZ);
+
+        final int minChunkX = minBlockX >> 4;
+        final int minChunkY = minBlockY >> 4;
+        final int minChunkZ = minBlockZ >> 4;
+
+        final int maxChunkX = maxBlockX >> 4;
+        final int maxChunkY = maxBlockY >> 4;
+        final int maxChunkZ = maxBlockZ >> 4;
+
+        final int minSection = ca.spottedleaf.moonrise.common.util.WorldUtil.getMinSection(world);
+        final net.minecraft.world.level.chunk.ChunkSource chunkSource = world.getChunkSource();
+        final BlockPos.MutableBlockPos mutablePos = new BlockPos.MutableBlockPos();
+
+        for (int currChunkZ = minChunkZ; currChunkZ <= maxChunkZ; ++currChunkZ) {
+            for (int currChunkX = minChunkX; currChunkX <= maxChunkX; ++currChunkX) {
+                final net.minecraft.world.level.chunk.LevelChunkSection[] sections = chunkSource.getChunk(currChunkX, currChunkZ, net.minecraft.world.level.chunk.status.ChunkStatus.FULL, true).getSections();
+
+                for (int currChunkY = minChunkY; currChunkY <= maxChunkY; ++currChunkY) {
+                    final int sectionIdx = currChunkY - minSection;
+                    if (sectionIdx < 0 || sectionIdx >= sections.length) {
+                        continue;
+                    }
+                    final net.minecraft.world.level.chunk.LevelChunkSection section = sections[sectionIdx];
+                    if (section.hasOnlyAir()) {
+                        // empty
+                        continue;
+                    }
+
+                    final net.minecraft.world.level.chunk.PalettedContainer<net.minecraft.world.level.block.state.BlockState> blocks = section.states;
+
+                    final int minXIterate = currChunkX == minChunkX ? (minBlockX & 15) : 0;
+                    final int maxXIterate = currChunkX == maxChunkX ? (maxBlockX & 15) : 15;
+                    final int minZIterate = currChunkZ == minChunkZ ? (minBlockZ & 15) : 0;
+                    final int maxZIterate = currChunkZ == maxChunkZ ? (maxBlockZ & 15) : 15;
+                    final int minYIterate = currChunkY == minChunkY ? (minBlockY & 15) : 0;
+                    final int maxYIterate = currChunkY == maxChunkY ? (maxBlockY & 15) : 15;
+
+                    for (int currY = minYIterate; currY <= maxYIterate; ++currY) {
+                        final int blockY = currY | (currChunkY << 4);
+                        mutablePos.setY(blockY);
+                        for (int currZ = minZIterate; currZ <= maxZIterate; ++currZ) {
+                            final int blockZ = currZ | (currChunkZ << 4);
+                            mutablePos.setZ(blockZ);
+                            for (int currX = minXIterate; currX <= maxXIterate; ++currX) {
+                                final int blockX = currX | (currChunkX << 4);
+                                mutablePos.setX(blockX);
+
+                                final BlockState blockState = blocks.get((currX) | (currZ << 4) | ((currY) << 8));
+
+                                if (((ca.spottedleaf.moonrise.patches.collisions.block.CollisionBlockState)blockState).moonrise$emptyCollisionShape()
+                                    || !blockState.isSuffocating(world, mutablePos)) {
+                                    continue;
+                                }
+
+                                // Yes, it does not use the Entity context stuff.
+                                final VoxelShape collisionShape = blockState.getCollisionShape(world, mutablePos);
+
+                                if (collisionShape.isEmpty()) {
+                                    continue;
+                                }
+
+                                final AABB toCollide = boundingBox.move(-(double)blockX, -(double)blockY, -(double)blockZ);
+
+                                final AABB singleAABB = ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)collisionShape).moonrise$getSingleAABBRepresentation();
+                                if (singleAABB != null) {
+                                    if (ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.voxelShapeIntersect(singleAABB, toCollide)) {
+                                        return true;
+                                    }
+                                    continue;
+                                }
+
+                                if (ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.voxelShapeIntersectNoEmpty(collisionShape, toCollide)) {
+                                    return true;
+                                }
+                                continue;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        return false;
+        // Paper end - optimise collisions
     }
 
     public InteractionResult interact(Player player, InteractionHand hand) {
@@ -0,0 +0,0 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
     }
 
     public Iterable<Entity> getIndirectPassengers() {
-        // Paper start - Optimize indirect passenger iteration
-        if (this.passengers.isEmpty()) { return ImmutableList.of(); }
-        ImmutableList.Builder<Entity> indirectPassengers = ImmutableList.builder();
-        for (Entity passenger : this.passengers) {
-            indirectPassengers.add(passenger);
-            indirectPassengers.addAll(passenger.getIndirectPassengers());
+        // Paper start - optimise entity tracker
+        final List<Entity> ret = new ArrayList<>();
+
+        if (this.passengers.isEmpty()) {
+            return ret;
         }
-        return indirectPassengers.build();
+
+        collectIndirectPassengers(ret, this.passengers);
+
+        return ret;
+        // Paper end - optimise entity tracker
     }
     private Iterable<Entity> getIndirectPassengers_old() {
         // Paper end - Optimize indirect passenger iteration
@@ -0,0 +0,0 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
         return Mth.lerp(delta, this.yRotO, this.yRot);
     }
 
-    public boolean updateFluidHeightAndDoFluidPushing(TagKey<Fluid> tag, double speed) {
+    // Paper start - optimise collisions
+    public boolean updateFluidHeightAndDoFluidPushing(final TagKey<Fluid> fluid, final double flowScale) {
         if (this.touchingUnloadedChunk()) {
             return false;
-        } else {
-            AABB axisalignedbb = this.getBoundingBox().deflate(0.001D);
-            int i = Mth.floor(axisalignedbb.minX);
-            int j = Mth.ceil(axisalignedbb.maxX);
-            int k = Mth.floor(axisalignedbb.minY);
-            int l = Mth.ceil(axisalignedbb.maxY);
-            int i1 = Mth.floor(axisalignedbb.minZ);
-            int j1 = Mth.ceil(axisalignedbb.maxZ);
-            double d1 = 0.0D;
-            boolean flag = this.isPushedByFluid();
-            boolean flag1 = false;
-            Vec3 vec3d = Vec3.ZERO;
-            int k1 = 0;
-            BlockPos.MutableBlockPos blockposition_mutableblockposition = new BlockPos.MutableBlockPos();
-
-            for (int l1 = i; l1 < j; ++l1) {
-                for (int i2 = k; i2 < l; ++i2) {
-                    for (int j2 = i1; j2 < j1; ++j2) {
-                        blockposition_mutableblockposition.set(l1, i2, j2);
-                        FluidState fluid = this.level().getFluidState(blockposition_mutableblockposition);
-
-                        if (fluid.is(tag)) {
-                            double d2 = (double) ((float) i2 + fluid.getHeight(this.level(), blockposition_mutableblockposition));
-
-                            if (d2 >= axisalignedbb.minY) {
-                                flag1 = true;
-                                d1 = Math.max(d2 - axisalignedbb.minY, d1);
-                                if (flag) {
-                                    Vec3 vec3d1 = fluid.getFlow(this.level(), blockposition_mutableblockposition);
-
-                                    if (d1 < 0.4D) {
-                                        vec3d1 = vec3d1.scale(d1);
-                                    }
+        }
+
+        final AABB boundingBox = this.getBoundingBox().deflate(1.0E-3);
+
+        final Level world = this.level;
+        final int minSection = ca.spottedleaf.moonrise.common.util.WorldUtil.getMinSection(world);
+
+        final int minBlockX = Mth.floor(boundingBox.minX);
+        final int minBlockY = Math.max((minSection << 4), Mth.floor(boundingBox.minY));
+        final int minBlockZ = Mth.floor(boundingBox.minZ);
+
+        // note: bounds are exclusive in Vanilla, so we subtract 1 - our loop expects bounds to be inclusive
+        final int maxBlockX = Mth.ceil(boundingBox.maxX) - 1;
+        final int maxBlockY = Math.min((ca.spottedleaf.moonrise.common.util.WorldUtil.getMaxSection(world) << 4) | 15, Mth.ceil(boundingBox.maxY) - 1);
+        final int maxBlockZ = Mth.ceil(boundingBox.maxZ) - 1;
+
+        final boolean isPushable = this.isPushedByFluid();
+        final BlockPos.MutableBlockPos mutablePos = new BlockPos.MutableBlockPos();
+
+        Vec3 pushVector = Vec3.ZERO;
+        double totalPushes = 0.0;
+        double maxHeightDiff = 0.0;
+        boolean inFluid = false;
+
+        final int minChunkX = minBlockX >> 4;
+        final int maxChunkX = maxBlockX >> 4;
+
+        final int minChunkY = minBlockY >> 4;
+        final int maxChunkY = maxBlockY >> 4;
+
+        final int minChunkZ = minBlockZ >> 4;
+        final int maxChunkZ = maxBlockZ >> 4;
+
+        final net.minecraft.world.level.chunk.ChunkSource chunkSource = world.getChunkSource();
+
+        for (int currChunkZ = minChunkZ; currChunkZ <= maxChunkZ; ++currChunkZ) {
+            for (int currChunkX = minChunkX; currChunkX <= maxChunkX; ++currChunkX) {
+                final net.minecraft.world.level.chunk.LevelChunkSection[] sections = chunkSource.getChunk(currChunkX, currChunkZ, net.minecraft.world.level.chunk.status.ChunkStatus.FULL, false).getSections();
+
+                // bound y
+                for (int currChunkY = minChunkY; currChunkY <= maxChunkY; ++currChunkY) {
+                    final int sectionIdx = currChunkY - minSection;
+                    if (sectionIdx < 0 || sectionIdx >= sections.length) {
+                        continue;
+                    }
+                    final net.minecraft.world.level.chunk.LevelChunkSection section = sections[sectionIdx];
+                    if (section.hasOnlyAir()) {
+                        // empty
+                        continue;
+                    }
+
+                    final net.minecraft.world.level.chunk.PalettedContainer<net.minecraft.world.level.block.state.BlockState> blocks = section.states;
+
+                    final int minXIterate = currChunkX == minChunkX ? (minBlockX & 15) : 0;
+                    final int maxXIterate = currChunkX == maxChunkX ? (maxBlockX & 15) : 15;
+                    final int minZIterate = currChunkZ == minChunkZ ? (minBlockZ & 15) : 0;
+                    final int maxZIterate = currChunkZ == maxChunkZ ? (maxBlockZ & 15) : 15;
+                    final int minYIterate = currChunkY == minChunkY ? (minBlockY & 15) : 0;
+                    final int maxYIterate = currChunkY == maxChunkY ? (maxBlockY & 15) : 15;
 
-                                    vec3d = vec3d.add(vec3d1);
-                                    ++k1;
+                    for (int currY = minYIterate; currY <= maxYIterate; ++currY) {
+                        for (int currZ = minZIterate; currZ <= maxZIterate; ++currZ) {
+                            for (int currX = minXIterate; currX <= maxXIterate; ++currX) {
+                                final FluidState fluidState = blocks.get((currX) | (currZ << 4) | ((currY) << 8)).getFluidState();
+
+                                if (fluidState.isEmpty() || !fluidState.is(fluid)) {
+                                    continue;
                                 }
-                                // CraftBukkit start - store last lava contact location
-                                if (tag == FluidTags.LAVA) {
-                                    this.lastLavaContact = blockposition_mutableblockposition.immutable();
+
+                                mutablePos.set(currX | (currChunkX << 4), currY | (currChunkY << 4), currZ | (currChunkZ << 4));
+
+                                final double height = (double)((float)mutablePos.getY() + fluidState.getHeight(world, mutablePos));
+                                final double diff = height - boundingBox.minY;
+
+                                if (diff < 0.0) {
+                                    continue;
+                                }
+
+                                inFluid = true;
+                                maxHeightDiff = Math.max(maxHeightDiff, diff);
+
+                                if (!isPushable) {
+                                    continue;
+                                }
+
+                                ++totalPushes;
+
+                                final Vec3 flow = fluidState.getFlow(world, mutablePos);
+
+                                if (diff < 0.4) {
+                                    pushVector = pushVector.add(flow.scale(diff));
+                                } else {
+                                    pushVector = pushVector.add(flow);
                                 }
-                                // CraftBukkit end
                             }
                         }
                     }
                 }
             }
+        }
 
-            if (vec3d.length() > 0.0D) {
-                if (k1 > 0) {
-                    vec3d = vec3d.scale(1.0D / (double) k1);
-                }
+        this.fluidHeight.put(fluid, maxHeightDiff);
 
-                if (!(this instanceof Player)) {
-                    vec3d = vec3d.normalize();
-                }
+        if (pushVector.lengthSqr() == 0.0) {
+            return inFluid;
+        }
 
-                Vec3 vec3d2 = this.getDeltaMovement();
+        // note: totalPushes != 0 as pushVector != 0
+        pushVector = pushVector.scale(1.0 / totalPushes);
+        final Vec3 currMovement = this.getDeltaMovement();
 
-                vec3d = vec3d.scale(speed);
-                double d3 = 0.003D;
+        if (!((Entity)(Object)this instanceof Player)) {
+            pushVector = pushVector.normalize();
+        }
 
-                if (Math.abs(vec3d2.x) < 0.003D && Math.abs(vec3d2.z) < 0.003D && vec3d.length() < 0.0045000000000000005D) {
-                    vec3d = vec3d.normalize().scale(0.0045000000000000005D);
-                }
+        pushVector = pushVector.scale(flowScale);
+        if (Math.abs(currMovement.x) < 0.003 && Math.abs(currMovement.z) < 0.003 && pushVector.length() < 0.0045000000000000005) {
+            pushVector = pushVector.normalize().scale(0.0045000000000000005);
+        }
 
-                this.setDeltaMovement(this.getDeltaMovement().add(vec3d));
-            }
+        this.setDeltaMovement(currMovement.add(pushVector));
 
-            this.fluidHeight.put(tag, d1);
-            return flag1;
-        }
+        // note: inFluid = true here as pushVector != 0
+        return true;
     }
+    // Paper end - optimise collisions
 
     public boolean touchingUnloadedChunk() {
         AABB axisalignedbb = this.getBoundingBox().inflate(1.0D);
@@ -0,0 +0,0 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
         this.setPosRaw(x, y, z, false);
     }
     public final void setPosRaw(double x, double y, double z, boolean forceBoundingBoxUpdate) {
+        // Paper start - rewrite chunk system
+        if (this.updatingSectionStatus) {
+            LOGGER.error(
+                "Refusing to update position for entity " + this + " to position " + new Vec3(x, y, z)
+                    + " since it is processing a section status update", new Throwable()
+            );
+            return;
+        }
+        // Paper end - rewrite chunk system
         if (!checkPosition(this, x, y, z)) {
             return;
         }
@@ -0,0 +0,0 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
 
     @Override
     public final void setRemoved(Entity.RemovalReason entity_removalreason, EntityRemoveEvent.Cause cause) {
+        // Paper start - rewrite chunk system
+        if (!((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel)this.level).moonrise$getEntityLookup().canRemoveEntity((Entity)(Object)this)) {
+            LOGGER.warn("Entity " + this + " is currently prevented from being removed from the world since it is processing section status updates", new Throwable());
+            return;
+        }
+        // Paper end - rewrite chunk system
         CraftEventFactory.callEntityRemoveEvent(this, cause);
         // CraftBukkit end
         final boolean alreadyRemoved = this.removalReason != null; // Paper - Folia schedulers
@@ -0,0 +0,0 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
             this.stopRiding();
         }
 
-        this.getPassengers().forEach(Entity::stopRiding);
+        if (this.removalReason != Entity.RemovalReason.UNLOADED_TO_CHUNK) { this.getPassengers().forEach(Entity::stopRiding); } // Paper - rewrite chunk system
         this.levelCallback.onRemove(entity_removalreason);
         this.onRemoval(entity_removalreason);
         // Paper start - Folia schedulers
@@ -0,0 +0,0 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
 
     @Override
     public boolean shouldBeSaved() {
-        return this.removalReason != null && !this.removalReason.shouldSave() ? false : (this.isPassenger() ? false : !this.isVehicle() || !this.hasExactlyOnePlayerPassenger());
+        return this.removalReason != null && !this.removalReason.shouldSave() ? false : (this.isPassenger() ? false : !this.isVehicle() || !((ca.spottedleaf.moonrise.patches.chunk_system.entity.ChunkSystemEntity)this).moonrise$hasAnyPlayerPassengers()); // Paper - rewrite chunk system
     }
 
     @Override
diff --git a/src/main/java/net/minecraft/world/entity/ai/village/poi/PoiManager.java b/src/main/java/net/minecraft/world/entity/ai/village/poi/PoiManager.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/entity/ai/village/poi/PoiManager.java
+++ b/src/main/java/net/minecraft/world/entity/ai/village/poi/PoiManager.java
@@ -0,0 +0,0 @@ import net.minecraft.world.level.chunk.storage.RegionStorageInfo;
 import net.minecraft.world.level.chunk.storage.SectionStorage;
 import net.minecraft.world.level.chunk.storage.SimpleRegionStorage;
 
-public class PoiManager extends SectionStorage<PoiSection, PoiSection.Packed> {
+public class PoiManager extends SectionStorage<PoiSection, PoiSection.Packed> implements ca.spottedleaf.moonrise.patches.chunk_system.level.poi.ChunkSystemPoiManager { // Paper - rewrite chunk system
     public static final int MAX_VILLAGE_DISTANCE = 6;
     public static final int VILLAGE_SECTION_SIZE = 1;
     private final PoiManager.DistanceTracker distanceTracker;
     private final LongSet loadedChunks = new LongOpenHashSet();
 
+    // Paper start - rewrite chunk system
+    private final net.minecraft.server.level.ServerLevel world;
+
+    // the vanilla tracker needs to be replaced because it does not support level removes, and we need level removes
+    // to support poi unloading
+    private final ca.spottedleaf.moonrise.common.misc.Delayed26WayDistancePropagator3D villageDistanceTracker = new ca.spottedleaf.moonrise.common.misc.Delayed26WayDistancePropagator3D();
+
+    private static final int POI_DATA_SOURCE = 7;
+
+    private static int convertBetweenLevels(final int level) {
+        return POI_DATA_SOURCE - level;
+    }
+
+    private void updateDistanceTracking(long section) {
+        if (this.isVillageCenter(section)) {
+            this.villageDistanceTracker.setSource(section, POI_DATA_SOURCE);
+        } else {
+            this.villageDistanceTracker.removeSource(section);
+        }
+    }
+
+    @Override
+    public Optional<PoiSection> get(final long pos) {
+        final int chunkX = ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkSectionX(pos);
+        final int chunkY = ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkSectionY(pos);
+        final int chunkZ = ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkSectionZ(pos);
+
+        ca.spottedleaf.moonrise.common.util.TickThread.ensureTickThread(this.world, chunkX, chunkZ, "Accessing poi chunk off-main");
+
+        final ca.spottedleaf.moonrise.patches.chunk_system.level.poi.PoiChunk ret = ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.world).moonrise$getChunkTaskScheduler().chunkHolderManager.getPoiChunkIfLoaded(chunkX, chunkZ, true);
+
+        return ret == null ? Optional.empty() : ret.getSectionForVanilla(chunkY);
+    }
+
+    @Override
+    public Optional<PoiSection> getOrLoad(final long pos) {
+        final int chunkX = ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkSectionX(pos);
+        final int chunkY = ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkSectionY(pos);
+        final int chunkZ = ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkSectionZ(pos);
+
+        ca.spottedleaf.moonrise.common.util.TickThread.ensureTickThread(this.world, chunkX, chunkZ, "Accessing poi chunk off-main");
+
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkHolderManager manager = ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.world).moonrise$getChunkTaskScheduler().chunkHolderManager;
+
+        if (chunkY >= ca.spottedleaf.moonrise.common.util.WorldUtil.getMinSection(this.world) && chunkY <= ca.spottedleaf.moonrise.common.util.WorldUtil.getMaxSection(this.world)) {
+            final ca.spottedleaf.moonrise.patches.chunk_system.level.poi.PoiChunk ret = manager.getPoiChunkIfLoaded(chunkX, chunkZ, true);
+            if (ret != null) {
+                return ret.getSectionForVanilla(chunkY);
+            } else {
+                return manager.loadPoiChunk(chunkX, chunkZ).getSectionForVanilla(chunkY);
+            }
+        }
+        // retain vanilla behavior: do not load section if out of bounds!
+        return Optional.empty();
+    }
+
+    @Override
+    protected PoiSection getOrCreate(final long pos) {
+        final int chunkX = ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkSectionX(pos);
+        final int chunkY = ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkSectionY(pos);
+        final int chunkZ = ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkSectionZ(pos);
+
+        ca.spottedleaf.moonrise.common.util.TickThread.ensureTickThread(this.world, chunkX, chunkZ, "Accessing poi chunk off-main");
+
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkHolderManager manager = ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.world).moonrise$getChunkTaskScheduler().chunkHolderManager;
+
+        final ca.spottedleaf.moonrise.patches.chunk_system.level.poi.PoiChunk ret = manager.getPoiChunkIfLoaded(chunkX, chunkZ, true);
+        if (ret != null) {
+            return ret.getOrCreateSection(chunkY);
+        } else {
+            return manager.loadPoiChunk(chunkX, chunkZ).getOrCreateSection(chunkY);
+        }
+    }
+
+    @Override
+    public final net.minecraft.server.level.ServerLevel moonrise$getWorld() {
+        return this.world;
+    }
+
+    @Override
+    public final void moonrise$onUnload(final long coordinate) { // Paper - rewrite chunk system
+        final int chunkX = ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkX(coordinate);
+        final int chunkZ = ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkZ(coordinate);
+
+        final int minY = ca.spottedleaf.moonrise.common.util.WorldUtil.getMinSection(this.world);
+        final int maxY = ca.spottedleaf.moonrise.common.util.WorldUtil.getMaxSection(this.world);
+
+        ca.spottedleaf.moonrise.common.util.TickThread.ensureTickThread(this.world, chunkX, chunkZ, "Unloading poi chunk off-main");
+        for (int sectionY = minY; sectionY <= maxY; ++sectionY) {
+            final long sectionPos = SectionPos.asLong(chunkX, sectionY, chunkZ);
+            this.updateDistanceTracking(sectionPos);
+        }
+    }
+
+    @Override
+    public final void moonrise$loadInPoiChunk(final ca.spottedleaf.moonrise.patches.chunk_system.level.poi.PoiChunk poiChunk) {
+        final int chunkX = poiChunk.chunkX;
+        final int chunkZ = poiChunk.chunkZ;
+
+        final int minY = ca.spottedleaf.moonrise.common.util.WorldUtil.getMinSection(this.world);
+        final int maxY = ca.spottedleaf.moonrise.common.util.WorldUtil.getMaxSection(this.world);
+
+        ca.spottedleaf.moonrise.common.util.TickThread.ensureTickThread(this.world, chunkX, chunkZ, "Loading poi chunk off-main");
+        for (int sectionY = minY; sectionY <= maxY; ++sectionY) {
+            final PoiSection section = poiChunk.getSection(sectionY);
+            if (section != null && !((ca.spottedleaf.moonrise.patches.chunk_system.level.poi.ChunkSystemPoiSection)section).moonrise$isEmpty()) {
+                this.onSectionLoad(SectionPos.asLong(chunkX, sectionY, chunkZ));
+            }
+        }
+    }
+
+    @Override
+    public final void moonrise$checkConsistency(final net.minecraft.world.level.chunk.ChunkAccess chunk) {
+        final int chunkX = chunk.getPos().x;
+        final int chunkZ = chunk.getPos().z;
+
+        final int minY = ca.spottedleaf.moonrise.common.util.WorldUtil.getMinSection(chunk);
+        final int maxY = ca.spottedleaf.moonrise.common.util.WorldUtil.getMaxSection(chunk);
+        final LevelChunkSection[] sections = chunk.getSections();
+        for (int section = minY; section <= maxY; ++section) {
+            this.checkConsistencyWithBlocks(SectionPos.of(chunkX, section, chunkZ), sections[section - minY]);
+        }
+    }
+    // Paper end - rewrite chunk system
+
     public PoiManager(
         RegionStorageInfo storageKey,
         Path directory,
@@ -0,0 +0,0 @@ public class PoiManager extends SectionStorage<PoiSection, PoiSection.Packed> {
             world
         );
         this.distanceTracker = new PoiManager.DistanceTracker();
+        this.world = (net.minecraft.server.level.ServerLevel)world; // Paper - rewrite chunk system
     }
 
     public void add(BlockPos pos, Holder<PoiType> type) {
@@ -0,0 +0,0 @@ public class PoiManager extends SectionStorage<PoiSection, PoiSection.Packed> {
     }
 
     public int sectionsToVillage(SectionPos pos) {
-        this.distanceTracker.runAllUpdates();
-        return this.distanceTracker.getLevel(pos.asLong());
+        // Paper start - rewrite chunk system
+        this.villageDistanceTracker.propagateUpdates();
+        return convertBetweenLevels(this.villageDistanceTracker.getLevel(ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkSectionKey(pos)));
+        // Paper end - rewrite chunk system
     }
 
     boolean isVillageCenter(long pos) {
@@ -0,0 +0,0 @@ public class PoiManager extends SectionStorage<PoiSection, PoiSection.Packed> {
 
     @Override
     public void tick(BooleanSupplier shouldKeepTicking) {
-        super.tick(shouldKeepTicking);
-        this.distanceTracker.runAllUpdates();
+        this.villageDistanceTracker.propagateUpdates(); // Paper - rewrite chunk system
     }
 
     @Override
-    protected void setDirty(long pos) {
-        super.setDirty(pos);
-        this.distanceTracker.update(pos, this.distanceTracker.getLevelFromSource(pos), false);
+    public void setDirty(long pos) { // Paper - public
+        // Paper start - rewrite chunk system
+        final int chunkX = ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkSectionX(pos);
+        final int chunkZ = ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkSectionZ(pos);
+        final ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkHolderManager manager = ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.world).moonrise$getChunkTaskScheduler().chunkHolderManager;
+        final ca.spottedleaf.moonrise.patches.chunk_system.level.poi.PoiChunk chunk = manager.getPoiChunkIfLoaded(chunkX, chunkZ, false);
+        if (chunk != null) {
+            chunk.setDirty(true);
+        }
+        this.updateDistanceTracking(pos);
+        // Paper end - rewrite chunk system
     }
 
     @Override
     protected void onSectionLoad(long pos) {
-        this.distanceTracker.update(pos, this.distanceTracker.getLevelFromSource(pos), false);
+        this.updateDistanceTracking(pos); // Paper - rewrite chunk system
     }
 
     public void checkConsistencyWithBlocks(SectionPos sectionPos, LevelChunkSection chunkSection) {
@@ -0,0 +0,0 @@ public class PoiManager extends SectionStorage<PoiSection, PoiSection.Packed> {
             .map(sectionPos -> Pair.of(sectionPos, this.getOrLoad(sectionPos.asLong())))
             .filter(pair -> !pair.getSecond().map(PoiSection::isValid).orElse(false))
             .map(pair -> pair.getFirst().chunk())
-            .filter(chunkPos -> this.loadedChunks.add(chunkPos.toLong()))
+            // Paper - rewrite chunk system
             .forEach(chunkPos -> world.getChunk(chunkPos.x, chunkPos.z, ChunkStatus.EMPTY));
     }
 
diff --git a/src/main/java/net/minecraft/world/entity/ai/village/poi/PoiSection.java b/src/main/java/net/minecraft/world/entity/ai/village/poi/PoiSection.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/entity/ai/village/poi/PoiSection.java
+++ b/src/main/java/net/minecraft/world/entity/ai/village/poi/PoiSection.java
@@ -0,0 +0,0 @@ import net.minecraft.core.SectionPos;
 import net.minecraft.util.VisibleForDebug;
 import org.slf4j.Logger;
 
-public class PoiSection {
+public class PoiSection implements ca.spottedleaf.moonrise.patches.chunk_system.level.poi.ChunkSystemPoiSection { // Paper - rewrite chunk system
     private static final Logger LOGGER = LogUtils.getLogger();
     private final Short2ObjectMap<PoiRecord> records = new Short2ObjectOpenHashMap<>();
     private final Map<Holder<PoiType>, Set<PoiRecord>> byType = Maps.newHashMap();
     private final Runnable setDirty;
     private boolean isValid;
 
+    // Paper start - rewrite chunk system
+    private final Optional<PoiSection> noAllocOptional = Optional.of((PoiSection)(Object)this);
+
+    @Override
+    public final boolean moonrise$isEmpty() {
+        return this.isValid && this.records.isEmpty() && this.byType.isEmpty();
+    }
+
+    @Override
+    public final Optional<PoiSection> moonrise$asOptional() {
+        return this.noAllocOptional;
+    }
+    // Paper end - rewrite chunk system
+
     public PoiSection(Runnable updateListener) {
         this(updateListener, true, ImmutableList.of());
     }
diff --git a/src/main/java/net/minecraft/world/entity/decoration/ArmorStand.java b/src/main/java/net/minecraft/world/entity/decoration/ArmorStand.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/entity/decoration/ArmorStand.java
+++ b/src/main/java/net/minecraft/world/entity/decoration/ArmorStand.java
@@ -0,0 +0,0 @@ public class ArmorStand extends LivingEntity {
     @Override
     protected void pushEntities() {
         if (!this.level().paperConfig().entities.armorStands.doCollisionEntityLookups) return; // Paper - Option to prevent armor stands from doing entity lookups
-        List<Entity> list = this.level().getEntities((Entity) this, this.getBoundingBox(), ArmorStand.RIDABLE_MINECARTS);
+        List<AbstractMinecart> list = this.level().getEntitiesOfClass(AbstractMinecart.class, this.getBoundingBox(), RIDABLE_MINECARTS); // Paper - optimise collisions
         Iterator iterator = list.iterator();
 
         while (iterator.hasNext()) {
diff --git a/src/main/java/net/minecraft/world/level/ClipContext.java b/src/main/java/net/minecraft/world/level/ClipContext.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/ClipContext.java
+++ b/src/main/java/net/minecraft/world/level/ClipContext.java
@@ -0,0 +0,0 @@ public class ClipContext {
     private final Vec3 from;
     private final Vec3 to;
     private final ClipContext.Block block;
-    private final ClipContext.Fluid fluid;
+    public final ClipContext.Fluid fluid; // Paper - optimise collisions - public
     private final CollisionContext collisionContext;
 
     public ClipContext(Vec3 start, Vec3 end, ClipContext.Block shapeType, ClipContext.Fluid fluidHandling, Entity entity) {
diff --git a/src/main/java/net/minecraft/world/level/EntityGetter.java b/src/main/java/net/minecraft/world/level/EntityGetter.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/EntityGetter.java
+++ b/src/main/java/net/minecraft/world/level/EntityGetter.java
@@ -0,0 +0,0 @@ import net.minecraft.world.phys.shapes.BooleanOp;
 import net.minecraft.world.phys.shapes.Shapes;
 import net.minecraft.world.phys.shapes.VoxelShape;
 
-public interface EntityGetter {
+public interface EntityGetter extends ca.spottedleaf.moonrise.patches.chunk_system.world.ChunkSystemEntityGetter { // Paper - rewrite chunk system
     List<Entity> getEntities(@Nullable Entity except, AABB box, Predicate<? super Entity> predicate);
 
     <T extends Entity> List<T> getEntities(EntityTypeTest<Entity, T> filter, AABB box, Predicate<? super T> predicate);
@@ -0,0 +0,0 @@ public interface EntityGetter {
         return this.getEntities(except, box, EntitySelector.NO_SPECTATORS);
     }
 
-    default boolean isUnobstructed(@Nullable Entity except, VoxelShape shape) {
-        if (shape.isEmpty()) {
-            return true;
-        } else {
-            for (Entity entity : this.getEntities(except, shape.bounds())) {
-                if (!entity.isRemoved()
-                    && entity.blocksBuilding
-                    && (except == null || !entity.isPassengerOfSameVehicle(except))
-                    && Shapes.joinIsNotEmpty(shape, Shapes.create(entity.getBoundingBox()), BooleanOp.AND)) {
-                    return false;
+    // Paper start - rewrite chunk system
+    @Override
+    default List<Entity> moonrise$getHardCollidingEntities(final Entity entity, final AABB box, final Predicate<? super Entity> predicate) {
+        return this.getEntities(entity, box, predicate);
+    }
+    // Paper end - rewrite chunk system
+
+    // Paper start - optimise collisions
+    default boolean isUnobstructed(@Nullable Entity entity, VoxelShape voxel) {
+        if (voxel.isEmpty()) {
+            return false;
+        }
+
+        final AABB singleAABB = ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)voxel).moonrise$getSingleAABBRepresentation();
+        final List<Entity> entities = this.getEntities(
+            entity,
+            singleAABB == null ? voxel.bounds() : singleAABB.inflate(-ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON, -ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON, -ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON)
+        );
+
+        for (int i = 0, len = entities.size(); i < len; ++i) {
+            final Entity otherEntity = entities.get(i);
+
+            if (otherEntity.isRemoved() || !otherEntity.blocksBuilding || (entity != null && otherEntity.isPassengerOfSameVehicle(entity))) {
+                continue;
+            }
+
+            if (singleAABB == null) {
+                final AABB entityBB = otherEntity.getBoundingBox();
+                if (ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.isEmpty(entityBB) || !ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.voxelShapeIntersectNoEmpty(voxel, entityBB)) {
+                    continue;
                 }
             }
 
-            return true;
+            return false;
         }
+
+        return true;
+        // Paper end - optimise collisions
     }
 
     default <T extends Entity> List<T> getEntitiesOfClass(Class<T> entityClass, AABB box) {
@@ -0,0 +0,0 @@ public interface EntityGetter {
     }
 
     default List<VoxelShape> getEntityCollisions(@Nullable Entity entity, AABB box) {
-        if (box.getSize() < 1.0E-7) {
-            return List.of();
+        // Paper start - optimise collisions
+        // first behavior change is to correctly check for empty AABB
+        if (ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.isEmpty(box)) {
+            // reduce indirection by always returning type with same class
+            return new java.util.ArrayList<>();
+        }
+
+        // to comply with vanilla intersection rules, expand by -epsilon so that we only get stuff we definitely collide with.
+        // Vanilla for hard collisions has this backwards, and they expand by +epsilon but this causes terrible problems
+        // specifically with boat collisions.
+        box = box.inflate(-ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON, -ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON, -ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON);
+
+        final List<Entity> entities;
+        if (entity != null && ((ca.spottedleaf.moonrise.patches.chunk_system.entity.ChunkSystemEntity)entity).moonrise$isHardColliding()) {
+            entities = this.getEntities(entity, box, null);
         } else {
-            Predicate<Entity> predicate = entity == null ? EntitySelector.CAN_BE_COLLIDED_WITH : EntitySelector.NO_SPECTATORS.and(entity::canCollideWith);
-            List<Entity> list = this.getEntities(entity, box.inflate(1.0E-7), predicate);
-            if (list.isEmpty()) {
-                return List.of();
-            } else {
-                Builder<VoxelShape> builder = ImmutableList.builderWithExpectedSize(list.size());
-
-                for (Entity entity2 : list) {
-                    builder.add(Shapes.create(entity2.getBoundingBox()));
-                }
+            entities = ((ca.spottedleaf.moonrise.patches.chunk_system.world.ChunkSystemEntityGetter)this).moonrise$getHardCollidingEntities(entity, box, null);
+        }
 
-                return builder.build();
+        final List<VoxelShape> ret = new java.util.ArrayList<>(Math.min(25, entities.size()));
+
+        for (int i = 0, len = entities.size(); i < len; ++i) {
+            final Entity otherEntity = entities.get(i);
+
+            if (otherEntity.isSpectator()) {
+                continue;
+            }
+
+            if ((entity == null && otherEntity.canBeCollidedWith()) || (entity != null && entity.canCollideWith(otherEntity))) {
+                ret.add(Shapes.create(otherEntity.getBoundingBox()));
             }
         }
+
+        return ret;
+        // Paper end - optimise collisions
     }
 
     // Paper start - Affects Spawning API
diff --git a/src/main/java/net/minecraft/world/level/Level.java b/src/main/java/net/minecraft/world/level/Level.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/Level.java
+++ b/src/main/java/net/minecraft/world/level/Level.java
@@ -0,0 +0,0 @@ import net.minecraft.world.level.storage.LevelData;
 import net.minecraft.world.level.storage.WritableLevelData;
 import net.minecraft.world.phys.AABB;
 import net.minecraft.world.phys.Vec3;
+import net.minecraft.world.phys.shapes.VoxelShape;
 import net.minecraft.world.scores.Scoreboard;
 
 // CraftBukkit start
@@ -0,0 +0,0 @@ import org.bukkit.entity.SpawnCategory;
 import org.bukkit.event.block.BlockPhysicsEvent;
 // CraftBukkit end
 
-public abstract class Level implements LevelAccessor, AutoCloseable {
+public abstract class Level implements LevelAccessor, AutoCloseable, ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel, ca.spottedleaf.moonrise.patches.chunk_system.world.ChunkSystemEntityGetter { // Paper - rewrite chunk system // Paper - optimise collisions
 
     public static final Codec<ResourceKey<Level>> RESOURCE_KEY_CODEC = ResourceKey.codec(Registries.DIMENSION);
     public static final ResourceKey<Level> OVERWORLD = ResourceKey.create(Registries.DIMENSION, ResourceLocation.withDefaultNamespace("overworld"));
@@ -0,0 +0,0 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
     public float rainLevel;
     protected float oThunderLevel;
     public float thunderLevel;
-    public final RandomSource random = RandomSource.create();
+    public final RandomSource random = new ca.spottedleaf.moonrise.common.util.ThreadUnsafeRandom(net.minecraft.world.level.levelgen.RandomSupport.generateUniqueSeed()); // Paper - replace random
     /** @deprecated */
     @Deprecated
     private final RandomSource threadSafeRandom = RandomSource.createThreadSafe();
@@ -0,0 +0,0 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
 
     public abstract ResourceKey<LevelStem> getTypeKey();
 
+    // Paper start - rewrite chunk system
+    private ca.spottedleaf.moonrise.patches.chunk_system.level.entity.EntityLookup entityLookup;
+    private final ca.spottedleaf.concurrentutil.map.ConcurrentLong2ReferenceChainedHashTable<ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkData> chunkData = new ca.spottedleaf.concurrentutil.map.ConcurrentLong2ReferenceChainedHashTable<>();
+
+    @Override
+    public final ca.spottedleaf.moonrise.patches.chunk_system.level.entity.EntityLookup moonrise$getEntityLookup() {
+        return this.entityLookup;
+    }
+
+    @Override
+    public final void moonrise$setEntityLookup(final ca.spottedleaf.moonrise.patches.chunk_system.level.entity.EntityLookup entityLookup) {
+        if (this.entityLookup != null && !(this.entityLookup instanceof ca.spottedleaf.moonrise.patches.chunk_system.level.entity.dfl.DefaultEntityLookup)) {
+            throw new IllegalStateException("Entity lookup already initialised");
+        }
+        this.entityLookup = entityLookup;
+    }
+
+    @Override
+    public final <T extends Entity> List<T> getEntitiesOfClass(final Class<T> entityClass, final AABB boundingBox, final Predicate<? super T> predicate) {
+        Profiler.get().incrementCounter("getEntities");
+        final List<T> ret = new java.util.ArrayList<>();
+
+        ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel)this).moonrise$getEntityLookup().getEntities(entityClass, null, boundingBox, ret, predicate);
+
+        return ret;
+    }
+
+    @Override
+    public final List<Entity> moonrise$getHardCollidingEntities(final Entity entity, final AABB box, final Predicate<? super Entity> predicate) {
+        Profiler.get().incrementCounter("getEntities");
+        final List<Entity> ret = new java.util.ArrayList<>();
+
+        ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel)this).moonrise$getEntityLookup().getHardCollidingEntities(entity, box, ret, predicate);
+
+        return ret;
+    }
+
+    @Override
+    public LevelChunk moonrise$getFullChunkIfLoaded(final int chunkX, final int chunkZ) {
+        return (LevelChunk)this.getChunkSource().getChunk(chunkX, chunkZ, ChunkStatus.FULL, false);
+    }
+
+    @Override
+    public ChunkAccess moonrise$getAnyChunkIfLoaded(final int chunkX, final int chunkZ) {
+        return this.getChunkSource().getChunk(chunkX, chunkZ, ChunkStatus.EMPTY, false);
+    }
+
+    @Override
+    public ChunkAccess moonrise$getSpecificChunkIfLoaded(final int chunkX, final int chunkZ, final ChunkStatus leastStatus) {
+        return this.getChunkSource().getChunk(chunkX, chunkZ, leastStatus, false);
+    }
+
+    @Override
+    public void moonrise$midTickTasks() {
+        // no-op on ClientLevel
+    }
+
+    @Override
+    public final ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkData moonrise$getChunkData(final long chunkKey) {
+        return this.chunkData.get(chunkKey);
+    }
+
+    @Override
+    public final ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkData moonrise$getChunkData(final int chunkX, final int chunkZ) {
+        return this.chunkData.get(ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkKey(chunkX, chunkZ));
+    }
+
+    @Override
+    public final ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkData moonrise$requestChunkData(final long chunkKey) {
+        return this.chunkData.compute(chunkKey, (final long keyInMap, final ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkData valueInMap) -> {
+            if (valueInMap == null) {
+                final ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkData ret = new ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkData();
+                ret.increaseRef();
+                return ret;
+            }
+
+            valueInMap.increaseRef();
+            return valueInMap;
+        });
+    }
+
+    @Override
+    public final ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkData moonrise$releaseChunkData(final long chunkKey) {
+        return this.chunkData.compute(chunkKey, (final long keyInMap, final ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkData chunkData) -> {
+            return chunkData.decreaseRef() == 0 ? null : chunkData;
+        });
+    }
+
+    @Override
+    public boolean moonrise$areChunksLoaded(final int fromX, final int fromZ, final int toX, final int toZ) {
+        final ChunkSource chunkSource = this.getChunkSource();
+
+        for (int currZ = fromZ; currZ <= toZ; ++currZ) {
+            for (int currX = fromX; currX <= toX; ++currX) {
+                if (!chunkSource.hasChunk(currX, currZ)) {
+                    return false;
+                }
+            }
+        }
+
+        return true;
+    }
+
+    @Override
+    public boolean hasChunksAt(final int minBlockX, final int minBlockZ, final int maxBlockX, final int maxBlockZ) {
+        return this.moonrise$areChunksLoaded(
+            minBlockX >> 4, minBlockZ >> 4, maxBlockX >> 4, maxBlockZ >> 4
+        );
+    }
+
+    /**
+     * @reason Turn all getChunk(x, z, status) calls into virtual invokes, instead of interface invokes:
+     *         1. The interface invoke is expensive
+     *         2. The method makes other interface invokes (again, expensive)
+     *         Instead, we just directly call getChunk(x, z, status, true) which avoids the interface invokes entirely.
+     * @author Spottedleaf
+     */
+    @Override
+    public ChunkAccess getChunk(final int x, final int z, final ChunkStatus status) {
+        return ((Level)(Object)this).getChunk(x, z, status, true);
+    }
+
+    @Override
+    public BlockPos getHeightmapPos(Heightmap.Types types, BlockPos blockPos) {
+        return new BlockPos(blockPos.getX(), this.getHeight(types, blockPos.getX(), blockPos.getZ()), blockPos.getZ());
+    }
+    // Paper end - rewrite chunk system
+    // Paper start - optimise collisions
+    /**
+     * Route to faster lookup.
+     * See {@link EntityGetter#isUnobstructed(Entity, VoxelShape)} for expected behavior
+     * @author Spottedleaf
+     */
+    @Override
+    public boolean isUnobstructed(final Entity entity) {
+        final AABB boundingBox = entity.getBoundingBox();
+        if (ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.isEmpty(boundingBox)) {
+            return false;
+        }
+
+        final List<Entity> entities = this.getEntities(
+            entity,
+            boundingBox.inflate(-ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON, -ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON, -ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON),
+            null
+        );
+
+        for (int i = 0, len = entities.size(); i < len; ++i) {
+            final Entity otherEntity = entities.get(i);
+
+            if (otherEntity.isSpectator() || otherEntity.isRemoved() || !otherEntity.blocksBuilding || otherEntity.isPassengerOfSameVehicle(entity)) {
+                continue;
+            }
+
+            return false;
+        }
+
+        return true;
+    }
+
+
+    private static net.minecraft.world.phys.BlockHitResult miss(final ClipContext clipContext) {
+        final Vec3 to = clipContext.getTo();
+        final Vec3 from = clipContext.getFrom();
+
+        return net.minecraft.world.phys.BlockHitResult.miss(to, Direction.getApproximateNearest(from.x - to.x, from.y - to.y, from.z - to.z), BlockPos.containing(to.x, to.y, to.z));
+    }
+
+    private static final FluidState AIR_FLUIDSTATE = Fluids.EMPTY.defaultFluidState();
+
+    private static net.minecraft.world.phys.BlockHitResult fastClip(final Vec3 from, final Vec3 to, final Level level,
+                                                                    final ClipContext clipContext) {
+        final double adjX = ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON * (from.x - to.x);
+        final double adjY = ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON * (from.y - to.y);
+        final double adjZ = ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON * (from.z - to.z);
+
+        if (adjX == 0.0 && adjY == 0.0 && adjZ == 0.0) {
+            return miss(clipContext);
+        }
+
+        final double toXAdj = to.x - adjX;
+        final double toYAdj = to.y - adjY;
+        final double toZAdj = to.z - adjZ;
+        final double fromXAdj = from.x + adjX;
+        final double fromYAdj = from.y + adjY;
+        final double fromZAdj = from.z + adjZ;
+
+        int currX = Mth.floor(fromXAdj);
+        int currY = Mth.floor(fromYAdj);
+        int currZ = Mth.floor(fromZAdj);
+
+        final BlockPos.MutableBlockPos currPos = new BlockPos.MutableBlockPos();
+
+        final double diffX = toXAdj - fromXAdj;
+        final double diffY = toYAdj - fromYAdj;
+        final double diffZ = toZAdj - fromZAdj;
+
+        final double dxDouble = Math.signum(diffX);
+        final double dyDouble = Math.signum(diffY);
+        final double dzDouble = Math.signum(diffZ);
+
+        final int dx = (int)dxDouble;
+        final int dy = (int)dyDouble;
+        final int dz = (int)dzDouble;
+
+        final double normalizedDiffX = diffX == 0.0 ? Double.MAX_VALUE : dxDouble / diffX;
+        final double normalizedDiffY = diffY == 0.0 ? Double.MAX_VALUE : dyDouble / diffY;
+        final double normalizedDiffZ = diffZ == 0.0 ? Double.MAX_VALUE : dzDouble / diffZ;
+
+        double normalizedCurrX = normalizedDiffX * (diffX > 0.0 ? (1.0 - Mth.frac(fromXAdj)) : Mth.frac(fromXAdj));
+        double normalizedCurrY = normalizedDiffY * (diffY > 0.0 ? (1.0 - Mth.frac(fromYAdj)) : Mth.frac(fromYAdj));
+        double normalizedCurrZ = normalizedDiffZ * (diffZ > 0.0 ? (1.0 - Mth.frac(fromZAdj)) : Mth.frac(fromZAdj));
+
+        net.minecraft.world.level.chunk.LevelChunkSection[] lastChunk = null;
+        net.minecraft.world.level.chunk.PalettedContainer<net.minecraft.world.level.block.state.BlockState> lastSection = null;
+        int lastChunkX = Integer.MIN_VALUE;
+        int lastChunkY = Integer.MIN_VALUE;
+        int lastChunkZ = Integer.MIN_VALUE;
+
+        final int minSection = ca.spottedleaf.moonrise.common.util.WorldUtil.getMinSection(level);
+
+        for (;;) {
+            currPos.set(currX, currY, currZ);
+
+            final int newChunkX = currX >> 4;
+            final int newChunkY = currY >> 4;
+            final int newChunkZ = currZ >> 4;
+
+            final int chunkDiff = ((newChunkX ^ lastChunkX) | (newChunkZ ^ lastChunkZ));
+            final int chunkYDiff = newChunkY ^ lastChunkY;
+
+            if ((chunkDiff | chunkYDiff) != 0) {
+                if (chunkDiff != 0) {
+                    lastChunk = level.getChunk(newChunkX, newChunkZ).getSections();
+                }
+                final int sectionY = newChunkY - minSection;
+                lastSection = sectionY >= 0 && sectionY < lastChunk.length ? lastChunk[sectionY].states : null;
+
+                lastChunkX = newChunkX;
+                lastChunkY = newChunkY;
+                lastChunkZ = newChunkZ;
+            }
+
+            final BlockState blockState;
+            if (lastSection != null && !(blockState = lastSection.get((currX & 15) | ((currZ & 15) << 4) | ((currY & 15) << (4+4)))).isAir()) {
+                final VoxelShape blockCollision = clipContext.getBlockShape(blockState, level, currPos);
+
+                final net.minecraft.world.phys.BlockHitResult blockHit = blockCollision.isEmpty() ? null : level.clipWithInteractionOverride(from, to, currPos, blockCollision, blockState);
+
+                final VoxelShape fluidCollision;
+                final FluidState fluidState;
+                if (clipContext.fluid != ClipContext.Fluid.NONE && (fluidState = blockState.getFluidState()) != AIR_FLUIDSTATE) {
+                    fluidCollision = clipContext.getFluidShape(fluidState, level, currPos);
+
+                    final net.minecraft.world.phys.BlockHitResult fluidHit = fluidCollision.clip(from, to, currPos);
+
+                    if (fluidHit != null) {
+                        if (blockHit == null) {
+                            return fluidHit;
+                        }
+
+                        return from.distanceToSqr(blockHit.getLocation()) <= from.distanceToSqr(fluidHit.getLocation()) ? blockHit : fluidHit;
+                    }
+                }
+
+                if (blockHit != null) {
+                    return blockHit;
+                }
+            } // else: usually fall here
+
+            if (normalizedCurrX > 1.0 && normalizedCurrY > 1.0 && normalizedCurrZ > 1.0) {
+                return miss(clipContext);
+            }
+
+            // inc the smallest normalized coordinate
+
+            if (normalizedCurrX < normalizedCurrY) {
+                if (normalizedCurrX < normalizedCurrZ) {
+                    currX += dx;
+                    normalizedCurrX += normalizedDiffX;
+                } else {
+                    // x < y && x >= z <--> z < y && z <= x
+                    currZ += dz;
+                    normalizedCurrZ += normalizedDiffZ;
+                }
+            } else if (normalizedCurrY < normalizedCurrZ) {
+                // y <= x && y < z
+                currY += dy;
+                normalizedCurrY += normalizedDiffY;
+            } else {
+                // y <= x && z <= y <--> z <= y && z <= x
+                currZ += dz;
+                normalizedCurrZ += normalizedDiffZ;
+            }
+        }
+    }
+
+    /**
+     * @reason Route to optimized call
+     * @author Spottedleaf
+     */
+    @Override
+    public net.minecraft.world.phys.BlockHitResult clip(final ClipContext clipContext) {
+        // can only do this in this class, as not everything that implements BlockGetter can retrieve chunks
+        return fastClip(clipContext.getFrom(), clipContext.getTo(), (Level)(Object)this, clipContext);
+    }
+
+    /**
+     * @reason Route to faster logic
+     * @author Spottedleaf
+     */
+    @Override
+    public boolean collidesWithSuffocatingBlock(final Entity entity, final AABB box) {
+        return ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.getCollisionsForBlocksOrWorldBorder((Level)(Object)this, entity, box, null, null,
+            ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_FLAG_CHECK_ONLY,
+            (final BlockState state, final BlockPos pos) -> {
+                return state.isSuffocating((Level)(Object)Level.this, pos);
+            }
+        );
+    }
+
+    private static VoxelShape inflateAABBToVoxel(final AABB aabb, final double x, final double y, final double z) {
+        return net.minecraft.world.phys.shapes.Shapes.create(
+            aabb.minX - x,
+            aabb.minY - y,
+            aabb.minZ - z,
+
+            aabb.maxX + x,
+            aabb.maxY + y,
+            aabb.maxZ + z
+        );
+    }
+
+    /**
+     * @reason Use optimised OR operator join strategy, avoid streams
+     * @author Spottedleaf
+     */
+    @Override
+    public java.util.Optional<net.minecraft.world.phys.Vec3> findFreePosition(final Entity entity, final VoxelShape boundsShape, final Vec3 fromPosition,
+                                                                              final double rangeX, final double rangeY, final double rangeZ) {
+        if (boundsShape.isEmpty()) {
+            return java.util.Optional.empty();
+        }
+
+        final double expandByX = rangeX * 0.5;
+        final double expandByY = rangeY * 0.5;
+        final double expandByZ = rangeZ * 0.5;
+
+        // note: it is useless to look at shapes outside of range / 2.0
+        final AABB collectionVolume = boundsShape.bounds().inflate(expandByX, expandByY, expandByZ);
+
+        final List<AABB> aabbs = new java.util.ArrayList<>();
+        final List<VoxelShape> voxels = new java.util.ArrayList<>();
+
+        ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.getCollisionsForBlocksOrWorldBorder(
+            (Level)(Object)this, entity, collectionVolume, voxels, aabbs,
+            ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_FLAG_CHECK_BORDER,
+            null
+        );
+
+        final WorldBorder worldBorder = this.getWorldBorder();
+        if (worldBorder != null) {
+            aabbs.removeIf((final AABB aabb) -> {
+                return !worldBorder.isWithinBounds(aabb);
+            });
+            voxels.removeIf((final VoxelShape shape) -> {
+                return !worldBorder.isWithinBounds(shape.bounds());
+            });
+        }
+
+        // push voxels into aabbs
+        for (int i = 0, len = voxels.size(); i < len; ++i) {
+            aabbs.addAll(voxels.get(i).toAabbs());
+        }
+
+        // expand AABBs
+        final VoxelShape first = aabbs.isEmpty() ? net.minecraft.world.phys.shapes.Shapes.empty() : inflateAABBToVoxel(aabbs.get(0), expandByX, expandByY, expandByZ);
+        final VoxelShape[] rest = new VoxelShape[Math.max(0, aabbs.size() - 1)];
+
+        for (int i = 1, len = aabbs.size(); i < len; ++i) {
+            rest[i - 1] = inflateAABBToVoxel(aabbs.get(i), expandByX, expandByY, expandByZ);
+        }
+
+        // use optimized implementation of ORing the shapes together
+        final VoxelShape joined = net.minecraft.world.phys.shapes.Shapes.or(first, rest);
+
+        // find free space
+        // can use unoptimized join here (instead of join()), as closestPointTo uses toAabbs()
+        final VoxelShape freeSpace = net.minecraft.world.phys.shapes.Shapes.joinUnoptimized(boundsShape, joined, net.minecraft.world.phys.shapes.BooleanOp.ONLY_FIRST);
+
+        return freeSpace.closestPointTo(fromPosition);
+    }
+
+    /**
+     * @reason Route to faster logic
+     * @author Spottedleaf
+     */
+    @Override
+    public java.util.Optional<net.minecraft.core.BlockPos> findSupportingBlock(final Entity entity, final AABB aabb) {
+        final int minSection = ca.spottedleaf.moonrise.common.util.WorldUtil.getMinSection((Level)(Object)this);
+
+        final int minBlockX = Mth.floor(aabb.minX - ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON) - 1;
+        final int maxBlockX = Mth.floor(aabb.maxX + ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON) + 1;
+
+        final int minBlockY = Math.max((minSection << 4) - 1, Mth.floor(aabb.minY - ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON) - 1);
+        final int maxBlockY = Math.min((ca.spottedleaf.moonrise.common.util.WorldUtil.getMaxSection((Level)(Object)this) << 4) + 16, Mth.floor(aabb.maxY + ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON) + 1);
+
+        final int minBlockZ = Mth.floor(aabb.minZ - ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON) - 1;
+        final int maxBlockZ = Mth.floor(aabb.maxZ + ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON) + 1;
+
+        final BlockPos.MutableBlockPos mutablePos = new BlockPos.MutableBlockPos();
+        final ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.LazyEntityCollisionContext collisionShape = new ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.LazyEntityCollisionContext(entity);
+        BlockPos selected = null;
+        double selectedDistance = Double.MAX_VALUE;
+        final Vec3 entityPos = entity.position();
+
+        // special cases:
+        if (minBlockY > maxBlockY) {
+            // no point in checking
+            return java.util.Optional.empty();
+        }
+
+        final int minChunkX = minBlockX >> 4;
+        final int maxChunkX = maxBlockX >> 4;
+
+        final int minChunkY = minBlockY >> 4;
+        final int maxChunkY = maxBlockY >> 4;
+
+        final int minChunkZ = minBlockZ >> 4;
+        final int maxChunkZ = maxBlockZ >> 4;
+
+        final ChunkSource chunkSource = this.getChunkSource();
+
+        for (int currChunkZ = minChunkZ; currChunkZ <= maxChunkZ; ++currChunkZ) {
+            for (int currChunkX = minChunkX; currChunkX <= maxChunkX; ++currChunkX) {
+                final ChunkAccess chunk = chunkSource.getChunk(currChunkX, currChunkZ, ChunkStatus.FULL, false);
+
+                if (chunk == null) {
+                    continue;
+                }
+
+                final net.minecraft.world.level.chunk.LevelChunkSection[] sections = chunk.getSections();
+
+                // bound y
+                for (int currChunkY = minChunkY; currChunkY <= maxChunkY; ++currChunkY) {
+                    final int sectionIdx = currChunkY - minSection;
+                    if (sectionIdx < 0 || sectionIdx >= sections.length) {
+                        continue;
+                    }
+                    final net.minecraft.world.level.chunk.LevelChunkSection section = sections[sectionIdx];
+                    if (section.hasOnlyAir()) {
+                        // empty
+                        continue;
+                    }
+
+                    final boolean hasSpecial = ((ca.spottedleaf.moonrise.patches.block_counting.BlockCountingChunkSection)section).moonrise$hasSpecialCollidingBlocks();
+                    final int sectionAdjust = !hasSpecial ? 1 : 0;
+
+                    final net.minecraft.world.level.chunk.PalettedContainer<net.minecraft.world.level.block.state.BlockState> blocks = section.states;
+
+                    final int minXIterate = currChunkX == minChunkX ? (minBlockX & 15) + sectionAdjust : 0;
+                    final int maxXIterate = currChunkX == maxChunkX ? (maxBlockX & 15) - sectionAdjust : 15;
+                    final int minZIterate = currChunkZ == minChunkZ ? (minBlockZ & 15) + sectionAdjust : 0;
+                    final int maxZIterate = currChunkZ == maxChunkZ ? (maxBlockZ & 15) - sectionAdjust : 15;
+                    final int minYIterate = currChunkY == minChunkY ? (minBlockY & 15) + sectionAdjust : 0;
+                    final int maxYIterate = currChunkY == maxChunkY ? (maxBlockY & 15) - sectionAdjust : 15;
+
+                    for (int currY = minYIterate; currY <= maxYIterate; ++currY) {
+                        final int blockY = currY | (currChunkY << 4);
+                        mutablePos.setY(blockY);
+                        for (int currZ = minZIterate; currZ <= maxZIterate; ++currZ) {
+                            final int blockZ = currZ | (currChunkZ << 4);
+                            mutablePos.setZ(blockZ);
+                            for (int currX = minXIterate; currX <= maxXIterate; ++currX) {
+                                final int localBlockIndex = (currX) | (currZ << 4) | ((currY) << 8);
+                                final int blockX = currX | (currChunkX << 4);
+                                mutablePos.setX(blockX);
+
+                                final int edgeCount = hasSpecial ? ((blockX == minBlockX || blockX == maxBlockX) ? 1 : 0) +
+                                    ((blockY == minBlockY || blockY == maxBlockY) ? 1 : 0) +
+                                    ((blockZ == minBlockZ || blockZ == maxBlockZ) ? 1 : 0) : 0;
+                                if (edgeCount == 3) {
+                                    continue;
+                                }
+
+                                final double distance = mutablePos.distToCenterSqr(entityPos);
+                                if (distance > selectedDistance || (distance == selectedDistance && selected.compareTo(mutablePos) >= 0)) {
+                                    continue;
+                                }
+
+                                final BlockState blockData = blocks.get(localBlockIndex);
+
+                                if (((ca.spottedleaf.moonrise.patches.collisions.block.CollisionBlockState)blockData).moonrise$emptyContextCollisionShape()) {
+                                    continue;
+                                }
+
+                                VoxelShape blockCollision = ((ca.spottedleaf.moonrise.patches.collisions.block.CollisionBlockState)blockData).moonrise$getConstantContextCollisionShape();
+
+                                if (edgeCount == 0 || ((edgeCount != 1 || blockData.hasLargeCollisionShape()) && (edgeCount != 2 || blockData.getBlock() == Blocks.MOVING_PISTON))) {
+                                    if (blockCollision == null) {
+                                        blockCollision = blockData.getCollisionShape((Level)(Object)this, mutablePos, collisionShape);
+
+                                        if (blockCollision.isEmpty()) {
+                                            continue;
+                                        }
+                                    }
+
+                                    // avoid VoxelShape#move by shifting the entity collision shape instead
+                                    final AABB shiftedAABB = aabb.move(-(double)blockX, -(double)blockY, -(double)blockZ);
+
+                                    final AABB singleAABB = ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)blockCollision).moonrise$getSingleAABBRepresentation();
+                                    if (singleAABB != null) {
+                                        if (!ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.voxelShapeIntersect(singleAABB, shiftedAABB)) {
+                                            continue;
+                                        }
+
+                                        selected = mutablePos.immutable();
+                                        selectedDistance = distance;
+                                        continue;
+                                    }
+
+                                    if (!ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.voxelShapeIntersectNoEmpty(blockCollision, shiftedAABB)) {
+                                        continue;
+                                    }
+
+                                    selected = mutablePos.immutable();
+                                    selectedDistance = distance;
+                                    continue;
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        return java.util.Optional.ofNullable(selected);
+    }
+    // Paper end - optimise collisions
+    // Paper start - getblock optimisations - cache world height/sections
+    private final int minY;
+    private final int height;
+    private final int maxY;
+    private final int minSectionY;
+    private final int maxSectionY;
+    private final int sectionsCount;
+
+    @Override
+    public int getMinY() {
+        return this.minY;
+    }
+
+    @Override
+    public int getHeight() {
+        return this.height;
+    }
+
+    @Override
+    public int getMaxY() {
+        return this.maxY;
+    }
+
+    @Override
+    public int getSectionsCount() {
+        return this.sectionsCount;
+    }
+
+    @Override
+    public int getMinSectionY() {
+        return this.minSectionY;
+    }
+
+    @Override
+    public int getMaxSectionY() {
+        return this.maxSectionY;
+    }
+
+    @Override
+    public boolean isInsideBuildHeight(final int blockY) {
+        return blockY >= this.minY && blockY <= this.maxY;
+    }
+
+    @Override
+    public boolean isOutsideBuildHeight(final BlockPos pos) {
+        return this.isOutsideBuildHeight(pos.getY());
+    }
+
+    @Override
+    public boolean isOutsideBuildHeight(final int blockY) {
+        return blockY < this.minY || blockY > this.maxY;
+    }
+
+    @Override
+    public int getSectionIndex(final int blockY) {
+        return (blockY >> 4) - this.minSectionY;
+    }
+
+    @Override
+    public int getSectionIndexFromSectionY(final int sectionY) {
+        return sectionY - this.minSectionY;
+    }
+
+    @Override
+    public int getSectionYFromSectionIndex(final int sectionIdx) {
+        return sectionIdx + this.minSectionY;
+    }
+    // Paper end - getblock optimisations - cache world height/sections
+    // Paper start - optimise random ticking
+    @Override
+    public abstract Holder<Biome> getUncachedNoiseBiome(final int x, final int y, final int z);
+
+    /**
+     * @reason Make getChunk and getUncachedNoiseBiome virtual calls instead of interface calls
+     *         by implementing the superclass method in this class.
+     * @author Spottedleaf
+     */
+    @Override
+    public Holder<Biome> getNoiseBiome(final int x, final int y, final int z) {
+        final ChunkAccess chunk = this.getChunk(x >> 2, z >> 2, ChunkStatus.BIOMES, false);
+
+        return chunk != null ? chunk.getNoiseBiome(x, y, z) : this.getUncachedNoiseBiome(x, y, z);
+    }
+    // Paper end - optimise random ticking
+
     protected Level(WritableLevelData worlddatamutable, ResourceKey<Level> resourcekey, RegistryAccess iregistrycustom, Holder<DimensionType> holder, boolean flag, boolean flag1, long i, int j, org.bukkit.generator.ChunkGenerator gen, org.bukkit.generator.BiomeProvider biomeProvider, org.bukkit.World.Environment env, java.util.function.Function<org.spigotmc.SpigotWorldConfig, io.papermc.paper.configuration.WorldConfiguration> paperWorldConfigCreator, java.util.concurrent.Executor executor) { // Paper - create paper world config & Anti-Xray
+        // Paper start - getblock optimisations - cache world height/sections
+        final DimensionType dimType = holder.value();
+        this.minY = dimType.minY();
+        this.height = dimType.height();
+        this.maxY = this.minY + this.height - 1;
+        this.minSectionY = this.minY >> 4;
+        this.maxSectionY = this.maxY >> 4;
+        this.sectionsCount = this.maxSectionY - this.minSectionY + 1;
+        // Paper end - getblock optimisations - cache world height/sections
         this.spigotConfig = new org.spigotmc.SpigotWorldConfig(((net.minecraft.world.level.storage.PrimaryLevelData) worlddatamutable).getLevelName()); // Spigot
         this.paperConfig = paperWorldConfigCreator.apply(this.spigotConfig); // Paper - create paper world config
         this.generator = gen;
@@ -0,0 +0,0 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
         this.entityLimiter = new org.spigotmc.TickLimiter(this.spigotConfig.entityMaxTickTime);
         this.tileLimiter = new org.spigotmc.TickLimiter(this.spigotConfig.tileMaxTickTime);
         this.chunkPacketBlockController = this.paperConfig().anticheat.antiXray.enabled ? new com.destroystokyo.paper.antixray.ChunkPacketBlockControllerAntiXray(this, executor) : com.destroystokyo.paper.antixray.ChunkPacketBlockController.NO_OPERATION_INSTANCE; // Paper - Anti-Xray
+        this.entityLookup = new ca.spottedleaf.moonrise.patches.chunk_system.level.entity.dfl.DefaultEntityLookup(this); // Paper - rewrite chunk system
     }
 
     // Paper start - Cancel hit for vanished players
@@ -0,0 +0,0 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
                 this.setBlocksDirty(blockposition, iblockdata1, iblockdata2);
             }
 
-            if ((i & 2) != 0 && (!this.isClientSide || (i & 4) == 0) && (this.isClientSide || chunk == null || (chunk.getFullStatus() != null && chunk.getFullStatus().isOrAfter(FullChunkStatus.BLOCK_TICKING)))) { // allow chunk to be null here as chunk.isReady() is false when we send our notification during block placement
+            if ((i & 2) != 0 && (!this.isClientSide || (i & 4) == 0) && (this.isClientSide || chunk == null || (chunk.getFullStatus() != null && chunk.getFullStatus().isOrAfter(FullChunkStatus.FULL)))) { // allow chunk to be null here as chunk.isReady() is false when we send our notification during block placement // Paper - rewrite chunk system - change from ticking to full
                 this.sendBlockUpdated(blockposition, iblockdata1, iblockdata, i);
             }
 
@@ -0,0 +0,0 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
         // Iterator<TickingBlockEntity> iterator = this.blockEntityTickers.iterator();
         boolean flag = this.tickRateManager().runsNormally();
 
+        int tickedEntities = 0; // Paper - rewrite chunk system
+
         int tilesThisCycle = 0;
         var toRemove = new it.unimi.dsi.fastutil.objects.ReferenceOpenHashSet<TickingBlockEntity>(); // Paper - Fix MC-117075; use removeAll
         toRemove.add(null); // Paper - Fix MC-117075
@@ -0,0 +0,0 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
                 // Spigot end
             } else if (flag && this.shouldTickBlocksAt(tickingblockentity.getPos())) {
                 tickingblockentity.tick();
+                // Paper start - rewrite chunk system
+                if ((++tickedEntities & 7) == 0) {
+                    ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel)(Level)(Object)this).moonrise$midTickTasks();
+                }
+                // Paper end - rewrite chunk system
             }
         }
         this.blockEntityTickers.removeAll(toRemove); // Paper - Fix MC-117075
@@ -0,0 +0,0 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
             entity.discard(org.bukkit.event.entity.EntityRemoveEvent.Cause.DISCARD);
             // Paper end - Prevent block entity and entity crashes
         }
+        this.moonrise$midTickTasks(); // Paper - rewrite chunk system
     }
     // Paper start - Option to prevent armor stands from doing entity lookups
     @Override
     public boolean noCollision(@Nullable Entity entity, AABB box) {
         if (entity instanceof net.minecraft.world.entity.decoration.ArmorStand && !entity.level().paperConfig().entities.armorStands.doCollisionEntityLookups) return false;
-        return LevelAccessor.super.noCollision(entity, box);
+        // Paper start - optimise collisions
+        final int flags = entity == null ? (ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_FLAG_CHECK_BORDER | ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_FLAG_CHECK_ONLY) : ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_FLAG_CHECK_ONLY;
+        if (ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.getCollisionsForBlocksOrWorldBorder((Level)(Object)this, entity, box, null, null, flags, null)) {
+            return false;
+        }
+
+        return !ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.getEntityHardCollisions((Level)(Object)this, entity, box, null, flags, null);
+        // Paper end - optimise collisions
     }
     // Paper end - Option to prevent armor stands from doing entity lookups
 
@@ -0,0 +0,0 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
         }
         // Paper end - Perf: Optimize capturedTileEntities lookup
         // CraftBukkit end
-        return this.isOutsideBuildHeight(blockposition) ? null : (!this.isClientSide && Thread.currentThread() != this.thread ? null : this.getChunkAt(blockposition).getBlockEntity(blockposition, LevelChunk.EntityCreationType.IMMEDIATE));
+        return this.isOutsideBuildHeight(blockposition) ? null : (!this.isClientSide && !ca.spottedleaf.moonrise.common.util.TickThread.isTickThread() ? null : this.getChunkAt(blockposition).getBlockEntity(blockposition, LevelChunk.EntityCreationType.IMMEDIATE)); // Paper - rewrite chunk system
     }
 
     public void setBlockEntity(BlockEntity blockEntity) {
@@ -0,0 +0,0 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
         Profiler.get().incrementCounter("getEntities");
         List<Entity> list = Lists.newArrayList();
 
-        this.getEntities().get(box, (entity1) -> {
-            if (entity1 != except && predicate.test(entity1)) {
-                list.add(entity1);
-            }
-
-        });
-        Iterator iterator = this.dragonParts().iterator();
+        // Paper start - rewrite chunk system
+        final List<Entity> ret = new java.util.ArrayList<>();
 
-        while (iterator.hasNext()) {
-            EnderDragonPart entitycomplexpart = (EnderDragonPart) iterator.next();
+        ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel)this).moonrise$getEntityLookup().getEntities(except, box, ret, predicate);
 
-            if (entitycomplexpart != except && entitycomplexpart.parentMob != except && predicate.test(entitycomplexpart) && box.intersects(entitycomplexpart.getBoundingBox())) {
-                list.add(entitycomplexpart);
-            }
-        }
+        ca.spottedleaf.moonrise.common.PlatformHooks.get().addToGetEntities((Level)(Object)this, except, box, predicate, ret);
 
-        return list;
+        return ret;
+        // Paper end - rewrite chunk system
     }
 
     @Override
@@ -0,0 +0,0 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
         this.getEntities(filter, box, predicate, result, Integer.MAX_VALUE);
     }
 
-    public <T extends Entity> void getEntities(EntityTypeTest<Entity, T> filter, AABB box, Predicate<? super T> predicate, List<? super T> result, int limit) {
+    // Paper start - rewrite chunk system
+    public <T extends Entity> void getEntities(final EntityTypeTest<Entity, T> entityTypeTest,
+                                               final AABB boundingBox, final Predicate<? super T> predicate,
+                                               final List<? super T> into, final int maxCount) {
         Profiler.get().incrementCounter("getEntities");
-        this.getEntities().get(filter, box, (entity) -> {
-            if (predicate.test(entity)) {
-                result.add(entity);
-                if (result.size() >= limit) {
-                    return AbortableIterationConsumer.Continuation.ABORT;
-                }
+
+        if (entityTypeTest instanceof net.minecraft.world.entity.EntityType<T> byType) {
+            if (maxCount != Integer.MAX_VALUE) {
+                ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel)this).moonrise$getEntityLookup().getEntities(byType, boundingBox, into, predicate, maxCount);
+                ca.spottedleaf.moonrise.common.PlatformHooks.get().addToGetEntities((Level)(Object)this, entityTypeTest, boundingBox, predicate, into, maxCount);
+                return;
+            } else {
+                ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel)this).moonrise$getEntityLookup().getEntities(byType, boundingBox, into, predicate);
+                ca.spottedleaf.moonrise.common.PlatformHooks.get().addToGetEntities((Level)(Object)this, entityTypeTest, boundingBox, predicate, into, maxCount);
+                return;
             }
+        }
 
-            if (entity instanceof EnderDragon entityenderdragon) {
-                EnderDragonPart[] aentitycomplexpart = entityenderdragon.getSubEntities();
-                int j = aentitycomplexpart.length;
+        if (entityTypeTest == null) {
+            if (maxCount != Integer.MAX_VALUE) {
+                ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel)this).moonrise$getEntityLookup().getEntities((Entity)null, boundingBox, (List)into, (Predicate)predicate, maxCount);
+                ca.spottedleaf.moonrise.common.PlatformHooks.get().addToGetEntities((Level)(Object)this, entityTypeTest, boundingBox, predicate, into, maxCount);
+                return;
+            } else {
+                ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel)this).moonrise$getEntityLookup().getEntities((Entity)null, boundingBox, (List)into, (Predicate)predicate);
+                ca.spottedleaf.moonrise.common.PlatformHooks.get().addToGetEntities((Level)(Object)this, entityTypeTest, boundingBox, predicate, into, maxCount);
+                return;
+            }
+        }
 
-                for (int k = 0; k < j; ++k) {
-                    EnderDragonPart entitycomplexpart = aentitycomplexpart[k];
-                    T t0 = filter.tryCast(entitycomplexpart); // CraftBukkit - decompile error
+        final Class<? extends Entity> base = entityTypeTest.getBaseClass();
 
-                    if (t0 != null && predicate.test(t0)) {
-                        result.add(t0);
-                        if (result.size() >= limit) {
-                            return AbortableIterationConsumer.Continuation.ABORT;
-                        }
-                    }
+        final Predicate<? super T> modifiedPredicate;
+        if (predicate == null) {
+            modifiedPredicate = (final T obj) -> {
+                return entityTypeTest.tryCast(obj) != null;
+            };
+        } else {
+            modifiedPredicate = (final Entity obj) -> {
+                final T casted = entityTypeTest.tryCast(obj);
+                if (casted == null) {
+                    return false;
                 }
+
+                return predicate.test(casted);
+            };
+        }
+
+        if (base == null || base == Entity.class) {
+            if (maxCount != Integer.MAX_VALUE) {
+                ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel)this).moonrise$getEntityLookup().getEntities((Entity)null, boundingBox, (List)into, (Predicate)modifiedPredicate, maxCount);
+                ca.spottedleaf.moonrise.common.PlatformHooks.get().addToGetEntities((Level)(Object)this, entityTypeTest, boundingBox, predicate, into, maxCount);
+                return;
+            } else {
+                ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel)this).moonrise$getEntityLookup().getEntities((Entity)null, boundingBox, (List)into, (Predicate)modifiedPredicate);
+                ca.spottedleaf.moonrise.common.PlatformHooks.get().addToGetEntities((Level)(Object)this, entityTypeTest, boundingBox, predicate, into, maxCount);
+                return;
+            }
+        } else {
+            if (maxCount != Integer.MAX_VALUE) {
+                ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel)this).moonrise$getEntityLookup().getEntities(base, null, boundingBox, (List)into, (Predicate)modifiedPredicate, maxCount);
+                ca.spottedleaf.moonrise.common.PlatformHooks.get().addToGetEntities((Level)(Object)this, entityTypeTest, boundingBox, predicate, into, maxCount);
+                return;
+            } else {
+                ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevel)this).moonrise$getEntityLookup().getEntities(base, null, boundingBox, (List)into, (Predicate)modifiedPredicate);
+                ca.spottedleaf.moonrise.common.PlatformHooks.get().addToGetEntities((Level)(Object)this, entityTypeTest, boundingBox, predicate, into, maxCount);
+                return;
             }
+        }
+    }
 
-            return AbortableIterationConsumer.Continuation.CONTINUE;
-        });
+    public org.bukkit.entity.Entity[] getChunkEntities(int chunkX, int chunkZ) {
+        ca.spottedleaf.moonrise.patches.chunk_system.level.entity.ChunkEntitySlices slices = ((ServerLevel)this).moonrise$getEntityLookup().getChunk(chunkX, chunkZ);
+        if (slices == null) {
+            return new org.bukkit.entity.Entity[0];
+        }
+
+        List<org.bukkit.entity.Entity> ret = new java.util.ArrayList<>();
+        for (Entity entity : slices.getAllEntities()) {
+            org.bukkit.entity.Entity bukkit = entity.getBukkitEntity();
+            if (bukkit != null && bukkit.isValid()) {
+                ret.add(bukkit);
+            }
+        }
+
+        return ret.toArray(new org.bukkit.entity.Entity[0]);
     }
+    // Paper end - rewrite chunk system
 
     @Nullable
     public abstract Entity getEntity(int id);
diff --git a/src/main/java/net/minecraft/world/level/LevelReader.java b/src/main/java/net/minecraft/world/level/LevelReader.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/LevelReader.java
+++ b/src/main/java/net/minecraft/world/level/LevelReader.java
@@ -0,0 +0,0 @@ import net.minecraft.world.level.dimension.DimensionType;
 import net.minecraft.world.level.levelgen.Heightmap;
 import net.minecraft.world.phys.AABB;
 
-public interface LevelReader extends BlockAndTintGetter, CollisionGetter, SignalGetter, BiomeManager.NoiseBiomeSource {
+public interface LevelReader extends ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevelReader, BlockAndTintGetter, CollisionGetter, SignalGetter, BiomeManager.NoiseBiomeSource { // Paper - rewrite chunk system
+
+    // Paper start - rewrite chunk system
+    @Override
+    public default ChunkAccess moonrise$syncLoadNonFull(final int chunkX, final int chunkZ, final ChunkStatus status) {
+        if (status == null || status.isOrAfter(ChunkStatus.FULL)) {
+            throw new IllegalArgumentException("Status: " + status.toString());
+        }
+        return ((LevelReader)this).getChunk(chunkX, chunkZ, status, true);
+    }
+    // Paper end - rewrite chunk system
+
     @Nullable
     ChunkAccess getChunk(int chunkX, int chunkZ, ChunkStatus leastStatus, boolean create);
 
diff --git a/src/main/java/net/minecraft/world/level/ServerExplosion.java b/src/main/java/net/minecraft/world/level/ServerExplosion.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/ServerExplosion.java
+++ b/src/main/java/net/minecraft/world/level/ServerExplosion.java
@@ -0,0 +0,0 @@ public class ServerExplosion implements Explosion {
     public float yield;
     // CraftBukkit end
     public boolean excludeSourceFromDamage = true; // Paper - Allow explosions to damage source
+    // Paper start - collisions optimisations
+    private static final double[] CACHED_RAYS;
+    static {
+        final it.unimi.dsi.fastutil.doubles.DoubleArrayList rayCoords = new it.unimi.dsi.fastutil.doubles.DoubleArrayList();
+
+        for (int x = 0; x <= 15; ++x) {
+            for (int y = 0; y <= 15; ++y) {
+                for (int z = 0; z <= 15; ++z) {
+                    if ((x == 0 || x == 15) || (y == 0 || y == 15) || (z == 0 || z == 15)) {
+                        double xDir = (double)((float)x / 15.0F * 2.0F - 1.0F);
+                        double yDir = (double)((float)y / 15.0F * 2.0F - 1.0F);
+                        double zDir = (double)((float)z / 15.0F * 2.0F - 1.0F);
+
+                        double mag = Math.sqrt(
+                                xDir * xDir + yDir * yDir + zDir * zDir
+                        );
+
+                        rayCoords.add((xDir / mag) * (double)0.3F);
+                        rayCoords.add((yDir / mag) * (double)0.3F);
+                        rayCoords.add((zDir / mag) * (double)0.3F);
+                    }
+                }
+            }
+        }
+
+        CACHED_RAYS = rayCoords.toDoubleArray();
+    }
+
+    private static final int CHUNK_CACHE_SHIFT = 2;
+    private static final int CHUNK_CACHE_MASK = (1 << CHUNK_CACHE_SHIFT) - 1;
+    private static final int CHUNK_CACHE_WIDTH = 1 << CHUNK_CACHE_SHIFT;
+
+    private static final int BLOCK_EXPLOSION_CACHE_SHIFT = 3;
+    private static final int BLOCK_EXPLOSION_CACHE_MASK = (1 << BLOCK_EXPLOSION_CACHE_SHIFT) - 1;
+    private static final int BLOCK_EXPLOSION_CACHE_WIDTH = 1 << BLOCK_EXPLOSION_CACHE_SHIFT;
+
+    // resistance = (res + 0.3F) * 0.3F;
+    // so for resistance = 0, we need res = -0.3F
+    private static final Float ZERO_RESISTANCE = Float.valueOf(-0.3f);
+    private it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap<ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache> blockCache = null;
+    private long[] chunkPosCache = null;
+    private net.minecraft.world.level.chunk.LevelChunk[] chunkCache = null;
+    private ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache[] directMappedBlockCache;
+    private BlockPos.MutableBlockPos mutablePos;
+
+    private ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache getOrCacheExplosionBlock(final int x, final int y, final int z,
+                                                                                                    final long key, final boolean calculateResistance) {
+        ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache ret = this.blockCache.get(key);
+        if (ret != null) {
+            return ret;
+        }
+
+        BlockPos pos = new BlockPos(x, y, z);
+
+        if (!this.level.isInWorldBounds(pos)) {
+            ret = new ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache(key, pos, null, null, 0.0f, true);
+        } else {
+            net.minecraft.world.level.chunk.LevelChunk chunk;
+            long chunkKey = ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkKey(x >> 4, z >> 4);
+            int chunkCacheKey = ((x >> 4) & CHUNK_CACHE_MASK) | (((z >> 4) << CHUNK_CACHE_SHIFT) & (CHUNK_CACHE_MASK << CHUNK_CACHE_SHIFT));
+            if (this.chunkPosCache[chunkCacheKey] == chunkKey) {
+                chunk = this.chunkCache[chunkCacheKey];
+            } else {
+                this.chunkPosCache[chunkCacheKey] = chunkKey;
+                this.chunkCache[chunkCacheKey] = chunk = this.level.getChunk(x >> 4, z >> 4);
+            }
+
+            BlockState blockState = ((ca.spottedleaf.moonrise.patches.getblock.GetBlockChunk)chunk).moonrise$getBlock(x, y, z);
+            FluidState fluidState = blockState.getFluidState();
+
+            Optional<Float> resistance = !calculateResistance ? Optional.empty() : this.damageCalculator.getBlockExplosionResistance((Explosion)(Object)this, this.level, pos, blockState, fluidState);
+
+            ret = new ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache(
+                    key, pos, blockState, fluidState,
+                    (resistance.orElse(ZERO_RESISTANCE).floatValue() + 0.3f) * 0.3f,
+                    false
+            );
+        }
+
+        this.blockCache.put(key, ret);
+
+        return ret;
+    }
+
+    private boolean clipsAnything(final Vec3 from, final Vec3 to,
+                                  final ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.LazyEntityCollisionContext context,
+                                  final ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache[] blockCache,
+                                  final BlockPos.MutableBlockPos currPos) {
+        // assume that context.delegated = false
+        final double adjX = ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON * (from.x - to.x);
+        final double adjY = ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON * (from.y - to.y);
+        final double adjZ = ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON * (from.z - to.z);
+
+        if (adjX == 0.0 && adjY == 0.0 && adjZ == 0.0) {
+            return false;
+        }
+
+        final double toXAdj = to.x - adjX;
+        final double toYAdj = to.y - adjY;
+        final double toZAdj = to.z - adjZ;
+        final double fromXAdj = from.x + adjX;
+        final double fromYAdj = from.y + adjY;
+        final double fromZAdj = from.z + adjZ;
+
+        int currX = Mth.floor(fromXAdj);
+        int currY = Mth.floor(fromYAdj);
+        int currZ = Mth.floor(fromZAdj);
+
+        final double diffX = toXAdj - fromXAdj;
+        final double diffY = toYAdj - fromYAdj;
+        final double diffZ = toZAdj - fromZAdj;
+
+        final double dxDouble = Math.signum(diffX);
+        final double dyDouble = Math.signum(diffY);
+        final double dzDouble = Math.signum(diffZ);
+
+        final int dx = (int)dxDouble;
+        final int dy = (int)dyDouble;
+        final int dz = (int)dzDouble;
+
+        final double normalizedDiffX = diffX == 0.0 ? Double.MAX_VALUE : dxDouble / diffX;
+        final double normalizedDiffY = diffY == 0.0 ? Double.MAX_VALUE : dyDouble / diffY;
+        final double normalizedDiffZ = diffZ == 0.0 ? Double.MAX_VALUE : dzDouble / diffZ;
+
+        double normalizedCurrX = normalizedDiffX * (diffX > 0.0 ? (1.0 - Mth.frac(fromXAdj)) : Mth.frac(fromXAdj));
+        double normalizedCurrY = normalizedDiffY * (diffY > 0.0 ? (1.0 - Mth.frac(fromYAdj)) : Mth.frac(fromYAdj));
+        double normalizedCurrZ = normalizedDiffZ * (diffZ > 0.0 ? (1.0 - Mth.frac(fromZAdj)) : Mth.frac(fromZAdj));
+
+        for (;;) {
+            currPos.set(currX, currY, currZ);
+
+            // ClipContext.Block.COLLIDER -> BlockBehaviour.BlockStateBase::getCollisionShape
+            // ClipContext.Fluid.NONE -> ignore fluids
+
+            // read block from cache
+            final long key = BlockPos.asLong(currX, currY, currZ);
+
+            final int cacheKey =
+                    (currX & BLOCK_EXPLOSION_CACHE_MASK) |
+                    (currY & BLOCK_EXPLOSION_CACHE_MASK) << (BLOCK_EXPLOSION_CACHE_SHIFT) |
+                    (currZ & BLOCK_EXPLOSION_CACHE_MASK) << (BLOCK_EXPLOSION_CACHE_SHIFT + BLOCK_EXPLOSION_CACHE_SHIFT);
+            ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache cachedBlock = blockCache[cacheKey];
+            if (cachedBlock == null || cachedBlock.key != key) {
+                blockCache[cacheKey] = cachedBlock = this.getOrCacheExplosionBlock(currX, currY, currZ, key, false);
+            }
+
+            final BlockState blockState = cachedBlock.blockState;
+            if (blockState != null && !((ca.spottedleaf.moonrise.patches.collisions.block.CollisionBlockState)blockState).moonrise$emptyContextCollisionShape()) {
+                net.minecraft.world.phys.shapes.VoxelShape collision = cachedBlock.cachedCollisionShape;
+                if (collision == null) {
+                    collision = ((ca.spottedleaf.moonrise.patches.collisions.block.CollisionBlockState)blockState).moonrise$getConstantContextCollisionShape();
+                    if (collision == null) {
+                        collision = blockState.getCollisionShape(this.level, currPos, context);
+                        if (!context.isDelegated()) {
+                            // if it was not delegated during this call, assume that for any future ones it will not be delegated
+                            // again, and cache the result
+                            cachedBlock.cachedCollisionShape = collision;
+                        }
+                    } else {
+                        cachedBlock.cachedCollisionShape = collision;
+                    }
+                }
+
+                if (!collision.isEmpty() && collision.clip(from, to, currPos) != null) {
+                    return true;
+                }
+            }
+
+            if (normalizedCurrX > 1.0 && normalizedCurrY > 1.0 && normalizedCurrZ > 1.0) {
+                return false;
+            }
+
+            // inc the smallest normalized coordinate
+
+            if (normalizedCurrX < normalizedCurrY) {
+                if (normalizedCurrX < normalizedCurrZ) {
+                    currX += dx;
+                    normalizedCurrX += normalizedDiffX;
+                } else {
+                    // x < y && x >= z <--> z < y && z <= x
+                    currZ += dz;
+                    normalizedCurrZ += normalizedDiffZ;
+                }
+            } else if (normalizedCurrY < normalizedCurrZ) {
+                // y <= x && y < z
+                currY += dy;
+                normalizedCurrY += normalizedDiffY;
+            } else {
+                // y <= x && z <= y <--> z <= y && z <= x
+                currZ += dz;
+                normalizedCurrZ += normalizedDiffZ;
+            }
+        }
+    }
+
+    private float getSeenFraction(final Vec3 source, final Entity target,
+                                   final ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache[] blockCache,
+                                   final BlockPos.MutableBlockPos blockPos) {
+        final AABB boundingBox = target.getBoundingBox();
+        final double diffX = boundingBox.maxX - boundingBox.minX;
+        final double diffY = boundingBox.maxY - boundingBox.minY;
+        final double diffZ = boundingBox.maxZ - boundingBox.minZ;
+
+        final double incX = 1.0 / (diffX * 2.0 + 1.0);
+        final double incY = 1.0 / (diffY * 2.0 + 1.0);
+        final double incZ = 1.0 / (diffZ * 2.0 + 1.0);
+
+        if (incX < 0.0 || incY < 0.0 || incZ < 0.0) {
+            return 0.0f;
+        }
+
+        final double offX = (1.0 - Math.floor(1.0 / incX) * incX) * 0.5 + boundingBox.minX;
+        final double offY = boundingBox.minY;
+        final double offZ = (1.0 - Math.floor(1.0 / incZ) * incZ) * 0.5 + boundingBox.minZ;
+
+        final ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.LazyEntityCollisionContext context = new ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.LazyEntityCollisionContext(target);
+
+        int totalRays = 0;
+        int missedRays = 0;
+
+        for (double dx = 0.0; dx <= 1.0; dx += incX) {
+            final double fromX = Math.fma(dx, diffX, offX);
+            for (double dy = 0.0; dy <= 1.0; dy += incY) {
+                final double fromY = Math.fma(dy, diffY, offY);
+                for (double dz = 0.0; dz <= 1.0; dz += incZ) {
+                    ++totalRays;
+
+                    final Vec3 from = new Vec3(
+                            fromX,
+                            fromY,
+                            Math.fma(dz, diffZ, offZ)
+                    );
+
+                    if (!this.clipsAnything(from, source, context, blockCache, blockPos)) {
+                        ++missedRays;
+                    }
+                }
+            }
+        }
+
+        return (float)missedRays / (float)totalRays;
+    }
+    // Paper end - collisions optimisations
 
     public ServerExplosion(ServerLevel world, @Nullable Entity entity, @Nullable DamageSource damageSource, @Nullable ExplosionDamageCalculator behavior, Vec3 pos, float power, boolean createFire, Explosion.BlockInteraction destructionType) {
         this.level = world;
@@ -0,0 +0,0 @@ public class ServerExplosion implements Explosion {
     }
 
     private List<BlockPos> calculateExplodedPositions() {
-        Set<BlockPos> set = new HashSet();
-        boolean flag = true;
-
-        for (int i = 0; i < 16; ++i) {
-            for (int j = 0; j < 16; ++j) {
-                for (int k = 0; k < 16; ++k) {
-                    if (i == 0 || i == 15 || j == 0 || j == 15 || k == 0 || k == 15) {
-                        double d0 = (double) ((float) i / 15.0F * 2.0F - 1.0F);
-                        double d1 = (double) ((float) j / 15.0F * 2.0F - 1.0F);
-                        double d2 = (double) ((float) k / 15.0F * 2.0F - 1.0F);
-                        double d3 = Math.sqrt(d0 * d0 + d1 * d1 + d2 * d2);
-
-                        d0 /= d3;
-                        d1 /= d3;
-                        d2 /= d3;
-                        float f = this.radius * (0.7F + this.level.random.nextFloat() * 0.6F);
-                        double d4 = this.center.x;
-                        double d5 = this.center.y;
-                        double d6 = this.center.z;
-
-                        for (float f1 = 0.3F; f > 0.0F; f -= 0.22500001F) {
-                            BlockPos blockposition = BlockPos.containing(d4, d5, d6);
-                            BlockState iblockdata = this.level.getBlockState(blockposition);
-                            if (!iblockdata.isDestroyable()) continue; // Paper - Protect Bedrock and End Portal/Frames from being destroyed
-                            FluidState fluid = iblockdata.getFluidState(); // Paper - Perf: Optimize call to getFluid for explosions
-
-                            if (!this.level.isInWorldBounds(blockposition)) {
-                                break;
-                            }
+        // Paper start - collision optimisations
+        final ObjectArrayList<BlockPos> ret = new ObjectArrayList<>();
 
-                            Optional<Float> optional = this.damageCalculator.getBlockExplosionResistance(this, this.level, blockposition, iblockdata, fluid);
+        final Vec3 center = this.center;
 
-                            if (optional.isPresent()) {
-                                f -= ((Float) optional.get() + 0.3F) * 0.3F;
-                            }
+        final ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache[] blockCache = this.directMappedBlockCache;
 
-                            if (f > 0.0F && this.damageCalculator.shouldBlockExplode(this, this.level, blockposition, iblockdata, f)) {
-                                set.add(blockposition);
-                                // Paper start - prevent headless pistons from forming
-                                if (!io.papermc.paper.configuration.GlobalConfiguration.get().unsupportedSettings.allowHeadlessPistons && iblockdata.getBlock() == Blocks.MOVING_PISTON) {
-                                    net.minecraft.world.level.block.entity.BlockEntity extension = this.level.getBlockEntity(blockposition);
-                                    if (extension instanceof net.minecraft.world.level.block.piston.PistonMovingBlockEntity blockEntity && blockEntity.isSourcePiston()) {
-                                        net.minecraft.core.Direction direction = iblockdata.getValue(net.minecraft.world.level.block.piston.PistonHeadBlock.FACING);
-                                        set.add(blockposition.relative(direction.getOpposite()));
-                                    }
+        // use initial cache value that is most likely to be used: the source position
+        final ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache initialCache;
+        {
+            final int blockX = Mth.floor(center.x);
+            final int blockY = Mth.floor(center.y);
+            final int blockZ = Mth.floor(center.z);
+
+            final long key = BlockPos.asLong(blockX, blockY, blockZ);
+
+            initialCache = this.getOrCacheExplosionBlock(blockX, blockY, blockZ, key, true);
+        }
+
+        // only ~1/3rd of the loop iterations in vanilla will result in a ray, as it is iterating the perimeter of
+        // a 16x16x16 cube
+        // we can cache the rays and their normals as well, so that we eliminate the excess iterations / checks and
+        // calculations in one go
+        // additional aggressive caching of block retrieval is very significant, as at low power (i.e tnt) most
+        // block retrievals are not unique
+        for (int ray = 0, len = CACHED_RAYS.length; ray < len;) {
+            ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache cachedBlock = initialCache;
+
+            double currX = center.x;
+            double currY = center.y;
+            double currZ = center.z;
+
+            final double incX = CACHED_RAYS[ray];
+            final double incY = CACHED_RAYS[ray + 1];
+            final double incZ = CACHED_RAYS[ray + 2];
+
+            ray += 3;
+
+            float power = this.radius * (0.7F + this.level.random.nextFloat() * 0.6F);
+
+            do {
+                final int blockX = Mth.floor(currX);
+                final int blockY = Mth.floor(currY);
+                final int blockZ = Mth.floor(currZ);
+
+                final long key = BlockPos.asLong(blockX, blockY, blockZ);
+
+                if (cachedBlock.key != key) {
+                    final int cacheKey =
+                        (blockX & BLOCK_EXPLOSION_CACHE_MASK) |
+                            (blockY & BLOCK_EXPLOSION_CACHE_MASK) << (BLOCK_EXPLOSION_CACHE_SHIFT) |
+                            (blockZ & BLOCK_EXPLOSION_CACHE_MASK) << (BLOCK_EXPLOSION_CACHE_SHIFT + BLOCK_EXPLOSION_CACHE_SHIFT);
+                    cachedBlock = blockCache[cacheKey];
+                    if (cachedBlock == null || cachedBlock.key != key) {
+                        blockCache[cacheKey] = cachedBlock = this.getOrCacheExplosionBlock(blockX, blockY, blockZ, key, true);
+                    }
+                }
+
+                if (cachedBlock.outOfWorld) {
+                    break;
+                }
+                final BlockState iblockdata = cachedBlock.blockState;
+
+                power -= cachedBlock.resistance;
+
+                if (power > 0.0f && cachedBlock.shouldExplode == null) {
+                    // note: we expect shouldBlockExplode to be pure with respect to power, as Vanilla currently is.
+                    // basically, it is unused, which allows us to cache the result
+                    final boolean shouldExplode = iblockdata.isDestroyable() && this.damageCalculator.shouldBlockExplode((Explosion)(Object)this, this.level, cachedBlock.immutablePos, cachedBlock.blockState, power); // Paper - Protect Bedrock and End Portal/Frames from being destroyed
+                    cachedBlock.shouldExplode = shouldExplode ? Boolean.TRUE : Boolean.FALSE;
+                    if (shouldExplode) {
+                        if (this.fire || !cachedBlock.blockState.isAir()) {
+                            ret.add(cachedBlock.immutablePos);
+                            // Paper start - prevent headless pistons from forming
+                            if (!io.papermc.paper.configuration.GlobalConfiguration.get().unsupportedSettings.allowHeadlessPistons && iblockdata.getBlock() == Blocks.MOVING_PISTON) {
+                                net.minecraft.world.level.block.entity.BlockEntity extension = this.level.getBlockEntity(cachedBlock.immutablePos); // Paper - optimise collisions
+                                if (extension instanceof net.minecraft.world.level.block.piston.PistonMovingBlockEntity blockEntity && blockEntity.isSourcePiston()) {
+                                    net.minecraft.core.Direction direction = iblockdata.getValue(net.minecraft.world.level.block.piston.PistonHeadBlock.FACING);
+                                    ret.add(cachedBlock.immutablePos.relative(direction.getOpposite())); // Paper - optimise collisions
                                 }
-                                // Paper end - prevent headless pistons from forming
                             }
-
-                            d4 += d0 * 0.30000001192092896D;
-                            d5 += d1 * 0.30000001192092896D;
-                            d6 += d2 * 0.30000001192092896D;
+                            // Paper end - prevent headless pistons from forming
                         }
                     }
                 }
-            }
+
+                power -= 0.22500001F;
+                currX += incX;
+                currY += incY;
+                currZ += incZ;
+            } while (power > 0.0f);
         }
 
-        return new ObjectArrayList(set);
+        return ret;
+        // Paper end - collision optimisations
     }
 
     private void hurtEntities() {
@@ -0,0 +0,0 @@ public class ServerExplosion implements Explosion {
             return;
         }
         // CraftBukkit end
+        // Paper start - collision optimisations
+        this.blockCache = new it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap<>();
+        this.chunkPosCache = new long[CHUNK_CACHE_WIDTH * CHUNK_CACHE_WIDTH];
+        java.util.Arrays.fill(this.chunkPosCache, ChunkPos.INVALID_CHUNK_POS);
+        this.chunkCache = new net.minecraft.world.level.chunk.LevelChunk[CHUNK_CACHE_WIDTH * CHUNK_CACHE_WIDTH];
+        this.directMappedBlockCache = new ca.spottedleaf.moonrise.patches.collisions.ExplosionBlockCache[BLOCK_EXPLOSION_CACHE_WIDTH * BLOCK_EXPLOSION_CACHE_WIDTH * BLOCK_EXPLOSION_CACHE_WIDTH];
+        this.mutablePos = new BlockPos.MutableBlockPos();
+        // Paper end - collision optimisations
         this.level.gameEvent(this.source, (Holder) GameEvent.EXPLODE, this.center);
         List<BlockPos> list = this.calculateExplodedPositions();
 
@@ -0,0 +0,0 @@ public class ServerExplosion implements Explosion {
         if (this.fire) {
             this.createFire(list);
         }
+        // Paper start - collision optimisations
+        this.blockCache = null;
+        this.chunkPosCache = null;
+        this.chunkCache = null;
+        this.directMappedBlockCache = null;
+        this.mutablePos = null;
+        // Paper end - collision optimisations
 
     }
 
@@ -0,0 +0,0 @@ public class ServerExplosion implements Explosion {
     // Paper start - Optimize explosions
     private float getBlockDensity(Vec3 vec3d, Entity entity) {
         if (!this.level.paperConfig().environment.optimizeExplosions) {
-            return getSeenPercent(vec3d, entity);
+            return this.getSeenFraction(vec3d, entity, this.directMappedBlockCache, this.mutablePos); // Paper - collision optimisations
         }
         CacheKey key = new CacheKey(this, entity.getBoundingBox());
         Float blockDensity = this.level.explosionDensityCache.get(key);
         if (blockDensity == null) {
-            blockDensity = getSeenPercent(vec3d, entity);
+            blockDensity = this.getSeenFraction(vec3d, entity, this.directMappedBlockCache, this.mutablePos); // Paper - collision optimisations
             this.level.explosionDensityCache.put(key, blockDensity);
         }
 
diff --git a/src/main/java/net/minecraft/world/level/biome/Biome.java b/src/main/java/net/minecraft/world/level/biome/Biome.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/biome/Biome.java
+++ b/src/main/java/net/minecraft/world/level/biome/Biome.java
@@ -0,0 +0,0 @@ public final class Biome {
 
     @Deprecated
     public float getTemperature(BlockPos blockPos, int seaLevel) {
-        long l = blockPos.asLong();
-        Long2FloatLinkedOpenHashMap long2FloatLinkedOpenHashMap = this.temperatureCache.get();
-        float f = long2FloatLinkedOpenHashMap.get(l);
-        if (!Float.isNaN(f)) {
-            return f;
-        } else {
-            float g = this.getHeightAdjustedTemperature(blockPos, seaLevel);
-            if (long2FloatLinkedOpenHashMap.size() == 1024) {
-                long2FloatLinkedOpenHashMap.removeFirstFloat();
-            }
-
-            long2FloatLinkedOpenHashMap.put(l, g);
-            return g;
-        }
+        return this.getHeightAdjustedTemperature(blockPos, seaLevel); // Paper - optimise random ticking
     }
 
     public boolean shouldFreeze(LevelReader world, BlockPos blockPos) {
diff --git a/src/main/java/net/minecraft/world/level/biome/BiomeManager.java b/src/main/java/net/minecraft/world/level/biome/BiomeManager.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/biome/BiomeManager.java
+++ b/src/main/java/net/minecraft/world/level/biome/BiomeManager.java
@@ -0,0 +0,0 @@ public class BiomeManager {
     }
 
     private static double getFiddle(long l) {
-        double d = (double)Math.floorMod(l >> 24, 1024) / 1024.0;
-        return (d - 0.5) * 0.9;
+        return (double)(((l >> 24) & (1024 - 1)) - (1024/2)) * (0.9 / 1024.0); // Paper - avoid floorMod, fp division, and fp subtraction
     }
 
     public interface NoiseBiomeSource {
diff --git a/src/main/java/net/minecraft/world/level/block/Block.java b/src/main/java/net/minecraft/world/level/block/Block.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/block/Block.java
+++ b/src/main/java/net/minecraft/world/level/block/Block.java
@@ -0,0 +0,0 @@ public class Block extends BlockBehaviour implements ItemLike {
     }
 
     public static boolean isShapeFullBlock(VoxelShape shape) {
-        return (Boolean) Block.SHAPE_FULL_BLOCK_CACHE.getUnchecked(shape);
+        return ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)shape).moonrise$isFullBlock(); // Paper - optimise collisions
     }
 
     public void animateTick(BlockState state, Level world, BlockPos pos, RandomSource random) {}
diff --git a/src/main/java/net/minecraft/world/level/block/state/BlockBehaviour.java b/src/main/java/net/minecraft/world/level/block/state/BlockBehaviour.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/block/state/BlockBehaviour.java
+++ b/src/main/java/net/minecraft/world/level/block/state/BlockBehaviour.java
@@ -0,0 +0,0 @@ public abstract class BlockBehaviour implements FeatureElement {
         boolean test(BlockState state, BlockGetter world, BlockPos pos);
     }
 
-    public abstract static class BlockStateBase extends StateHolder<Block, BlockState> {
+    public abstract static class BlockStateBase extends StateHolder<Block, BlockState> implements ca.spottedleaf.moonrise.patches.starlight.blockstate.StarlightAbstractBlockState, ca.spottedleaf.moonrise.patches.collisions.block.CollisionBlockState { // Paper - rewrite chunk system // Paper - optimise collisions
 
         private static final Direction[] DIRECTIONS = Direction.values();
         private static final VoxelShape[] EMPTY_OCCLUSION_SHAPES = (VoxelShape[]) Util.make(new VoxelShape[BlockBehaviour.BlockStateBase.DIRECTIONS.length], (avoxelshape) -> {
@@ -0,0 +0,0 @@ public abstract class BlockBehaviour implements FeatureElement {
         private boolean propagatesSkylightDown;
         private int lightBlock;
 
+        // Paper start - rewrite chunk system
+        private boolean isConditionallyFullOpaque;
+
+        @Override
+        public final boolean starlight$isConditionallyFullOpaque() {
+            return this.isConditionallyFullOpaque;
+        }
+        // Paper end - rewrite chunk system
+        // Paper start - optimise collisions
+        private static final int RANDOM_OFFSET = 704237939;
+        private static final Direction[] DIRECTIONS_CACHED = Direction.values();
+        private static final java.util.concurrent.atomic.AtomicInteger ID_GENERATOR = new java.util.concurrent.atomic.AtomicInteger();
+        private final int id1 = it.unimi.dsi.fastutil.HashCommon.murmurHash3(it.unimi.dsi.fastutil.HashCommon.murmurHash3(ID_GENERATOR.getAndIncrement() + RANDOM_OFFSET) + RANDOM_OFFSET);
+        private final int id2 = it.unimi.dsi.fastutil.HashCommon.murmurHash3(it.unimi.dsi.fastutil.HashCommon.murmurHash3(ID_GENERATOR.getAndIncrement() + RANDOM_OFFSET) + RANDOM_OFFSET);
+        private boolean occludesFullBlock;
+        private boolean emptyCollisionShape;
+        private boolean emptyConstantCollisionShape;
+        private VoxelShape constantCollisionShape;
+
+        private static void initCaches(final VoxelShape shape, final boolean neighbours) {
+            ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)shape).moonrise$isFullBlock();
+            ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)shape).moonrise$occludesFullBlock();
+            shape.toAabbs();
+            if (!shape.isEmpty()) {
+                shape.bounds();
+            }
+            if (neighbours) {
+                for (final Direction direction : DIRECTIONS_CACHED) {
+                    initCaches(((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)shape).moonrise$getFaceShapeClamped(direction), false);
+                    initCaches(shape.getFaceShape(direction), false);
+                }
+            }
+        }
+
+        @Override
+        public final boolean moonrise$hasCache() {
+            return this.cache != null;
+        }
+
+        @Override
+        public final boolean moonrise$occludesFullBlock() {
+            return this.occludesFullBlock;
+        }
+
+        @Override
+        public final boolean moonrise$emptyCollisionShape() {
+            return this.emptyCollisionShape;
+        }
+
+        @Override
+        public final boolean moonrise$emptyContextCollisionShape() {
+            return this.emptyConstantCollisionShape;
+        }
+
+        @Override
+        public final int moonrise$uniqueId1() {
+            return this.id1;
+        }
+
+        @Override
+        public final int moonrise$uniqueId2() {
+            return this.id2;
+        }
+
+        @Override
+        public final VoxelShape moonrise$getConstantContextCollisionShape() {
+            return this.constantCollisionShape;
+        }
+        // Paper end - optimise collisions
+
         protected BlockStateBase(Block block, Reference2ObjectArrayMap<Property<?>, Comparable<?>> propertyMap, MapCodec<BlockState> codec) {
             super(block, propertyMap, codec);
             this.fluidState = Fluids.EMPTY.defaultFluidState();
@@ -0,0 +0,0 @@ public abstract class BlockBehaviour implements FeatureElement {
 
             this.propagatesSkylightDown = ((Block) this.owner).propagatesSkylightDown(this.asState());
             this.lightBlock = ((Block) this.owner).getLightBlock(this.asState());
+            // Paper start - rewrite chunk system
+            this.isConditionallyFullOpaque = this.canOcclude & this.useShapeForLightOcclusion;
+            // Paper end - rewrite chunk system
+            // Paper start - optimise collisions
+            if (this.cache != null) {
+                final VoxelShape collisionShape = this.cache.collisionShape;
+                if (this.isAir()) {
+                    this.constantCollisionShape = Shapes.empty();
+                } else {
+                    this.constantCollisionShape = null;
+                }
+                this.occludesFullBlock = ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)collisionShape).moonrise$occludesFullBlock();
+                this.emptyCollisionShape = collisionShape.isEmpty();
+                this.emptyConstantCollisionShape = this.constantCollisionShape != null && this.constantCollisionShape.isEmpty();
+                // init caches
+                initCaches(collisionShape, true);
+                if (this.constantCollisionShape != null) {
+                    initCaches(this.constantCollisionShape, true);
+                }
+            } else {
+                this.occludesFullBlock = false;
+                this.emptyCollisionShape = false;
+                this.emptyConstantCollisionShape = false;
+                this.constantCollisionShape = null;
+            }
+
+            if (this.occlusionShape != null) {
+                initCaches(this.occlusionShape, true);
+            }
+            if (this.occlusionShapesByFace != null) {
+                for (final VoxelShape shape : this.occlusionShapesByFace) {
+                    initCaches(shape, true);
+                }
+            }
+            // Paper end - optimise collisions
         }
 
         public Block getBlock() {
diff --git a/src/main/java/net/minecraft/world/level/block/state/StateHolder.java b/src/main/java/net/minecraft/world/level/block/state/StateHolder.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/block/state/StateHolder.java
+++ b/src/main/java/net/minecraft/world/level/block/state/StateHolder.java
@@ -0,0 +0,0 @@ import java.util.stream.Collectors;
 import javax.annotation.Nullable;
 import net.minecraft.world.level.block.state.properties.Property;
 
-public abstract class StateHolder<O, S> {
+public abstract class StateHolder<O, S> implements ca.spottedleaf.moonrise.patches.blockstate_propertyaccess.PropertyAccessStateHolder { // Paper - optimise blockstate property access
     public static final String NAME_TAG = "Name";
     public static final String PROPERTIES_TAG = "Properties";
     public static final Function<Entry<Property<?>, Comparable<?>>, String> PROPERTY_ENTRY_TO_STRING_FUNCTION = new Function<Entry<Property<?>, Comparable<?>>, String>() {
@@ -0,0 +0,0 @@ public abstract class StateHolder<O, S> {
         }
     };
     protected final O owner;
-    private final Reference2ObjectArrayMap<Property<?>, Comparable<?>> values;
+    private Reference2ObjectArrayMap<Property<?>, Comparable<?>> values; // Paper - optimise blockstate property access - remove final
     private Map<Property<?>, S[]> neighbours;
     protected final MapCodec<S> propertiesCodec;
 
+    // Paper start - optimise blockstate property access
+    protected ca.spottedleaf.moonrise.patches.blockstate_propertyaccess.util.ZeroCollidingReferenceStateTable<O, S> optimisedTable;
+    protected final long tableIndex;
+
+    @Override
+    public final long moonrise$getTableIndex() {
+        return this.tableIndex;
+    }
+    // Paper end - optimise blockstate property access
+
     protected StateHolder(O owner, Reference2ObjectArrayMap<Property<?>, Comparable<?>> propertyMap, MapCodec<S> codec) {
         this.owner = owner;
         this.values = propertyMap;
         this.propertiesCodec = codec;
+        // Paper start - optimise blockstate property access
+        this.optimisedTable = new ca.spottedleaf.moonrise.patches.blockstate_propertyaccess.util.ZeroCollidingReferenceStateTable<>(this.values.keySet());
+        this.tableIndex = this.optimisedTable.getIndex((StateHolder<O, S>)(Object)this);
+        // Paper end - optimise blockstate property access
     }
 
     public <T extends Comparable<T>> S cycle(Property<T> property) {
@@ -0,0 +0,0 @@ public abstract class StateHolder<O, S> {
     }
 
     public Collection<Property<?>> getProperties() {
-        return Collections.unmodifiableCollection(this.values.keySet());
+        return this.optimisedTable.getProperties(); // Paper - optimise blockstate property access
     }
 
     public <T extends Comparable<T>> boolean hasProperty(Property<T> property) {
-        return this.values.containsKey(property);
+        return property != null && this.optimisedTable.hasProperty(property); // Paper - optimise blockstate property access
     }
 
     public <T extends Comparable<T>> T getValue(Property<T> property) {
-        Comparable<?> comparable = this.values.get(property);
-        if (comparable == null) {
-            throw new IllegalArgumentException("Cannot get property " + property + " as it does not exist in " + this.owner);
-        } else {
-            return property.getValueClass().cast(comparable);
+        // Paper start - optimise blockstate property access
+        final T ret = this.optimisedTable.get(this.tableIndex, property);
+        if (ret != null) {
+            return ret;
         }
+        throw new IllegalArgumentException("Cannot get property " + property + " as it does not exist in " + this.owner);
+        // Paper end - optimise blockstate property access
     }
 
     public <T extends Comparable<T>> Optional<T> getOptionalValue(Property<T> property) {
@@ -0,0 +0,0 @@ public abstract class StateHolder<O, S> {
 
     @Nullable
     public <T extends Comparable<T>> T getNullableValue(Property<T> property) {
-        Comparable<?> comparable = this.values.get(property);
-        return comparable == null ? null : property.getValueClass().cast(comparable);
+        return property == null ? null : this.optimisedTable.get(this.tableIndex, property); // Paper - optimise blockstate property access
     }
 
     public <T extends Comparable<T>, V extends T> S setValue(Property<T> property, V value) {
-        Comparable<?> comparable = this.values.get(property);
-        if (comparable == null) {
-            throw new IllegalArgumentException("Cannot set property " + property + " as it does not exist in " + this.owner);
-        } else {
-            return this.setValueInternal(property, value, comparable);
+        // Paper start - optimise blockstate property access
+        final S ret = this.optimisedTable.set(this.tableIndex, property, value);
+        if (ret != null) {
+            return ret;
         }
+        throw new IllegalArgumentException("Cannot set property " + property + " to " + value + " on " + this.owner);
+        // Paper end - optimise blockstate property access
     }
 
     public <T extends Comparable<T>, V extends T> S trySetValue(Property<T> property, V value) {
-        Comparable<?> comparable = this.values.get(property);
-        return (S)(comparable == null ? this : this.setValueInternal(property, value, comparable));
+        // Paper start - optimise blockstate property access
+        if (property == null) {
+            return (S)(StateHolder<O, S>)(Object)this;
+        }
+        final S ret = this.optimisedTable.trySet(this.tableIndex, property, value, (S)(StateHolder<O, S>)(Object)this);
+        if (ret != null) {
+            return ret;
+        }
+        throw new IllegalArgumentException("Cannot set property " + property + " to " + value + " on " + this.owner);
+        // Paper end - optimise blockstate property access
     }
 
     private <T extends Comparable<T>, V extends T> S setValueInternal(Property<T> property, V newValue, Comparable<?> oldValue) {
@@ -0,0 +0,0 @@ public abstract class StateHolder<O, S> {
     }
 
     public void populateNeighbours(Map<Map<Property<?>, Comparable<?>>, S> states) {
-        if (this.neighbours != null) {
-            throw new IllegalStateException();
-        } else {
-            Map<Property<?>, S[]> map = new Reference2ObjectArrayMap<>(this.values.size());
+        // Paper start - optimise blockstate property access
+        final Map<Map<Property<?>, Comparable<?>>, S> map = states;
+        if (this.optimisedTable.isLoaded()) {
+            return;
+        }
+        this.optimisedTable.loadInTable(map);
 
-            for (Entry<Property<?>, Comparable<?>> entry : this.values.entrySet()) {
-                Property<?> property = entry.getKey();
-                map.put(property, property.getPossibleValues().stream().map(value -> states.get(this.makeNeighbourValues(property, value))).toArray());
-            }
+        // de-duplicate the tables
+        for (final Map.Entry<Map<Property<?>, Comparable<?>>, S> entry : map.entrySet()) {
+            final S value = entry.getValue();
+            ((StateHolder<O, S>)value).optimisedTable = this.optimisedTable;
+        }
 
-            this.neighbours = map;
+        // remove values arrays
+        for (final Map.Entry<Map<Property<?>, Comparable<?>>, S> entry : map.entrySet()) {
+            final S value = entry.getValue();
+            ((StateHolder<O, S>)value).values = null;
         }
+
+        return;
+        // Paper end  optimise blockstate property access
     }
 
     private Map<Property<?>, Comparable<?>> makeNeighbourValues(Property<?> property, Comparable<?> value) {
@@ -0,0 +0,0 @@ public abstract class StateHolder<O, S> {
     }
 
     public Map<Property<?>, Comparable<?>> getValues() {
-        return this.values;
+        // Paper start - optimise blockstate property access
+        ca.spottedleaf.moonrise.patches.blockstate_propertyaccess.util.ZeroCollidingReferenceStateTable<O, S> table = this.optimisedTable;
+        // We have to use this.values until the table is loaded
+        return table.isLoaded() ? table.getMapView(this.tableIndex) : this.values;
+        // Paper end - optimise blockstate property access
     }
 
     protected static <O, S extends StateHolder<O, S>> Codec<S> codec(Codec<O> codec, Function<O, S> ownerToStateFunction) {
diff --git a/src/main/java/net/minecraft/world/level/block/state/properties/BooleanProperty.java b/src/main/java/net/minecraft/world/level/block/state/properties/BooleanProperty.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/block/state/properties/BooleanProperty.java
+++ b/src/main/java/net/minecraft/world/level/block/state/properties/BooleanProperty.java
@@ -0,0 +0,0 @@ package net.minecraft.world.level.block.state.properties;
 import java.util.List;
 import java.util.Optional;
 
-public final class BooleanProperty extends Property<Boolean> {
+public final class BooleanProperty extends Property<Boolean> implements ca.spottedleaf.moonrise.patches.blockstate_propertyaccess.PropertyAccess<Boolean> { // Paper - optimise blockstate property access
     private static final List<Boolean> VALUES = List.of(true, false);
     private static final int TRUE_INDEX = 0;
     private static final int FALSE_INDEX = 1;
 
+    // Paper start - optimise blockstate property access
+    private static final Boolean[] BY_ID = new Boolean[]{ Boolean.FALSE, Boolean.TRUE };
+
+    @Override
+    public final int moonrise$getIdFor(final Boolean value) {
+        return value.booleanValue() ? 1 : 0;
+    }
+    // Paper end - optimise blockstate property access
+
     private BooleanProperty(String name) {
         super(name, Boolean.class);
+        this.moonrise$setById(BY_ID); // Paper - optimise blockstate property access
     }
 
     @Override
diff --git a/src/main/java/net/minecraft/world/level/block/state/properties/EnumProperty.java b/src/main/java/net/minecraft/world/level/block/state/properties/EnumProperty.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/block/state/properties/EnumProperty.java
+++ b/src/main/java/net/minecraft/world/level/block/state/properties/EnumProperty.java
@@ -0,0 +0,0 @@ import java.util.function.Predicate;
 import java.util.stream.Collectors;
 import net.minecraft.util.StringRepresentable;
 
-public final class EnumProperty<T extends Enum<T> & StringRepresentable> extends Property<T> {
+public final class EnumProperty<T extends Enum<T> & StringRepresentable> extends Property<T> implements ca.spottedleaf.moonrise.patches.blockstate_propertyaccess.PropertyAccess<T> { // Paper - optimise blockstate property access
     private final List<T> values;
     private final Map<String, T> names;
     private final int[] ordinalToIndex;
 
+    // Paper start - optimise blockstate property access
+    private int[] idLookupTable;
+
+    @Override
+    public final int moonrise$getIdFor(final T value) {
+        final Class<T> target = this.getValueClass();
+        return ((value.getClass() != target && value.getDeclaringClass() != target)) ? -1 : this.idLookupTable[value.ordinal()];
+    }
+
+    private void init() {
+        final java.util.Collection<T> values = this.getPossibleValues();
+        final Class<T> clazz = this.getValueClass();
+
+        int id = 0;
+        this.idLookupTable = new int[clazz.getEnumConstants().length];
+        Arrays.fill(this.idLookupTable, -1);
+        final T[] byId = (T[])java.lang.reflect.Array.newInstance(clazz, values.size());
+
+        for (final T value : values) {
+            final int valueId = id++;
+            this.idLookupTable[value.ordinal()] = valueId;
+            byId[valueId] = value;
+        }
+
+        this.moonrise$setById(byId);
+    }
+    // Paper end - optimise blockstate property access
+
     private EnumProperty(String name, Class<T> type, List<T> values) {
         super(name, type);
         if (values.isEmpty()) {
@@ -0,0 +0,0 @@ public final class EnumProperty<T extends Enum<T> & StringRepresentable> extends
 
             this.names = builder.buildOrThrow();
         }
+        this.init(); // Paper - optimise blockstate property access
     }
 
     @Override
diff --git a/src/main/java/net/minecraft/world/level/block/state/properties/IntegerProperty.java b/src/main/java/net/minecraft/world/level/block/state/properties/IntegerProperty.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/block/state/properties/IntegerProperty.java
+++ b/src/main/java/net/minecraft/world/level/block/state/properties/IntegerProperty.java
@@ -0,0 +0,0 @@ import java.util.List;
 import java.util.Optional;
 import java.util.stream.IntStream;
 
-public final class IntegerProperty extends Property<Integer> {
+public final class IntegerProperty extends Property<Integer> implements ca.spottedleaf.moonrise.patches.blockstate_propertyaccess.PropertyAccess<Integer> { // Paper - optimise blockstate property access
     private final IntImmutableList values;
     public final int min;
     public final int max;
 
+    // Paper start - optimise blockstate property access
+    @Override
+    public final int moonrise$getIdFor(final Integer value) {
+        final int val = value.intValue();
+        final int ret = val - this.min;
+
+        return ret | ((this.max - ret) >> 31);
+    }
+
+    private void init() {
+        final int min = this.min;
+        final int max = this.max;
+
+        final Integer[] byId = new Integer[max - min + 1];
+        for (int i = min; i <= max; ++i) {
+            byId[i - min] = Integer.valueOf(i);
+        }
+
+        this.moonrise$setById(byId);
+    }
+    // Paper end - optimise blockstate property access
+
     private IntegerProperty(String name, int min, int max) {
         super(name, Integer.class);
         if (min < 0) {
@@ -0,0 +0,0 @@ public final class IntegerProperty extends Property<Integer> {
             this.max = max;
             this.values = IntImmutableList.toList(IntStream.range(min, max + 1));
         }
+        this.init(); // Paper - optimise blockstate property access
     }
 
     @Override
diff --git a/src/main/java/net/minecraft/world/level/block/state/properties/Property.java b/src/main/java/net/minecraft/world/level/block/state/properties/Property.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/block/state/properties/Property.java
+++ b/src/main/java/net/minecraft/world/level/block/state/properties/Property.java
@@ -0,0 +0,0 @@ import java.util.stream.Stream;
 import javax.annotation.Nullable;
 import net.minecraft.world.level.block.state.StateHolder;
 
-public abstract class Property<T extends Comparable<T>> {
+public abstract class Property<T extends Comparable<T>> implements ca.spottedleaf.moonrise.patches.blockstate_propertyaccess.PropertyAccess<T> { // Paper - optimise blockstate property access
     private final Class<T> clazz;
     private final String name;
     @Nullable
@@ -0,0 +0,0 @@ public abstract class Property<T extends Comparable<T>> {
         );
     private final Codec<Property.Value<T>> valueCodec = this.codec.xmap(this::value, Property.Value::value);
 
+    // Paper start - optimise blockstate property access
+    private static final java.util.concurrent.atomic.AtomicInteger ID_GENERATOR = new java.util.concurrent.atomic.AtomicInteger();
+    private final int id;
+    private T[] byId;
+
+    @Override
+    public final int moonrise$getId() {
+        return this.id;
+    }
+
+    @Override
+    public final T moonrise$getById(final int id) {
+        final T[] byId = this.byId;
+        return id < 0 || id >= byId.length ? null : this.byId[id];
+    }
+
+    @Override
+    public final void moonrise$setById(final T[] byId) {
+        if (this.byId != null) {
+            throw new IllegalStateException();
+        }
+        this.byId = byId;
+    }
+
+    @Override
+    public abstract int moonrise$getIdFor(final T value);
+    // Paper end - optimise blockstate property access
+
     protected Property(String name, Class<T> type) {
         this.clazz = type;
         this.name = name;
+        this.id = ID_GENERATOR.getAndIncrement(); // Paper - optimise blockstate property access
     }
 
     public Property.Value<T> value(T value) {
diff --git a/src/main/java/net/minecraft/world/level/chunk/ChunkAccess.java b/src/main/java/net/minecraft/world/level/chunk/ChunkAccess.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/ChunkAccess.java
+++ b/src/main/java/net/minecraft/world/level/chunk/ChunkAccess.java
@@ -0,0 +0,0 @@ import net.minecraft.world.ticks.SavedTick;
 import net.minecraft.world.ticks.TickContainerAccess;
 import org.slf4j.Logger;
 
-public abstract class ChunkAccess implements BiomeManager.NoiseBiomeSource, LightChunk, StructureAccess {
+public abstract class ChunkAccess implements BiomeManager.NoiseBiomeSource, LightChunk, StructureAccess, ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk { // Paper - rewrite chunk system
 
     public static final int NO_FILLED_SECTION = -1;
     private static final Logger LOGGER = LogUtils.getLogger();
@@ -0,0 +0,0 @@ public abstract class ChunkAccess implements BiomeManager.NoiseBiomeSource, Ligh
     @Nullable
     protected BlendingData blendingData;
     public final Map<Heightmap.Types, Heightmap> heightmaps = Maps.newEnumMap(Heightmap.Types.class);
-    protected ChunkSkyLightSources skyLightSources;
+    // Paper - rewrite chunk system
     private final Map<Structure, StructureStart> structureStarts = Maps.newHashMap();
     private final Map<Structure, LongSet> structuresRefences = Maps.newHashMap();
     protected final Map<BlockPos, CompoundTag> pendingBlockEntities = Maps.newHashMap();
@@ -0,0 +0,0 @@ public abstract class ChunkAccess implements BiomeManager.NoiseBiomeSource, Ligh
     public org.bukkit.craftbukkit.persistence.DirtyCraftPersistentDataContainer persistentDataContainer = new org.bukkit.craftbukkit.persistence.DirtyCraftPersistentDataContainer(ChunkAccess.DATA_TYPE_REGISTRY);
     // CraftBukkit end
 
+    // Paper start - rewrite chunk system
+    private volatile ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray[] blockNibbles;
+    private volatile ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray[] skyNibbles;
+    private volatile boolean[] skyEmptinessMap;
+    private volatile boolean[] blockEmptinessMap;
+
+    @Override
+    public ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray[] starlight$getBlockNibbles() {
+        return this.blockNibbles;
+    }
+
+    @Override
+    public void starlight$setBlockNibbles(final ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray[] nibbles) {
+        this.blockNibbles = nibbles;
+    }
+
+    @Override
+    public ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray[] starlight$getSkyNibbles() {
+        return this.skyNibbles;
+    }
+
+    @Override
+    public void starlight$setSkyNibbles(final ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray[] nibbles) {
+        this.skyNibbles = nibbles;
+    }
+
+    @Override
+    public boolean[] starlight$getSkyEmptinessMap() {
+        return this.skyEmptinessMap;
+    }
+
+    @Override
+    public void starlight$setSkyEmptinessMap(final boolean[] emptinessMap) {
+        this.skyEmptinessMap = emptinessMap;
+    }
+
+    @Override
+    public boolean[] starlight$getBlockEmptinessMap() {
+        return this.blockEmptinessMap;
+    }
+
+    @Override
+    public void starlight$setBlockEmptinessMap(final boolean[] emptinessMap) {
+        this.blockEmptinessMap = emptinessMap;
+    }
+    // Paper end - rewrite chunk system
+    // Paper start - get block chunk optimisation
+    private final int minSection;
+    private final int maxSection;
+    // Paper end - get block chunk optimisation
+
     public ChunkAccess(ChunkPos pos, UpgradeData upgradeData, LevelHeightAccessor heightLimitView, Registry<Biome> biomeRegistry, long inhabitedTime, @Nullable LevelChunkSection[] sectionArray, @Nullable BlendingData blendingData) {
         this.locX = pos.x; this.locZ = pos.z; // Paper - reduce need for field lookups
         this.chunkPos = pos; this.coordinateKey = ChunkPos.asLong(locX, locZ); // Paper - cache long key
@@ -0,0 +0,0 @@ public abstract class ChunkAccess implements BiomeManager.NoiseBiomeSource, Ligh
         this.inhabitedTime = inhabitedTime;
         this.postProcessing = new ShortList[heightLimitView.getSectionsCount()];
         this.blendingData = blendingData;
-        this.skyLightSources = new ChunkSkyLightSources(heightLimitView);
+        // Paper - rewrite chunk system
         if (sectionArray != null) {
             if (this.sections.length == sectionArray.length) {
                 System.arraycopy(sectionArray, 0, this.sections, 0, this.sections.length);
@@ -0,0 +0,0 @@ public abstract class ChunkAccess implements BiomeManager.NoiseBiomeSource, Ligh
         this.replaceMissingSections(biomeRegistry, this.sections); // Paper - Anti-Xray - make it a non-static method
         // CraftBukkit start
         this.biomeRegistry = biomeRegistry;
+        // Paper start - rewrite chunk system
+        if (!((Object)this instanceof ImposterProtoChunk)) {
+            this.starlight$setBlockNibbles(ca.spottedleaf.moonrise.patches.starlight.light.StarLightEngine.getFilledEmptyLight(heightLimitView));
+            this.starlight$setSkyNibbles(ca.spottedleaf.moonrise.patches.starlight.light.StarLightEngine.getFilledEmptyLight(heightLimitView));
+        }
+        // Paper end - rewrite chunk system
+        // Paper start - get block chunk optimisation
+        this.minSection = ca.spottedleaf.moonrise.common.util.WorldUtil.getMinSection(levelHeightAccessor);
+        this.maxSection = ca.spottedleaf.moonrise.common.util.WorldUtil.getMaxSection(levelHeightAccessor);
+        // Paper end - get block chunk optimisation
     }
     public final Registry<Biome> biomeRegistry;
     // CraftBukkit end
@@ -0,0 +0,0 @@ public abstract class ChunkAccess implements BiomeManager.NoiseBiomeSource, Ligh
 
     @Override
     public Holder<Biome> getNoiseBiome(int biomeX, int biomeY, int biomeZ) {
-        try {
-            int l = QuartPos.fromBlock(this.getMinY());
-            int i1 = l + QuartPos.fromBlock(this.getHeight()) - 1;
-            int j1 = Mth.clamp(biomeY, l, i1);
-            int k1 = this.getSectionIndex(QuartPos.toBlock(j1));
-
-            return this.sections[k1].getNoiseBiome(biomeX & 3, j1 & 3, biomeZ & 3);
-        } catch (Throwable throwable) {
-            CrashReport crashreport = CrashReport.forThrowable(throwable, "Getting biome");
-            CrashReportCategory crashreportsystemdetails = crashreport.addCategory("Biome being got");
-
-            crashreportsystemdetails.setDetail("Location", () -> {
-                return CrashReportCategory.formatLocation(this, biomeX, biomeY, biomeZ);
-            });
-            throw new ReportedException(crashreport);
+        // Paper start - get block chunk optimisation
+        int sectionY = (biomeY >> 2) - this.minSection;
+        int rel = biomeY & 3;
+
+        final LevelChunkSection[] sections = this.sections;
+
+        if (sectionY < 0) {
+            sectionY = 0;
+            rel = 0;
+        } else if (sectionY >= sections.length) {
+            sectionY = sections.length - 1;
+            rel = 3;
         }
+
+        return sections[sectionY].getNoiseBiome(biomeX & 3, rel, biomeZ & 3);
+        // Paper end - get block chunk optimisation
     }
 
     // CraftBukkit start
@@ -0,0 +0,0 @@ public abstract class ChunkAccess implements BiomeManager.NoiseBiomeSource, Ligh
     }
 
     public void initializeLightSources() {
-        this.skyLightSources.fillFrom(this);
+        // Paper - rewrite chunk system
     }
 
     @Override
     public ChunkSkyLightSources getSkyLightSources() {
-        return this.skyLightSources;
+        return null; // Paper - rewrite chunk system
     }
 
     public static record PackedTicks(List<SavedTick<Block>> blocks, List<SavedTick<Fluid>> fluids) {
diff --git a/src/main/java/net/minecraft/world/level/chunk/ChunkGenerator.java b/src/main/java/net/minecraft/world/level/chunk/ChunkGenerator.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/ChunkGenerator.java
+++ b/src/main/java/net/minecraft/world/level/chunk/ChunkGenerator.java
@@ -0,0 +0,0 @@ public abstract class ChunkGenerator {
         return CompletableFuture.supplyAsync(() -> {
             chunk.fillBiomesFromNoise(this.biomeSource, noiseConfig.sampler());
             return chunk;
-        }, Util.backgroundExecutor().forName("init_biomes"));
+        }, Runnable::run);  // Paper - rewrite chunk system
     }
 
     public abstract void applyCarvers(WorldGenRegion chunkRegion, long seed, RandomState noiseConfig, BiomeManager biomeAccess, StructureManager structureAccessor, ChunkAccess chunk);
@@ -0,0 +0,0 @@ public abstract class ChunkGenerator {
                         return Pair.of(placement.getLocatePos(pos), holder);
                     }
 
-                    ChunkAccess ichunkaccess = world.getChunk(pos.x, pos.z, ChunkStatus.STRUCTURE_STARTS);
+                    ChunkAccess ichunkaccess = ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemLevelReader)world).moonrise$syncLoadNonFull(pos.x, pos.z, ChunkStatus.STRUCTURE_STARTS); // Paper - rewrite chunk system
 
                     structurestart = structureAccessor.getStartForStructure(SectionPos.bottomOf(ichunkaccess), (Structure) holder.value(), ichunkaccess);
                 } while (structurestart == null);
diff --git a/src/main/java/net/minecraft/world/level/chunk/EmptyLevelChunk.java b/src/main/java/net/minecraft/world/level/chunk/EmptyLevelChunk.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/EmptyLevelChunk.java
+++ b/src/main/java/net/minecraft/world/level/chunk/EmptyLevelChunk.java
@@ -0,0 +0,0 @@ import net.minecraft.world.level.block.state.BlockState;
 import net.minecraft.world.level.material.FluidState;
 import net.minecraft.world.level.material.Fluids;
 
-public class EmptyLevelChunk extends LevelChunk {
+public class EmptyLevelChunk extends LevelChunk implements ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk { // Paper - rewrite chunk system
     private final Holder<Biome> biome;
 
     public EmptyLevelChunk(Level world, ChunkPos pos, Holder<Biome> biomeEntry) {
@@ -0,0 +0,0 @@ public class EmptyLevelChunk extends LevelChunk {
         this.biome = biomeEntry;
     }
 
+    // Paper start - rewrite chunk system
+    @Override
+    public ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray[] starlight$getBlockNibbles() {
+        return ca.spottedleaf.moonrise.patches.starlight.light.StarLightEngine.getFilledEmptyLight(this.getLevel());
+    }
+
+    @Override
+    public void starlight$setBlockNibbles(final ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray[] nibbles) {}
+
+    @Override
+    public ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray[] starlight$getSkyNibbles() {
+        return ca.spottedleaf.moonrise.patches.starlight.light.StarLightEngine.getFilledEmptyLight(this.getLevel());
+    }
+
+    @Override
+    public void starlight$setSkyNibbles(final ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray[] nibbles) {}
+
+    @Override
+    public boolean[] starlight$getSkyEmptinessMap() {
+        return null;
+    }
+
+    @Override
+    public void starlight$setSkyEmptinessMap(final boolean[] emptinessMap) {}
+
+    @Override
+    public boolean[] starlight$getBlockEmptinessMap() {
+        return null;
+    }
+
+    @Override
+    public void starlight$setBlockEmptinessMap(final boolean[] emptinessMap) {}
+    // Paper end - rewrite chunk system
+
     @Override
     public BlockState getBlockState(BlockPos pos) {
         return Blocks.VOID_AIR.defaultBlockState();
diff --git a/src/main/java/net/minecraft/world/level/chunk/HashMapPalette.java b/src/main/java/net/minecraft/world/level/chunk/HashMapPalette.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/HashMapPalette.java
+++ b/src/main/java/net/minecraft/world/level/chunk/HashMapPalette.java
@@ -0,0 +0,0 @@ import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.network.VarInt;
 import net.minecraft.util.CrudeIncrementalIntIdentityHashBiMap;
 
-public class HashMapPalette<T> implements Palette<T> {
+public class HashMapPalette<T> implements Palette<T>, ca.spottedleaf.moonrise.patches.fast_palette.FastPalette<T> { // Paper - optimise palette reads
     private final IdMap<T> registry;
     private final CrudeIncrementalIntIdentityHashBiMap<T> values;
     private final PaletteResize<T> resizeHandler;
     private final int bits;
 
+    // Paper start - optimise palette reads
+    @Override
+    public final T[] moonrise$getRawPalette(final ca.spottedleaf.moonrise.patches.fast_palette.FastPaletteData<T> container) {
+        return ((ca.spottedleaf.moonrise.patches.fast_palette.FastPalette<T>)this.values).moonrise$getRawPalette(container);
+    }
+    // Paper end - optimise palette reads
+
     public HashMapPalette(IdMap<T> idList, int bits, PaletteResize<T> listener, List<T> entries) {
         this(idList, bits, listener);
         entries.forEach(this.values::add);
diff --git a/src/main/java/net/minecraft/world/level/chunk/ImposterProtoChunk.java b/src/main/java/net/minecraft/world/level/chunk/ImposterProtoChunk.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/ImposterProtoChunk.java
+++ b/src/main/java/net/minecraft/world/level/chunk/ImposterProtoChunk.java
@@ -0,0 +0,0 @@ import net.minecraft.world.level.material.FluidState;
 import net.minecraft.world.ticks.BlackholeTickAccess;
 import net.minecraft.world.ticks.TickContainerAccess;
 
-public class ImposterProtoChunk extends ProtoChunk {
+public class ImposterProtoChunk extends ProtoChunk implements ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk { // Paper - rewrite chunk system
     private final LevelChunk wrapped;
     private final boolean allowWrites;
 
@@ -0,0 +0,0 @@ public class ImposterProtoChunk extends ProtoChunk {
         this.allowWrites = propagateToWrapped;
     }
 
+    // Paper start - rewrite chunk system
+    @Override
+    public ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray[] starlight$getBlockNibbles() {
+        return ((ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk)this.wrapped).starlight$getBlockNibbles();
+    }
+
+    @Override
+    public void starlight$setBlockNibbles(final ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray[] nibbles) {
+        ((ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk)this.wrapped).starlight$setBlockNibbles(nibbles);
+    }
+
+    @Override
+    public ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray[] starlight$getSkyNibbles() {
+        return ((ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk)this.wrapped).starlight$getSkyNibbles();
+    }
+
+    @Override
+    public void starlight$setSkyNibbles(final ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray[] nibbles) {
+        ((ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk)this.wrapped).starlight$setSkyNibbles(nibbles);
+    }
+
+    @Override
+    public boolean[] starlight$getSkyEmptinessMap() {
+        return ((ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk)this.wrapped).starlight$getSkyEmptinessMap();
+    }
+
+    @Override
+    public void starlight$setSkyEmptinessMap(final boolean[] emptinessMap) {
+        ((ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk)this.wrapped).starlight$setSkyEmptinessMap(emptinessMap);
+    }
+
+    @Override
+    public boolean[] starlight$getBlockEmptinessMap() {
+        return ((ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk)this.wrapped).starlight$getBlockEmptinessMap();
+    }
+
+    @Override
+    public void starlight$setBlockEmptinessMap(final boolean[] emptinessMap) {
+        ((ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk)this.wrapped).starlight$setBlockEmptinessMap(emptinessMap);
+    }
+    // Paper end - rewrite chunk system
+
     @Nullable
     @Override
     public BlockEntity getBlockEntity(BlockPos pos) {
diff --git a/src/main/java/net/minecraft/world/level/chunk/LevelChunk.java b/src/main/java/net/minecraft/world/level/chunk/LevelChunk.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/LevelChunk.java
+++ b/src/main/java/net/minecraft/world/level/chunk/LevelChunk.java
@@ -0,0 +0,0 @@ import net.minecraft.world.ticks.LevelChunkTicks;
 import net.minecraft.world.ticks.TickContainerAccess;
 import org.slf4j.Logger;
 
-public class LevelChunk extends ChunkAccess {
+public class LevelChunk extends ChunkAccess implements ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemLevelChunk, ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk, ca.spottedleaf.moonrise.patches.getblock.GetBlockChunk { // Paper - rewrite chunk system // Paper - get block chunk optimisation
 
     static final Logger LOGGER = LogUtils.getLogger();
     private static final TickingBlockEntity NULL_TICKER = new TickingBlockEntity() {
@@ -0,0 +0,0 @@ public class LevelChunk extends ChunkAccess {
         this.postLoad = entityLoader;
         this.blockTicks = blockTickScheduler;
         this.fluidTicks = fluidTickScheduler;
+        // Paper start - get block chunk optimisation
+        this.minSection = ca.spottedleaf.moonrise.common.util.WorldUtil.getMinSection(level);
+        this.maxSection = ca.spottedleaf.moonrise.common.util.WorldUtil.getMaxSection(level);
+
+        final boolean empty = ((Object)this instanceof EmptyLevelChunk);
+        this.debug = !empty && this.level.isDebug();
+        this.defaultBlockState = empty ? VOID_AIR_BLOCKSTATE : AIR_BLOCKSTATE;
+        // Paper end - get block chunk optimisation
     }
 
     // CraftBukkit start
@@ -0,0 +0,0 @@ public class LevelChunk extends ChunkAccess {
     // Paper start
     boolean loadedTicketLevel;
     // Paper end
+    // Paper start - rewrite chunk system
+    private boolean postProcessingDone;
+    private net.minecraft.server.level.ServerChunkCache.ChunkAndHolder chunkAndHolder;
+
+    @Override
+    public final boolean moonrise$isPostProcessingDone() {
+        return this.postProcessingDone;
+    }
+
+    @Override
+    public final net.minecraft.server.level.ServerChunkCache.ChunkAndHolder moonrise$getChunkAndHolder() {
+        return this.chunkAndHolder;
+    }
+
+    @Override
+    public final void moonrise$setChunkAndHolder(final net.minecraft.server.level.ServerChunkCache.ChunkAndHolder holder) {
+        this.chunkAndHolder = holder;
+    }
+    // Paper end - rewrite chunk system
+    // Paper start - get block chunk optimisation
+    private static final BlockState AIR_BLOCKSTATE = Blocks.AIR.defaultBlockState();
+    private static final FluidState AIR_FLUIDSTATE = Fluids.EMPTY.defaultFluidState();
+    private static final BlockState VOID_AIR_BLOCKSTATE = Blocks.VOID_AIR.defaultBlockState();
+    private final int minSection;
+    private final int maxSection;
+    private final boolean debug;
+    private final BlockState defaultBlockState;
+
+    @Override
+    public final BlockState moonrise$getBlock(final int x, final int y, final int z) {
+        return this.getBlockStateFinal(x, y, z);
+    }
+    // Paper end - get block chunk optimisation
 
     public LevelChunk(ServerLevel world, ProtoChunk protoChunk, @Nullable LevelChunk.PostLoadProcessor entityLoader) {
         this(world, protoChunk.getPos(), protoChunk.getUpgradeData(), protoChunk.unpackBlockTicks(), protoChunk.unpackFluidTicks(), protoChunk.getInhabitedTime(), protoChunk.getSections(), entityLoader, protoChunk.getBlendingData());
@@ -0,0 +0,0 @@ public class LevelChunk extends ChunkAccess {
             }
         }
 
-        this.skyLightSources = protoChunk.skyLightSources;
+        // Paper - rewrite chunk system
         this.setLightCorrect(protoChunk.isLightCorrect());
         this.markUnsaved();
         this.needsDecoration = true; // CraftBukkit
         // CraftBukkit start
         this.persistentDataContainer = protoChunk.persistentDataContainer; // SPIGOT-6814: copy PDC to account for 1.17 to 1.18 chunk upgrading.
         // CraftBukkit end
+        // Paper start - rewrite chunk system
+        this.starlight$setBlockNibbles(((ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk)protoChunk).starlight$getBlockNibbles());
+        this.starlight$setSkyNibbles(((ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk)protoChunk).starlight$getSkyNibbles());
+        this.starlight$setSkyEmptinessMap(((ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk)protoChunk).starlight$getSkyEmptinessMap());
+        this.starlight$setBlockEmptinessMap(((ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk)protoChunk).starlight$getBlockEmptinessMap());
+        // Paper end - rewrite chunk system
     }
 
     public void setUnsavedListener(LevelChunk.UnsavedListener unsavedListener) {
@@ -0,0 +0,0 @@ public class LevelChunk extends ChunkAccess {
                     ProfilerFiller gameprofilerfiller = Profiler.get();
 
                     gameprofilerfiller.push("updateSkyLightSources");
-                    this.skyLightSources.update(this, j, i, l);
+                    // Paper - rewrite chunk system
                     gameprofilerfiller.popPush("queueCheckLight");
                     this.level.getChunkSource().getLightEngine().checkBlock(blockposition);
                     gameprofilerfiller.pop();
@@ -0,0 +0,0 @@ public class LevelChunk extends ChunkAccess {
 
     // CraftBukkit start
     public void loadCallback() {
+        if (this.loadedTicketLevel) { LOGGER.error("Double calling chunk load!", new Throwable()); } // Paper
         // Paper start
         this.loadedTicketLevel = true;
         // Paper end
         org.bukkit.Server server = this.level.getCraftServer();
-        this.level.getChunkSource().addLoadedChunk(this); // Paper
+        // Paper - rewrite chunk system
         if (server != null) {
             /*
              * If it's a new world, the first few chunks are generated inside
@@ -0,0 +0,0 @@ public class LevelChunk extends ChunkAccess {
              */
             org.bukkit.Chunk bukkitChunk = new org.bukkit.craftbukkit.CraftChunk(this);
             server.getPluginManager().callEvent(new org.bukkit.event.world.ChunkLoadEvent(bukkitChunk, this.needsDecoration));
+            org.bukkit.craftbukkit.event.CraftEventFactory.callEntitiesLoadEvent(this.level, this.chunkPos, ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getChunkTaskScheduler().chunkHolderManager.getChunkHolder(this.locX, this.locZ).getEntityChunk().getAllEntities()); // Paper - rewrite chunk system
 
             if (this.needsDecoration) {
                 this.needsDecoration = false;
@@ -0,0 +0,0 @@ public class LevelChunk extends ChunkAccess {
     }
 
     public void unloadCallback() {
+        if (!this.loadedTicketLevel) { LOGGER.error("Double calling chunk unload!", new Throwable()); } // Paper
         org.bukkit.Server server = this.level.getCraftServer();
+        org.bukkit.craftbukkit.event.CraftEventFactory.callEntitiesUnloadEvent(this.level, this.chunkPos, ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getChunkTaskScheduler().chunkHolderManager.getChunkHolder(this.locX, this.locZ).getEntityChunk().getAllEntities()); // Paper - rewrite chunk system
         org.bukkit.Chunk bukkitChunk = new org.bukkit.craftbukkit.CraftChunk(this);
-        org.bukkit.event.world.ChunkUnloadEvent unloadEvent = new org.bukkit.event.world.ChunkUnloadEvent(bukkitChunk, this.isUnsaved());
+        org.bukkit.event.world.ChunkUnloadEvent unloadEvent = new org.bukkit.event.world.ChunkUnloadEvent(bukkitChunk, true); // Paper - rewrite chunk system - force save to true so that mustNotSave is correctly set below
         server.getPluginManager().callEvent(unloadEvent);
         // note: saving can be prevented, but not forced if no saving is actually required
         this.mustNotSave = !unloadEvent.isSaveChunk();
-        this.level.getChunkSource().removeLoadedChunk(this); // Paper
+        // Paper - rewrite chunk system
         // Paper start
         this.loadedTicketLevel = false;
         // Paper end
@@ -0,0 +0,0 @@ public class LevelChunk extends ChunkAccess {
 
     @Override
     public boolean isUnsaved() {
-        return super.isUnsaved() && !this.mustNotSave;
+        // Paper start - rewrite chunk system
+        final long gameTime = this.level.getGameTime();
+        if (((ca.spottedleaf.moonrise.patches.chunk_system.ticks.ChunkSystemLevelChunkTicks)this.blockTicks).moonrise$isDirty(gameTime)
+            || ((ca.spottedleaf.moonrise.patches.chunk_system.ticks.ChunkSystemLevelChunkTicks)this.fluidTicks).moonrise$isDirty(gameTime)) {
+            return true;
+        }
+
+        return super.isUnsaved();
+        // Paper end - rewrite chunk system
+    }
+
+    // Paper start - rewrite chunk system
+    @Override
+    public boolean tryMarkSaved() {
+        if (!this.isUnsaved()) {
+            return false;
+        }
+        ((ca.spottedleaf.moonrise.patches.chunk_system.ticks.ChunkSystemLevelChunkTicks)this.blockTicks).moonrise$clearDirty();
+        ((ca.spottedleaf.moonrise.patches.chunk_system.ticks.ChunkSystemLevelChunkTicks)this.fluidTicks).moonrise$clearDirty();
+
+        super.tryMarkSaved();
+
+        return true;
     }
+    // Paper end - rewrite chunk system
     // CraftBukkit end
 
     public boolean isEmpty() {
@@ -0,0 +0,0 @@ public class LevelChunk extends ChunkAccess {
 
         this.pendingBlockEntities.clear();
         this.upgradeData.upgrade(this);
+        this.postProcessingDone = true; // Paper - rewrite chunk system
     }
 
     @Nullable
diff --git a/src/main/java/net/minecraft/world/level/chunk/LevelChunkSection.java b/src/main/java/net/minecraft/world/level/chunk/LevelChunkSection.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/LevelChunkSection.java
+++ b/src/main/java/net/minecraft/world/level/chunk/LevelChunkSection.java
@@ -0,0 +0,0 @@ import net.minecraft.world.level.block.Blocks;
 import net.minecraft.world.level.block.state.BlockState;
 import net.minecraft.world.level.material.FluidState;
 
-public class LevelChunkSection {
+public class LevelChunkSection implements ca.spottedleaf.moonrise.patches.block_counting.BlockCountingChunkSection { // Paper - block counting
 
     public static final int SECTION_WIDTH = 16;
     public static final int SECTION_HEIGHT = 16;
@@ -0,0 +0,0 @@ public class LevelChunkSection {
     public final PalettedContainer<BlockState> states;
     private PalettedContainer<Holder<Biome>> biomes; // CraftBukkit - read/write
 
+    // Paper start - block counting
+    private static final it.unimi.dsi.fastutil.shorts.ShortArrayList FULL_LIST = new it.unimi.dsi.fastutil.shorts.ShortArrayList(16*16*16);
+    static {
+        for (short i = 0; i < (16*16*16); ++i) {
+            FULL_LIST.add(i);
+        }
+    }
+
+    private boolean isClient;
+    private static final short CLIENT_FORCED_SPECIAL_COLLIDING_BLOCKS = (short)9999;
+    private short specialCollidingBlocks;
+    private final ca.spottedleaf.moonrise.common.list.ShortList tickingBlocks = new ca.spottedleaf.moonrise.common.list.ShortList();
+
+    @Override
+    public final boolean moonrise$hasSpecialCollidingBlocks() {
+        return this.specialCollidingBlocks != 0;
+    }
+
+    @Override
+    public final ca.spottedleaf.moonrise.common.list.ShortList moonrise$getTickingBlockList() {
+        return this.tickingBlocks;
+    }
+    // Paper end - block counting
+
     private LevelChunkSection(LevelChunkSection section) {
         this.nonEmptyBlockCount = section.nonEmptyBlockCount;
         this.tickingBlockCount = section.tickingBlockCount;
@@ -0,0 +0,0 @@ public class LevelChunkSection {
         return this.setBlockState(x, y, z, state, true);
     }
 
+    // Paper start - block counting
+    private void updateBlockCallback(final int x, final int y, final int z, final BlockState newState,
+                                     final BlockState oldState) {
+        if (oldState == newState) {
+            return;
+        }
+
+        if (this.isClient) {
+            if (ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.isSpecialCollidingBlock(newState)) {
+                this.specialCollidingBlocks = CLIENT_FORCED_SPECIAL_COLLIDING_BLOCKS;
+            }
+            return;
+        }
+
+        final boolean isSpecialOld = ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.isSpecialCollidingBlock(oldState);
+        final boolean isSpecialNew = ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.isSpecialCollidingBlock(newState);
+        if (isSpecialOld != isSpecialNew) {
+            if (isSpecialOld) {
+                --this.specialCollidingBlocks;
+            } else {
+                ++this.specialCollidingBlocks;
+            }
+        }
+
+        final boolean oldTicking = oldState.isRandomlyTicking();
+        final boolean newTicking = newState.isRandomlyTicking();
+        if (oldTicking != newTicking) {
+            final ca.spottedleaf.moonrise.common.list.ShortList tickingBlocks = this.tickingBlocks;
+            final short position = (short)(x | (z << 4) | (y << (4+4)));
+
+            if (oldTicking) {
+                tickingBlocks.remove(position);
+            } else {
+                tickingBlocks.add(position);
+            }
+        }
+    }
+    // Paper end - block counting
+
     public BlockState setBlockState(int x, int y, int z, BlockState state, boolean lock) {
         BlockState iblockdata1;
 
@@ -0,0 +0,0 @@ public class LevelChunkSection {
             }
         }
 
-        if (!fluid.isEmpty()) {
+        if (!!fluid.isRandomlyTicking()) { // Paper - block counting
             --this.tickingFluidCount;
         }
 
@@ -0,0 +0,0 @@ public class LevelChunkSection {
             }
         }
 
-        if (!fluid1.isEmpty()) {
+        if (!!fluid1.isRandomlyTicking()) { // Paper - block counting
             ++this.tickingFluidCount;
         }
 
+        this.updateBlockCallback(x, y, z, state, iblockdata1); // Paper - block counting
+
         return iblockdata1;
     }
 
@@ -0,0 +0,0 @@ public class LevelChunkSection {
     }
 
     public void recalcBlockCounts() {
-        class a implements PalettedContainer.CountConsumer<BlockState> {
+        // Paper start - block counting
+        // reset, then recalculate
+        this.nonEmptyBlockCount = (short)0;
+        this.tickingBlockCount = (short)0;
+        this.tickingFluidCount = (short)0;
+        this.specialCollidingBlocks = (short)0;
+        this.tickingBlocks.clear();
+
+        if (this.maybeHas((final BlockState state) -> !state.isAir())) {
+            final PalettedContainer.Data<BlockState> data = this.states.data;
+            final Palette<BlockState> palette = data.palette();
+            final int paletteSize = palette.getSize();
+            final net.minecraft.util.BitStorage storage = data.storage();
+
+            final it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap<it.unimi.dsi.fastutil.shorts.ShortArrayList> counts;
+            if (paletteSize == 1) {
+                counts = new it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap<>(1);
+                counts.put(0, FULL_LIST);
+            } else {
+                counts = ((ca.spottedleaf.moonrise.patches.block_counting.BlockCountingBitStorage)storage).moonrise$countEntries();
+            }
+
+            for (final java.util.Iterator<it.unimi.dsi.fastutil.ints.Int2ObjectMap.Entry<it.unimi.dsi.fastutil.shorts.ShortArrayList>> iterator = counts.int2ObjectEntrySet().fastIterator(); iterator.hasNext();) {
+                final it.unimi.dsi.fastutil.ints.Int2ObjectMap.Entry<it.unimi.dsi.fastutil.shorts.ShortArrayList> entry = iterator.next();
+                final int paletteIdx = entry.getIntKey();
+                final it.unimi.dsi.fastutil.shorts.ShortArrayList coordinates = entry.getValue();
+                final int paletteCount = coordinates.size();
 
-            public int nonEmptyBlockCount;
-            public int tickingBlockCount;
-            public int tickingFluidCount;
+                final BlockState state = palette.valueFor(paletteIdx);
 
-            a(final LevelChunkSection chunksection) {}
+                if (state.isAir()) {
+                    continue;
+                }
+
+                if (ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.isSpecialCollidingBlock(state)) {
+                    this.specialCollidingBlocks += (short)paletteCount;
+                }
+                this.nonEmptyBlockCount += (short)paletteCount;
+                if (state.isRandomlyTicking()) {
+                    this.tickingBlockCount += (short)paletteCount;
+                    final short[] raw = coordinates.elements();
+                    final int rawLen = raw.length;
+
+                    final ca.spottedleaf.moonrise.common.list.ShortList tickingBlocks = this.tickingBlocks;
 
-            public void accept(BlockState iblockdata, int i) {
-                FluidState fluid = iblockdata.getFluidState();
+                    tickingBlocks.setMinCapacity(Math.min((rawLen + tickingBlocks.size()) * 3 / 2, 16*16*16));
 
-                if (!iblockdata.isAir()) {
-                    this.nonEmptyBlockCount += i;
-                    if (iblockdata.isRandomlyTicking()) {
-                        this.tickingBlockCount += i;
+                    java.util.Objects.checkFromToIndex(0, paletteCount, raw.length);
+                    for (int i = 0; i < paletteCount; ++i) {
+                        tickingBlocks.add(raw[i]);
                     }
                 }
 
+                final FluidState fluid = state.getFluidState();
+
                 if (!fluid.isEmpty()) {
-                    this.nonEmptyBlockCount += i;
+                    //this.nonEmptyBlockCount += count; // fix vanilla bug: make non-empty block count correct
                     if (fluid.isRandomlyTicking()) {
-                        this.tickingFluidCount += i;
+                        this.tickingFluidCount += (short)paletteCount;
                     }
                 }
-
             }
         }
-
-        a a0 = new a(this);
-
-        this.states.count(a0);
-        this.nonEmptyBlockCount = (short) a0.nonEmptyBlockCount;
-        this.tickingBlockCount = (short) a0.tickingBlockCount;
-        this.tickingFluidCount = (short) a0.tickingFluidCount;
+        // Paper end - block counting
     }
 
     public PalettedContainer<BlockState> getStates() {
@@ -0,0 +0,0 @@ public class LevelChunkSection {
 
         datapaletteblock.read(buf);
         this.biomes = datapaletteblock;
+        // Paper start - block counting
+        this.isClient = true;
+        // force has special colliding blocks to be true
+        this.specialCollidingBlocks = this.nonEmptyBlockCount != (short)0 && this.maybeHas(ca.spottedleaf.moonrise.patches.collisions.CollisionUtil::isSpecialCollidingBlock) ? CLIENT_FORCED_SPECIAL_COLLIDING_BLOCKS : (short)0;
+        // Paper end - block counting
     }
 
     public void readBiomes(FriendlyByteBuf buf) {
diff --git a/src/main/java/net/minecraft/world/level/chunk/LinearPalette.java b/src/main/java/net/minecraft/world/level/chunk/LinearPalette.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/LinearPalette.java
+++ b/src/main/java/net/minecraft/world/level/chunk/LinearPalette.java
@@ -0,0 +0,0 @@ import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.network.VarInt;
 import org.apache.commons.lang3.Validate;
 
-public class LinearPalette<T> implements Palette<T> {
+public class LinearPalette<T> implements Palette<T>, ca.spottedleaf.moonrise.patches.fast_palette.FastPalette<T> { // Paper - optimise palette reads
     private final IdMap<T> registry;
     private final T[] values;
     private final PaletteResize<T> resizeHandler;
     private final int bits;
     private int size;
 
+    // Paper start - optimise palette reads
+    @Override
+    public final T[] moonrise$getRawPalette(final ca.spottedleaf.moonrise.patches.fast_palette.FastPaletteData<T> container) {
+        return this.values;
+    }
+    // Paper end - optimise palette reads
+
     private LinearPalette(IdMap<T> idList, int bits, PaletteResize<T> listener, List<T> list) {
         this.registry = idList;
         this.values = (T[])(new Object[1 << bits]);
diff --git a/src/main/java/net/minecraft/world/level/chunk/Palette.java b/src/main/java/net/minecraft/world/level/chunk/Palette.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/Palette.java
+++ b/src/main/java/net/minecraft/world/level/chunk/Palette.java
@@ -0,0 +0,0 @@ import java.util.function.Predicate;
 import net.minecraft.core.IdMap;
 import net.minecraft.network.FriendlyByteBuf;
 
-public interface Palette<T> {
+public interface Palette<T> extends ca.spottedleaf.moonrise.patches.fast_palette.FastPalette<T> { // Paper - optimise palette reads
     int idFor(T object);
 
     boolean maybeHas(Predicate<T> predicate);
diff --git a/src/main/java/net/minecraft/world/level/chunk/PalettedContainer.java b/src/main/java/net/minecraft/world/level/chunk/PalettedContainer.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/PalettedContainer.java
+++ b/src/main/java/net/minecraft/world/level/chunk/PalettedContainer.java
@@ -0,0 +0,0 @@ public class PalettedContainer<T> implements PaletteResize<T>, PalettedContainer
     private final PaletteResize<T> dummyPaletteResize = (newSize, added) -> 0;
     public final IdMap<T> registry;
     private final T @org.jetbrains.annotations.Nullable [] presetValues; // Paper - Anti-Xray - Add preset values
-    private volatile PalettedContainer.Data<T> data;
+    public volatile PalettedContainer.Data<T> data; // Paper - optimise collisions - public
     private final PalettedContainer.Strategy strategy;
     // private final ThreadingDetector threadingDetector = new ThreadingDetector("PalettedContainer"); // Paper - unused
 
@@ -0,0 +0,0 @@ public class PalettedContainer<T> implements PaletteResize<T>, PalettedContainer
             );
     }
 
+    // Paper start - optimise palette reads
+    private void updateData(final PalettedContainer.Data<T> data) {
+        if (data != null) {
+            ((ca.spottedleaf.moonrise.patches.fast_palette.FastPaletteData<T>)(Object)data).moonrise$setPalette(
+                ((ca.spottedleaf.moonrise.patches.fast_palette.FastPalette<T>)data.palette).moonrise$getRawPalette((ca.spottedleaf.moonrise.patches.fast_palette.FastPaletteData<T>)(Object)data)
+            );
+        }
+    }
+
+    private T readPaletteSlow(final PalettedContainer.Data<T> data, final int paletteIdx) {
+        return data.palette.valueFor(paletteIdx);
+    }
+
+    private T readPalette(final PalettedContainer.Data<T> data, final int paletteIdx) {
+        final T[] palette = ((ca.spottedleaf.moonrise.patches.fast_palette.FastPaletteData<T>)(Object)data).moonrise$getPalette();
+        if (palette == null) {
+            return this.readPaletteSlow(data, paletteIdx);
+        }
+
+        final T ret = palette[paletteIdx];
+        if (ret == null) {
+            throw new IllegalArgumentException("Palette index out of bounds");
+        }
+        return ret;
+    }
+    // Paper end - optimise palette reads
+
     // Paper start - Anti-Xray - Add preset values
     @Deprecated @io.papermc.paper.annotation.DoNotUse public PalettedContainer(IdMap<T> idList, PalettedContainer.Strategy paletteProvider, PalettedContainer.Configuration<T> dataProvider, BitStorage storage, List<T> paletteEntries) { this(idList, paletteProvider, dataProvider, storage, paletteEntries, null, null); }
     public PalettedContainer(
@@ -0,0 +0,0 @@ public class PalettedContainer<T> implements PaletteResize<T>, PalettedContainer
             }
         }
         // Paper end
+        this.updateData(this.data); // Paper - optimise palette reads
     }
 
     // Paper start - Anti-Xray - Add preset values
@@ -0,0 +0,0 @@ public class PalettedContainer<T> implements PaletteResize<T>, PalettedContainer
         this.registry = idList;
         this.strategy = paletteProvider;
         this.data = data;
+        this.updateData(this.data); // Paper - optimise palette reads
     }
 
     private PalettedContainer(PalettedContainer<T> container, T @org.jetbrains.annotations.Nullable [] presetValues) { // Paper - Anti-Xray - Add preset values
@@ -0,0 +0,0 @@ public class PalettedContainer<T> implements PaletteResize<T>, PalettedContainer
         this.registry = idList;
         this.data = this.createOrReuseData(null, 0);
         this.data.palette.idFor(object);
+        this.updateData(this.data); // Paper - optimise palette reads
     }
 
     private PalettedContainer.Data<T> createOrReuseData(@Nullable PalettedContainer.Data<T> previousData, int bits) {
@@ -0,0 +0,0 @@ public class PalettedContainer<T> implements PaletteResize<T>, PalettedContainer
         data2.copyFrom(data.palette, data.storage);
         this.data = data2;
         this.addPresetValues();
+        this.updateData(this.data); // Paper - optimise palette reads
         return object == null ? -1 : data2.palette.idFor(object);
         // Paper end
     }
@@ -0,0 +0,0 @@ public class PalettedContainer<T> implements PaletteResize<T>, PalettedContainer
     }
 
     private synchronized T getAndSet(int index, T value) { // Paper - synchronize
-        int i = this.data.palette.idFor(value);
-        int j = this.data.storage.getAndSet(index, i);
-        return this.data.palette.valueFor(j);
+        // Paper start - optimise palette reads
+        final int paletteIdx = this.data.palette.idFor(value);
+        final PalettedContainer.Data<T> data = this.data;
+        final int prev = data.storage.getAndSet(index, paletteIdx);
+        return this.readPalette(data, prev);
+        // Paper end - optimise palette reads
     }
 
     public void set(int x, int y, int z, T value) {
@@ -0,0 +0,0 @@ public class PalettedContainer<T> implements PaletteResize<T>, PalettedContainer
         return this.get(this.strategy.getIndex(x, y, z));
     }
 
-    protected T get(int index) {
-        PalettedContainer.Data<T> data = this.data;
-        return data.palette.valueFor(data.storage.get(index));
+    public T get(int index) { // Paper - public
+        // Paper start - optimise palette reads
+        final PalettedContainer.Data<T> data = this.data;
+        return this.readPalette(data, data.storage.get(index));
+        // Paper end - optimise palette reads
     }
 
     @Override
@@ -0,0 +0,0 @@ public class PalettedContainer<T> implements PaletteResize<T>, PalettedContainer
             buf.readLongArray(data.storage.getRaw());
             this.data = data;
             this.addPresetValues(); // Paper - Anti-Xray - Add preset values (inefficient, but this isn't used by the server)
+            this.updateData(this.data); // Paper - optimise palette reads
         } finally {
             this.release();
         }
@@ -0,0 +0,0 @@ public class PalettedContainer<T> implements PaletteResize<T>, PalettedContainer
         void accept(T object, int count);
     }
 
-    static record Data<T>(PalettedContainer.Configuration<T> configuration, BitStorage storage, Palette<T> palette) {
+    // Paper start - optimise palette reads
+    public static final class Data<T> implements ca.spottedleaf.moonrise.patches.fast_palette.FastPaletteData<T> {
+
+        private final PalettedContainer.Configuration<T> configuration;
+        private final BitStorage storage;
+        private final Palette<T> palette;
+
+        private T[] moonrise$palette;
+
+        public Data(final PalettedContainer.Configuration<T> configuration, final BitStorage storage, final Palette<T> palette) {
+            this.configuration = configuration;
+            this.storage = storage;
+            this.palette = palette;
+        }
+
+        public PalettedContainer.Configuration<T> configuration() {
+            return this.configuration;
+        }
+
+        public BitStorage storage() {
+            return this.storage;
+        }
+
+        public Palette<T> palette() {
+            return this.palette;
+        }
+
+        @Override
+        public final T[] moonrise$getPalette() {
+            return this.moonrise$palette;
+        }
+
+        @Override
+        public final void moonrise$setPalette(final T[] palette) {
+            this.moonrise$palette = palette;
+        }
+        // Paper end - optimise palette reads
+
         public void copyFrom(Palette<T> palette, BitStorage storage) {
             for (int i = 0; i < storage.getSize(); i++) {
                 T object = palette.valueFor(storage.get(i));
diff --git a/src/main/java/net/minecraft/world/level/chunk/ProtoChunk.java b/src/main/java/net/minecraft/world/level/chunk/ProtoChunk.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/ProtoChunk.java
+++ b/src/main/java/net/minecraft/world/level/chunk/ProtoChunk.java
@@ -0,0 +0,0 @@ public class ProtoChunk extends ChunkAccess {
                     }
 
                     if (LightEngine.hasDifferentLightProperties(blockState, state)) {
-                        this.skyLightSources.update(this, m, j, o);
+                        // Paper - rewrite chunk system
                         this.lightEngine.checkBlock(pos);
                     }
                 }
diff --git a/src/main/java/net/minecraft/world/level/chunk/SingleValuePalette.java b/src/main/java/net/minecraft/world/level/chunk/SingleValuePalette.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/SingleValuePalette.java
+++ b/src/main/java/net/minecraft/world/level/chunk/SingleValuePalette.java
@@ -0,0 +0,0 @@ import net.minecraft.network.FriendlyByteBuf;
 import net.minecraft.network.VarInt;
 import org.apache.commons.lang3.Validate;
 
-public class SingleValuePalette<T> implements Palette<T> {
+public class SingleValuePalette<T> implements Palette<T>, ca.spottedleaf.moonrise.patches.fast_palette.FastPalette<T> { // Paper - optimise palette reads
     private final IdMap<T> registry;
     @Nullable
     private T value;
     private final PaletteResize<T> resizeHandler;
 
+    // Paper start - optimise palette reads
+    private T[] rawPalette;
+
+    @Override
+    public final T[] moonrise$getRawPalette(final ca.spottedleaf.moonrise.patches.fast_palette.FastPaletteData<T> container) {
+        if (this.rawPalette != null) {
+            return this.rawPalette;
+        }
+        return this.rawPalette = (T[])new Object[] { this.value };
+    }
+    // Paper end - optimise palette reads
+
     public SingleValuePalette(IdMap<T> idList, PaletteResize<T> listener, List<T> entries) {
         this.registry = idList;
         this.resizeHandler = listener;
@@ -0,0 +0,0 @@ public class SingleValuePalette<T> implements Palette<T> {
             return this.resizeHandler.onResize(1, object);
         } else {
             this.value = object;
+            // Paper start - optimise palette reads
+            if (this.rawPalette != null) {
+                this.rawPalette[0] = object;
+            }
+            // Paper end - optimise palette reads
             return 0;
         }
     }
@@ -0,0 +0,0 @@ public class SingleValuePalette<T> implements Palette<T> {
     @Override
     public void read(FriendlyByteBuf buf) {
         this.value = this.registry.byIdOrThrow(buf.readVarInt());
+        // Paper start - optimise palette reads
+        if (this.rawPalette != null) {
+            this.rawPalette[0] = this.value;
+        }
+        // Paper end - optimise palette reads
     }
 
     @Override
diff --git a/src/main/java/net/minecraft/world/level/chunk/status/ChunkPyramid.java b/src/main/java/net/minecraft/world/level/chunk/status/ChunkPyramid.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/status/ChunkPyramid.java
+++ b/src/main/java/net/minecraft/world/level/chunk/status/ChunkPyramid.java
@@ -0,0 +0,0 @@ public record ChunkPyramid(ImmutableList<ChunkStep> steps) {
         .step(ChunkStatus.CARVERS, builder -> builder)
         .step(ChunkStatus.FEATURES, builder -> builder)
         .step(ChunkStatus.INITIALIZE_LIGHT, builder -> builder.setTask(ChunkStatusTasks::initializeLight))
-        .step(ChunkStatus.LIGHT, builder -> builder.addRequirement(ChunkStatus.INITIALIZE_LIGHT, 1).setTask(ChunkStatusTasks::light))
+        .step(ChunkStatus.LIGHT, builder -> builder.setTask(ChunkStatusTasks::light)) // Paper - rewrite chunk system - starlight does not need neighbours
         .step(ChunkStatus.SPAWN, builder -> builder)
         .step(ChunkStatus.FULL, builder -> builder.setTask(ChunkStatusTasks::full))
         .build();
diff --git a/src/main/java/net/minecraft/world/level/chunk/status/ChunkStatus.java b/src/main/java/net/minecraft/world/level/chunk/status/ChunkStatus.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/status/ChunkStatus.java
+++ b/src/main/java/net/minecraft/world/level/chunk/status/ChunkStatus.java
@@ -0,0 +0,0 @@ import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.level.levelgen.Heightmap;
 import org.jetbrains.annotations.VisibleForTesting;
 
-public class ChunkStatus {
+public class ChunkStatus implements ca.spottedleaf.moonrise.patches.chunk_system.level.chunk.ChunkSystemChunkStatus { // Paper - rewrite chunk system
     public static final int MAX_STRUCTURE_DISTANCE = 8;
     private static final EnumSet<Heightmap.Types> WORLDGEN_HEIGHTMAPS = EnumSet.of(Heightmap.Types.OCEAN_FLOOR_WG, Heightmap.Types.WORLD_SURFACE_WG);
     public static final EnumSet<Heightmap.Types> FINAL_HEIGHTMAPS = EnumSet.of(
@@ -0,0 +0,0 @@ public class ChunkStatus {
         return list;
     }
 
+    // Paper start - rewrite chunk system
+    private boolean isParallelCapable;
+    private boolean emptyLoadTask;
+    private int writeRadius;
+    private ChunkStatus nextStatus;
+    private java.util.concurrent.atomic.AtomicBoolean warnedAboutNoImmediateComplete;
+
+    @Override
+    public final boolean moonrise$isParallelCapable() {
+        return this.isParallelCapable;
+    }
+
+    @Override
+    public final void moonrise$setParallelCapable(final boolean value) {
+        this.isParallelCapable = value;
+    }
+
+    @Override
+    public final int moonrise$getWriteRadius() {
+        return this.writeRadius;
+    }
+
+    @Override
+    public final void moonrise$setWriteRadius(final int value) {
+        this.writeRadius = value;
+    }
+
+    @Override
+    public final ChunkStatus moonrise$getNextStatus() {
+        return this.nextStatus;
+    }
+
+    @Override
+    public final boolean moonrise$isEmptyLoadStatus() {
+        return this.emptyLoadTask;
+    }
+
+    @Override
+    public void moonrise$setEmptyLoadStatus(final boolean value) {
+        this.emptyLoadTask = value;
+    }
+
+    @Override
+    public final boolean moonrise$isEmptyGenStatus() {
+        return (Object)this == ChunkStatus.EMPTY;
+    }
+
+    @Override
+    public final java.util.concurrent.atomic.AtomicBoolean moonrise$getWarnedAboutNoImmediateComplete() {
+        return this.warnedAboutNoImmediateComplete;
+    }
+    // Paper end - rewrite chunk system
+
     @VisibleForTesting
     protected ChunkStatus(@Nullable ChunkStatus previous, EnumSet<Heightmap.Types> heightMapTypes, ChunkType chunkType) {
+        this.isParallelCapable = false;
+        this.writeRadius = -1;
+        this.nextStatus = (ChunkStatus)(Object)this;
+        if (previous != null) {
+            previous.nextStatus = (ChunkStatus)(Object)this;
+        }
+        this.warnedAboutNoImmediateComplete = new java.util.concurrent.atomic.AtomicBoolean();
         this.parent = previous == null ? this : previous;
         this.chunkType = chunkType;
         this.heightmapsAfter = heightMapTypes;
diff --git a/src/main/java/net/minecraft/world/level/chunk/status/ChunkStatusTasks.java b/src/main/java/net/minecraft/world/level/chunk/status/ChunkStatusTasks.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/status/ChunkStatusTasks.java
+++ b/src/main/java/net/minecraft/world/level/chunk/status/ChunkStatusTasks.java
@@ -0,0 +0,0 @@ public class ChunkStatusTasks {
                 chunk1 = protochunkextension.getWrapped();
             } else {
                 chunk1 = new LevelChunk(worldserver, protochunk, ($) -> { // Paper - decompile fix
-                    ChunkStatusTasks.postLoadProtoChunk(worldserver, protochunk.getEntities());
+                    ChunkStatusTasks.postLoadProtoChunk(worldserver, protochunk.getEntities(), protochunk.getPos()); // Paper - rewrite chunk system
                 });
                 generationchunkholder.replaceProtoChunk(new ImposterProtoChunk(chunk1, false));
             }
@@ -0,0 +0,0 @@ public class ChunkStatusTasks {
         }, context.mainThreadExecutor());
     }
 
-    public static void postLoadProtoChunk(ServerLevel world, List<CompoundTag> entities) { // Paper - public
+    public static void postLoadProtoChunk(ServerLevel world, List<CompoundTag> entities, ChunkPos pos) { // Paper - public // Paper - rewrite chunk system - add ChunkPos param
         if (!entities.isEmpty()) {
             // CraftBukkit start - these are spawned serialized (DefinedStructure) and we don't call an add event below at the moment due to ordering complexities
             world.addWorldGenChunkEntities(EntityType.loadEntitiesRecursive(entities, world, EntitySpawnReason.LOAD).filter((entity) -> {
@@ -0,0 +0,0 @@ public class ChunkStatusTasks {
                 }
                 checkDupeUUID(world, entity); // Paper - duplicate uuid resolving
                 return !needsRemoval;
-            }));
+            }), pos); // Paper - rewrite chunk system
             // CraftBukkit end
         }
 
diff --git a/src/main/java/net/minecraft/world/level/chunk/status/ChunkStep.java b/src/main/java/net/minecraft/world/level/chunk/status/ChunkStep.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/status/ChunkStep.java
+++ b/src/main/java/net/minecraft/world/level/chunk/status/ChunkStep.java
@@ -0,0 +0,0 @@ import net.minecraft.util.profiling.jfr.callback.ProfiledDuration;
 import net.minecraft.world.level.chunk.ChunkAccess;
 import net.minecraft.world.level.chunk.ProtoChunk;
 
-public record ChunkStep(
-    ChunkStatus targetStatus, ChunkDependencies directDependencies, ChunkDependencies accumulatedDependencies, int blockStateWriteRadius, ChunkStatusTask task
-) {
+// Paper start - rewerite chunk system - convert record to class
+public final class ChunkStep implements ca.spottedleaf.moonrise.patches.chunk_system.status.ChunkSystemChunkStep { // Paper - rewrite chunk system
+    private final ChunkStatus targetStatus;
+    private final ChunkDependencies directDependencies;
+    private final ChunkDependencies accumulatedDependencies;
+    private final int blockStateWriteRadius;
+    private final ChunkStatusTask task;
+
+    private final ChunkStatus[] byRadius; // Paper - rewrite chunk system
+
+    public ChunkStep(
+        ChunkStatus targetStatus, ChunkDependencies directDependencies, ChunkDependencies accumulatedDependencies, int blockStateWriteRadius, ChunkStatusTask task
+    ) {
+        this.targetStatus = targetStatus;
+        this.directDependencies = directDependencies;
+        this.accumulatedDependencies = accumulatedDependencies;
+        this.blockStateWriteRadius = blockStateWriteRadius;
+        this.task = task;
+
+        // Paper start - rewrite chunk system
+        this.byRadius = new ChunkStatus[this.getAccumulatedRadiusOf(ChunkStatus.EMPTY) + 1];
+        this.byRadius[0] = targetStatus.getParent();
+
+        for (ChunkStatus status = targetStatus.getParent(); status != ChunkStatus.EMPTY; status = status.getParent()) {
+            final int radius = this.getAccumulatedRadiusOf(status);
+
+            for (int j = 0; j <= radius; ++j) {
+                if (this.byRadius[j] == null) {
+                    this.byRadius[j] = status;
+                }
+            }
+        }
+        // Paper end - rewrite chunk system
+    }
+
+    // Paper start - rewrite chunk system
+    @Override
+    public final ChunkStatus moonrise$getRequiredStatusAtRadius(final int radius) {
+        return this.byRadius[radius];
+    }
+    // Paper end - rewrite chunk system
+
+    // Paper start - rewerite chunk system - convert record to class
+
     public int getAccumulatedRadiusOf(ChunkStatus status) {
         return status == this.targetStatus ? 0 : this.accumulatedDependencies.getRadiusOf(status);
     }
@@ -0,0 +0,0 @@ public record ChunkStep(
         return chunk;
     }
 
+    // Paper start - rewerite chunk system - convert record to class
+    public ChunkStatus targetStatus() {
+        return targetStatus;
+    }
+
+    public ChunkDependencies directDependencies() {
+        return directDependencies;
+    }
+
+    public ChunkDependencies accumulatedDependencies() {
+        return accumulatedDependencies;
+    }
+
+    public int blockStateWriteRadius() {
+        return blockStateWriteRadius;
+    }
+
+    public ChunkStatusTask task() {
+        return task;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == this) return true;
+        if (obj == null || obj.getClass() != this.getClass()) return false;
+        var that = (net.minecraft.world.level.chunk.status.ChunkStep) obj;
+        return java.util.Objects.equals(this.targetStatus, that.targetStatus) &&
+            java.util.Objects.equals(this.directDependencies, that.directDependencies) &&
+            java.util.Objects.equals(this.accumulatedDependencies, that.accumulatedDependencies) &&
+            this.blockStateWriteRadius == that.blockStateWriteRadius &&
+            java.util.Objects.equals(this.task, that.task);
+    }
+
+    @Override
+    public int hashCode() {
+        return java.util.Objects.hash(targetStatus, directDependencies, accumulatedDependencies, blockStateWriteRadius, task);
+    }
+
+    @Override
+    public String toString() {
+        return "ChunkStep[" +
+            "targetStatus=" + targetStatus + ", " +
+            "directDependencies=" + directDependencies + ", " +
+            "accumulatedDependencies=" + accumulatedDependencies + ", " +
+            "blockStateWriteRadius=" + blockStateWriteRadius + ", " +
+            "task=" + task + ']';
+    }
+    // Paper end - rewerite chunk system - convert record to class
+
+
     public static class Builder {
         private final ChunkStatus status;
         @Nullable
diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/ChunkStorage.java b/src/main/java/net/minecraft/world/level/chunk/storage/ChunkStorage.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/storage/ChunkStorage.java
+++ b/src/main/java/net/minecraft/world/level/chunk/storage/ChunkStorage.java
@@ -0,0 +0,0 @@ import net.minecraft.world.level.dimension.LevelStem;
 import net.minecraft.world.level.levelgen.structure.LegacyStructureDataHandler;
 import net.minecraft.world.level.storage.DimensionDataStorage;
 
-public class ChunkStorage implements AutoCloseable {
+public class ChunkStorage implements AutoCloseable, ca.spottedleaf.moonrise.patches.chunk_system.storage.ChunkSystemChunkStorage { // Paper - rewrite chunk system
 
     public static final int LAST_MONOLYTH_STRUCTURE_DATA_VERSION = 1493;
-    private final IOWorker worker;
+    // Paper - rewrite chunk system
     protected final DataFixer fixerUpper;
     @Nullable
     private volatile LegacyStructureDataHandler legacyStructureHandler;
 
+    // Paper start - rewrite chunk system
+    private static final org.slf4j.Logger LOGGER = com.mojang.logging.LogUtils.getLogger();
+    private final RegionFileStorage storage;
+
+    @Override
+    public final RegionFileStorage moonrise$getRegionStorage() {
+        return this.storage;
+    }
+    // Paper end - rewrite chunk system
+
     public ChunkStorage(RegionStorageInfo storageKey, Path directory, DataFixer dataFixer, boolean dsync) {
         this.fixerUpper = dataFixer;
-        this.worker = new IOWorker(storageKey, directory, dsync);
+        this.storage = new IOWorker(storageKey, directory, dsync).storage; // Paper - rewrite chunk system
     }
 
     public boolean isOldChunkAround(ChunkPos chunkPos, int checkRadius) {
-        return this.worker.isOldChunkAround(chunkPos, checkRadius);
+        return true; // Paper - rewrite chunk system
     }
 
     // CraftBukkit start
@@ -0,0 +0,0 @@ public class ChunkStorage implements AutoCloseable {
                     if (nbttagcompound.getCompound("Level").getBoolean("hasLegacyStructureData")) {
                         LegacyStructureDataHandler persistentstructurelegacy = this.getLegacyStructureHandler(resourcekey, supplier);
 
+                        synchronized (persistentstructurelegacy) { // Paper - rewrite chunk system
                         nbttagcompound = persistentstructurelegacy.updateFromLegacy(nbttagcompound);
+                        } // Paper - rewrite chunk system
                     }
                 }
 
@@ -0,0 +0,0 @@ public class ChunkStorage implements AutoCloseable {
     }
 
     public CompletableFuture<Optional<CompoundTag>> read(ChunkPos chunkPos) {
-        return this.worker.loadAsync(chunkPos);
+        // Paper start - rewrite chunk system
+        try {
+            return CompletableFuture.completedFuture(Optional.ofNullable(this.storage.read(chunkPos)));
+        } catch (final Throwable throwable) {
+            return CompletableFuture.failedFuture(throwable);
+        }
+        // Paper end - rewrite chunk system
     }
 
     public CompletableFuture<Void> write(ChunkPos chunkPos, Supplier<CompoundTag> nbtSupplier) {
@@ -0,0 +0,0 @@ public class ChunkStorage implements AutoCloseable {
         };
         // Paper end - guard against possible chunk pos desync
         this.handleLegacyStructureIndex(chunkPos);
-        return this.worker.store(chunkPos, guardedPosCheck); // Paper - guard against possible chunk pos desync
+        // Paper start - rewrite chunk system
+        try {
+            this.storage.write(chunkPos, guardedPosCheck.get());
+            return CompletableFuture.completedFuture(null);
+        } catch (final Throwable throwable) {
+            return CompletableFuture.failedFuture(throwable);
+        }
+        // Paper end - rewrite chunk system
     }
 
     protected void handleLegacyStructureIndex(ChunkPos chunkPos) {
         if (this.legacyStructureHandler != null) {
+            synchronized (this.legacyStructureHandler) { // Paper - rewrite chunk system
             this.legacyStructureHandler.removeIndex(chunkPos.toLong());
+            } // Paper - rewrite chunk system
         }
 
     }
 
     public void flushWorker() {
-        this.worker.synchronize(true).join();
+        // Paper start - rewrite chunk system
+        try {
+            this.storage.flush();
+        } catch (final IOException ex) {
+            LOGGER.error("Failed to flush chunk storage", ex);
+        }
+        // Paper end - rewrite chunk system
     }
 
     public void close() throws IOException {
-        this.worker.close();
+        this.storage.close(); // Paper - rewrite chunk system
     }
 
     public ChunkScanAccess chunkScanner() {
-        return this.worker;
+        // Paper start - rewrite chunk system
+        // TODO ChunkMap implementation?
+        return (chunkPos, streamTagVisitor) -> {
+            try {
+                this.storage.scanChunk(chunkPos, streamTagVisitor);
+                return java.util.concurrent.CompletableFuture.completedFuture(null);
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+        };
+        // Paper end - rewrite chunk system
     }
 
-    protected RegionStorageInfo storageInfo() {
-        return this.worker.storageInfo();
+    public RegionStorageInfo storageInfo() { // Paper - public
+        return this.storage.info(); // Paper - rewrite chunk system
     }
 }
diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/EntityStorage.java b/src/main/java/net/minecraft/world/level/chunk/storage/EntityStorage.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/storage/EntityStorage.java
+++ b/src/main/java/net/minecraft/world/level/chunk/storage/EntityStorage.java
@@ -0,0 +0,0 @@ public class EntityStorage implements EntityPersistentStorage<Entity> {
         }
     }
 
-    private static ChunkPos readChunkPos(CompoundTag chunkNbt) {
+    public static ChunkPos readChunkPos(CompoundTag chunkNbt) { // Paper - public
         int[] is = chunkNbt.getIntArray("Position");
         return new ChunkPos(is[0], is[1]);
     }
 
-    private static void writeChunkPos(CompoundTag chunkNbt, ChunkPos pos) {
+    public static void writeChunkPos(CompoundTag chunkNbt, ChunkPos pos) { // Paper - public
         chunkNbt.put("Position", new IntArrayTag(new int[]{pos.x, pos.z}));
     }
 
diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/IOWorker.java b/src/main/java/net/minecraft/world/level/chunk/storage/IOWorker.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/storage/IOWorker.java
+++ b/src/main/java/net/minecraft/world/level/chunk/storage/IOWorker.java
@@ -0,0 +0,0 @@ public class IOWorker implements ChunkScanAccess, AutoCloseable {
     private static final Logger LOGGER = LogUtils.getLogger();
     private final AtomicBoolean shutdownRequested = new AtomicBoolean();
     private final PriorityConsecutiveExecutor consecutiveExecutor;
-    private final RegionFileStorage storage;
+    public final RegionFileStorage storage; // Paper - public
     private final SequencedMap<ChunkPos, IOWorker.PendingStore> pendingWrites = new LinkedHashMap<>();
     private final Long2ObjectLinkedOpenHashMap<CompletableFuture<BitSet>> regionCacheForBlender = new Long2ObjectLinkedOpenHashMap<>();
     private static final int REGION_CACHE_SIZE = 1024;
diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java
+++ b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java
@@ -0,0 +0,0 @@ import net.minecraft.nbt.NbtIo; // Paper
 import net.minecraft.world.level.ChunkPos;
 import org.slf4j.Logger;
 
-public class RegionFile implements AutoCloseable {
+public class RegionFile implements AutoCloseable, ca.spottedleaf.moonrise.patches.chunk_system.storage.ChunkSystemRegionFile { // Paper - rewrite chunk system
 
     private static final Logger LOGGER = LogUtils.getLogger();
     private static final int SECTOR_BYTES = 4096;
@@ -0,0 +0,0 @@ public class RegionFile implements AutoCloseable {
     @VisibleForTesting
     protected final RegionBitmap usedSectors;
 
+    // Paper start - rewrite chunk system
+    @Override
+    public final ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.WriteData moonrise$startWrite(final net.minecraft.nbt.CompoundTag data, final ChunkPos pos) throws IOException {
+        final RegionFile.ChunkBuffer buffer = ((RegionFile)(Object)this).new ChunkBuffer(pos);
+        ((ca.spottedleaf.moonrise.patches.chunk_system.storage.ChunkSystemChunkBuffer)buffer).moonrise$setWriteOnClose(false);
+
+        final DataOutputStream out = new DataOutputStream(this.version.wrap(buffer));
+
+        return new ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.WriteData(
+            data, ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.WriteData.WriteResult.WRITE,
+            out, ((ca.spottedleaf.moonrise.patches.chunk_system.storage.ChunkSystemChunkBuffer)buffer)::moonrise$write
+        );
+    }
+    // Paper end - rewrite chunk system
+
     public RegionFile(RegionStorageInfo storageKey, Path directory, Path path, boolean dsync) throws IOException {
         this(storageKey, directory, path, RegionFileVersion.getCompressionFormat(), dsync); // Paper - Configurable region compression format
     }
@@ -0,0 +0,0 @@ public class RegionFile implements AutoCloseable {
 
     @Nullable
     private DataInputStream createExternalChunkInputStream(ChunkPos pos, byte flags) throws IOException {
+        // Paper start - rewrite chunk system
+        final DataInputStream is = this.createExternalChunkInputStream0(pos, flags);
+        if (is == null) {
+            return is;
+        }
+        return new ca.spottedleaf.moonrise.patches.chunk_system.util.stream.ExternalChunkStreamMarker(is);
+    }
+    @Nullable
+    private DataInputStream createExternalChunkInputStream0(ChunkPos pos, byte flags) throws IOException {
+        // Paper end - rewrite chunk system
         Path path = this.getExternalChunkPath(pos);
 
         if (!Files.isRegularFile(path, new LinkOption[0])) {
@@ -0,0 +0,0 @@ public class RegionFile implements AutoCloseable {
 
     }
     // Paper end
-    private class ChunkBuffer extends ByteArrayOutputStream {
+    private class ChunkBuffer extends ByteArrayOutputStream implements ca.spottedleaf.moonrise.patches.chunk_system.storage.ChunkSystemChunkBuffer { // Paper - rewrite chunk system
 
         private final ChunkPos pos;
 
+        // Paper start - rewrite chunk system
+        private boolean writeOnClose = true;
+
+        @Override
+        public final boolean moonrise$getWriteOnClose() {
+            return this.writeOnClose;
+        }
+
+        @Override
+        public final void moonrise$setWriteOnClose(final boolean value) {
+            this.writeOnClose = value;
+        }
+
+        @Override
+        public final void moonrise$write(final RegionFile regionFile) throws IOException {
+            regionFile.write(this.pos, ByteBuffer.wrap(this.buf, 0, this.count));
+        }
+        // Paper end - rewrite chunk system
+
         public ChunkBuffer(final ChunkPos chunkcoordintpair) {
             super(8096);
             super.write(0);
@@ -0,0 +0,0 @@ public class RegionFile implements AutoCloseable {
 
             JvmProfiler.INSTANCE.onRegionFileWrite(RegionFile.this.info, this.pos, RegionFile.this.version, i);
             bytebuffer.putInt(0, i);
-            RegionFile.this.write(this.pos, bytebuffer);
+            if (this.writeOnClose) { RegionFile.this.write(this.pos, bytebuffer); } // Paper - rewrite chunk system
         }
     }
 
diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java
+++ b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java
@@ -0,0 +0,0 @@ import net.minecraft.nbt.StreamTagVisitor;
 import net.minecraft.util.ExceptionCollector;
 import net.minecraft.world.level.ChunkPos;
 
-public final class RegionFileStorage implements AutoCloseable {
+public class RegionFileStorage implements AutoCloseable, ca.spottedleaf.moonrise.patches.chunk_system.io.ChunkSystemRegionFileStorage { // Paper - rewrite chunk system
 
     public static final String ANVIL_EXTENSION = ".mca";
     private static final int MAX_CACHE_SIZE = 256;
@@ -0,0 +0,0 @@ public final class RegionFileStorage implements AutoCloseable {
     private final Path folder;
     private final boolean sync;
 
-    RegionFileStorage(RegionStorageInfo storageKey, Path directory, boolean dsync) {
+    // Paper start - rewrite chunk system
+    private static final int REGION_SHIFT = 5;
+    private static final int MAX_NON_EXISTING_CACHE = 1024 * 4;
+    private final it.unimi.dsi.fastutil.longs.LongLinkedOpenHashSet nonExistingRegionFiles = new it.unimi.dsi.fastutil.longs.LongLinkedOpenHashSet();
+    private static String getRegionFileName(final int chunkX, final int chunkZ) {
+        return "r." + (chunkX >> REGION_SHIFT) + "." + (chunkZ >> REGION_SHIFT) + ".mca";
+    }
+
+    private boolean doesRegionFilePossiblyExist(final long position) {
+        synchronized (this.nonExistingRegionFiles) {
+            if (this.nonExistingRegionFiles.contains(position)) {
+                this.nonExistingRegionFiles.addAndMoveToFirst(position);
+                return false;
+            }
+            return true;
+        }
+    }
+
+    private void createRegionFile(final long position) {
+        synchronized (this.nonExistingRegionFiles) {
+            this.nonExistingRegionFiles.remove(position);
+        }
+    }
+
+    private void markNonExisting(final long position) {
+        synchronized (this.nonExistingRegionFiles) {
+            if (this.nonExistingRegionFiles.addAndMoveToFirst(position)) {
+                while (this.nonExistingRegionFiles.size() >= MAX_NON_EXISTING_CACHE) {
+                    this.nonExistingRegionFiles.removeLastLong();
+                }
+            }
+        }
+    }
+
+    @Override
+    public final boolean moonrise$doesRegionFileNotExistNoIO(final int chunkX, final int chunkZ) {
+        return !this.doesRegionFilePossiblyExist(ChunkPos.asLong(chunkX >> REGION_SHIFT, chunkZ >> REGION_SHIFT));
+    }
+
+    @Override
+    public synchronized final RegionFile moonrise$getRegionFileIfLoaded(final int chunkX, final int chunkZ) {
+        return this.regionCache.getAndMoveToFirst(ChunkPos.asLong(chunkX >> REGION_SHIFT, chunkZ >> REGION_SHIFT));
+    }
+
+    @Override
+    public synchronized final RegionFile moonrise$getRegionFileIfExists(final int chunkX, final int chunkZ) throws IOException {
+        final long key = ChunkPos.asLong(chunkX >> REGION_SHIFT, chunkZ >> REGION_SHIFT);
+
+        RegionFile ret = this.regionCache.getAndMoveToFirst(key);
+        if (ret != null) {
+            return ret;
+        }
+
+        if (!this.doesRegionFilePossiblyExist(key)) {
+            return null;
+        }
+
+        if (this.regionCache.size() >= io.papermc.paper.configuration.GlobalConfiguration.get().misc.regionFileCacheSize) { // Paper
+            this.regionCache.removeLast().close();
+        }
+
+        final Path regionPath = this.folder.resolve(getRegionFileName(chunkX, chunkZ));
+
+        if (!java.nio.file.Files.exists(regionPath)) {
+            this.markNonExisting(key);
+            return null;
+        }
+
+        this.createRegionFile(key);
+
+        FileUtil.createDirectoriesSafe(this.folder);
+
+        ret = new RegionFile(this.info, regionPath, this.folder, this.sync);
+
+        this.regionCache.putAndMoveToFirst(key, ret);
+
+        return ret;
+    }
+
+    @Override
+    public final ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.WriteData moonrise$startWrite(
+        final int chunkX, final int chunkZ, final CompoundTag compound
+    ) throws IOException {
+        if (compound == null) {
+            return new ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.WriteData(
+                compound, ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.WriteData.WriteResult.DELETE,
+                null, null
+            );
+        }
+
+        final ChunkPos pos = new ChunkPos(chunkX, chunkZ);
+        final RegionFile regionFile = this.getRegionFile(pos);
+
+        // note: not required to keep regionfile loaded after this call, as the write param takes a regionfile as input
+        // (and, the regionfile parameter is unused for writing until the write call)
+        final ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.WriteData writeData = ((ca.spottedleaf.moonrise.patches.chunk_system.storage.ChunkSystemRegionFile)regionFile).moonrise$startWrite(compound, pos);
+
+        try {
+            NbtIo.write(compound, writeData.output());
+        } finally {
+            writeData.output().close();
+        }
+
+        return writeData;
+    }
+
+    @Override
+    public final void moonrise$finishWrite(
+        final int chunkX, final int chunkZ, final ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.WriteData writeData
+    ) throws IOException {
+        final ChunkPos pos = new ChunkPos(chunkX, chunkZ);
+        if (writeData.result() == ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.WriteData.WriteResult.DELETE) {
+            final RegionFile regionFile = this.moonrise$getRegionFileIfExists(chunkX, chunkZ);
+            if (regionFile != null) {
+                regionFile.clear(pos);
+            } // else: didn't exist
+
+            return;
+        }
+
+        writeData.write().run(this.getRegionFile(pos));
+    }
+
+    @Override
+    public final ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.ReadData moonrise$readData(
+        final int chunkX, final int chunkZ
+    ) throws IOException {
+        final RegionFile regionFile = this.moonrise$getRegionFileIfExists(chunkX, chunkZ);
+
+        final DataInputStream input = regionFile == null ? null : regionFile.getChunkDataInputStream(new ChunkPos(chunkX, chunkZ));
+
+        if (input == null) {
+            return new ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.ReadData(
+                ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.ReadData.ReadResult.NO_DATA, null, null
+            );
+        }
+
+        final ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.ReadData ret = new ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.ReadData(
+            ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.ReadData.ReadResult.HAS_DATA, input, null
+        );
+
+        if (!(input instanceof ca.spottedleaf.moonrise.patches.chunk_system.util.stream.ExternalChunkStreamMarker)) {
+            // internal stream, which is fully read
+            return ret;
+        }
+
+        final CompoundTag syncRead = this.moonrise$finishRead(chunkX, chunkZ, ret);
+
+        if (syncRead == null) {
+            // need to try again
+            return this.moonrise$readData(chunkX, chunkZ);
+        }
+
+        return new ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.ReadData(
+            ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.ReadData.ReadResult.SYNC_READ, null, syncRead
+        );
+    }
+
+    // if the return value is null, then the caller needs to re-try with a new call to readData()
+    @Override
+    public final CompoundTag moonrise$finishRead(
+        final int chunkX, final int chunkZ, final ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.ReadData readData
+    ) throws IOException {
+        try {
+            return NbtIo.read(readData.input());
+        } finally {
+            readData.input().close();
+        }
+    }
+    // Paper end - rewrite chunk system
+
+    protected RegionFileStorage(RegionStorageInfo storageKey, Path directory, boolean dsync) { // Paper - protected
         this.folder = directory;
         this.sync = dsync;
         this.info = storageKey;
     }
 
-    private RegionFile getRegionFile(ChunkPos chunkcoordintpair, boolean existingOnly) throws IOException { // CraftBukkit
-        long i = ChunkPos.asLong(chunkcoordintpair.getRegionX(), chunkcoordintpair.getRegionZ());
-        RegionFile regionfile = (RegionFile) this.regionCache.getAndMoveToFirst(i);
+    // Paper start - rewrite chunk system
+    public RegionFile getRegionFile(ChunkPos chunkcoordintpair) throws IOException {
+        return this.getRegionFile(chunkcoordintpair, false);
+    }
+    // Paper end - rewrite chunk system
 
-        if (regionfile != null) {
-            return regionfile;
-        } else {
-            if (this.regionCache.size() >= io.papermc.paper.configuration.GlobalConfiguration.get().misc.regionFileCacheSize) { // Paper - Sanitise RegionFileCache and make configurable
-                ((RegionFile) this.regionCache.removeLast()).close();
+    public RegionFile getRegionFile(ChunkPos chunkcoordintpair, boolean existingOnly) throws IOException { // CraftBukkit // Paper - public
+        // Paper start - rewrite chunk system
+        if (existingOnly) {
+            return this.moonrise$getRegionFileIfExists(chunkcoordintpair.x, chunkcoordintpair.z);
+        }
+        synchronized (this) {
+            final long key = ChunkPos.asLong(chunkcoordintpair.x >> REGION_SHIFT, chunkcoordintpair.z >> REGION_SHIFT);
+
+            RegionFile ret = this.regionCache.getAndMoveToFirst(key);
+            if (ret != null) {
+                return ret;
+            }
+
+            if (this.regionCache.size() >= io.papermc.paper.configuration.GlobalConfiguration.get().misc.regionFileCacheSize) { // Paper
+                this.regionCache.removeLast().close();
             }
 
+            final Path regionPath = this.folder.resolve(getRegionFileName(chunkcoordintpair.x, chunkcoordintpair.z));
+
+            this.createRegionFile(key);
+
             FileUtil.createDirectoriesSafe(this.folder);
-            Path path = this.folder;
-            int j = chunkcoordintpair.getRegionX();
-            Path path1 = path.resolve("r." + j + "." + chunkcoordintpair.getRegionZ() + ".mca");
-            if (existingOnly && !java.nio.file.Files.exists(path1)) return null; // CraftBukkit
-            RegionFile regionfile1 = new RegionFile(this.info, path1, this.folder, this.sync);
 
-            this.regionCache.putAndMoveToFirst(i, regionfile1);
-            return regionfile1;
+            ret = new RegionFile(this.info, regionPath, this.folder, this.sync);
+
+            this.regionCache.putAndMoveToFirst(key, ret);
+
+            return ret;
         }
+        // Paper end - rewrite chunk system
     }
 
     // Paper start
@@ -0,0 +0,0 @@ public final class RegionFileStorage implements AutoCloseable {
 
     }
 
-    protected void write(ChunkPos pos, @Nullable CompoundTag nbt) throws IOException {
-        RegionFile regionfile = this.getRegionFile(pos, false); // CraftBukkit
+    public void write(ChunkPos pos, @Nullable CompoundTag nbt) throws IOException { // Paper - rewrite chunk system - public
+        RegionFile regionfile = this.getRegionFile(pos, nbt == null); // CraftBukkit // Paper - rewrite chunk system
+        // Paper start - rewrite chunk system
+        if (regionfile == null) {
+            // if the RegionFile doesn't exist, no point in deleting from it
+            return;
+        }
+        // Paper end - rewrite chunk system
 
         if (nbt == null) {
             regionfile.clear(pos);
@@ -0,0 +0,0 @@ public final class RegionFileStorage implements AutoCloseable {
     }
 
     public void close() throws IOException {
-        ExceptionCollector<IOException> exceptionsuppressor = new ExceptionCollector<>();
-        ObjectIterator objectiterator = this.regionCache.values().iterator();
-
-        while (objectiterator.hasNext()) {
-            RegionFile regionfile = (RegionFile) objectiterator.next();
-
-            try {
-                regionfile.close();
-            } catch (IOException ioexception) {
-                exceptionsuppressor.add(ioexception);
+        // Paper start - rewrite chunk system
+        synchronized (this) {
+            final ExceptionCollector<IOException> exceptionCollector = new ExceptionCollector<>();
+            for (final RegionFile regionFile : this.regionCache.values()) {
+                try {
+                    regionFile.close();
+                } catch (final IOException ex) {
+                    exceptionCollector.add(ex);
+                }
             }
-        }
 
-        exceptionsuppressor.throwIfPresent();
+            exceptionCollector.throwIfPresent();
+        }
+        // Paper end - rewrite chunk system
     }
 
     public void flush() throws IOException {
-        ObjectIterator objectiterator = this.regionCache.values().iterator();
-
-        while (objectiterator.hasNext()) {
-            RegionFile regionfile = (RegionFile) objectiterator.next();
+        // Paper start - rewrite chunk system
+        synchronized (this) {
+            final ExceptionCollector<IOException> exceptionCollector = new ExceptionCollector<>();
+            for (final RegionFile regionFile : this.regionCache.values()) {
+                try {
+                    regionFile.flush();
+                } catch (final IOException ex) {
+                    exceptionCollector.add(ex);
+                }
+            }
 
-            regionfile.flush();
+            exceptionCollector.throwIfPresent();
         }
+        // Paper end - rewrite chunk system
 
     }
 
diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/SectionStorage.java b/src/main/java/net/minecraft/world/level/chunk/storage/SectionStorage.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/storage/SectionStorage.java
+++ b/src/main/java/net/minecraft/world/level/chunk/storage/SectionStorage.java
@@ -0,0 +0,0 @@ import net.minecraft.world.level.ChunkPos;
 import net.minecraft.world.level.LevelHeightAccessor;
 import org.slf4j.Logger;
 
-public class SectionStorage<R, P> implements AutoCloseable {
+public class SectionStorage<R, P> implements AutoCloseable, ca.spottedleaf.moonrise.patches.chunk_system.level.storage.ChunkSystemSectionStorage { // Paper - rewrite chunk system
     static final Logger LOGGER = LogUtils.getLogger();
     private static final String SECTIONS_TAG = "Sections";
-    private final SimpleRegionStorage simpleRegionStorage;
+    // Paper - rewrite chunk system
     private final Long2ObjectMap<Optional<R>> storage = new Long2ObjectOpenHashMap<>();
     private final LongLinkedOpenHashSet dirtyChunks = new LongLinkedOpenHashSet();
     private final Codec<P> codec;
@@ -0,0 +0,0 @@ public class SectionStorage<R, P> implements AutoCloseable {
     private final Long2ObjectMap<CompletableFuture<Optional<SectionStorage.PackedChunk<P>>>> pendingLoads = new Long2ObjectOpenHashMap<>();
     private final Object loadLock = new Object();
 
+    // Paper start - rewrite chunk system
+    private final RegionFileStorage regionStorage;
+
+    @Override
+    public final RegionFileStorage moonrise$getRegionStorage() {
+        return this.regionStorage;
+    }
+
+    @Override
+    public void moonrise$close() throws IOException {}
+    // Paper end - rewrite chunk system
+
     public SectionStorage(
         SimpleRegionStorage storageAccess,
         Codec<P> codec,
@@ -0,0 +0,0 @@ public class SectionStorage<R, P> implements AutoCloseable {
         ChunkIOErrorReporter errorHandler,
         LevelHeightAccessor world
     ) {
-        this.simpleRegionStorage = storageAccess;
+        // Paper - rewrite chunk system
         this.codec = codec;
         this.packer = serializer;
         this.unpacker = deserializer;
@@ -0,0 +0,0 @@ public class SectionStorage<R, P> implements AutoCloseable {
         this.registryAccess = registryManager;
         this.errorReporter = errorHandler;
         this.levelHeightAccessor = world;
+        this.regionStorage = storageAccess.worker.storage; // Paper - rewrite chunk system
     }
 
     protected void tick(BooleanSupplier shouldKeepTicking) {
@@ -0,0 +0,0 @@ public class SectionStorage<R, P> implements AutoCloseable {
     }
 
     private CompletableFuture<Optional<SectionStorage.PackedChunk<P>>> tryRead(ChunkPos chunkPos) {
-        RegistryOps<Tag> registryOps = this.registryAccess.createSerializationContext(NbtOps.INSTANCE);
-        return this.simpleRegionStorage
-            .read(chunkPos)
-            .thenApplyAsync(
-                chunkNbt -> chunkNbt.map(
-                        nbt -> SectionStorage.PackedChunk.parse(this.codec, registryOps, nbt, this.simpleRegionStorage, this.levelHeightAccessor)
-                    ),
-                Util.backgroundExecutor().forName("parseSection")
-            )
-            .exceptionally(throwable -> {
-                if (throwable instanceof CompletionException) {
-                    throwable = throwable.getCause();
-                }
-
-                if (throwable instanceof IOException iOException) {
-                    LOGGER.error("Error reading chunk {} data from disk", chunkPos, iOException);
-                    this.errorReporter.reportChunkLoadFailure(iOException, this.simpleRegionStorage.storageInfo(), chunkPos);
-                    return Optional.empty();
-                } else {
-                    throw new CompletionException(throwable);
-                }
-            });
+        throw new IllegalStateException("Only chunk system can write state, offending class:" + this.getClass().getName()); // Paper - rewrite chunk system
     }
 
     private void unpackChunk(ChunkPos chunkPos, @Nullable SectionStorage.PackedChunk<P> result) {
-        if (result == null) {
-            for (int i = this.levelHeightAccessor.getMinSectionY(); i <= this.levelHeightAccessor.getMaxSectionY(); i++) {
-                this.storage.put(getKey(chunkPos, i), Optional.empty());
-            }
-        } else {
-            boolean bl = result.versionChanged();
-
-            for (int j = this.levelHeightAccessor.getMinSectionY(); j <= this.levelHeightAccessor.getMaxSectionY(); j++) {
-                long l = getKey(chunkPos, j);
-                Optional<R> optional = Optional.ofNullable(result.sectionsByY.get(j)).map(section -> this.unpacker.apply((P)section, () -> this.setDirty(l)));
-                this.storage.put(l, optional);
-                optional.ifPresent(object -> {
-                    this.onSectionLoad(l);
-                    if (bl) {
-                        this.setDirty(l);
-                    }
-                });
-            }
-        }
+        throw new IllegalStateException("Only chunk system can load in state, offending class:" + this.getClass().getName()); // Paper - rewrite chunk system
     }
 
     private void writeChunk(ChunkPos pos) {
-        RegistryOps<Tag> registryOps = this.registryAccess.createSerializationContext(NbtOps.INSTANCE);
-        Dynamic<Tag> dynamic = this.writeChunk(pos, registryOps);
-        Tag tag = dynamic.getValue();
-        if (tag instanceof CompoundTag) {
-            this.simpleRegionStorage.write(pos, (CompoundTag)tag).exceptionally(throwable -> {
-                this.errorReporter.reportChunkSaveFailure(throwable, this.simpleRegionStorage.storageInfo(), pos);
-                return null;
-            });
-        } else {
-            LOGGER.error("Expected compound tag, got {}", tag);
-        }
+        throw new IllegalStateException("Only chunk system can write state, offending class:" + this.getClass().getName()); // Paper - rewrite chunk system
     }
 
     private <T> Dynamic<T> writeChunk(ChunkPos chunkPos, DynamicOps<T> ops) {
@@ -0,0 +0,0 @@ public class SectionStorage<R, P> implements AutoCloseable {
     protected void onSectionLoad(long pos) {
     }
 
-    protected void setDirty(long pos) {
+    public void setDirty(long pos) { // Paper - public
         Optional<R> optional = this.storage.get(pos);
         if (optional != null && !optional.isEmpty()) {
             this.dirtyChunks.add(ChunkPos.asLong(SectionPos.x(pos), SectionPos.z(pos)));
@@ -0,0 +0,0 @@ public class SectionStorage<R, P> implements AutoCloseable {
 
     @Override
     public void close() throws IOException {
-        this.simpleRegionStorage.close();
+        this.moonrise$close(); // Paper - rewrite chunk system
     }
 
     static record PackedChunk<T>(Int2ObjectMap<T> sectionsByY, boolean versionChanged) {
diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/SerializableChunkData.java b/src/main/java/net/minecraft/world/level/chunk/storage/SerializableChunkData.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/storage/SerializableChunkData.java
+++ b/src/main/java/net/minecraft/world/level/chunk/storage/SerializableChunkData.java
@@ -0,0 +0,0 @@ public record SerializableChunkData(Registry<Biome> biomeRegistry, ChunkPos chun
             long j = nbt.getLong("InhabitedTime");
             ChunkStatus chunkstatus = ChunkStatus.byName(nbt.getString("Status"));
             UpgradeData chunkconverter = nbt.contains("UpgradeData", 10) ? new UpgradeData(nbt.getCompound("UpgradeData"), world) : UpgradeData.EMPTY;
-            boolean flag = nbt.getBoolean("isLightOn");
+            boolean flag = chunkstatus.isOrAfter(ChunkStatus.LIGHT) && (nbt.get("isLightOn") != null && nbt.getInt(ca.spottedleaf.moonrise.patches.starlight.util.SaveUtil.STARLIGHT_VERSION_TAG) == ca.spottedleaf.moonrise.patches.starlight.util.SaveUtil.STARLIGHT_LIGHT_VERSION); // Paper - starlight
             DataResult dataresult;
             Logger logger;
             BlendingData.Packed blendingdata_d;
@@ -0,0 +0,0 @@ public record SerializableChunkData(Registry<Biome> biomeRegistry, ChunkPos chun
                 DataLayer nibblearray = nbttagcompound3.contains("BlockLight", 7) ? new DataLayer(nbttagcompound3.getByteArray("BlockLight")) : null;
                 DataLayer nibblearray1 = nbttagcompound3.contains("SkyLight", 7) ? new DataLayer(nbttagcompound3.getByteArray("SkyLight")) : null;
 
-                list4.add(new SerializableChunkData.SectionData(b0, chunksection, nibblearray, nibblearray1));
+                // Paper start - starlight
+                SerializableChunkData.SectionData serializableChunkData = new SerializableChunkData.SectionData(b0, chunksection, nibblearray, nibblearray1);
+                if (sectionData.contains(ca.spottedleaf.moonrise.patches.starlight.util.SaveUtil.BLOCKLIGHT_STATE_TAG, Tag.TAG_ANY_NUMERIC)) {
+                    ((ca.spottedleaf.moonrise.patches.starlight.storage.StarlightSectionData)(Object)serializableChunkData).starlight$setBlockLightState(sectionData.getInt(ca.spottedleaf.moonrise.patches.starlight.util.SaveUtil.BLOCKLIGHT_STATE_TAG));
+                }
+
+                if (sectionData.contains(ca.spottedleaf.moonrise.patches.starlight.util.SaveUtil.SKYLIGHT_STATE_TAG, Tag.TAG_ANY_NUMERIC)) {
+                    ((ca.spottedleaf.moonrise.patches.starlight.storage.StarlightSectionData)(Object)serializableChunkData).starlight$setSkyLightState(sectionData.getInt(ca.spottedleaf.moonrise.patches.starlight.util.SaveUtil.SKYLIGHT_STATE_TAG));
+                }
+                list4.add(serializableChunkData);
+                // Paper end - starlight
             }
 
             // CraftBukkit - ChunkBukkitValues
@@ -0,0 +0,0 @@ public record SerializableChunkData(Registry<Biome> biomeRegistry, ChunkPos chun
         }
     }
 
+    // Paper start - starlight
+    private ProtoChunk loadStarlightLightData(final ServerLevel world, final ProtoChunk ret) {
+
+        final boolean hasSkyLight = world.dimensionType().hasSkyLight();
+        final int minSection = ca.spottedleaf.moonrise.common.util.WorldUtil.getMinLightSection(world);
+
+        final ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray[] blockNibbles = ca.spottedleaf.moonrise.patches.starlight.light.StarLightEngine.getFilledEmptyLight(world);
+        final ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray[] skyNibbles = ca.spottedleaf.moonrise.patches.starlight.light.StarLightEngine.getFilledEmptyLight(world);
+
+        if (!this.lightCorrect) {
+            ((ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk)ret).starlight$setBlockNibbles(blockNibbles);
+            ((ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk)ret).starlight$setSkyNibbles(skyNibbles);
+            return ret;
+        }
+
+        try {
+            for (final SerializableChunkData.SectionData sectionData : this.sectionData) {
+                final int y = sectionData.y();
+                final DataLayer blockLight = sectionData.blockLight();
+                final DataLayer skyLight = sectionData.skyLight();
+
+                final int blockState = ((ca.spottedleaf.moonrise.patches.starlight.storage.StarlightSectionData)(Object)sectionData).starlight$getBlockLightState();
+                final int skyState = ((ca.spottedleaf.moonrise.patches.starlight.storage.StarlightSectionData)(Object)sectionData).starlight$getSkyLightState();
+
+                if (blockState >= 0) {
+                    if (blockLight != null) {
+                        blockNibbles[y - minSection] = new ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray(ca.spottedleaf.moonrise.common.util.MixinWorkarounds.clone(blockLight.getData()), blockState); // clone for data safety
+                    } else {
+                        blockNibbles[y - minSection] = new ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray(null, blockState);
+                    }
+                }
+
+                if (skyState >= 0 && hasSkyLight) {
+                    if (skyLight != null) {
+                        skyNibbles[y - minSection] = new ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray(ca.spottedleaf.moonrise.common.util.MixinWorkarounds.clone(skyLight.getData()), skyState); // clone for data safety
+                    } else {
+                        skyNibbles[y - minSection] = new ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray(null, skyState);
+                    }
+                }
+            }
+
+            ((ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk)ret).starlight$setBlockNibbles(blockNibbles);
+            ((ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk)ret).starlight$setSkyNibbles(skyNibbles);
+        } catch (final Throwable thr) {
+            ret.setLightCorrect(false);
+
+            LOGGER.error("Failed to parse light data for chunk " + ret.getPos() + " in world '" + ca.spottedleaf.moonrise.common.util.WorldUtil.getWorldName(world) + "'", thr);
+        }
+
+        return ret;
+    }
+    // Paper end - starlight
+
     public ProtoChunk read(ServerLevel world, PoiManager poiStorage, RegionStorageInfo key, ChunkPos expectedPos) {
         if (!Objects.equals(expectedPos, this.chunkPos)) {
             SerializableChunkData.LOGGER.error("Chunk file at {} is in the wrong location; relocating. (Expected {}, got {})", new Object[]{expectedPos, expectedPos, this.chunkPos});
@@ -0,0 +0,0 @@ public record SerializableChunkData(Registry<Biome> biomeRegistry, ChunkPos chun
 
             if (serializablechunkdata_b.chunkSection != null) {
                 achunksection[world.getSectionIndexFromSectionY(serializablechunkdata_b.y)] = serializablechunkdata_b.chunkSection;
-                poiStorage.checkConsistencyWithBlocks(sectionposition, serializablechunkdata_b.chunkSection);
+                //poiStorage.checkConsistencyWithBlocks(sectionposition, serializablechunkdata_b.chunkSection); // Paper - rewrite chunk system
             }
 
             boolean flag2 = serializablechunkdata_b.blockLight != null;
@@ -0,0 +0,0 @@ public record SerializableChunkData(Registry<Biome> biomeRegistry, ChunkPos chun
         }
 
         if (chunktype == ChunkType.LEVELCHUNK) {
-            return new ImposterProtoChunk((LevelChunk) object, false);
+            return this.loadStarlightLightData(world, new ImposterProtoChunk((LevelChunk) object, false)); // Paper - starlight
         } else {
             ProtoChunk protochunk1 = (ProtoChunk) object;
             Iterator iterator2 = this.entities.iterator();
@@ -0,0 +0,0 @@ public record SerializableChunkData(Registry<Biome> biomeRegistry, ChunkPos chun
                 protochunk1.setCarvingMask(new CarvingMask(this.carvingMask, ((ChunkAccess) object).getMinY()));
             }
 
-            return protochunk1;
+            return this.loadStarlightLightData(world, protochunk1); // Paper - starlight
         }
     }
 
@@ -0,0 +0,0 @@ public record SerializableChunkData(Registry<Biome> biomeRegistry, ChunkPos chun
             throw new IllegalArgumentException("Chunk can't be serialized: " + String.valueOf(chunk));
         } else {
             ChunkPos chunkcoordintpair = chunk.getPos();
-            List<SerializableChunkData.SectionData> list = new ArrayList();
+            List<SerializableChunkData.SectionData> list = new ArrayList(); final List<SerializableChunkData.SectionData> sections = list; // Paper - starlight - OBFHELPER
             LevelChunkSection[] achunksection = chunk.getSections();
             ThreadedLevelLightEngine lightenginethreaded = world.getChunkSource().getLightEngine();
 
-            for (int i = lightenginethreaded.getMinLightSection(); i < lightenginethreaded.getMaxLightSection(); ++i) {
-                int j = chunk.getSectionIndexFromSectionY(i);
-                boolean flag = j >= 0 && j < achunksection.length;
-                DataLayer nibblearray = lightenginethreaded.getLayerListener(LightLayer.BLOCK).getDataLayerData(SectionPos.of(chunkcoordintpair, i));
-                DataLayer nibblearray1 = lightenginethreaded.getLayerListener(LightLayer.SKY).getDataLayerData(SectionPos.of(chunkcoordintpair, i));
-                DataLayer nibblearray2 = nibblearray != null && !nibblearray.isEmpty() ? nibblearray.copy() : null;
-                DataLayer nibblearray3 = nibblearray1 != null && !nibblearray1.isEmpty() ? nibblearray1.copy() : null;
+            // Paper start - starlight
+            final int minLightSection = ca.spottedleaf.moonrise.common.util.WorldUtil.getMinLightSection(world);
+            final int maxLightSection = ca.spottedleaf.moonrise.common.util.WorldUtil.getMaxLightSection(world);
+            final int minBlockSection = ca.spottedleaf.moonrise.common.util.WorldUtil.getMinSection(world);
+
+            final LevelChunkSection[] chunkSections = chunk.getSections();
+            final ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray[] blockNibbles = ((ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk)chunk).starlight$getBlockNibbles();
+            final ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray[] skyNibbles = ((ca.spottedleaf.moonrise.patches.starlight.chunk.StarlightChunk)chunk).starlight$getSkyNibbles();
+
+            for (int lightSection = minLightSection; lightSection <= maxLightSection; ++lightSection) {
+                final int lightSectionIdx = lightSection - minLightSection;
+                final int blockSectionIdx = lightSection - minBlockSection;
 
-                if (flag || nibblearray2 != null || nibblearray3 != null) {
-                    LevelChunkSection chunksection = flag ? achunksection[j].copy() : null;
+                final LevelChunkSection chunkSection = (blockSectionIdx >= 0 && blockSectionIdx < chunkSections.length) ? chunkSections[blockSectionIdx].copy() : null;
+                final ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray.SaveState blockNibble = blockNibbles[lightSectionIdx].getSaveState();
+                final ca.spottedleaf.moonrise.patches.starlight.light.SWMRNibbleArray.SaveState skyNibble = skyNibbles[lightSectionIdx].getSaveState();
 
-                    list.add(new SerializableChunkData.SectionData(i, chunksection, nibblearray2, nibblearray3));
+                if (chunkSection == null && blockNibble == null && skyNibble == null) {
+                    continue;
                 }
+
+                final SerializableChunkData.SectionData sectionData = new SerializableChunkData.SectionData(
+                    lightSection, chunkSection,
+                    blockNibble == null ? null : (blockNibble.data == null ? null : new DataLayer(blockNibble.data)),
+                    skyNibble == null ? null : (skyNibble.data == null ? null : new DataLayer(skyNibble.data))
+                );
+
+                if (blockNibble != null) {
+                    ((ca.spottedleaf.moonrise.patches.starlight.storage.StarlightSectionData)(Object)sectionData).starlight$setBlockLightState(blockNibble.state);
+                }
+
+                if (skyNibble != null) {
+                    ((ca.spottedleaf.moonrise.patches.starlight.storage.StarlightSectionData)(Object)sectionData).starlight$setSkyLightState(skyNibble.state);
+                }
+
+                sections.add(sectionData);
             }
+            // Paper end - starlight
 
             List<CompoundTag> list1 = new ArrayList(chunk.getBlockEntitiesPos().size());
             Iterator iterator = chunk.getBlockEntitiesPos().iterator();
@@ -0,0 +0,0 @@ public record SerializableChunkData(Registry<Biome> biomeRegistry, ChunkPos chun
         Iterator iterator = this.sectionData.iterator();
 
         while (iterator.hasNext()) {
-            SerializableChunkData.SectionData serializablechunkdata_b = (SerializableChunkData.SectionData) iterator.next();
-            CompoundTag nbttagcompound1 = new CompoundTag();
+            SerializableChunkData.SectionData serializablechunkdata_b = (SerializableChunkData.SectionData) iterator.next(); final SerializableChunkData.SectionData sectionData = serializablechunkdata_b; // Paper - starlight - OBFHELPER
+            CompoundTag nbttagcompound1 = new CompoundTag(); final CompoundTag sectionNBT = nbttagcompound1; // Paper - starlight - OBFHELPER
             LevelChunkSection chunksection = serializablechunkdata_b.chunkSection;
 
             if (chunksection != null) {
@@ -0,0 +0,0 @@ public record SerializableChunkData(Registry<Biome> biomeRegistry, ChunkPos chun
                 nbttagcompound1.putByteArray("SkyLight", serializablechunkdata_b.skyLight.getData());
             }
 
+            // Paper start - starlight
+            final int blockState = ((ca.spottedleaf.moonrise.patches.starlight.storage.StarlightSectionData)(Object)sectionData).starlight$getBlockLightState();
+            final int skyState = ((ca.spottedleaf.moonrise.patches.starlight.storage.StarlightSectionData)(Object)sectionData).starlight$getSkyLightState();
+
+            if (blockState > 0) {
+                sectionNBT.putInt(ca.spottedleaf.moonrise.patches.starlight.util.SaveUtil.BLOCKLIGHT_STATE_TAG, blockState);
+            }
+
+            if (skyState > 0) {
+                sectionNBT.putInt(ca.spottedleaf.moonrise.patches.starlight.util.SaveUtil.SKYLIGHT_STATE_TAG, skyState);
+            }
+            // Paper end - starlight
+
             if (!nbttagcompound1.isEmpty()) {
                 nbttagcompound1.putByte("Y", (byte) serializablechunkdata_b.y);
                 nbttaglist.add(nbttagcompound1);
@@ -0,0 +0,0 @@ public record SerializableChunkData(Registry<Biome> biomeRegistry, ChunkPos chun
             nbttagcompound.put("ChunkBukkitValues", this.persistentDataContainer);
         }
         // CraftBukkit end
+        // Paper start - starlight
+        if (this.lightCorrect && !this.chunkStatus.isBefore(net.minecraft.world.level.chunk.status.ChunkStatus.LIGHT)) {
+            // clobber vanilla value to force vanilla to relight
+            nbttagcompound.putBoolean("isLightOn", false);
+            // store our light version
+            nbttagcompound.putInt(ca.spottedleaf.moonrise.patches.starlight.util.SaveUtil.STARLIGHT_VERSION_TAG, ca.spottedleaf.moonrise.patches.starlight.util.SaveUtil.STARLIGHT_LIGHT_VERSION);
+        }
+        // Paper end - starlight
         return nbttagcompound;
     }
 
@@ -0,0 +0,0 @@ public record SerializableChunkData(Registry<Biome> biomeRegistry, ChunkPos chun
         return nbttaglist;
     }
 
-    public static record SectionData(int y, @Nullable LevelChunkSection chunkSection, @Nullable DataLayer blockLight, @Nullable DataLayer skyLight) {
+    // Paper start - starlight - convert from record
+    public static final class SectionData implements ca.spottedleaf.moonrise.patches.starlight.storage.StarlightSectionData { // Paper - starlight - our diff
+        private final int y;
+        @javax.annotation.Nullable
+        private final net.minecraft.world.level.chunk.LevelChunkSection chunkSection;
+        @javax.annotation.Nullable
+        private final net.minecraft.world.level.chunk.DataLayer blockLight;
+        @javax.annotation.Nullable
+        private final net.minecraft.world.level.chunk.DataLayer skyLight;
+
+        // Paper start - starlight - our diff
+        private int blockLightState = -1;
+        private int skyLightState = -1;
+
+        @Override
+        public final int starlight$getBlockLightState() {
+            return this.blockLightState;
+        }
+
+        @Override
+        public final void starlight$setBlockLightState(final int state) {
+            this.blockLightState = state;
+        }
+
+        @Override
+        public final int starlight$getSkyLightState() {
+            return this.skyLightState;
+        }
+
+        @Override
+        public final void starlight$setSkyLightState(final int state) {
+            this.skyLightState = state;
+        }
+        // Paper end - starlight - our diff
+
+        public SectionData(int y, @javax.annotation.Nullable net.minecraft.world.level.chunk.LevelChunkSection chunkSection, @javax.annotation.Nullable net.minecraft.world.level.chunk.DataLayer blockLight, @javax.annotation.Nullable net.minecraft.world.level.chunk.DataLayer skyLight) {
+            this.y = y;
+            this.chunkSection = chunkSection;
+            this.blockLight = blockLight;
+            this.skyLight = skyLight;
+        }
+
+        public int y() {
+            return y;
+        }
+
+        @javax.annotation.Nullable
+        public net.minecraft.world.level.chunk.LevelChunkSection chunkSection() {
+            return chunkSection;
+        }
+
+        @javax.annotation.Nullable
+        public net.minecraft.world.level.chunk.DataLayer blockLight() {
+            return blockLight;
+        }
+
+        @javax.annotation.Nullable
+        public net.minecraft.world.level.chunk.DataLayer skyLight() {
+            return skyLight;
+        }
+        // Paper end - starlight - convert from record
 
     }
 
diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/SimpleRegionStorage.java b/src/main/java/net/minecraft/world/level/chunk/storage/SimpleRegionStorage.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/chunk/storage/SimpleRegionStorage.java
+++ b/src/main/java/net/minecraft/world/level/chunk/storage/SimpleRegionStorage.java
@@ -0,0 +0,0 @@ import net.minecraft.util.datafix.DataFixTypes;
 import net.minecraft.world.level.ChunkPos;
 
 public class SimpleRegionStorage implements AutoCloseable {
-    private final IOWorker worker;
+    public final IOWorker worker; // Paper - public
     private final DataFixer fixerUpper;
     private final DataFixTypes dataFixType;
 
diff --git a/src/main/java/net/minecraft/world/level/entity/EntityTickList.java b/src/main/java/net/minecraft/world/level/entity/EntityTickList.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/entity/EntityTickList.java
+++ b/src/main/java/net/minecraft/world/level/entity/EntityTickList.java
@@ -0,0 +0,0 @@ import javax.annotation.Nullable;
 import net.minecraft.world.entity.Entity;
 
 public class EntityTickList {
-    private Int2ObjectMap<Entity> active = new Int2ObjectLinkedOpenHashMap<>();
-    private Int2ObjectMap<Entity> passive = new Int2ObjectLinkedOpenHashMap<>();
-    @Nullable
-    private Int2ObjectMap<Entity> iterated;
+    private final ca.spottedleaf.moonrise.common.list.IteratorSafeOrderedReferenceSet<net.minecraft.world.entity.Entity> entities = new ca.spottedleaf.moonrise.common.list.IteratorSafeOrderedReferenceSet<>(); // Paper - rewrite chunk system
 
     private void ensureActiveIsNotIterated() {
-        if (this.iterated == this.active) {
-            this.passive.clear();
-
-            for (Entry<Entity> entry : Int2ObjectMaps.fastIterable(this.active)) {
-                this.passive.put(entry.getIntKey(), entry.getValue());
-            }
-
-            Int2ObjectMap<Entity> int2ObjectMap = this.active;
-            this.active = this.passive;
-            this.passive = int2ObjectMap;
-        }
+        // Paper - rewrite chunk system
     }
 
     public void add(Entity entity) {
         this.ensureActiveIsNotIterated();
-        this.active.put(entity.getId(), entity);
+        this.entities.add(entity); // Paper - rewrite chunk system
     }
 
     public void remove(Entity entity) {
         this.ensureActiveIsNotIterated();
-        this.active.remove(entity.getId());
+        this.entities.remove(entity); // Paper - rewrite chunk system
     }
 
     public boolean contains(Entity entity) {
-        return this.active.containsKey(entity.getId());
+        return this.entities.contains(entity); // Paper - rewrite chunk system
     }
 
     public void forEach(Consumer<Entity> action) {
-        if (this.iterated != null) {
-            throw new UnsupportedOperationException("Only one concurrent iteration supported");
-        } else {
-            this.iterated = this.active;
-
-            try {
-                for (Entity entity : this.active.values()) {
-                    action.accept(entity);
-                }
-            } finally {
-                this.iterated = null;
+        // Paper start - rewrite chunk system
+        // To ensure nothing weird happens with dimension travelling, do not iterate over new entries...
+        // (by dfl iterator() is configured to not iterate over new entries)
+        final ca.spottedleaf.moonrise.common.list.IteratorSafeOrderedReferenceSet.Iterator<Entity> iterator = this.entities.iterator();
+        try {
+            while (iterator.hasNext()) {
+                action.accept(iterator.next());
             }
+        } finally {
+            iterator.finishedIterating();
         }
+        // Paper end - rewrite chunk system
     }
 }
diff --git a/src/main/java/net/minecraft/world/level/levelgen/NoiseBasedChunkGenerator.java b/src/main/java/net/minecraft/world/level/levelgen/NoiseBasedChunkGenerator.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/levelgen/NoiseBasedChunkGenerator.java
+++ b/src/main/java/net/minecraft/world/level/levelgen/NoiseBasedChunkGenerator.java
@@ -0,0 +0,0 @@ public final class NoiseBasedChunkGenerator extends ChunkGenerator {
         return CompletableFuture.supplyAsync(() -> {
             this.doCreateBiomes(blender, noiseConfig, structureAccessor, chunk);
             return chunk;
-        }, Util.backgroundExecutor().forName("init_biomes"));
+        }, Runnable::run); // Paper - rewrite chunk system
     }
 
     private void doCreateBiomes(Blender blender, RandomState noiseConfig, StructureManager structureAccessor, ChunkAccess chunk) {
@@ -0,0 +0,0 @@ public final class NoiseBasedChunkGenerator extends ChunkGenerator {
             }
 
             return ichunkaccess1;
-        }, Util.backgroundExecutor().forName("wgen_fill_noise"));
+        }, Runnable::run); // Paper - rewrite chunk system
     }
 
     private ChunkAccess doFill(Blender blender, StructureManager structureAccessor, RandomState noiseConfig, ChunkAccess chunk, int minimumCellY, int cellHeight) {
diff --git a/src/main/java/net/minecraft/world/level/levelgen/structure/StructureCheck.java b/src/main/java/net/minecraft/world/level/levelgen/structure/StructureCheck.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/levelgen/structure/StructureCheck.java
+++ b/src/main/java/net/minecraft/world/level/levelgen/structure/StructureCheck.java
@@ -0,0 +0,0 @@ public class StructureCheck {
     private final BiomeSource biomeSource;
     private final long seed;
     private final DataFixer fixerUpper;
-    private final Long2ObjectMap<Object2IntMap<Structure>> loadedChunks = new Long2ObjectOpenHashMap<>();
-    private final Map<Structure, Long2BooleanMap> featureChecks = new HashMap<>();
+    // Paper start - rewrite chunk system
+    // make sure to purge entries from the maps to prevent memory leaks
+    private static final int CHUNK_TOTAL_LIMIT = 50 * (2 * 100 + 1) * (2 * 100 + 1); // cache 50 structure lookups
+    private static final int PER_FEATURE_CHECK_LIMIT = 50 * (2 * 100 + 1) * (2 * 100 + 1); // cache 50 structure lookups
+    private final ca.spottedleaf.moonrise.common.map.SynchronisedLong2ObjectMap<it.unimi.dsi.fastutil.objects.Object2IntMap<Structure>> loadedChunksSafe = new ca.spottedleaf.moonrise.common.map.SynchronisedLong2ObjectMap<>(CHUNK_TOTAL_LIMIT);
+    private final java.util.concurrent.ConcurrentHashMap<Structure, ca.spottedleaf.moonrise.common.map.SynchronisedLong2BooleanMap> featureChecksSafe = new java.util.concurrent.ConcurrentHashMap<>();
+    // Paper end - rewrite chunk system
 
     public StructureCheck(
         ChunkScanAccess chunkIoWorker,
@@ -0,0 +0,0 @@ public class StructureCheck {
 
     public StructureCheckResult checkStart(ChunkPos pos, Structure type, StructurePlacement placement, boolean skipReferencedStructures) {
         long l = pos.toLong();
-        Object2IntMap<Structure> object2IntMap = this.loadedChunks.get(l);
+        Object2IntMap<Structure> object2IntMap = this.loadedChunksSafe.get(l); // Paper - rewrite chunk system
         if (object2IntMap != null) {
             return this.checkStructureInfo(object2IntMap, type, skipReferencedStructures);
         } else {
@@ -0,0 +0,0 @@ public class StructureCheck {
             } else if (!placement.applyAdditionalChunkRestrictions(pos.x, pos.z, this.seed, this.getSaltOverride(type))) { // Paper - add missing structure seed configs
                 return StructureCheckResult.START_NOT_PRESENT;
             } else {
-                boolean bl = this.featureChecks
-                    .computeIfAbsent(type, structure2 -> new Long2BooleanOpenHashMap())
-                    .computeIfAbsent(l, chunkPos -> this.canCreateStructure(pos, type));
+                // Paper start - rewrite chunk system
+                boolean bl = this.featureChecksSafe
+                    .computeIfAbsent(type, structure2 -> new ca.spottedleaf.moonrise.common.map.SynchronisedLong2BooleanMap(PER_FEATURE_CHECK_LIMIT))
+                    .getOrCompute(l, chunkPos -> this.canCreateStructure(pos, type));
+                // Paper end - rewrite chunk system
                 return !bl ? StructureCheckResult.START_NOT_PRESENT : StructureCheckResult.CHUNK_LOAD_NEEDED;
             }
         }
@@ -0,0 +0,0 @@ public class StructureCheck {
     }
 
     private void storeFullResults(long pos, Object2IntMap<Structure> referencesByStructure) {
-        this.loadedChunks.put(pos, deduplicateEmptyMap(referencesByStructure));
-        this.featureChecks.values().forEach(generationPossibilityByChunkPos -> generationPossibilityByChunkPos.remove(pos));
+        // Paper start - rewrite chunk system
+        this.loadedChunksSafe.put(pos, deduplicateEmptyMap(referencesByStructure));
+        // once we insert into loadedChunks, we don't really need to be very careful about removing everything
+        // from this map, as everything that checks this map uses loadedChunks first
+        // so, one way or another it's a race condition that doesn't matter
+        for (ca.spottedleaf.moonrise.common.map.SynchronisedLong2BooleanMap value : this.featureChecksSafe.values()) {
+            value.remove(pos);
+        }
+        // Paper end - rewrite chunk system
     }
 
     public void incrementReference(ChunkPos pos, Structure structure) {
-        this.loadedChunks.compute(pos.toLong(), (posx, referencesByStructure) -> {
-            if (referencesByStructure == null || referencesByStructure.isEmpty()) {
+        this.loadedChunksSafe.compute(pos.toLong(), (posx, referencesByStructure) -> { // Paper start - rewrite chunk system
+            if (referencesByStructure == null) {
                 referencesByStructure = new Object2IntOpenHashMap<>();
+            } else {
+                referencesByStructure = referencesByStructure instanceof Object2IntOpenHashMap<Structure> fastClone ? fastClone.clone() : new Object2IntOpenHashMap<>(referencesByStructure);
             }
+            // Paper end - rewrite chunk system
 
             referencesByStructure.computeInt(structure, (feature, references) -> references == null ? 1 : references + 1);
             return referencesByStructure;
diff --git a/src/main/java/net/minecraft/world/level/lighting/LevelLightEngine.java b/src/main/java/net/minecraft/world/level/lighting/LevelLightEngine.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/lighting/LevelLightEngine.java
+++ b/src/main/java/net/minecraft/world/level/lighting/LevelLightEngine.java
@@ -0,0 +0,0 @@ import net.minecraft.world.level.LightLayer;
 import net.minecraft.world.level.chunk.DataLayer;
 import net.minecraft.world.level.chunk.LightChunkGetter;
 
-public class LevelLightEngine implements LightEventListener {
+public class LevelLightEngine implements LightEventListener, ca.spottedleaf.moonrise.patches.starlight.light.StarLightLightingProvider { // Paper - rewrite chunk system
     public static final int LIGHT_SECTION_PADDING = 1;
     public static final LevelLightEngine EMPTY = new LevelLightEngine();
     protected final LevelHeightAccessor levelHeightAccessor;
-    @Nullable
-    private final LightEngine<?, ?> blockEngine;
-    @Nullable
-    private final LightEngine<?, ?> skyEngine;
+    // Paper start - rewrite chunk system
+    protected final ca.spottedleaf.moonrise.patches.starlight.light.StarLightInterface lightEngine;
+
+    @Override
+    public final ca.spottedleaf.moonrise.patches.starlight.light.StarLightInterface starlight$getLightEngine() {
+        return this.lightEngine;
+    }
+
+    @Override
+    public void starlight$clientUpdateLight(final LightLayer lightType, final SectionPos pos,
+                                            final DataLayer nibble, final boolean trustEdges) {
+        throw new IllegalStateException("This hook is for the CLIENT ONLY"); // Paper - not implemented on server
+    }
+
+    @Override
+    public void starlight$clientRemoveLightData(final ChunkPos chunkPos) {
+        throw new IllegalStateException("This hook is for the CLIENT ONLY"); // Paper - not implemented on server
+    }
+
+    @Override
+    public void starlight$clientChunkLoad(final ChunkPos pos, final net.minecraft.world.level.chunk.LevelChunk chunk) {
+        throw new IllegalStateException("This hook is for the CLIENT ONLY"); // Paper - not implemented on server
+    }
+    // Paper end - rewrite chunk system
 
     public LevelLightEngine(LightChunkGetter chunkProvider, boolean hasBlockLight, boolean hasSkyLight) {
         this.levelHeightAccessor = chunkProvider.getLevel();
-        this.blockEngine = hasBlockLight ? new BlockLightEngine(chunkProvider) : null;
-        this.skyEngine = hasSkyLight ? new SkyLightEngine(chunkProvider) : null;
+        // Paper start - rewrite chunk system
+        if (chunkProvider.getLevel() instanceof net.minecraft.world.level.Level) {
+            this.lightEngine = new ca.spottedleaf.moonrise.patches.starlight.light.StarLightInterface(chunkProvider, hasSkyLight, hasBlockLight, (LevelLightEngine)(Object)this);
+        } else {
+            this.lightEngine = new ca.spottedleaf.moonrise.patches.starlight.light.StarLightInterface(null, hasSkyLight, hasBlockLight, (LevelLightEngine)(Object)this);
+        }
+        // Paper end - rewrite chunk system
     }
 
     private LevelLightEngine() {
         this.levelHeightAccessor = LevelHeightAccessor.create(0, 0);
-        this.blockEngine = null;
-        this.skyEngine = null;
+        // Paper start - rewrite chunk system
+        this.lightEngine = new ca.spottedleaf.moonrise.patches.starlight.light.StarLightInterface(null, false, false, (LevelLightEngine)(Object)this);
+        // Paper end - rewrite chunk system
     }
 
     @Override
     public void checkBlock(BlockPos pos) {
-        if (this.blockEngine != null) {
-            this.blockEngine.checkBlock(pos);
-        }
-
-        if (this.skyEngine != null) {
-            this.skyEngine.checkBlock(pos);
-        }
+        this.lightEngine.blockChange(pos.immutable()); // Paper - rewrite chunk system
     }
 
     @Override
     public boolean hasLightWork() {
-        return this.skyEngine != null && this.skyEngine.hasLightWork() || this.blockEngine != null && this.blockEngine.hasLightWork();
+        return this.lightEngine.hasUpdates(); // Paper - rewrite chunk system
     }
 
     @Override
     public int runLightUpdates() {
-        int i = 0;
-        if (this.blockEngine != null) {
-            i += this.blockEngine.runLightUpdates();
-        }
-
-        if (this.skyEngine != null) {
-            i += this.skyEngine.runLightUpdates();
-        }
-
-        return i;
+        final boolean hadUpdates = this.hasLightWork();
+        this.lightEngine.propagateChanges();
+        return hadUpdates ? 1 : 0; // Paper - rewrite chunk system
     }
 
     @Override
     public void updateSectionStatus(SectionPos pos, boolean notReady) {
-        if (this.blockEngine != null) {
-            this.blockEngine.updateSectionStatus(pos, notReady);
-        }
-
-        if (this.skyEngine != null) {
-            this.skyEngine.updateSectionStatus(pos, notReady);
-        }
+        this.lightEngine.sectionChange(pos, notReady); // Paper - rewrite chunk system
     }
 
     @Override
     public void setLightEnabled(ChunkPos pos, boolean retainData) {
-        if (this.blockEngine != null) {
-            this.blockEngine.setLightEnabled(pos, retainData);
-        }
-
-        if (this.skyEngine != null) {
-            this.skyEngine.setLightEnabled(pos, retainData);
-        }
+        // Paper - rewrite chunk system
     }
 
     @Override
     public void propagateLightSources(ChunkPos chunkPos) {
-        if (this.blockEngine != null) {
-            this.blockEngine.propagateLightSources(chunkPos);
-        }
-
-        if (this.skyEngine != null) {
-            this.skyEngine.propagateLightSources(chunkPos);
-        }
+        // Paper - rewrite chunk system
     }
 
     public LayerLightEventListener getLayerListener(LightLayer lightType) {
-        if (lightType == LightLayer.BLOCK) {
-            return (LayerLightEventListener)(this.blockEngine == null ? LayerLightEventListener.DummyLightLayerEventListener.INSTANCE : this.blockEngine);
-        } else {
-            return (LayerLightEventListener)(this.skyEngine == null ? LayerLightEventListener.DummyLightLayerEventListener.INSTANCE : this.skyEngine);
-        }
+        return lightType == LightLayer.BLOCK ? this.lightEngine.getBlockReader() : this.lightEngine.getSkyReader(); // Paper - rewrite chunk system
     }
 
     public String getDebugData(LightLayer lightType, SectionPos pos) {
-        if (lightType == LightLayer.BLOCK) {
-            if (this.blockEngine != null) {
-                return this.blockEngine.getDebugData(pos.asLong());
-            }
-        } else if (this.skyEngine != null) {
-            return this.skyEngine.getDebugData(pos.asLong());
-        }
-
-        return "n/a";
+        return "n/a"; // Paper - rewrite chunk system
     }
 
     public LayerLightSectionStorage.SectionType getDebugSectionType(LightLayer lightType, SectionPos pos) {
-        if (lightType == LightLayer.BLOCK) {
-            if (this.blockEngine != null) {
-                return this.blockEngine.getDebugSectionType(pos.asLong());
-            }
-        } else if (this.skyEngine != null) {
-            return this.skyEngine.getDebugSectionType(pos.asLong());
-        }
-
-        return LayerLightSectionStorage.SectionType.EMPTY;
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system
     }
 
     public void queueSectionData(LightLayer lightType, SectionPos pos, @Nullable DataLayer nibbles) {
-        if (lightType == LightLayer.BLOCK) {
-            if (this.blockEngine != null) {
-                this.blockEngine.queueSectionData(pos.asLong(), nibbles);
-            }
-        } else if (this.skyEngine != null) {
-            this.skyEngine.queueSectionData(pos.asLong(), nibbles);
-        }
+        // Paper - rewrite chunk system
     }
 
     public void retainData(ChunkPos pos, boolean retainData) {
-        if (this.blockEngine != null) {
-            this.blockEngine.retainData(pos, retainData);
-        }
-
-        if (this.skyEngine != null) {
-            this.skyEngine.retainData(pos, retainData);
-        }
+        // Paper - rewrite chunk system
     }
 
     public int getRawBrightness(BlockPos pos, int ambientDarkness) {
-        int i = this.skyEngine == null ? 0 : this.skyEngine.getLightValue(pos) - ambientDarkness;
-        int j = this.blockEngine == null ? 0 : this.blockEngine.getLightValue(pos);
-        return Math.max(j, i);
+        return this.lightEngine.getRawBrightness(pos, ambientDarkness); // Paper - rewrite chunk system
     }
 
     public boolean lightOnInColumn(long sectionPos) {
-        return this.blockEngine == null
-            || this.blockEngine.storage.lightOnInColumn(sectionPos) && (this.skyEngine == null || this.skyEngine.storage.lightOnInColumn(sectionPos));
+        throw new UnsupportedOperationException(); // Paper - rewrite chunk system // Paper - not implemented on server
     }
 
     public int getLightSectionCount() {
diff --git a/src/main/java/net/minecraft/world/level/material/FlowingFluid.java b/src/main/java/net/minecraft/world/level/material/FlowingFluid.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/material/FlowingFluid.java
+++ b/src/main/java/net/minecraft/world/level/material/FlowingFluid.java
@@ -0,0 +0,0 @@ public abstract class FlowingFluid extends Fluid {
     });
     private final Map<FluidState, VoxelShape> shapes = Maps.newIdentityHashMap();
 
+    // Paper start - fluid method optimisations
+    private FluidState sourceFalling;
+    private FluidState sourceNotFalling;
+
+    private static final int TOTAL_FLOWING_STATES = FALLING.getPossibleValues().size() * LEVEL.getPossibleValues().size();
+    private static final int MIN_LEVEL = LEVEL.getPossibleValues().stream().sorted().findFirst().get().intValue();
+
+    // index = (falling ? 1 : 0) + level*2
+    private FluidState[] flowingLookUp;
+    private volatile boolean init;
+
+    private static final int COLLISION_OCCLUSION_CACHE_SIZE = 2048;
+    private static final ThreadLocal<ca.spottedleaf.moonrise.patches.collisions.util.FluidOcclusionCacheKey[]> COLLISION_OCCLUSION_CACHE = ThreadLocal.withInitial(() -> new ca.spottedleaf.moonrise.patches.collisions.util.FluidOcclusionCacheKey[COLLISION_OCCLUSION_CACHE_SIZE]);
+
+
+    /**
+     * Due to init order, we need to use callbacks to initialise our state
+     */
+    private void init() {
+        synchronized (this) {
+            if (this.init) {
+                return;
+            }
+            this.flowingLookUp = new FluidState[TOTAL_FLOWING_STATES];
+            final FluidState defaultFlowState = this.getFlowing().defaultFluidState();
+            for (int i = 0; i < TOTAL_FLOWING_STATES; ++i) {
+                final int falling = i & 1;
+                final int level = (i >>> 1) + MIN_LEVEL;
+
+                this.flowingLookUp[i] = defaultFlowState.setValue(FALLING, falling == 1 ? Boolean.TRUE : Boolean.FALSE)
+                    .setValue(LEVEL, Integer.valueOf(level));
+            }
+
+            final FluidState defaultFallState = this.getSource().defaultFluidState();
+            this.sourceFalling = defaultFallState.setValue(FALLING, Boolean.TRUE);
+            this.sourceNotFalling = defaultFallState.setValue(FALLING, Boolean.FALSE);
+
+            this.init = true;
+        }
+    }
+    // Paper end - fluid method optimisations
+
     public FlowingFluid() {}
 
     @Override
@@ -0,0 +0,0 @@ public abstract class FlowingFluid extends Fluid {
         }
     }
 
-    private static boolean canPassThroughWall(Direction face, BlockGetter world, BlockPos pos, BlockState state, BlockPos fromPos, BlockState fromState) {
-        VoxelShape voxelshape = fromState.getCollisionShape(world, fromPos);
+    // Paper start - fluid method optimisations
+    private static boolean canPassThroughWall(final Direction direction, final BlockGetter level,
+                                             final BlockPos fromPos, final BlockState fromState,
+                                             final BlockPos toPos, final BlockState toState) {
+        if (((ca.spottedleaf.moonrise.patches.collisions.block.CollisionBlockState)fromState).moonrise$emptyCollisionShape() & ((ca.spottedleaf.moonrise.patches.collisions.block.CollisionBlockState)toState).moonrise$emptyCollisionShape()) {
+            // don't even try to cache simple cases
+            return true;
+        }
 
-        if (voxelshape == Shapes.block()) {
+        if (((ca.spottedleaf.moonrise.patches.collisions.block.CollisionBlockState)fromState).moonrise$occludesFullBlock() | ((ca.spottedleaf.moonrise.patches.collisions.block.CollisionBlockState)toState).moonrise$occludesFullBlock()) {
+            // don't even try to cache simple cases
             return false;
-        } else {
-            VoxelShape voxelshape1 = state.getCollisionShape(world, pos);
-
-            if (voxelshape1 == Shapes.block()) {
-                return false;
-            } else if (voxelshape1 == Shapes.empty() && voxelshape == Shapes.empty()) {
-                return true;
-            } else {
-                Object2ByteLinkedOpenHashMap object2bytelinkedopenhashmap;
-
-                if (!state.getBlock().hasDynamicShape() && !fromState.getBlock().hasDynamicShape()) {
-                    object2bytelinkedopenhashmap = (Object2ByteLinkedOpenHashMap) FlowingFluid.OCCLUSION_CACHE.get();
-                } else {
-                    object2bytelinkedopenhashmap = null;
-                }
+        }
 
-                FlowingFluid.BlockStatePairKey fluidtypeflowing_a;
+        final ca.spottedleaf.moonrise.patches.collisions.util.FluidOcclusionCacheKey[] cache = ((ca.spottedleaf.moonrise.patches.collisions.block.CollisionBlockState)fromState).moonrise$hasCache() & ((ca.spottedleaf.moonrise.patches.collisions.block.CollisionBlockState)toState).moonrise$hasCache() ?
+            COLLISION_OCCLUSION_CACHE.get() : null;
 
-                if (object2bytelinkedopenhashmap != null) {
-                    fluidtypeflowing_a = new FlowingFluid.BlockStatePairKey(state, fromState, face);
-                    byte b0 = object2bytelinkedopenhashmap.getAndMoveToFirst(fluidtypeflowing_a);
+        final int keyIndex
+            = (((ca.spottedleaf.moonrise.patches.collisions.block.CollisionBlockState)fromState).moonrise$uniqueId1() ^ ((ca.spottedleaf.moonrise.patches.collisions.block.CollisionBlockState)toState).moonrise$uniqueId2() ^ ((ca.spottedleaf.moonrise.patches.collisions.util.CollisionDirection)(Object)direction).moonrise$uniqueId())
+            & (COLLISION_OCCLUSION_CACHE_SIZE - 1);
 
-                    if (b0 != 127) {
-                        return b0 != 0;
-                    }
-                } else {
-                    fluidtypeflowing_a = null;
-                }
-
-                boolean flag = !Shapes.mergedFaceOccludes(voxelshape1, voxelshape, face);
+        if (cache != null) {
+            final ca.spottedleaf.moonrise.patches.collisions.util.FluidOcclusionCacheKey cached = cache[keyIndex];
+            if (cached != null && cached.first() == fromState && cached.second() == toState && cached.direction() == direction) {
+                return cached.result();
+            }
+        }
 
-                if (object2bytelinkedopenhashmap != null) {
-                    if (object2bytelinkedopenhashmap.size() == 200) {
-                        object2bytelinkedopenhashmap.removeLastByte();
-                    }
+        final VoxelShape shape1 = fromState.getCollisionShape(level, fromPos);
+        final VoxelShape shape2 = toState.getCollisionShape(level, toPos);
 
-                    object2bytelinkedopenhashmap.putAndMoveToFirst(fluidtypeflowing_a, (byte) (flag ? 1 : 0));
-                }
+        final boolean result = !Shapes.mergedFaceOccludes(shape1, shape2, direction);
 
-                return flag;
-            }
+        if (cache != null) {
+            // we can afford to replace in-use keys more often due to the excessive caching the collision patch does in mergedFaceOccludes
+            cache[keyIndex] = new ca.spottedleaf.moonrise.patches.collisions.util.FluidOcclusionCacheKey(fromState, toState, direction, result);
         }
+
+        return result;
     }
+    // Paper end - fluid method optimisations
 
     public abstract Fluid getFlowing();
 
     public FluidState getFlowing(int level, boolean falling) {
-        return (FluidState) ((FluidState) this.getFlowing().defaultFluidState().setValue(FlowingFluid.LEVEL, level)).setValue(FlowingFluid.FALLING, falling);
+        // Paper start - fluid method optimisations
+        final int amount = level;
+        if (!this.init) {
+            this.init();
+        }
+        final int index = (falling ? 1 : 0) | ((amount - MIN_LEVEL) << 1);
+        return this.flowingLookUp[index];
+        // Paper end - fluid method optimisations
     }
 
     public abstract Fluid getSource();
 
     public FluidState getSource(boolean falling) {
-        return (FluidState) this.getSource().defaultFluidState().setValue(FlowingFluid.FALLING, falling);
+        // Paper start - fluid method optimisations
+        if (!this.init) {
+            this.init();
+        }
+        return falling ? this.sourceFalling : this.sourceNotFalling;
+        // Paper end - fluid method optimisations
     }
 
     protected abstract boolean canConvertToSource(ServerLevel world);
diff --git a/src/main/java/net/minecraft/world/level/material/FluidState.java b/src/main/java/net/minecraft/world/level/material/FluidState.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/material/FluidState.java
+++ b/src/main/java/net/minecraft/world/level/material/FluidState.java
@@ -0,0 +0,0 @@ import net.minecraft.world.level.block.state.properties.Property;
 import net.minecraft.world.phys.Vec3;
 import net.minecraft.world.phys.shapes.VoxelShape;
 
-public final class FluidState extends StateHolder<Fluid, FluidState> {
+public final class FluidState extends StateHolder<Fluid, FluidState> implements ca.spottedleaf.moonrise.patches.fluid.FluidFluidState { // Paper - fluid method optimisations
     public static final Codec<FluidState> CODEC = codec(BuiltInRegistries.FLUID.byNameCodec(), Fluid::defaultFluidState).stable();
     public static final int AMOUNT_MAX = 9;
     public static final int AMOUNT_FULL = 8;
     protected final boolean isEmpty; // Paper - Perf: moved from isEmpty()
 
+    // Paper start - fluid method optimisations
+    private int amount;
+    //private boolean isEmpty;
+    private boolean isSource;
+    private float ownHeight;
+    private boolean isRandomlyTicking;
+    private BlockState legacyBlock;
+
+    @Override
+    public final void moonrise$initCaches() {
+        this.amount = this.getType().getAmount((FluidState)(Object)this);
+        //this.isEmpty = this.getType().isEmpty();
+        this.isSource = this.getType().isSource((FluidState)(Object)this);
+        this.ownHeight = this.getType().getOwnHeight((FluidState)(Object)this);
+        this.isRandomlyTicking = this.getType().isRandomlyTicking();
+    }
+    // Paper end - fluid method optimisations
+
     public FluidState(Fluid fluid, Reference2ObjectArrayMap<Property<?>, Comparable<?>> propertyMap, MapCodec<FluidState> codec) {
         super(fluid, propertyMap, codec);
         this.isEmpty = fluid.isEmpty(); // Paper - Perf: moved from isEmpty()
@@ -0,0 +0,0 @@ public final class FluidState extends StateHolder<Fluid, FluidState> {
     }
 
     public boolean isSource() {
-        return this.getType().isSource(this);
+        return this.isSource; // Paper - fluid method optimisations
     }
 
     public boolean isSourceOfType(Fluid fluid) {
-        return this.owner == fluid && this.owner.isSource(this);
+        return this.isSource && this.owner == fluid;  // Paper - fluid method optimisations
     }
 
     public boolean isEmpty() {
@@ -0,0 +0,0 @@ public final class FluidState extends StateHolder<Fluid, FluidState> {
     }
 
     public float getOwnHeight() {
-        return this.getType().getOwnHeight(this);
+        return this.ownHeight; // Paper - fluid method optimisations
     }
 
     public int getAmount() {
-        return this.getType().getAmount(this);
+        return this.amount; // Paper - fluid method optimisations
     }
 
     public boolean shouldRenderBackwardUpFace(BlockGetter world, BlockPos pos) {
@@ -0,0 +0,0 @@ public final class FluidState extends StateHolder<Fluid, FluidState> {
     }
 
     public boolean isRandomlyTicking() {
-        return this.getType().isRandomlyTicking();
+        return this.isRandomlyTicking; // Paper - fluid method optimisations
     }
 
     public void randomTick(ServerLevel world, BlockPos pos, RandomSource random) {
@@ -0,0 +0,0 @@ public final class FluidState extends StateHolder<Fluid, FluidState> {
     }
 
     public BlockState createLegacyBlock() {
-        return this.getType().createLegacyBlock(this);
+        // Paper start - fluid method optimisations
+        if (this.legacyBlock != null) {
+            return this.legacyBlock;
+        }
+        return this.legacyBlock = this.getType().createLegacyBlock((FluidState)(Object)this);
+        // Paper end - fluid method optimisations
     }
 
     @Nullable
diff --git a/src/main/java/net/minecraft/world/phys/AABB.java b/src/main/java/net/minecraft/world/phys/AABB.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/phys/AABB.java
+++ b/src/main/java/net/minecraft/world/phys/AABB.java
@@ -0,0 +0,0 @@ public class AABB {
     }
 
     @Nullable
-    private static Direction getDirection(
+    public static Direction getDirection( // Paper - optimise collisions - public
         AABB box, Vec3 intersectingVector, double[] traceDistanceResult, @Nullable Direction approachDirection, double deltaX, double deltaY, double deltaZ
     ) {
         return getDirection(
diff --git a/src/main/java/net/minecraft/world/phys/shapes/ArrayVoxelShape.java b/src/main/java/net/minecraft/world/phys/shapes/ArrayVoxelShape.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/phys/shapes/ArrayVoxelShape.java
+++ b/src/main/java/net/minecraft/world/phys/shapes/ArrayVoxelShape.java
@@ -0,0 +0,0 @@ public class ArrayVoxelShape extends VoxelShape {
         );
     }
 
-    ArrayVoxelShape(DiscreteVoxelShape shape, DoubleList xPoints, DoubleList yPoints, DoubleList zPoints) {
+    public ArrayVoxelShape(DiscreteVoxelShape shape, DoubleList xPoints, DoubleList yPoints, DoubleList zPoints) { // Paper - optimise collisions - public
         super(shape);
         int i = shape.getXSize() + 1;
         int j = shape.getYSize() + 1;
@@ -0,0 +0,0 @@ public class ArrayVoxelShape extends VoxelShape {
                 new IllegalArgumentException("Lengths of point arrays must be consistent with the size of the VoxelShape.")
             );
         }
+        ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)this).moonrise$initCache(); // Paper - optimise collisions
     }
 
     @Override
diff --git a/src/main/java/net/minecraft/world/phys/shapes/BitSetDiscreteVoxelShape.java b/src/main/java/net/minecraft/world/phys/shapes/BitSetDiscreteVoxelShape.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/phys/shapes/BitSetDiscreteVoxelShape.java
+++ b/src/main/java/net/minecraft/world/phys/shapes/BitSetDiscreteVoxelShape.java
@@ -0,0 +0,0 @@ import java.util.BitSet;
 import net.minecraft.core.Direction;
 
 public final class BitSetDiscreteVoxelShape extends DiscreteVoxelShape {
-    private final BitSet storage;
-    private int xMin;
-    private int yMin;
-    private int zMin;
-    private int xMax;
-    private int yMax;
-    private int zMax;
+    public final BitSet storage; // Paper - optimise collisions - public
+    public int xMin; // Paper - optimise collisions - public
+    public int yMin; // Paper - optimise collisions - public
+    public int zMin; // Paper - optimise collisions - public
+    public int xMax; // Paper - optimise collisions - public
+    public int yMax; // Paper - optimise collisions - public
+    public int zMax; // Paper - optimise collisions - public
 
     public BitSetDiscreteVoxelShape(int sizeX, int sizeY, int sizeZ) {
         super(sizeX, sizeY, sizeZ);
@@ -0,0 +0,0 @@ public final class BitSetDiscreteVoxelShape extends DiscreteVoxelShape {
         return bitSetDiscreteVoxelShape;
     }
 
-    protected static void forAllBoxes(DiscreteVoxelShape voxelSet, DiscreteVoxelShape.IntLineConsumer callback, boolean coalesce) {
-        BitSetDiscreteVoxelShape bitSetDiscreteVoxelShape = new BitSetDiscreteVoxelShape(voxelSet);
+    // Paper start - optimise collisions
+    public static void forAllBoxes(final DiscreteVoxelShape shape, final DiscreteVoxelShape.IntLineConsumer consumer, final boolean mergeAdjacent) {
+        // Paper - remove debug
+        // called with the shape of a VoxelShape, so we can expect the cache to exist
+        final ca.spottedleaf.moonrise.patches.collisions.shape.CachedShapeData cache = ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionDiscreteVoxelShape) shape).moonrise$getOrCreateCachedShapeData();
+
+        final int sizeX = cache.sizeX();
+        final int sizeY = cache.sizeY();
+        final int sizeZ = cache.sizeZ();
+
+        int indexX;
+        int indexY = 0;
+        int indexZ;
+
+        int incY = sizeZ;
+        int incX = sizeZ * sizeY;
+
+        long[] bitset = cache.voxelSet();
+
+        // index = z + y*size_z + x*(size_z*size_y)
+
+        if (!mergeAdjacent) {
+            // due to the odd selection of loop order (which does affect behavior, unfortunately) we can't simply
+            // increment an index in the Z loop, and have to perform this trash (keeping track of 3 counters) to avoid
+            // the multiplication
+            for (int y = 0; y < sizeY; ++y, indexY += incY) {
+                indexX = indexY;
+                for (int x = 0; x < sizeX; ++x, indexX += incX) {
+                    indexZ = indexX;
+                    for (int z = 0; z < sizeZ; ++z, ++indexZ) {
+                        if ((bitset[indexZ >>> 6] & (1L << indexZ)) != 0L) {
+                            consumer.consume(x, y, z, x + 1, y + 1, z + 1);
+                        }
+                    }
+                }
+            }
+        } else {
+            // same notes about loop order as the above
+            // this branch is actually important to optimise, as it affects uncached toAabbs() (which affects optimize())
 
-        for (int i = 0; i < bitSetDiscreteVoxelShape.ySize; i++) {
-            for (int j = 0; j < bitSetDiscreteVoxelShape.xSize; j++) {
-                int k = -1;
+            // only clone when we may write to it
+            bitset = ca.spottedleaf.moonrise.common.util.MixinWorkarounds.clone(bitset);
 
-                for (int l = 0; l <= bitSetDiscreteVoxelShape.zSize; l++) {
-                    if (bitSetDiscreteVoxelShape.isFullWide(j, i, l)) {
-                        if (coalesce) {
-                            if (k == -1) {
-                                k = l;
-                            }
-                        } else {
-                            callback.consume(j, i, l, j + 1, i + 1, l + 1);
+            for (int y = 0; y < sizeY; ++y, indexY += incY) {
+                indexX = indexY;
+                for (int x = 0; x < sizeX; ++x, indexX += incX) {
+                    for (int zIdx = indexX, endIndex = indexX + sizeZ; zIdx < endIndex; ) {
+                        final int firstSetZ = ca.spottedleaf.moonrise.common.util.FlatBitsetUtil.firstSet(bitset, zIdx, endIndex);
+
+                        if (firstSetZ == -1) {
+                            break;
+                        }
+
+                        int lastSetZ = ca.spottedleaf.moonrise.common.util.FlatBitsetUtil.firstClear(bitset, firstSetZ, endIndex);
+                        if (lastSetZ == -1) {
+                            lastSetZ = endIndex;
                         }
-                    } else if (k != -1) {
-                        int m = j;
-                        int n = i;
-                        bitSetDiscreteVoxelShape.clearZStrip(k, l, j, i);
-
-                        while (bitSetDiscreteVoxelShape.isZStripFull(k, l, m + 1, i)) {
-                            bitSetDiscreteVoxelShape.clearZStrip(k, l, m + 1, i);
-                            m++;
+
+                        ca.spottedleaf.moonrise.common.util.FlatBitsetUtil.clearRange(bitset, firstSetZ, lastSetZ);
+
+                        // try to merge neighbouring on the X axis
+                        int endX = x + 1; // exclusive
+                        for (int neighbourIdxStart = firstSetZ + incX, neighbourIdxEnd = lastSetZ + incX;
+                             endX < sizeX && ca.spottedleaf.moonrise.common.util.FlatBitsetUtil.isRangeSet(bitset, neighbourIdxStart, neighbourIdxEnd);
+                             neighbourIdxStart += incX, neighbourIdxEnd += incX) {
+
+                            ++endX;
+                            ca.spottedleaf.moonrise.common.util.FlatBitsetUtil.clearRange(bitset, neighbourIdxStart, neighbourIdxEnd);
                         }
 
-                        while (bitSetDiscreteVoxelShape.isXZRectangleFull(j, m + 1, k, l, n + 1)) {
-                            for (int o = j; o <= m; o++) {
-                                bitSetDiscreteVoxelShape.clearZStrip(k, l, o, n + 1);
+                        // try to merge neighbouring on the Y axis
+
+                        int endY; // exclusive
+                        int firstSetZY, lastSetZY;
+                        y_merge:
+                        for (endY = y + 1, firstSetZY = firstSetZ + incY, lastSetZY = lastSetZ + incY; endY < sizeY;
+                             firstSetZY += incY, lastSetZY += incY) {
+
+                            // test the whole XZ range
+                            for (int testX = x, start = firstSetZY, end = lastSetZY; testX < endX;
+                                 ++testX, start += incX, end += incX) {
+                                if (!ca.spottedleaf.moonrise.common.util.FlatBitsetUtil.isRangeSet(bitset, start, end)) {
+                                    break y_merge;
+                                }
                             }
 
-                            n++;
+                            ++endY;
+
+                            // passed, so we can clear it
+                            for (int testX = x, start = firstSetZY, end = lastSetZY; testX < endX;
+                                 ++testX, start += incX, end += incX) {
+                                ca.spottedleaf.moonrise.common.util.FlatBitsetUtil.clearRange(bitset, start, end);
+                            }
                         }
 
-                        callback.consume(j, i, k, m + 1, n + 1, l);
-                        k = -1;
+                        consumer.consume(x, y, firstSetZ - indexX, endX, endY, lastSetZ - indexX);
+                        zIdx = lastSetZ;
                     }
                 }
             }
         }
     }
+    // Paper end - optimise collisions
 
     private boolean isZStripFull(int z1, int z2, int x, int y) {
         return x < this.xSize && y < this.ySize && this.storage.nextClearBit(this.getIndex(x, y, z1)) >= this.getIndex(x, y, z2);
diff --git a/src/main/java/net/minecraft/world/phys/shapes/CubeVoxelShape.java b/src/main/java/net/minecraft/world/phys/shapes/CubeVoxelShape.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/phys/shapes/CubeVoxelShape.java
+++ b/src/main/java/net/minecraft/world/phys/shapes/CubeVoxelShape.java
@@ -0,0 +0,0 @@ import net.minecraft.util.Mth;
 public final class CubeVoxelShape extends VoxelShape {
     protected CubeVoxelShape(DiscreteVoxelShape voxels) {
         super(voxels);
+        ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)this).moonrise$initCache(); // Paper - optimise collisions
     }
 
     @Override
diff --git a/src/main/java/net/minecraft/world/phys/shapes/DiscreteVoxelShape.java b/src/main/java/net/minecraft/world/phys/shapes/DiscreteVoxelShape.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/phys/shapes/DiscreteVoxelShape.java
+++ b/src/main/java/net/minecraft/world/phys/shapes/DiscreteVoxelShape.java
@@ -0,0 +0,0 @@ package net.minecraft.world.phys.shapes;
 import net.minecraft.core.AxisCycle;
 import net.minecraft.core.Direction;
 
-public abstract class DiscreteVoxelShape {
+public abstract class DiscreteVoxelShape implements ca.spottedleaf.moonrise.patches.collisions.shape.CollisionDiscreteVoxelShape { // Paper - optimise collisions
     private static final Direction.Axis[] AXIS_VALUES = Direction.Axis.values();
     protected final int xSize;
     protected final int ySize;
     protected final int zSize;
 
+    // Paper start - optimise collisions
+    // ignore race conditions on field read/write: the shape is static, so it doesn't matter
+    private ca.spottedleaf.moonrise.patches.collisions.shape.CachedShapeData cachedShapeData;
+
+    @Override
+    public final ca.spottedleaf.moonrise.patches.collisions.shape.CachedShapeData moonrise$getOrCreateCachedShapeData() {
+        if (this.cachedShapeData != null) {
+            return this.cachedShapeData;
+        }
+
+        final DiscreteVoxelShape discreteVoxelShape = (DiscreteVoxelShape)(Object)this;
+
+        final int sizeX = discreteVoxelShape.getXSize();
+        final int sizeY = discreteVoxelShape.getYSize();
+        final int sizeZ = discreteVoxelShape.getZSize();
+
+        final int maxIndex = sizeX * sizeY * sizeZ; // exclusive
+
+        final int longsRequired = (maxIndex + (Long.SIZE - 1)) >>> 6;
+        long[] voxelSet;
+
+        final boolean isEmpty = discreteVoxelShape.isEmpty();
+
+        if (discreteVoxelShape instanceof BitSetDiscreteVoxelShape bitsetShape) {
+            voxelSet = bitsetShape.storage.toLongArray();
+            if (voxelSet.length < longsRequired) {
+                // happens when the later long values are 0L, so we need to resize
+                voxelSet = java.util.Arrays.copyOf(voxelSet, longsRequired);
+            }
+        } else {
+            voxelSet = new long[longsRequired];
+            if (!isEmpty) {
+                final int mulX = sizeZ * sizeY;
+                for (int x = 0; x < sizeX; ++x) {
+                    for (int y = 0; y < sizeY; ++y) {
+                        for (int z = 0; z < sizeZ; ++z) {
+                            if (discreteVoxelShape.isFull(x, y, z)) {
+                                // index = z + y*size_z + x*(size_z*size_y)
+                                final int index = z + y * sizeZ + x * mulX;
+
+                                voxelSet[index >>> 6] |= 1L << index;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        final boolean hasSingleAABB = sizeX == 1 && sizeY == 1 && sizeZ == 1 && !isEmpty && (voxelSet[0] & 1L) != 0L;
+
+        final int minFullX = discreteVoxelShape.firstFull(Direction.Axis.X);
+        final int minFullY = discreteVoxelShape.firstFull(Direction.Axis.Y);
+        final int minFullZ = discreteVoxelShape.firstFull(Direction.Axis.Z);
+
+        final int maxFullX = discreteVoxelShape.lastFull(Direction.Axis.X);
+        final int maxFullY = discreteVoxelShape.lastFull(Direction.Axis.Y);
+        final int maxFullZ = discreteVoxelShape.lastFull(Direction.Axis.Z);
+
+        return this.cachedShapeData = new ca.spottedleaf.moonrise.patches.collisions.shape.CachedShapeData(
+            sizeX, sizeY, sizeZ, voxelSet,
+            minFullX, minFullY, minFullZ,
+            maxFullX, maxFullY, maxFullZ,
+            isEmpty, hasSingleAABB
+        );
+    }
+    // Paper end - optimise collisions
+
     protected DiscreteVoxelShape(int sizeX, int sizeY, int sizeZ) {
         if (sizeX >= 0 && sizeY >= 0 && sizeZ >= 0) {
             this.xSize = sizeX;
diff --git a/src/main/java/net/minecraft/world/phys/shapes/OffsetDoubleList.java b/src/main/java/net/minecraft/world/phys/shapes/OffsetDoubleList.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/phys/shapes/OffsetDoubleList.java
+++ b/src/main/java/net/minecraft/world/phys/shapes/OffsetDoubleList.java
@@ -0,0 +0,0 @@ import it.unimi.dsi.fastutil.doubles.AbstractDoubleList;
 import it.unimi.dsi.fastutil.doubles.DoubleList;
 
 public class OffsetDoubleList extends AbstractDoubleList {
-    private final DoubleList delegate;
-    private final double offset;
+    public final DoubleList delegate; // Paper - optimise collisions - public
+    public final double offset; // Paper - optimise collisions - public
 
     public OffsetDoubleList(DoubleList oldList, double offset) {
         this.delegate = oldList;
diff --git a/src/main/java/net/minecraft/world/phys/shapes/Shapes.java b/src/main/java/net/minecraft/world/phys/shapes/Shapes.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/phys/shapes/Shapes.java
+++ b/src/main/java/net/minecraft/world/phys/shapes/Shapes.java
@@ -0,0 +0,0 @@ public final class Shapes {
     public static final double EPSILON = 1.0E-7;
     public static final double BIG_EPSILON = 1.0E-6;
     private static final VoxelShape BLOCK = Util.make(() -> {
-        DiscreteVoxelShape discreteVoxelShape = new BitSetDiscreteVoxelShape(1, 1, 1);
-        discreteVoxelShape.fill(0, 0, 0);
-        return new CubeVoxelShape(discreteVoxelShape);
+        // Paper start - optimise collisions
+        final DiscreteVoxelShape shape = new BitSetDiscreteVoxelShape(1, 1, 1);
+        shape.fill(0, 0, 0);
+
+        return new ArrayVoxelShape(
+            shape,
+            ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.ZERO_ONE, ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.ZERO_ONE, ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.ZERO_ONE
+        );
+        // Paper end - optimise collisions
     });
     public static final VoxelShape INFINITY = box(
         Double.NEGATIVE_INFINITY,
@@ -0,0 +0,0 @@ public final class Shapes {
         return BLOCK;
     }
 
+    // Paper start - optimise collisions
+    private static final DoubleArrayList[] PARTS_BY_BITS = new DoubleArrayList[] {
+        DoubleArrayList.wrap(generateCubeParts(1 << 0)),
+        DoubleArrayList.wrap(generateCubeParts(1 << 1)),
+        DoubleArrayList.wrap(generateCubeParts(1 << 2)),
+        DoubleArrayList.wrap(generateCubeParts(1 << 3))
+    };
+
+    private static double[] generateCubeParts(final int parts) {
+        // note: parts is a power of two, so we do not need to worry about loss of precision here
+        // note: parts is from [2^0, 2^3]
+        final double inc = 1.0 / (double)parts;
+
+        final double[] ret = new double[parts + 1];
+        double val = 0.0;
+        for (int i = 0; i <= parts; ++i) {
+            ret[i] = val;
+            val += inc;
+        }
+
+        return ret;
+    }
+    // Paper end - optimise collisions
+
     public static VoxelShape box(double minX, double minY, double minZ, double maxX, double maxY, double maxZ) {
         if (!(minX > maxX) && !(minY > maxY) && !(minZ > maxZ)) {
             return create(minX, minY, minZ, maxX, maxY, maxZ);
@@ -0,0 +0,0 @@ public final class Shapes {
     }
 
     public static VoxelShape create(double minX, double minY, double minZ, double maxX, double maxY, double maxZ) {
+        // Paper start - optimise collisions
         if (!(maxX - minX < 1.0E-7) && !(maxY - minY < 1.0E-7) && !(maxZ - minZ < 1.0E-7)) {
-            int i = findBits(minX, maxX);
-            int j = findBits(minY, maxY);
-            int k = findBits(minZ, maxZ);
-            if (i < 0 || j < 0 || k < 0) {
+            final int bitsX = findBits(minX, maxX);
+            final int bitsY = findBits(minY, maxY);
+            final int bitsZ = findBits(minZ, maxZ);
+            if (bitsX >= 0 && bitsY >= 0 && bitsZ >= 0) {
+                if (bitsX == 0 && bitsY == 0 && bitsZ == 0) {
+                    return BLOCK;
+                } else {
+                    final int sizeX = 1 << bitsX;
+                    final int sizeY = 1 << bitsY;
+                    final int sizeZ = 1 << bitsZ;
+                    final BitSetDiscreteVoxelShape shape = BitSetDiscreteVoxelShape.withFilledBounds(
+                        sizeX, sizeY, sizeZ,
+                        (int)Math.round(minX * (double)sizeX), (int)Math.round(minY * (double)sizeY), (int)Math.round(minZ * (double)sizeZ),
+                        (int)Math.round(maxX * (double)sizeX), (int)Math.round(maxY * (double)sizeY), (int)Math.round(maxZ * (double)sizeZ)
+                    );
+                    return new ArrayVoxelShape(
+                        shape,
+                        PARTS_BY_BITS[bitsX],
+                        PARTS_BY_BITS[bitsY],
+                        PARTS_BY_BITS[bitsZ]
+                    );
+                }
+            } else {
                 return new ArrayVoxelShape(
                     BLOCK.shape,
-                    DoubleArrayList.wrap(new double[]{minX, maxX}),
-                    DoubleArrayList.wrap(new double[]{minY, maxY}),
-                    DoubleArrayList.wrap(new double[]{minZ, maxZ})
+                    minX == 0.0 && maxX == 1.0 ? ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.ZERO_ONE : DoubleArrayList.wrap(new double[] { minX, maxX }),
+                    minY == 0.0 && maxY == 1.0 ? ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.ZERO_ONE : DoubleArrayList.wrap(new double[] { minY, maxY }),
+                    minZ == 0.0 && maxZ == 1.0 ? ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.ZERO_ONE : DoubleArrayList.wrap(new double[] { minZ, maxZ })
                 );
-            } else if (i == 0 && j == 0 && k == 0) {
-                return block();
-            } else {
-                int l = 1 << i;
-                int m = 1 << j;
-                int n = 1 << k;
-                BitSetDiscreteVoxelShape bitSetDiscreteVoxelShape = BitSetDiscreteVoxelShape.withFilledBounds(
-                    l,
-                    m,
-                    n,
-                    (int)Math.round(minX * (double)l),
-                    (int)Math.round(minY * (double)m),
-                    (int)Math.round(minZ * (double)n),
-                    (int)Math.round(maxX * (double)l),
-                    (int)Math.round(maxY * (double)m),
-                    (int)Math.round(maxZ * (double)n)
-                );
-                return new CubeVoxelShape(bitSetDiscreteVoxelShape);
             }
         } else {
-            return empty();
+            return EMPTY;
         }
+        // Paper end - optimise collisions
     }
 
     public static VoxelShape create(AABB box) {
@@ -0,0 +0,0 @@ public final class Shapes {
         return join(first, second, BooleanOp.OR);
     }
 
-    public static VoxelShape or(VoxelShape first, VoxelShape... others) {
-        return Arrays.stream(others).reduce(first, Shapes::or);
+    // Paper start - optimise collisions
+    public static VoxelShape or(VoxelShape shape, VoxelShape... others) {
+        int size = others.length;
+        if (size == 0) {
+            return shape;
+        }
+
+        // reduce complexity of joins by splitting the merges
+
+        // add extra slot for first shape
+        ++size;
+        final VoxelShape[] tmp = Arrays.copyOf(others, size);
+        // insert first shape
+        tmp[size - 1] = shape;
+
+        while (size > 1) {
+            int newSize = 0;
+            for (int i = 0; i < size; i += 2) {
+                final int next = i + 1;
+                if (next >= size) {
+                    // nothing to merge with, so leave it for next iteration
+                    tmp[newSize++] = tmp[i];
+                    break;
+                } else {
+                    // merge with adjacent
+                    final VoxelShape first = tmp[i];
+                    final VoxelShape second = tmp[next];
+
+                    tmp[newSize++] = Shapes.joinUnoptimized(first, second, BooleanOp.OR);
+                }
+            }
+            size = newSize;
+        }
+
+        return tmp[0].optimize();
+        // Paper end - optimise collisions
     }
 
     public static VoxelShape join(VoxelShape first, VoxelShape second, BooleanOp function) {
-        return joinUnoptimized(first, second, function).optimize();
+        return ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.joinOptimized(first, second, function); // Paper - optimise collisions
     }
 
     public static VoxelShape joinUnoptimized(VoxelShape one, VoxelShape two, BooleanOp function) {
-        if (function.apply(false, false)) {
-            throw (IllegalArgumentException)Util.pauseInIde(new IllegalArgumentException());
-        } else if (one == two) {
-            return function.apply(true, true) ? one : empty();
-        } else {
-            boolean bl = function.apply(true, false);
-            boolean bl2 = function.apply(false, true);
-            if (one.isEmpty()) {
-                return bl2 ? two : empty();
-            } else if (two.isEmpty()) {
-                return bl ? one : empty();
-            } else {
-                IndexMerger indexMerger = createIndexMerger(1, one.getCoords(Direction.Axis.X), two.getCoords(Direction.Axis.X), bl, bl2);
-                IndexMerger indexMerger2 = createIndexMerger(indexMerger.size() - 1, one.getCoords(Direction.Axis.Y), two.getCoords(Direction.Axis.Y), bl, bl2);
-                IndexMerger indexMerger3 = createIndexMerger(
-                    (indexMerger.size() - 1) * (indexMerger2.size() - 1), one.getCoords(Direction.Axis.Z), two.getCoords(Direction.Axis.Z), bl, bl2
-                );
-                BitSetDiscreteVoxelShape bitSetDiscreteVoxelShape = BitSetDiscreteVoxelShape.join(
-                    one.shape, two.shape, indexMerger, indexMerger2, indexMerger3, function
-                );
-                return (VoxelShape)(indexMerger instanceof DiscreteCubeMerger
-                        && indexMerger2 instanceof DiscreteCubeMerger
-                        && indexMerger3 instanceof DiscreteCubeMerger
-                    ? new CubeVoxelShape(bitSetDiscreteVoxelShape)
-                    : new ArrayVoxelShape(bitSetDiscreteVoxelShape, indexMerger.getList(), indexMerger2.getList(), indexMerger3.getList()));
-            }
-        }
+        return ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.joinUnoptimized(one, two, function); // Paper - optimise collisions
     }
 
     public static boolean joinIsNotEmpty(VoxelShape shape1, VoxelShape shape2, BooleanOp predicate) {
-        if (predicate.apply(false, false)) {
-            throw (IllegalArgumentException)Util.pauseInIde(new IllegalArgumentException());
-        } else {
-            boolean bl = shape1.isEmpty();
-            boolean bl2 = shape2.isEmpty();
-            if (!bl && !bl2) {
-                if (shape1 == shape2) {
-                    return predicate.apply(true, true);
-                } else {
-                    boolean bl3 = predicate.apply(true, false);
-                    boolean bl4 = predicate.apply(false, true);
-
-                    for (Direction.Axis axis : AxisCycle.AXIS_VALUES) {
-                        if (shape1.max(axis) < shape2.min(axis) - 1.0E-7) {
-                            return bl3 || bl4;
-                        }
-
-                        if (shape2.max(axis) < shape1.min(axis) - 1.0E-7) {
-                            return bl3 || bl4;
-                        }
-                    }
-
-                    IndexMerger indexMerger = createIndexMerger(1, shape1.getCoords(Direction.Axis.X), shape2.getCoords(Direction.Axis.X), bl3, bl4);
-                    IndexMerger indexMerger2 = createIndexMerger(
-                        indexMerger.size() - 1, shape1.getCoords(Direction.Axis.Y), shape2.getCoords(Direction.Axis.Y), bl3, bl4
-                    );
-                    IndexMerger indexMerger3 = createIndexMerger(
-                        (indexMerger.size() - 1) * (indexMerger2.size() - 1), shape1.getCoords(Direction.Axis.Z), shape2.getCoords(Direction.Axis.Z), bl3, bl4
-                    );
-                    return joinIsNotEmpty(indexMerger, indexMerger2, indexMerger3, shape1.shape, shape2.shape, predicate);
-                }
-            } else {
-                return predicate.apply(!bl, !bl2);
-            }
-        }
+        return ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.isJoinNonEmpty(shape1, shape2, predicate); // Paper - optimise collisions
     }
 
     private static boolean joinIsNotEmpty(
@@ -0,0 +0,0 @@ public final class Shapes {
         return maxDist;
     }
 
-    public static boolean blockOccudes(VoxelShape shape, VoxelShape neighbor, Direction direction) {
-        if (shape == block() && neighbor == block()) {
+    // Paper start - optimise collisions
+    public static boolean blockOccudes(final VoxelShape first, final VoxelShape second, final Direction direction) {
+        final boolean firstBlock = first == BLOCK;
+        final boolean secondBlock = second == BLOCK;
+
+        if (firstBlock & secondBlock) {
             return true;
-        } else if (neighbor.isEmpty()) {
+        }
+
+        if (first.isEmpty() | second.isEmpty()) {
+            return false;
+        }
+
+        // we optimise getOpposite, so we can use it
+        // secondly, use our cache to retrieve sliced shape
+        final VoxelShape newFirst = ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)first).moonrise$getFaceShapeClamped(direction);
+        if (newFirst.isEmpty()) {
             return false;
-        } else {
-            Direction.Axis axis = direction.getAxis();
-            Direction.AxisDirection axisDirection = direction.getAxisDirection();
-            VoxelShape voxelShape = axisDirection == Direction.AxisDirection.POSITIVE ? shape : neighbor;
-            VoxelShape voxelShape2 = axisDirection == Direction.AxisDirection.POSITIVE ? neighbor : shape;
-            BooleanOp booleanOp = axisDirection == Direction.AxisDirection.POSITIVE ? BooleanOp.ONLY_FIRST : BooleanOp.ONLY_SECOND;
-            return DoubleMath.fuzzyEquals(voxelShape.max(axis), 1.0, 1.0E-7)
-                && DoubleMath.fuzzyEquals(voxelShape2.min(axis), 0.0, 1.0E-7)
-                && !joinIsNotEmpty(new SliceShape(voxelShape, axis, voxelShape.shape.getSize(axis) - 1), new SliceShape(voxelShape2, axis, 0), booleanOp);
         }
+        final VoxelShape newSecond = ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)second).moonrise$getFaceShapeClamped(direction.getOpposite());
+        if (newSecond.isEmpty()) {
+            return false;
+        }
+
+        return !joinIsNotEmpty(newFirst, newSecond, BooleanOp.ONLY_FIRST);
+        // Paper end - optimise collisions
     }
 
-    public static boolean mergedFaceOccludes(VoxelShape one, VoxelShape two, Direction direction) {
-        if (one != block() && two != block()) {
-            Direction.Axis axis = direction.getAxis();
-            Direction.AxisDirection axisDirection = direction.getAxisDirection();
-            VoxelShape voxelShape = axisDirection == Direction.AxisDirection.POSITIVE ? one : two;
-            VoxelShape voxelShape2 = axisDirection == Direction.AxisDirection.POSITIVE ? two : one;
-            if (!DoubleMath.fuzzyEquals(voxelShape.max(axis), 1.0, 1.0E-7)) {
-                voxelShape = empty();
-            }
+    // Paper start - optimise collisions
+    private static boolean mergedMayOccludeBlock(final VoxelShape shape1, final VoxelShape shape2) {
+        // if the combined bounds of the two shapes cannot occlude, then neither can the merged
+        final AABB bounds1 = shape1.bounds();
+        final AABB bounds2 = shape2.bounds();
 
-            if (!DoubleMath.fuzzyEquals(voxelShape2.min(axis), 0.0, 1.0E-7)) {
-                voxelShape2 = empty();
-            }
+        final double minX = Math.min(bounds1.minX, bounds2.minX);
+        final double minY = Math.min(bounds1.minY, bounds2.minY);
+        final double minZ = Math.min(bounds1.minZ, bounds2.minZ);
 
-            return !joinIsNotEmpty(
-                block(),
-                joinUnoptimized(new SliceShape(voxelShape, axis, voxelShape.shape.getSize(axis) - 1), new SliceShape(voxelShape2, axis, 0), BooleanOp.OR),
-                BooleanOp.ONLY_FIRST
-            );
-        } else {
+        final double maxX = Math.max(bounds1.maxX, bounds2.maxX);
+        final double maxY = Math.max(bounds1.maxY, bounds2.maxY);
+        final double maxZ = Math.max(bounds1.maxZ, bounds2.maxZ);
+
+        return (minX <= ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON && maxX >= (1 - ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON)) &&
+            (minY <= ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON && maxY >= (1 - ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON)) &&
+            (minZ <= ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON && maxZ >= (1 - ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON));
+    }
+    // Paper end - optimise collisions
+
+    // Paper start - optimise collisions
+    public static boolean mergedFaceOccludes(final VoxelShape first, final VoxelShape second, final Direction direction) {
+        // see if any of the shapes on their own occludes, only if cached
+        if (((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)first).moonrise$occludesFullBlockIfCached() || ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)second).moonrise$occludesFullBlockIfCached()) {
+            return true;
+        }
+
+        if (first.isEmpty() & second.isEmpty()) {
+            return false;
+        }
+
+        // we optimise getOpposite, so we can use it
+        // secondly, use our cache to retrieve sliced shape
+        final VoxelShape newFirst = ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)first).moonrise$getFaceShapeClamped(direction);
+        final VoxelShape newSecond = ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)second).moonrise$getFaceShapeClamped(direction.getOpposite());
+
+        // see if any of the shapes on their own occludes, only if cached
+        if (((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)newFirst).moonrise$occludesFullBlockIfCached() || ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)newSecond).moonrise$occludesFullBlockIfCached()) {
             return true;
         }
+
+        final boolean firstEmpty = newFirst.isEmpty();
+        final boolean secondEmpty = newSecond.isEmpty();
+
+        if (firstEmpty & secondEmpty) {
+            return false;
+        }
+
+        if (firstEmpty | secondEmpty) {
+            return secondEmpty ? ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)newFirst).moonrise$occludesFullBlock() : ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)newSecond).moonrise$occludesFullBlock();
+        }
+
+        if (newFirst == newSecond) {
+            return ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)newFirst).moonrise$occludesFullBlock();
+        }
+
+        return mergedMayOccludeBlock(newFirst, newSecond) && ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)newFirst).moonrise$orUnoptimized(newSecond)).moonrise$occludesFullBlock();
     }
+    // Paper end - optimise collisions
+
+    // Paper start - optimise collisions
+    public static boolean faceShapeOccludes(final VoxelShape shape1, final VoxelShape shape2) {
+        if (((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)shape1).moonrise$occludesFullBlockIfCached() || ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)shape2).moonrise$occludesFullBlockIfCached()) {
+            return true;
+        }
+
+        final boolean s1Empty = shape1.isEmpty();
+        final boolean s2Empty = shape2.isEmpty();
+        if (s1Empty & s2Empty) {
+            return false;
+        }
+
+        if (s1Empty | s2Empty) {
+            return s2Empty ? ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)shape1).moonrise$occludesFullBlock() : ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)shape2).moonrise$occludesFullBlock();
+        }
+
+        if (shape1 == shape2) {
+            return ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)shape1).moonrise$occludesFullBlock();
+        }
 
-    public static boolean faceShapeOccludes(VoxelShape one, VoxelShape two) {
-        return one == block()
-            || two == block()
-            || (!one.isEmpty() || !two.isEmpty()) && !joinIsNotEmpty(block(), joinUnoptimized(one, two, BooleanOp.OR), BooleanOp.ONLY_FIRST);
+        return mergedMayOccludeBlock(shape1, shape2) && ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)shape1).moonrise$orUnoptimized(shape2)).moonrise$occludesFullBlock();
+        // Paper end - optimise collisions
     }
 
     @VisibleForTesting
diff --git a/src/main/java/net/minecraft/world/phys/shapes/SliceShape.java b/src/main/java/net/minecraft/world/phys/shapes/SliceShape.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/phys/shapes/SliceShape.java
+++ b/src/main/java/net/minecraft/world/phys/shapes/SliceShape.java
@@ -0,0 +0,0 @@ public class SliceShape extends VoxelShape {
         super(makeSlice(shape.shape, axis, sliceWidth));
         this.delegate = shape;
         this.axis = axis;
+        ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape)this).moonrise$initCache(); // Paper - optimise collisions
     }
 
     private static DiscreteVoxelShape makeSlice(DiscreteVoxelShape voxelSet, Direction.Axis axis, int sliceWidth) {
diff --git a/src/main/java/net/minecraft/world/phys/shapes/VoxelShape.java b/src/main/java/net/minecraft/world/phys/shapes/VoxelShape.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/phys/shapes/VoxelShape.java
+++ b/src/main/java/net/minecraft/world/phys/shapes/VoxelShape.java
@@ -0,0 +0,0 @@ import net.minecraft.world.phys.AABB;
 import net.minecraft.world.phys.BlockHitResult;
 import net.minecraft.world.phys.Vec3;
 
-public abstract class VoxelShape {
-    protected final DiscreteVoxelShape shape;
+public abstract class VoxelShape implements ca.spottedleaf.moonrise.patches.collisions.shape.CollisionVoxelShape { // Paper - optimise collisions
+    public final DiscreteVoxelShape shape; // Paper - optimise collisions - public
     @Nullable
     private VoxelShape[] faces;
 
+    // Paper start - optimise collisions
+    private double offsetX;
+    private double offsetY;
+    private double offsetZ;
+    private AABB singleAABBRepresentation;
+    private double[] rootCoordinatesX;
+    private double[] rootCoordinatesY;
+    private double[] rootCoordinatesZ;
+    private ca.spottedleaf.moonrise.patches.collisions.shape.CachedShapeData cachedShapeData;
+    private boolean isEmpty;
+    private ca.spottedleaf.moonrise.patches.collisions.shape.CachedToAABBs cachedToAABBs;
+    private AABB cachedBounds;
+    private Boolean isFullBlock;
+    private Boolean occludesFullBlock;
+
+    // must be power of two
+    private static final int MERGED_CACHE_SIZE = 16;
+    private ca.spottedleaf.moonrise.patches.collisions.shape.MergedORCache[] mergedORCache;
+
+    @Override
+    public final double moonrise$offsetX() {
+        return this.offsetX;
+    }
+
+    @Override
+    public final double moonrise$offsetY() {
+        return this.offsetY;
+    }
+
+    @Override
+    public final double moonrise$offsetZ() {
+        return this.offsetZ;
+    }
+
+    @Override
+    public final AABB moonrise$getSingleAABBRepresentation() {
+        return this.singleAABBRepresentation;
+    }
+
+    @Override
+    public final double[] moonrise$rootCoordinatesX() {
+        return this.rootCoordinatesX;
+    }
+
+    @Override
+    public final double[] moonrise$rootCoordinatesY() {
+        return this.rootCoordinatesY;
+    }
+
+    @Override
+    public final double[] moonrise$rootCoordinatesZ() {
+        return this.rootCoordinatesZ;
+    }
+
+    private static double[] extractRawArray(final DoubleList list) {
+        if (list instanceof it.unimi.dsi.fastutil.doubles.DoubleArrayList rawList) {
+            final double[] raw = rawList.elements();
+            final int expected = rawList.size();
+            if (raw.length == expected) {
+                return raw;
+            } else {
+                return java.util.Arrays.copyOf(raw, expected);
+            }
+        } else {
+            return list.toDoubleArray();
+        }
+    }
+
+    @Override
+    public final void moonrise$initCache() {
+        this.cachedShapeData = ((ca.spottedleaf.moonrise.patches.collisions.shape.CollisionDiscreteVoxelShape)this.shape).moonrise$getOrCreateCachedShapeData();
+        this.isEmpty = this.cachedShapeData.isEmpty();
+
+        final DoubleList xList = this.getCoords(Direction.Axis.X);
+        final DoubleList yList = this.getCoords(Direction.Axis.Y);
+        final DoubleList zList = this.getCoords(Direction.Axis.Z);
+
+        if (xList instanceof OffsetDoubleList offsetDoubleList) {
+            this.offsetX = offsetDoubleList.offset;
+            this.rootCoordinatesX = extractRawArray(offsetDoubleList.delegate);
+        } else {
+            this.rootCoordinatesX = extractRawArray(xList);
+        }
+
+        if (yList instanceof OffsetDoubleList offsetDoubleList) {
+            this.offsetY = offsetDoubleList.offset;
+            this.rootCoordinatesY = extractRawArray(offsetDoubleList.delegate);
+        } else {
+            this.rootCoordinatesY = extractRawArray(yList);
+        }
+
+        if (zList instanceof OffsetDoubleList offsetDoubleList) {
+            this.offsetZ = offsetDoubleList.offset;
+            this.rootCoordinatesZ = extractRawArray(offsetDoubleList.delegate);
+        } else {
+            this.rootCoordinatesZ = extractRawArray(zList);
+        }
+
+        if (this.cachedShapeData.hasSingleAABB()) {
+            this.singleAABBRepresentation = new AABB(
+                this.rootCoordinatesX[0] + this.offsetX, this.rootCoordinatesY[0] + this.offsetY, this.rootCoordinatesZ[0] + this.offsetZ,
+                this.rootCoordinatesX[1] + this.offsetX, this.rootCoordinatesY[1] + this.offsetY, this.rootCoordinatesZ[1] + this.offsetZ
+            );
+            this.cachedBounds = this.singleAABBRepresentation;
+        }
+    }
+
+    @Override
+    public final ca.spottedleaf.moonrise.patches.collisions.shape.CachedShapeData moonrise$getCachedVoxelData() {
+        return this.cachedShapeData;
+    }
+
+    private VoxelShape[] faceShapeClampedCache;
+
+    @Override
+    public final VoxelShape moonrise$getFaceShapeClamped(final Direction direction) {
+        if (this.isEmpty) {
+            return (VoxelShape)(Object)this;
+        }
+        if ((VoxelShape)(Object)this == Shapes.block()) {
+            return (VoxelShape)(Object)this;
+        }
+
+        VoxelShape[] cache = this.faceShapeClampedCache;
+        if (cache != null) {
+            final VoxelShape ret = cache[direction.ordinal()];
+            if (ret != null) {
+                return ret;
+            }
+        }
+
+
+        if (cache == null) {
+            this.faceShapeClampedCache = cache = new VoxelShape[6];
+        }
+
+        final Direction.Axis axis = direction.getAxis();
+
+        final VoxelShape ret;
+
+        if (direction.getAxisDirection() == Direction.AxisDirection.POSITIVE) {
+            if (DoubleMath.fuzzyEquals(this.max(axis), 1.0, ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON)) {
+                ret = ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.sliceShape((VoxelShape)(Object)this, axis, this.shape.getSize(axis) - 1);
+            } else {
+                ret = Shapes.empty();
+            }
+        } else {
+            if (DoubleMath.fuzzyEquals(this.min(axis), 0.0, ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON)) {
+                ret = ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.sliceShape((VoxelShape)(Object)this, axis, 0);
+            } else {
+                ret = Shapes.empty();
+            }
+        }
+
+        cache[direction.ordinal()] = ret;
+
+        return ret;
+    }
+
+    private boolean computeOccludesFullBlock() {
+        if (this.isEmpty) {
+            this.occludesFullBlock = Boolean.FALSE;
+            return false;
+        }
+
+        if (this.moonrise$isFullBlock()) {
+            this.occludesFullBlock = Boolean.TRUE;
+            return true;
+        }
+
+        final AABB singleAABB = this.singleAABBRepresentation;
+        if (singleAABB != null) {
+            // check if the bounding box encloses the full cube
+            final boolean ret =
+                (singleAABB.minY <= ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON && singleAABB.maxY >= (1 - ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON)) &&
+                    (singleAABB.minX <= ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON && singleAABB.maxX >= (1 - ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON)) &&
+                    (singleAABB.minZ <= ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON && singleAABB.maxZ >= (1 - ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON));
+            this.occludesFullBlock = Boolean.valueOf(ret);
+            return ret;
+        }
+
+        final boolean ret = !Shapes.joinIsNotEmpty(Shapes.block(), ((VoxelShape)(Object)this), BooleanOp.ONLY_FIRST);
+        this.occludesFullBlock = Boolean.valueOf(ret);
+        return ret;
+    }
+
+    @Override
+    public final boolean moonrise$occludesFullBlock() {
+        final Boolean ret = this.occludesFullBlock;
+        if (ret != null) {
+            return ret.booleanValue();
+        }
+
+        return this.computeOccludesFullBlock();
+    }
+
+    @Override
+    public final boolean moonrise$occludesFullBlockIfCached() {
+        final Boolean ret = this.occludesFullBlock;
+        return ret != null ? ret.booleanValue() : false;
+    }
+
+    private static int hash(final VoxelShape key) {
+        return it.unimi.dsi.fastutil.HashCommon.mix(System.identityHashCode(key));
+    }
+
+    @Override
+    public final VoxelShape moonrise$orUnoptimized(final VoxelShape other) {
+        // don't cache simple cases
+        if (((VoxelShape)(Object)this) == other) {
+            return other;
+        }
+
+        if (this.isEmpty) {
+            return other;
+        }
+
+        if (other.isEmpty()) {
+            return (VoxelShape)(Object)this;
+        }
+
+        // try this cache first
+        final int thisCacheKey = hash(other) & (MERGED_CACHE_SIZE - 1);
+        final ca.spottedleaf.moonrise.patches.collisions.shape.MergedORCache cached = this.mergedORCache == null ? null : this.mergedORCache[thisCacheKey];
+        if (cached != null && cached.key() == other) {
+            return cached.result();
+        }
+
+        // try other cache
+        final int otherCacheKey = hash((VoxelShape)(Object)this) & (MERGED_CACHE_SIZE - 1);
+        final ca.spottedleaf.moonrise.patches.collisions.shape.MergedORCache otherCache = ((VoxelShape)(Object)other).mergedORCache == null ? null : ((VoxelShape)(Object)other).mergedORCache[otherCacheKey];
+        if (otherCache != null && otherCache.key() == (VoxelShape)(Object)this) {
+            return otherCache.result();
+        }
+
+        // note: unsure if joinUnoptimized(1, 2, OR) == joinUnoptimized(2, 1, OR) for all cases
+        final VoxelShape result = Shapes.joinUnoptimized((VoxelShape)(Object)this, other, BooleanOp.OR);
+
+        if (cached != null && otherCache == null) {
+            // try to use second cache instead of replacing an entry in this cache
+            if (((VoxelShape)(Object)other).mergedORCache == null) {
+                ((VoxelShape)(Object)other).mergedORCache = new ca.spottedleaf.moonrise.patches.collisions.shape.MergedORCache[MERGED_CACHE_SIZE];
+            }
+            ((VoxelShape)(Object)other).mergedORCache[otherCacheKey] = new ca.spottedleaf.moonrise.patches.collisions.shape.MergedORCache((VoxelShape)(Object)this, result);
+        } else {
+            // line is not occupied or other cache line is full
+            // always bias to replace this cache, as this cache is the first we check
+            if (this.mergedORCache == null) {
+                this.mergedORCache = new ca.spottedleaf.moonrise.patches.collisions.shape.MergedORCache[MERGED_CACHE_SIZE];
+            }
+            this.mergedORCache[thisCacheKey] = new ca.spottedleaf.moonrise.patches.collisions.shape.MergedORCache(other, result);
+        }
+
+        return result;
+    }
+
+    private static DoubleList offsetList(final double[] src, final double by) {
+        final it.unimi.dsi.fastutil.doubles.DoubleArrayList wrap = it.unimi.dsi.fastutil.doubles.DoubleArrayList.wrap(src);
+        if (by == 0.0) {
+            return wrap;
+        }
+        return new OffsetDoubleList(wrap, by);
+    }
+
+    private List<AABB> toAabbsUncached() {
+        final List<AABB> ret;
+        if (this.singleAABBRepresentation != null) {
+            ret = new java.util.ArrayList<>(1);
+            ret.add(this.singleAABBRepresentation);
+        } else {
+            ret = new java.util.ArrayList<>();
+            final double[] coordsX = this.rootCoordinatesX;
+            final double[] coordsY = this.rootCoordinatesY;
+            final double[] coordsZ = this.rootCoordinatesZ;
+
+            final double offX = this.offsetX;
+            final double offY = this.offsetY;
+            final double offZ = this.offsetZ;
+
+            this.shape.forAllBoxes((final int minX, final int minY, final int minZ,
+                                    final int maxX, final int maxY, final int maxZ) -> {
+                ret.add(new AABB(
+                    coordsX[minX] + offX,
+                    coordsY[minY] + offY,
+                    coordsZ[minZ] + offZ,
+
+
+                    coordsX[maxX] + offX,
+                    coordsY[maxY] + offY,
+                    coordsZ[maxZ] + offZ
+                ));
+            }, true);
+        }
+
+        // cache result
+        this.cachedToAABBs = new ca.spottedleaf.moonrise.patches.collisions.shape.CachedToAABBs(ret, false, 0.0, 0.0, 0.0);
+
+        return ret;
+    }
+
+    private boolean computeFullBlock() {
+        Boolean ret;
+        if (this.isEmpty) {
+            ret = Boolean.FALSE;
+        } else if ((VoxelShape)(Object)this == Shapes.block()) {
+            ret = Boolean.TRUE;
+        } else {
+            final AABB singleAABB = this.singleAABBRepresentation;
+            if (singleAABB == null) {
+                final ca.spottedleaf.moonrise.patches.collisions.shape.CachedShapeData shapeData = this.cachedShapeData;
+                final int sMinX = shapeData.minFullX();
+                final int sMinY = shapeData.minFullY();
+                final int sMinZ = shapeData.minFullZ();
+
+                final int sMaxX = shapeData.maxFullX();
+                final int sMaxY = shapeData.maxFullY();
+                final int sMaxZ = shapeData.maxFullZ();
+
+                if (Math.abs(this.rootCoordinatesX[sMinX] + this.offsetX) <= ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON &&
+                    Math.abs(this.rootCoordinatesY[sMinY] + this.offsetY) <= ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON &&
+                    Math.abs(this.rootCoordinatesZ[sMinZ] + this.offsetZ) <= ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON &&
+
+                    Math.abs(1.0 - (this.rootCoordinatesX[sMaxX] + this.offsetX)) <= ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON &&
+                    Math.abs(1.0 - (this.rootCoordinatesY[sMaxY] + this.offsetY)) <= ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON &&
+                    Math.abs(1.0 - (this.rootCoordinatesZ[sMaxZ] + this.offsetZ)) <= ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON) {
+
+                    // index = z + y*sizeZ + x*(sizeZ*sizeY)
+
+                    final int sizeY = shapeData.sizeY();
+                    final int sizeZ = shapeData.sizeZ();
+
+                    final long[] bitset = shapeData.voxelSet();
+
+                    ret = Boolean.TRUE;
+
+                    check_full:
+                    for (int x = sMinX; x < sMaxX; ++x) {
+                        for (int y = sMinY; y < sMaxY; ++y) {
+                            final int baseIndex = y*sizeZ + x*(sizeZ*sizeY);
+                            if (!ca.spottedleaf.moonrise.common.util.FlatBitsetUtil.isRangeSet(bitset, baseIndex + sMinZ, baseIndex + sMaxZ)) {
+                                ret = Boolean.FALSE;
+                                break check_full;
+                            }
+                        }
+                    }
+                } else {
+                    ret = Boolean.FALSE;
+                }
+            } else {
+                ret = Boolean.valueOf(
+                    Math.abs(singleAABB.minX) <= ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON &&
+                        Math.abs(singleAABB.minY) <= ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON &&
+                        Math.abs(singleAABB.minZ) <= ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON &&
+
+                        Math.abs(1.0 - singleAABB.maxX) <= ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON &&
+                        Math.abs(1.0 - singleAABB.maxY) <= ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON &&
+                        Math.abs(1.0 - singleAABB.maxZ) <= ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON
+                );
+            }
+        }
+
+        this.isFullBlock = ret;
+
+        return ret.booleanValue();
+    }
+
+    @Override
+    public final boolean moonrise$isFullBlock() {
+        final Boolean ret = this.isFullBlock;
+
+        if (ret != null) {
+            return ret.booleanValue();
+        }
+
+        return this.computeFullBlock();
+    }
+
+    private static BlockHitResult clip(final AABB aabb, final Vec3 from, final Vec3 to, final BlockPos offset) {
+        final double[] minDistanceArr = new double[] { 1.0 };
+        final double diffX = to.x - from.x;
+        final double diffY = to.y - from.y;
+        final double diffZ = to.z - from.z;
+
+        final Direction direction = AABB.getDirection(aabb.move(offset), from, minDistanceArr, null, diffX, diffY, diffZ);
+
+        if (direction == null) {
+            return null;
+        }
+
+        final double minDistance = minDistanceArr[0];
+        return new BlockHitResult(from.add(minDistance * diffX, minDistance * diffY, minDistance * diffZ), direction, offset, false);
+    }
+
+    private VoxelShape calculateFaceDirect(final Direction direction, final Direction.Axis axis, final double[] coords, final double offset) {
+        if (coords.length == 2 &&
+            DoubleMath.fuzzyEquals(coords[0] + offset, 0.0, ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON) &&
+            DoubleMath.fuzzyEquals(coords[1] + offset, 1.0, ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON)) {
+            return (VoxelShape)(Object)this;
+        }
+
+        final boolean positiveDir = direction.getAxisDirection() == Direction.AxisDirection.POSITIVE;
+
+        // see findIndex
+        final int index = ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.findFloor(
+            coords, offset, (positiveDir ? (1.0 - ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON) : (0.0 + ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON)),
+            0, coords.length - 1
+        );
+
+        return ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.sliceShape(
+            (VoxelShape)(Object)this, axis, index
+        );
+    }
+    // Paper end - optimise collisions
+
     protected VoxelShape(DiscreteVoxelShape voxels) {
         this.shape = voxels;
     }
 
     public double min(Direction.Axis axis) {
-        int i = this.shape.firstFull(axis);
-        return i >= this.shape.getSize(axis) ? Double.POSITIVE_INFINITY : this.get(axis, i);
+        // Paper start - optimise collisions
+        final ca.spottedleaf.moonrise.patches.collisions.shape.CachedShapeData shapeData = this.cachedShapeData;
+        switch (axis) {
+            case X: {
+                final int idx = shapeData.minFullX();
+                return idx >= shapeData.sizeX() ? Double.POSITIVE_INFINITY : (this.rootCoordinatesX[idx] + this.offsetX);
+            }
+            case Y: {
+                final int idx = shapeData.minFullY();
+                return idx >= shapeData.sizeY() ? Double.POSITIVE_INFINITY : (this.rootCoordinatesY[idx] + this.offsetY);
+            }
+            case Z: {
+                final int idx = shapeData.minFullZ();
+                return idx >= shapeData.sizeZ() ? Double.POSITIVE_INFINITY : (this.rootCoordinatesZ[idx] + this.offsetZ);
+            }
+            default: {
+                // should never get here
+                return Double.POSITIVE_INFINITY;
+            }
+        }
+        // Paper end - optimise collisions
     }
 
     public double max(Direction.Axis axis) {
-        int i = this.shape.lastFull(axis);
-        return i <= 0 ? Double.NEGATIVE_INFINITY : this.get(axis, i);
+        // Paper start - optimise collisions
+        final ca.spottedleaf.moonrise.patches.collisions.shape.CachedShapeData shapeData = this.cachedShapeData;
+        switch (axis) {
+            case X: {
+                final int idx = shapeData.maxFullX();
+                return idx <= 0 ? Double.NEGATIVE_INFINITY : (this.rootCoordinatesX[idx] + this.offsetX);
+            }
+            case Y: {
+                final int idx = shapeData.maxFullY();
+                return idx <= 0 ? Double.NEGATIVE_INFINITY : (this.rootCoordinatesY[idx] + this.offsetY);
+            }
+            case Z: {
+                final int idx = shapeData.maxFullZ();
+                return idx <= 0 ? Double.NEGATIVE_INFINITY : (this.rootCoordinatesZ[idx] + this.offsetZ);
+            }
+            default: {
+                // should never get here
+                return Double.NEGATIVE_INFINITY;
+            }
+        }
+        // Paper end - optimise collisions
     }
 
     public AABB bounds() {
-        if (this.isEmpty()) {
-            throw (UnsupportedOperationException)Util.pauseInIde(new UnsupportedOperationException("No bounds for empty shape."));
-        } else {
-            return new AABB(
-                this.min(Direction.Axis.X),
-                this.min(Direction.Axis.Y),
-                this.min(Direction.Axis.Z),
-                this.max(Direction.Axis.X),
-                this.max(Direction.Axis.Y),
-                this.max(Direction.Axis.Z)
-            );
+        // Paper start - optimise collisions
+        if (this.isEmpty) {
+            throw Util.pauseInIde(new UnsupportedOperationException("No bounds for empty shape."));
+        }
+        AABB cached = this.cachedBounds;
+        if (cached != null) {
+            return cached;
         }
+
+        final ca.spottedleaf.moonrise.patches.collisions.shape.CachedShapeData shapeData = this.cachedShapeData;
+
+        final double[] coordsX = this.rootCoordinatesX;
+        final double[] coordsY = this.rootCoordinatesY;
+        final double[] coordsZ = this.rootCoordinatesZ;
+
+        final double offX = this.offsetX;
+        final double offY = this.offsetY;
+        final double offZ = this.offsetZ;
+
+        // note: if not empty, then there is one full AABB so no bounds checks are needed on the minFull/maxFull indices
+        cached = new AABB(
+            coordsX[shapeData.minFullX()] + offX,
+            coordsY[shapeData.minFullY()] + offY,
+            coordsZ[shapeData.minFullZ()] + offZ,
+
+            coordsX[shapeData.maxFullX()] + offX,
+            coordsY[shapeData.maxFullY()] + offY,
+            coordsZ[shapeData.maxFullZ()] + offZ
+        );
+
+        this.cachedBounds = cached;
+        return cached;
+        // Paper end - optimise collisions
     }
 
     public VoxelShape singleEncompassing() {
-        return this.isEmpty()
-            ? Shapes.empty()
-            : Shapes.box(
-                this.min(Direction.Axis.X),
-                this.min(Direction.Axis.Y),
-                this.min(Direction.Axis.Z),
-                this.max(Direction.Axis.X),
-                this.max(Direction.Axis.Y),
-                this.max(Direction.Axis.Z)
-            );
+        // Paper start - optimise collisions
+        if (this.isEmpty) {
+            return Shapes.empty();
+        }
+        return Shapes.create(this.bounds());
+        // Paper end - optimise collisions
     }
 
     protected double get(Direction.Axis axis, int index) {
-        return this.getCoords(axis).getDouble(index);
+        // Paper start - optimise collisions
+        final int idx = index;
+        switch (axis) {
+            case X: {
+                return this.rootCoordinatesX[idx] + this.offsetX;
+            }
+            case Y: {
+                return this.rootCoordinatesY[idx] + this.offsetY;
+            }
+            case Z: {
+                return this.rootCoordinatesZ[idx] + this.offsetZ;
+            }
+            default: {
+                throw new IllegalStateException("Unknown axis: " + axis);
+            }
+        }
+        // Paper end - optimise collisions
     }
 
     public abstract DoubleList getCoords(Direction.Axis axis);
 
     public boolean isEmpty() {
-        return this.shape.isEmpty();
+        return this.isEmpty; // Paper - optimise collisions
     }
 
     public VoxelShape move(Vec3 vec3d) {
@@ -0,0 +0,0 @@ public abstract class VoxelShape {
     }
 
     public VoxelShape move(double x, double y, double z) {
-        return (VoxelShape)(this.isEmpty()
-            ? Shapes.empty()
-            : new ArrayVoxelShape(
-                this.shape,
-                new OffsetDoubleList(this.getCoords(Direction.Axis.X), x),
-                new OffsetDoubleList(this.getCoords(Direction.Axis.Y), y),
-                new OffsetDoubleList(this.getCoords(Direction.Axis.Z), z)
-            ));
+        // Paper start - optimise collisions
+        if (this.isEmpty) {
+            return Shapes.empty();
+        }
+
+        final ArrayVoxelShape ret = new ArrayVoxelShape(
+            this.shape,
+            offsetList(this.rootCoordinatesX, this.offsetX + x),
+            offsetList(this.rootCoordinatesY, this.offsetY + y),
+            offsetList(this.rootCoordinatesZ, this.offsetZ + z)
+        );
+
+        final ca.spottedleaf.moonrise.patches.collisions.shape.CachedToAABBs cachedToAABBs = this.cachedToAABBs;
+        if (cachedToAABBs != null) {
+            ((VoxelShape)(Object)ret).cachedToAABBs = ca.spottedleaf.moonrise.patches.collisions.shape.CachedToAABBs.offset(cachedToAABBs, x, y, z);
+        }
+
+        return ret;
+        // Paper end - optimise collisions
     }
 
     public VoxelShape optimize() {
-        VoxelShape[] voxelShapes = new VoxelShape[]{Shapes.empty()};
-        this.forAllBoxes(
-            (minX, minY, minZ, maxX, maxY, maxZ) -> voxelShapes[0] = Shapes.joinUnoptimized(
-                    voxelShapes[0], Shapes.box(minX, minY, minZ, maxX, maxY, maxZ), BooleanOp.OR
-                )
-        );
-        return voxelShapes[0];
+        // Paper start - optimise collisions
+        if (this.isEmpty) {
+            return Shapes.empty();
+        }
+
+        if (this.singleAABBRepresentation != null) {
+            // note: the isFullBlock() is fuzzy, and Shapes.create() is also fuzzy which would return block()
+            return this.moonrise$isFullBlock() ? Shapes.block() : (VoxelShape)(Object)this;
+        }
+
+        final List<AABB> aabbs = this.toAabbs();
+
+        if (aabbs.isEmpty()) {
+            // We are a SliceShape, which does not properly fill isEmpty for every case
+            return Shapes.empty();
+        }
+
+        if (aabbs.size() == 1) {
+            final AABB singleAABB = aabbs.get(0);
+            final VoxelShape ret = Shapes.create(singleAABB);
+
+            // forward AABB cache
+            if (((VoxelShape)(Object)ret).cachedToAABBs == null) {
+                ((VoxelShape)(Object)ret).cachedToAABBs = this.cachedToAABBs;
+            }
+
+            return ret;
+        } else {
+            // reduce complexity of joins by splitting the merges (old complexity: n^2, new: nlogn)
+
+            // set up flat array so that this merge is done in-place
+            final VoxelShape[] tmp = new VoxelShape[aabbs.size()];
+
+            // initialise as unmerged
+            for (int i = 0, len = aabbs.size(); i < len; ++i) {
+                tmp[i] = Shapes.create(aabbs.get(i));
+            }
+
+            int size = aabbs.size();
+            while (size > 1) {
+                int newSize = 0;
+                for (int i = 0; i < size; i += 2) {
+                    final int next = i + 1;
+                    if (next >= size) {
+                        // nothing to merge with, so leave it for next iteration
+                        tmp[newSize++] = tmp[i];
+                        break;
+                    } else {
+                        // merge with adjacent
+                        final VoxelShape first = tmp[i];
+                        final VoxelShape second = tmp[next];
+
+                        tmp[newSize++] = Shapes.joinUnoptimized(first, second, BooleanOp.OR);
+                    }
+                }
+                size = newSize;
+            }
+
+            final VoxelShape ret = tmp[0];
+
+            // forward AABB cache
+            if (((VoxelShape)(Object)ret).cachedToAABBs == null) {
+                ((VoxelShape)(Object)ret).cachedToAABBs = this.cachedToAABBs;
+            }
+
+            return ret;
+        }
+        // Paper end - optimise collisions
     }
 
     public void forAllEdges(Shapes.DoubleLineConsumer consumer) {
@@ -0,0 +0,0 @@ public abstract class VoxelShape {
     }
 
     public List<AABB> toAabbs() {
-        List<AABB> list = Lists.newArrayList();
-        this.forAllBoxes((x1, y1, z1, x2, y2, z2) -> list.add(new AABB(x1, y1, z1, x2, y2, z2)));
-        return list;
+        // Paper start - optimise collisions
+        ca.spottedleaf.moonrise.patches.collisions.shape.CachedToAABBs cachedToAABBs = this.cachedToAABBs;
+        if (cachedToAABBs != null) {
+            if (!cachedToAABBs.isOffset()) {
+                return cachedToAABBs.aabbs();
+            }
+
+            // all we need to do is offset the cache
+            cachedToAABBs = cachedToAABBs.removeOffset();
+            // update cache
+            this.cachedToAABBs = cachedToAABBs;
+
+            return cachedToAABBs.aabbs();
+        }
+
+        // make new cache
+        return this.toAabbsUncached();
+        // Paper end - optimise collisions
     }
 
     public double min(Direction.Axis axis, double from, double to) {
@@ -0,0 +0,0 @@ public abstract class VoxelShape {
     }
 
     protected int findIndex(Direction.Axis axis, double coord) {
-        return Mth.binarySearch(0, this.shape.getSize(axis) + 1, i -> coord < this.get(axis, i)) - 1;
+        // Paper start - optimise collisions
+        final double value = coord;
+        switch (axis) {
+            case X: {
+                final double[] values = this.rootCoordinatesX;
+                return ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.findFloor(
+                    values, this.offsetX, value, 0, values.length - 1
+                );
+            }
+            case Y: {
+                final double[] values = this.rootCoordinatesY;
+                return ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.findFloor(
+                    values, this.offsetY, value, 0, values.length - 1
+                );
+            }
+            case Z: {
+                final double[] values = this.rootCoordinatesZ;
+                return ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.findFloor(
+                    values, this.offsetZ, value, 0, values.length - 1
+                );
+            }
+            default: {
+                throw new IllegalStateException("Unknown axis: " + axis);
+            }
+        }
+        // Paper end - optimise collisions
     }
 
     @Nullable
-    public BlockHitResult clip(Vec3 start, Vec3 end, BlockPos pos) {
-        if (this.isEmpty()) {
+    // Paper start - optimise collisions
+    public BlockHitResult clip(final Vec3 from, final Vec3 to, final BlockPos offset) {
+        if (this.isEmpty) {
             return null;
-        } else {
-            Vec3 vec3 = end.subtract(start);
-            if (vec3.lengthSqr() < 1.0E-7) {
-                return null;
-            } else {
-                Vec3 vec32 = start.add(vec3.scale(0.001));
-                return this.shape
-                        .isFullWide(
-                            this.findIndex(Direction.Axis.X, vec32.x - (double)pos.getX()),
-                            this.findIndex(Direction.Axis.Y, vec32.y - (double)pos.getY()),
-                            this.findIndex(Direction.Axis.Z, vec32.z - (double)pos.getZ())
-                        )
-                    ? new BlockHitResult(vec32, Direction.getApproximateNearest(vec3.x, vec3.y, vec3.z).getOpposite(), pos, true)
-                    : AABB.clip(this.toAabbs(), start, end, pos);
+        }
+
+        final Vec3 directionOpposite = to.subtract(from);
+        if (directionOpposite.lengthSqr() < ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON) {
+            return null;
+        }
+
+        final Vec3 fromBehind = from.add(directionOpposite.scale(0.001));
+        final double fromBehindOffsetX = fromBehind.x - (double)offset.getX();
+        final double fromBehindOffsetY = fromBehind.y - (double)offset.getY();
+        final double fromBehindOffsetZ = fromBehind.z - (double)offset.getZ();
+
+        final AABB singleAABB = this.singleAABBRepresentation;
+        if (singleAABB != null) {
+            if (singleAABB.contains(fromBehindOffsetX, fromBehindOffsetY, fromBehindOffsetZ)) {
+                return new BlockHitResult(fromBehind, Direction.getApproximateNearest(directionOpposite.x, directionOpposite.y, directionOpposite.z).getOpposite(), offset, true);
             }
+            return clip(singleAABB, from, to, offset);
+        }
+
+        if (ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.strictlyContains((VoxelShape)(Object)this, fromBehindOffsetX, fromBehindOffsetY, fromBehindOffsetZ)) {
+            return new BlockHitResult(fromBehind, Direction.getApproximateNearest(directionOpposite.x, directionOpposite.y, directionOpposite.z).getOpposite(), offset, true);
         }
+
+        return AABB.clip(((VoxelShape)(Object)this).toAabbs(), from, to, offset);
+        // Paper end - optimise collisions
     }
 
-    public Optional<Vec3> closestPointTo(Vec3 target) {
-        if (this.isEmpty()) {
+    // Paper start - optimise collisions
+    public Optional<Vec3> closestPointTo(Vec3 point) {
+        if (this.isEmpty) {
             return Optional.empty();
-        } else {
-            Vec3[] vec3s = new Vec3[1];
-            this.forAllBoxes((minX, minY, minZ, maxX, maxY, maxZ) -> {
-                double d = Mth.clamp(target.x(), minX, maxX);
-                double e = Mth.clamp(target.y(), minY, maxY);
-                double f = Mth.clamp(target.z(), minZ, maxZ);
-                if (vec3s[0] == null || target.distanceToSqr(d, e, f) < target.distanceToSqr(vec3s[0])) {
-                    vec3s[0] = new Vec3(d, e, f);
-                }
-            });
-            return Optional.of(vec3s[0]);
         }
+
+        Vec3 ret = null;
+        double retDistance = Double.MAX_VALUE;
+
+        final List<AABB> aabbs = this.toAabbs();
+        for (int i = 0, len = aabbs.size(); i < len; ++i) {
+            final AABB aabb = aabbs.get(i);
+            final double x = Mth.clamp(point.x, aabb.minX, aabb.maxX);
+            final double y = Mth.clamp(point.y, aabb.minY, aabb.maxY);
+            final double z = Mth.clamp(point.z, aabb.minZ, aabb.maxZ);
+
+            double dist = point.distanceToSqr(x, y, z);
+            if (dist < retDistance) {
+                ret = new Vec3(x, y, z);
+                retDistance = dist;
+            }
+        }
+
+        return Optional.ofNullable(ret);
+        // Paper end - optimise collisions
     }
 
     public VoxelShape getFaceShape(Direction facing) {
@@ -0,0 +0,0 @@ public abstract class VoxelShape {
         }
     }
 
-    private VoxelShape calculateFace(Direction facing) {
-        Direction.Axis axis = facing.getAxis();
-        if (this.isCubeLikeAlong(axis)) {
-            return this;
-        } else {
-            Direction.AxisDirection axisDirection = facing.getAxisDirection();
-            int i = this.findIndex(axis, axisDirection == Direction.AxisDirection.POSITIVE ? 0.9999999 : 1.0E-7);
-            SliceShape sliceShape = new SliceShape(this, axis, i);
-            if (sliceShape.isEmpty()) {
-                return Shapes.empty();
-            } else {
-                return (VoxelShape)(sliceShape.isCubeLike() ? Shapes.block() : sliceShape);
+    private VoxelShape calculateFace(Direction direction) {
+        // Paper start - optimise collisions
+        final Direction.Axis axis = direction.getAxis();
+        switch (axis) {
+            case X: {
+                return this.calculateFaceDirect(direction, axis, this.rootCoordinatesX, this.offsetX);
+            }
+            case Y: {
+                return this.calculateFaceDirect(direction, axis, this.rootCoordinatesY, this.offsetY);
+            }
+            case Z: {
+                return this.calculateFaceDirect(direction, axis, this.rootCoordinatesZ, this.offsetZ);
+            }
+            default: {
+                throw new IllegalStateException("Unknown axis: " + axis);
             }
         }
+        // Paper end - optimise collisions
     }
 
     protected boolean isCubeLike() {
@@ -0,0 +0,0 @@ public abstract class VoxelShape {
             && DoubleMath.fuzzyEquals(doubleList.getDouble(1), 1.0, 1.0E-7);
     }
 
-    public double collide(Direction.Axis axis, AABB box, double maxDist) {
-        return this.collideX(AxisCycle.between(axis, Direction.Axis.X), box, maxDist);
+    // Paper start - optimise collisions
+    public double collide(final Direction.Axis axis, final AABB source, final double source_move) {
+        if (this.isEmpty) {
+            return source_move;
+        }
+        if (Math.abs(source_move) < ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.COLLISION_EPSILON) {
+            return 0.0;
+        }
+        switch (axis) {
+            case X: {
+                return ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.collideX((VoxelShape) (Object) this, source, source_move);
+            }
+            case Y: {
+                return ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.collideY((VoxelShape) (Object) this, source, source_move);
+            }
+            case Z: {
+                return ca.spottedleaf.moonrise.patches.collisions.CollisionUtil.collideZ((VoxelShape) (Object) this, source, source_move);
+            }
+            default: {
+                throw new RuntimeException("Unknown axis: " + axis);
+            }
+        }
     }
+    // Paper end - optimise collisions
 
     protected double collideX(AxisCycle axisCycle, AABB box, double maxDist) {
         if (this.isEmpty()) {
diff --git a/src/main/java/net/minecraft/world/ticks/LevelChunkTicks.java b/src/main/java/net/minecraft/world/ticks/LevelChunkTicks.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/ticks/LevelChunkTicks.java
+++ b/src/main/java/net/minecraft/world/ticks/LevelChunkTicks.java
@@ -0,0 +0,0 @@ import net.minecraft.core.BlockPos;
 import net.minecraft.nbt.ListTag;
 import net.minecraft.world.level.ChunkPos;
 
-public class LevelChunkTicks<T> implements SerializableTickContainer<T>, TickContainerAccess<T> {
+public class LevelChunkTicks<T> implements SerializableTickContainer<T>, TickContainerAccess<T>, ca.spottedleaf.moonrise.patches.chunk_system.ticks.ChunkSystemLevelChunkTicks { // Paper - rewrite chunk system
     private final Queue<ScheduledTick<T>> tickQueue = new PriorityQueue<>(ScheduledTick.DRAIN_ORDER);
     @Nullable
     private List<SavedTick<T>> pendingTicks;
@@ -0,0 +0,0 @@ public class LevelChunkTicks<T> implements SerializableTickContainer<T>, TickCon
     @Nullable
     private BiConsumer<LevelChunkTicks<T>, ScheduledTick<T>> onTickAdded;
 
+    // Paper start - rewrite chunk system
+    /*
+     * Since ticks are saved using relative delays, we need to consider the entire tick list dirty when there are scheduled ticks
+     * and the last saved tick is not equal to the current tick
+     */
+    /*
+     * In general, it would be nice to be able to "re-pack" ticks once the chunk becomes non-ticking again, but that is a
+     * bit out of scope for the chunk system
+     */
+
+    private boolean dirty;
+    private long lastSaved = Long.MIN_VALUE;
+
+    @Override
+    public final boolean moonrise$isDirty(final long tick) {
+        return this.dirty || (!this.tickQueue.isEmpty() && tick != this.lastSaved);
+    }
+
+    @Override
+    public final void moonrise$clearDirty() {
+        this.dirty = false;
+    }
+    // Paper end - rewrite chunk system
+
     public LevelChunkTicks() {
     }
 
@@ -0,0 +0,0 @@ public class LevelChunkTicks<T> implements SerializableTickContainer<T>, TickCon
     public ScheduledTick<T> poll() {
         ScheduledTick<T> scheduledTick = this.tickQueue.poll();
         if (scheduledTick != null) {
-            this.ticksPerPosition.remove(scheduledTick);
+            this.ticksPerPosition.remove(scheduledTick); this.dirty = true; // Paper - rewrite chunk system
         }
 
         return scheduledTick;
@@ -0,0 +0,0 @@ public class LevelChunkTicks<T> implements SerializableTickContainer<T>, TickCon
     @Override
     public void schedule(ScheduledTick<T> orderedTick) {
         if (this.ticksPerPosition.add(orderedTick)) {
-            this.scheduleUnchecked(orderedTick);
+            this.scheduleUnchecked(orderedTick); this.dirty = true; // Paper - rewrite chunk system
         }
     }
 
@@ -0,0 +0,0 @@ public class LevelChunkTicks<T> implements SerializableTickContainer<T>, TickCon
         while (iterator.hasNext()) {
             ScheduledTick<T> scheduledTick = iterator.next();
             if (predicate.test(scheduledTick)) {
-                iterator.remove();
+                iterator.remove(); this.dirty = true; // Paper - rewrite chunk system
                 this.ticksPerPosition.remove(scheduledTick);
             }
         }
@@ -0,0 +0,0 @@ public class LevelChunkTicks<T> implements SerializableTickContainer<T>, TickCon
     }
 
     public ListTag save(long time, Function<T, String> typeToNameFunction) {
+        this.lastSaved = time; // Paper - rewrite chunk system
         ListTag listTag = new ListTag();
 
         for (SavedTick<T> savedTick : this.pack(time)) {
@@ -0,0 +0,0 @@ public class LevelChunkTicks<T> implements SerializableTickContainer<T>, TickCon
 
     public void unpack(long time) {
         if (this.pendingTicks != null) {
+            this.lastSaved = time; // Paper - rewrite chunk system
             int i = -this.pendingTicks.size();
 
             for (SavedTick<T> savedTick : this.pendingTicks) {
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftChunk.java b/src/main/java/org/bukkit/craftbukkit/CraftChunk.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftChunk.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftChunk.java
@@ -0,0 +0,0 @@ public class CraftChunk implements Chunk {
     }
 
     public ChunkAccess getHandle(ChunkStatus chunkStatus) {
+        // Paper start - rewrite chunk system
+        net.minecraft.world.level.chunk.LevelChunk full = this.worldServer.getChunkIfLoaded(this.x, this.z);
+        if (full != null) {
+            return full;
+        }
+        // Paper end - rewrite chunk system
         ChunkAccess chunkAccess = this.worldServer.getChunk(this.x, this.z, chunkStatus);
 
         // SPIGOT-7332: Get unwrapped extension
@@ -0,0 +0,0 @@ public class CraftChunk implements Chunk {
 
     @Override
     public boolean isEntitiesLoaded() {
-        return this.getCraftWorld().getHandle().entityManager.areEntitiesLoaded(ChunkPos.asLong(this.x, this.z));
+        return this.getCraftWorld().getHandle().areEntitiesLoaded(ca.spottedleaf.moonrise.common.util.CoordinateUtils.getChunkKey(this.x, this.z)); // Paper - rewrite chunk system
     }
 
     @Override
     public Entity[] getEntities() {
-        if (!this.isLoaded()) {
-            this.getWorld().getChunkAt(this.x, this.z); // Transient load for this tick
-        }
-
-        PersistentEntitySectionManager<net.minecraft.world.entity.Entity> entityManager = this.getCraftWorld().getHandle().entityManager;
-        long pair = ChunkPos.asLong(this.x, this.z);
-
-        if (entityManager.areEntitiesLoaded(pair)) {
-            return entityManager.getEntities(new ChunkPos(this.x, this.z)).stream()
-                    .map(net.minecraft.world.entity.Entity::getBukkitEntity)
-                    .filter(Objects::nonNull).toArray(Entity[]::new);
-        }
-
-        entityManager.ensureChunkQueuedForLoad(pair); // Start entity loading
-
-        // SPIGOT-6772: Use entity mailbox and re-schedule entities if they get unloaded
-        ConsecutiveExecutor mailbox = ((EntityStorage) entityManager.permanentStorage).entityDeserializerQueue;
-        BooleanSupplier supplier = () -> {
-            // only execute inbox if our entities are not present
-            if (entityManager.areEntitiesLoaded(pair)) {
-                return true;
-            }
-
-            if (!entityManager.isPending(pair)) {
-                // Our entities got unloaded, this should normally not happen.
-                entityManager.ensureChunkQueuedForLoad(pair); // Re-start entity loading
-            }
-
-            // tick loading inbox, which loads the created entities to the world
-            // (if present)
-            entityManager.tick();
-            // check if our entities are loaded
-            return entityManager.areEntitiesLoaded(pair);
-        };
-
-        // now we wait until the entities are loaded,
-        // the converting from NBT to entity object is done on the main Thread which is why we wait
-        while (!supplier.getAsBoolean()) {
-            if (mailbox.size() != 0) {
-                mailbox.run();
-            } else {
-                Thread.yield();
-                LockSupport.parkNanos("waiting for entity loading", 100000L);
-            }
-        }
-
-        return entityManager.getEntities(new ChunkPos(this.x, this.z)).stream()
-                .map(net.minecraft.world.entity.Entity::getBukkitEntity)
-                .filter(Objects::nonNull).toArray(Entity[]::new);
+        return this.getCraftWorld().getHandle().getChunkEntities(this.x, this.z); // Paper - rewrite chunk system
     }
 
     @Override
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -0,0 +0,0 @@ public final class CraftServer implements Server {
         // Paper - Put world into worldlist before initing the world; move up
 
         this.getServer().prepareLevels(internal.getChunkSource().chunkMap.progressListener, internal);
-        internal.entityManager.tick(); // SPIGOT-6526: Load pending entities so they are available to the API
+        // Paper - rewrite chunk system
 
         this.pluginManager.callEvent(new WorldLoadEvent(internal.getWorld()));
         return internal.getWorld();
@@ -0,0 +0,0 @@ public final class CraftServer implements Server {
             }
 
             handle.getChunkSource().close(save);
-            handle.entityManager.close(save); // SPIGOT-6722: close entityManager
+            // Paper - rewrite chunk system
             handle.convertable.close();
         } catch (Exception ex) {
             this.getLogger().log(Level.SEVERE, null, ex);
@@ -0,0 +0,0 @@ public final class CraftServer implements Server {
 
     @Override
     public boolean isPrimaryThread() {
-        return Thread.currentThread().equals(this.console.serverThread) || this.console.hasStopped() || !org.spigotmc.AsyncCatcher.enabled; // All bets are off if we have shut down (e.g. due to watchdog)
+        return ca.spottedleaf.moonrise.common.util.TickThread.isTickThread(); // Paper - rewrite chunk system
     }
 
     // Paper start - Adventure
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
@@ -0,0 +0,0 @@ public class CraftWorld extends CraftRegionAccessor implements World {
         ChunkHolder playerChunk = this.world.getChunkSource().chunkMap.getVisibleChunkIfPresent(ChunkPos.asLong(x, z));
         if (playerChunk == null) return false;
 
-        playerChunk.getTickingChunkFuture().thenAccept(either -> {
-            either.ifSuccess(chunk -> {
+        // Paper start - chunk system
+        net.minecraft.world.level.chunk.LevelChunk chunk = playerChunk.getChunkToSend();
+        if (chunk == null) {
+            return false;
+        }
+        // Paper end - chunk system
                 List<ServerPlayer> playersInRange = playerChunk.playerProvider.getPlayers(playerChunk.getPos(), false);
-                if (playersInRange.isEmpty()) return;
+                if (playersInRange.isEmpty()) return true; // Paper - chunk system
 
                 FeatureHooks.sendChunkRefreshPackets(playersInRange, chunk);
-            });
-        });
-
+        // Paper - chunk system
         return true;
     }
 
@@ -0,0 +0,0 @@ public class CraftWorld extends CraftRegionAccessor implements World {
     @Override
     public Collection<Plugin> getPluginChunkTickets(int x, int z) {
         DistanceManager chunkDistanceManager = this.world.getChunkSource().chunkMap.distanceManager;
-        SortedArraySet<Ticket<?>> tickets = chunkDistanceManager.tickets.get(ChunkPos.asLong(x, z));
-
-        if (tickets == null) {
-            return Collections.emptyList();
-        }
 
-        ImmutableList.Builder<Plugin> ret = ImmutableList.builder();
-        for (Ticket<?> ticket : tickets) {
-            if (ticket.getType() == TicketType.PLUGIN_TICKET) {
-                ret.add((Plugin) ticket.key);
-            }
-        }
-
-        return ret.build();
+        return chunkDistanceManager.moonrise$getChunkHolderManager().getPluginChunkTickets(x, z); // Paper - rewrite chunk system
     }
 
     @Override
@@ -0,0 +0,0 @@ public class CraftWorld extends CraftRegionAccessor implements World {
         Map<Plugin, ImmutableList.Builder<Chunk>> ret = new HashMap<>();
         DistanceManager chunkDistanceManager = this.world.getChunkSource().chunkMap.distanceManager;
 
-        for (Long2ObjectMap.Entry<SortedArraySet<Ticket<?>>> chunkTickets : chunkDistanceManager.tickets.long2ObjectEntrySet()) {
+        for (Long2ObjectMap.Entry<SortedArraySet<Ticket<?>>> chunkTickets : chunkDistanceManager.moonrise$getChunkHolderManager().getTicketsCopy().long2ObjectEntrySet()) {  // Paper - rewrite chunk system
             long chunkKey = chunkTickets.getLongKey();
             SortedArraySet<Ticket<?>> tickets = chunkTickets.getValue();
 
@@ -0,0 +0,0 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public int getViewDistance() {
-        return this.world.getChunkSource().chunkMap.serverViewDistance;
+        return this.getHandle().moonrise$getPlayerChunkLoader().getAPIViewDistance(); // Paper - rewrite chunk system
     }
 
     @Override
     public int getSimulationDistance() {
-        return this.world.getChunkSource().chunkMap.getDistanceManager().simulationDistance;
+        return this.getHandle().moonrise$getPlayerChunkLoader().getAPITickDistance(); // Paper - rewrite chunk system
     }
 
     public BlockMetadataStore getBlockMetadata() {
@@ -0,0 +0,0 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public void setSimulationDistance(final int simulationDistance) {
-        throw new UnsupportedOperationException("Not implemented yet");
+        if (simulationDistance < 2 || simulationDistance > 32) {
+            throw new IllegalArgumentException("Simulation distance " + simulationDistance + " is out of range of [2, 32]");
+        }
+        this.getHandle().chunkSource.setSimulationDistance(simulationDistance); // Paper - rewrite chunk system
     }
 
     @Override
     public int getSendViewDistance() {
-        return this.getViewDistance();
+        return this.getHandle().moonrise$getPlayerChunkLoader().getAPISendViewDistance(); // Paper - rewrite chunk system
     }
 
     @Override
     public void setSendViewDistance(final int viewDistance) {
-        throw new UnsupportedOperationException("Not implemented yet");
+        this.getHandle().chunkSource.setSendViewDistance(viewDistance); // Paper - rewrite chunk system
     }
 
     // Paper start - implement pointers
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -0,0 +0,0 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void setViewDistance(final int viewDistance) {
-        throw new UnsupportedOperationException("Not implemented yet");
+        // Paper - rewrite chunk system - TODO do this better
+        ((ca.spottedleaf.moonrise.patches.chunk_system.player.ChunkSystemServerPlayer)this.getHandle())
+            .moonrise$getViewDistanceHolder().setLoadViewDistance(viewDistance + 1);
     }
 
     @Override
@@ -0,0 +0,0 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void setSimulationDistance(final int simulationDistance) {
-        throw new UnsupportedOperationException("Not implemented yet");
+        // Paper - rewrite chunk system - TODO do this better
+        ((ca.spottedleaf.moonrise.patches.chunk_system.player.ChunkSystemServerPlayer)this.getHandle())
+            .moonrise$getViewDistanceHolder().setTickViewDistance(simulationDistance);
     }
 
     @Override
@@ -0,0 +0,0 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void setSendViewDistance(final int viewDistance) {
-        throw new UnsupportedOperationException("Not implemented yet");
+        // Paper - rewrite chunk system - TODO do this better
+        ((ca.spottedleaf.moonrise.patches.chunk_system.player.ChunkSystemServerPlayer)this.getHandle())
+            .moonrise$getViewDistanceHolder().setSendViewDistance(viewDistance);
     }
 
     // Paper start - entity effect API
diff --git a/src/main/java/org/bukkit/craftbukkit/generator/CustomChunkGenerator.java b/src/main/java/org/bukkit/craftbukkit/generator/CustomChunkGenerator.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/org/bukkit/craftbukkit/generator/CustomChunkGenerator.java
+++ b/src/main/java/org/bukkit/craftbukkit/generator/CustomChunkGenerator.java
@@ -0,0 +0,0 @@ public class CustomChunkGenerator extends InternalChunkGenerator {
             return ichunkaccess1;
         };
 
-        return future == null ? CompletableFuture.supplyAsync(() -> function.apply(chunk), net.minecraft.Util.backgroundExecutor()) : future.thenApply(function);
+        return future == null ? CompletableFuture.supplyAsync(() -> function.apply(chunk), Runnable::run) : future.thenApply(function); // Paper - rewrite chunk system
     }
 
     @Override
diff --git a/src/main/java/org/bukkit/craftbukkit/util/DelegatedGeneratorAccess.java b/src/main/java/org/bukkit/craftbukkit/util/DelegatedGeneratorAccess.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/org/bukkit/craftbukkit/util/DelegatedGeneratorAccess.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/DelegatedGeneratorAccess.java
@@ -0,0 +0,0 @@ public abstract class DelegatedGeneratorAccess implements WorldGenLevel {
     public ChunkAccess getChunkIfLoadedImmediately(final int x, final int z) {
         return this.handle.getChunkIfLoadedImmediately(x, z);
     }
+
+    // Paper start - rewrite chunk system
+    @Override
+    public java.util.List<net.minecraft.world.entity.Entity> moonrise$getHardCollidingEntities(final net.minecraft.world.entity.Entity entity, final net.minecraft.world.phys.AABB box, final java.util.function.Predicate<? super net.minecraft.world.entity.Entity> predicate) {
+        return this.handle.moonrise$getHardCollidingEntities(entity, box, predicate);
+    }
+    // Paper end - rewrite chunk system
     // Paper end
 }
 
diff --git a/src/main/java/org/spigotmc/AsyncCatcher.java b/src/main/java/org/spigotmc/AsyncCatcher.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/org/spigotmc/AsyncCatcher.java
+++ b/src/main/java/org/spigotmc/AsyncCatcher.java
@@ -0,0 +0,0 @@ public class AsyncCatcher
 
     public static void catchOp(String reason)
     {
-        if ( AsyncCatcher.enabled && Thread.currentThread() != MinecraftServer.getServer().serverThread )
+        if (!ca.spottedleaf.moonrise.common.util.TickThread.isTickThread()) // Paper // Paper - rewrite chunk system
         {
             MinecraftServer.LOGGER.error("Thread " + Thread.currentThread().getName() + " failed main thread check: " + reason, new Throwable()); // Paper
             throw new IllegalStateException( "Asynchronous " + reason + "!" );
diff --git a/src/main/java/org/spigotmc/WatchdogThread.java b/src/main/java/org/spigotmc/WatchdogThread.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/org/spigotmc/WatchdogThread.java
+++ b/src/main/java/org/spigotmc/WatchdogThread.java
@@ -0,0 +0,0 @@ import java.util.logging.Logger;
 import net.minecraft.server.MinecraftServer;
 import org.bukkit.Bukkit;
 
-public class WatchdogThread extends Thread
+public class WatchdogThread extends ca.spottedleaf.moonrise.common.util.TickThread // Paper - rewrite chunk system
 {
 
     private static WatchdogThread instance;
@@ -0,0 +0,0 @@ public class WatchdogThread extends Thread
                 // Paper end - Different message for short timeout
                 log.log( Level.SEVERE, "------------------------------" );
                 log.log( Level.SEVERE, "Server thread dump (Look for plugins here before reporting to Paper!):" ); // Paper
+                ca.spottedleaf.moonrise.patches.chunk_system.scheduling.ChunkTaskScheduler.dumpAllChunkLoadInfo(MinecraftServer.getServer(), isLongTimeout); // Paper - rewrite chunk system
                 WatchdogThread.dumpThread( ManagementFactory.getThreadMXBean().getThreadInfo( MinecraftServer.getServer().serverThread.getId(), Integer.MAX_VALUE ), log );
                 log.log( Level.SEVERE, "------------------------------" );
                 //