From 2a20fde3327fb139b0b5594423ddcca2919d2b0c Mon Sep 17 00:00:00 2001
From: Nassim Jahnke <nassim@njahnke.dev>
Date: Thu, 5 Dec 2024 13:00:22 +0100
Subject: [PATCH] Add feature patch hook for overrides

---
 .../java/io/papermc/paper/FeatureHooks.java   | 72 +++++++++++++++++++
 .../papermc/paper/command/PaperCommand.java   |  2 +
 .../configuration/GlobalConfiguration.java    | 17 +++++
 .../org/bukkit/craftbukkit/CraftChunk.java    |  3 +-
 .../org/bukkit/craftbukkit/CraftServer.java   |  2 +-
 .../org/bukkit/craftbukkit/CraftWorld.java    |  8 +--
 .../craftbukkit/entity/CraftPlayer.java       | 15 ++--
 .../generator/OldCraftChunkData.java          | 10 ++-
 .../bukkit/craftbukkit/map/RenderData.java    |  2 +-
 9 files changed, 110 insertions(+), 21 deletions(-)
 create mode 100644 paper-server/src/main/java/io/papermc/paper/FeatureHooks.java

diff --git a/paper-server/src/main/java/io/papermc/paper/FeatureHooks.java b/paper-server/src/main/java/io/papermc/paper/FeatureHooks.java
new file mode 100644
index 0000000000..cfd47bcdcd
--- /dev/null
+++ b/paper-server/src/main/java/io/papermc/paper/FeatureHooks.java
@@ -0,0 +1,72 @@
+package io.papermc.paper;
+
+import io.papermc.paper.command.PaperSubcommand;
+import it.unimi.dsi.fastutil.longs.LongOpenHashSet;
+import it.unimi.dsi.fastutil.longs.LongSet;
+import it.unimi.dsi.fastutil.longs.LongSets;
+import it.unimi.dsi.fastutil.objects.ObjectOpenHashSet;
+import it.unimi.dsi.fastutil.objects.ObjectSet;
+import it.unimi.dsi.fastutil.objects.ObjectSets;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import net.minecraft.core.Registry;
+import net.minecraft.network.protocol.game.ClientboundLevelChunkWithLightPacket;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.level.ChunkPos;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.biome.Biome;
+import net.minecraft.world.level.block.Block;
+import net.minecraft.world.level.block.Blocks;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.chunk.LevelChunk;
+import net.minecraft.world.level.chunk.LevelChunkSection;
+import net.minecraft.world.level.chunk.PalettedContainer;
+import org.bukkit.Chunk;
+import org.bukkit.World;
+
+public final class FeatureHooks {
+
+    public static void initChunkTaskScheduler(final boolean useParallelGen) {
+    }
+
+    public static void registerPaperCommands(final Map<Set<String>, PaperSubcommand> commands) {
+    }
+
+    public static LevelChunkSection createSection(final Registry<Biome> biomeRegistry, final Level level, final ChunkPos chunkPos, final int chunkSection) {
+        return new LevelChunkSection(biomeRegistry);
+    }
+
+    public static void sendChunkRefreshPackets(final List<ServerPlayer> playersInRange, final LevelChunk chunk) {
+        final ClientboundLevelChunkWithLightPacket refreshPacket = new ClientboundLevelChunkWithLightPacket(chunk, chunk.level.getLightEngine(), null, null);
+        for (final ServerPlayer player : playersInRange) {
+            if (player.connection == null) continue;
+
+            player.connection.send(refreshPacket);
+        }
+    }
+
+    public static PalettedContainer<BlockState> emptyPalettedBlockContainer() {
+        return new PalettedContainer<>(Block.BLOCK_STATE_REGISTRY, Blocks.AIR.defaultBlockState(), PalettedContainer.Strategy.SECTION_STATES);
+    }
+
+    public static Set<Long> getSentChunkKeys(final ServerPlayer player) {
+        final LongSet keys = new LongOpenHashSet();
+        player.getChunkTrackingView().forEach(pos -> keys.add(pos.longKey));
+        return LongSets.unmodifiable(keys);
+    }
+
+    public static Set<Chunk> getSentChunks(final ServerPlayer player) {
+        final ObjectSet<Chunk> chunks = new ObjectOpenHashSet<>();
+        final World world = player.serverLevel().getWorld();
+        player.getChunkTrackingView().forEach(pos -> {
+            final org.bukkit.Chunk chunk = world.getChunkAt(pos.longKey);
+            chunks.add(chunk);
+        });
+        return ObjectSets.unmodifiable(chunks);
+    }
+
+    public static boolean isChunkSent(final ServerPlayer player, final long chunkKey) {
+        return player.getChunkTrackingView().contains(new ChunkPos(chunkKey));
+    }
+}
diff --git a/paper-server/src/main/java/io/papermc/paper/command/PaperCommand.java b/paper-server/src/main/java/io/papermc/paper/command/PaperCommand.java
index 46bf42d5ea..8d04711538 100644
--- a/paper-server/src/main/java/io/papermc/paper/command/PaperCommand.java
+++ b/paper-server/src/main/java/io/papermc/paper/command/PaperCommand.java
@@ -1,5 +1,6 @@
 package io.papermc.paper.command;
 
+import io.papermc.paper.FeatureHooks;
 import io.papermc.paper.command.subcommands.*;
 import it.unimi.dsi.fastutil.Pair;
 import java.util.ArrayList;
@@ -42,6 +43,7 @@ public final class PaperCommand extends Command {
         commands.put(Set.of("dumpitem"), new DumpItemCommand());
         commands.put(Set.of("mobcaps", "playermobcaps"), new MobcapsCommand());
         commands.put(Set.of("dumplisteners"), new DumpListenersCommand());
+        FeatureHooks.registerPaperCommands(commands);
 
         return commands.entrySet().stream()
             .flatMap(entry -> entry.getKey().stream().map(s -> Map.entry(s, entry.getValue())))
diff --git a/paper-server/src/main/java/io/papermc/paper/configuration/GlobalConfiguration.java b/paper-server/src/main/java/io/papermc/paper/configuration/GlobalConfiguration.java
index 2d2ff82635..088b8fe5d1 100644
--- a/paper-server/src/main/java/io/papermc/paper/configuration/GlobalConfiguration.java
+++ b/paper-server/src/main/java/io/papermc/paper/configuration/GlobalConfiguration.java
@@ -1,6 +1,7 @@
 package io.papermc.paper.configuration;
 
 import com.mojang.logging.LogUtils;
+import io.papermc.paper.FeatureHooks;
 import io.papermc.paper.configuration.constraint.Constraints;
 import io.papermc.paper.configuration.type.number.DoubleOr;
 import io.papermc.paper.configuration.type.number.IntOr;
@@ -217,6 +218,22 @@ public class GlobalConfiguration extends ConfigurationPart {
         @PostProcess
         private void postProcess() {
             ca.spottedleaf.moonrise.common.util.MoonriseCommon.adjustWorkerThreads(this.workerThreads, this.ioThreads);
+            String newChunkSystemGenParallelism = this.genParallelism;
+            if (newChunkSystemGenParallelism.equalsIgnoreCase("default")) {
+                newChunkSystemGenParallelism = "true";
+            }
+
+            final boolean useParallelGen;
+            if (newChunkSystemGenParallelism.equalsIgnoreCase("on") || newChunkSystemGenParallelism.equalsIgnoreCase("enabled")
+                || newChunkSystemGenParallelism.equalsIgnoreCase("true")) {
+                useParallelGen = true;
+            } else if (newChunkSystemGenParallelism.equalsIgnoreCase("off") || newChunkSystemGenParallelism.equalsIgnoreCase("disabled")
+                || newChunkSystemGenParallelism.equalsIgnoreCase("false")) {
+                useParallelGen = false;
+            } else {
+                throw new IllegalStateException("Invalid option for gen-parallelism: must be one of [on, off, enabled, disabled, true, false, default]");
+            }
+            FeatureHooks.initChunkTaskScheduler(useParallelGen);
         }
     }
 
diff --git a/paper-server/src/main/java/org/bukkit/craftbukkit/CraftChunk.java b/paper-server/src/main/java/org/bukkit/craftbukkit/CraftChunk.java
index bfc8b87941..f3ab07e44e 100644
--- a/paper-server/src/main/java/org/bukkit/craftbukkit/CraftChunk.java
+++ b/paper-server/src/main/java/org/bukkit/craftbukkit/CraftChunk.java
@@ -3,6 +3,7 @@ package org.bukkit.craftbukkit;
 import com.google.common.base.Preconditions;
 import com.google.common.base.Predicates;
 import com.mojang.serialization.Codec;
+import io.papermc.paper.FeatureHooks;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Objects;
@@ -56,7 +57,7 @@ public class CraftChunk implements Chunk {
     private final ServerLevel worldServer;
     private final int x;
     private final int z;
-    private static final PalettedContainer<net.minecraft.world.level.block.state.BlockState> emptyBlockIDs = new PalettedContainer<>(net.minecraft.world.level.block.Block.BLOCK_STATE_REGISTRY, Blocks.AIR.defaultBlockState(), PalettedContainer.Strategy.SECTION_STATES);
+    private static final PalettedContainer<net.minecraft.world.level.block.state.BlockState> emptyBlockIDs = FeatureHooks.emptyPalettedBlockContainer();
     private static final byte[] FULL_LIGHT = new byte[2048];
     private static final byte[] EMPTY_LIGHT = new byte[2048];
 
diff --git a/paper-server/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/paper-server/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index 6370b780af..5b64111bc8 100644
--- a/paper-server/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/paper-server/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -2718,7 +2718,7 @@ public final class CraftServer implements Server {
     public ChunkGenerator.ChunkData createChunkData(World world) {
         Preconditions.checkArgument(world != null, "World cannot be null");
         ServerLevel handle = ((CraftWorld) world).getHandle();
-        return new OldCraftChunkData(world.getMinHeight(), world.getMaxHeight(), handle.registryAccess().lookupOrThrow(Registries.BIOME));
+        return new OldCraftChunkData(world.getMinHeight(), world.getMaxHeight(), handle.registryAccess().lookupOrThrow(Registries.BIOME), world);
     }
 
     @Override
diff --git a/paper-server/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/paper-server/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
index 73b0438908..ca62105a0f 100644
--- a/paper-server/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+++ b/paper-server/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
@@ -5,6 +5,7 @@ import com.google.common.base.Predicates;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.mojang.datafixers.util.Pair;
+import io.papermc.paper.FeatureHooks;
 import it.unimi.dsi.fastutil.longs.Long2ObjectLinkedOpenHashMap;
 import it.unimi.dsi.fastutil.longs.Long2ObjectMap;
 import it.unimi.dsi.fastutil.objects.Object2IntOpenHashMap;
@@ -511,12 +512,7 @@ public class CraftWorld extends CraftRegionAccessor implements World {
                 List<ServerPlayer> playersInRange = playerChunk.playerProvider.getPlayers(playerChunk.getPos(), false);
                 if (playersInRange.isEmpty()) return;
 
-                ClientboundLevelChunkWithLightPacket refreshPacket = new ClientboundLevelChunkWithLightPacket(chunk, this.world.getLightEngine(), null, null);
-                for (ServerPlayer player : playersInRange) {
-                    if (player.connection == null) continue;
-
-                    player.connection.send(refreshPacket);
-                }
+                FeatureHooks.sendChunkRefreshPackets(playersInRange, chunk);
             });
         });
 
diff --git a/paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index 58b485c4cf..d5dc10cf94 100644
--- a/paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -6,6 +6,7 @@ import com.google.common.io.BaseEncoding;
 import com.mojang.authlib.GameProfile;
 import com.mojang.datafixers.util.Pair;
 import io.netty.buffer.Unpooled;
+import io.papermc.paper.FeatureHooks;
 import it.unimi.dsi.fastutil.shorts.ShortArraySet;
 import it.unimi.dsi.fastutil.shorts.ShortSet;
 import java.io.ByteArrayOutputStream;
@@ -3489,27 +3490,19 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
     @Override
     public Set<java.lang.Long> getSentChunkKeys() {
         org.spigotmc.AsyncCatcher.catchOp("accessing sent chunks");
-        final it.unimi.dsi.fastutil.longs.LongOpenHashSet keys = new it.unimi.dsi.fastutil.longs.LongOpenHashSet();
-        this.getHandle().getChunkTrackingView().forEach(pos -> keys.add(pos.longKey));
-        return it.unimi.dsi.fastutil.longs.LongSets.unmodifiable(keys);
+        return FeatureHooks.getSentChunkKeys(this.getHandle());
     }
 
     @Override
     public Set<org.bukkit.Chunk> getSentChunks() {
         org.spigotmc.AsyncCatcher.catchOp("accessing sent chunks");
-        final it.unimi.dsi.fastutil.objects.ObjectOpenHashSet<org.bukkit.Chunk> chunks = new it.unimi.dsi.fastutil.objects.ObjectOpenHashSet<>();
-        final org.bukkit.World world = this.getWorld();
-        this.getHandle().getChunkTrackingView().forEach(pos -> {
-            final org.bukkit.Chunk chunk = world.getChunkAt(pos.longKey);
-            chunks.add(chunk);
-        });
-        return it.unimi.dsi.fastutil.objects.ObjectSets.unmodifiable(chunks);
+        return FeatureHooks.getSentChunks(this.getHandle());
     }
 
     @Override
     public boolean isChunkSent(final long chunkKey) {
         org.spigotmc.AsyncCatcher.catchOp("accessing sent chunks");
-        return this.getHandle().getChunkTrackingView().contains(new net.minecraft.world.level.ChunkPos(chunkKey));
+        return FeatureHooks.isChunkSent(this.getHandle(), chunkKey);
     }
     // Paper end
 
diff --git a/paper-server/src/main/java/org/bukkit/craftbukkit/generator/OldCraftChunkData.java b/paper-server/src/main/java/org/bukkit/craftbukkit/generator/OldCraftChunkData.java
index e7f7a246e9..719fe4cbe9 100644
--- a/paper-server/src/main/java/org/bukkit/craftbukkit/generator/OldCraftChunkData.java
+++ b/paper-server/src/main/java/org/bukkit/craftbukkit/generator/OldCraftChunkData.java
@@ -1,5 +1,6 @@
 package org.bukkit.craftbukkit.generator;
 
+import io.papermc.paper.FeatureHooks;
 import java.util.HashSet;
 import java.util.Set;
 import net.minecraft.core.BlockPos;
@@ -27,8 +28,15 @@ public final class OldCraftChunkData implements ChunkGenerator.ChunkData {
     private final Registry<net.minecraft.world.level.biome.Biome> biomes;
     private Set<BlockPos> tiles;
     private final Set<BlockPos> lights = new HashSet<>();
+    private final org.bukkit.World world;
 
+    @Deprecated @io.papermc.paper.annotation.DoNotUse
     public OldCraftChunkData(int minHeight, int maxHeight, Registry<net.minecraft.world.level.biome.Biome> biomes) {
+        this(minHeight, maxHeight, biomes, null);
+    }
+
+    public OldCraftChunkData(int minHeight, int maxHeight, Registry<net.minecraft.world.level.biome.Biome> biomes, org.bukkit.World world) {
+        this.world = world;
         this.minHeight = minHeight;
         this.maxHeight = maxHeight;
         this.biomes = biomes;
@@ -176,7 +184,7 @@ public final class OldCraftChunkData implements ChunkGenerator.ChunkData {
         int offset = (y - this.minHeight) >> 4;
         LevelChunkSection section = this.sections[offset];
         if (create && section == null) {
-            this.sections[offset] = section = new LevelChunkSection(this.biomes);
+            this.sections[offset] = section = FeatureHooks.createSection(this.biomes, this.world instanceof org.bukkit.craftbukkit.CraftWorld ? ((org.bukkit.craftbukkit.CraftWorld) this.world).getHandle() : null, null, offset + (this.minHeight >> 4)); // Paper - Anti-Xray - Add parameters
         }
         return section;
     }
diff --git a/paper-server/src/main/java/org/bukkit/craftbukkit/map/RenderData.java b/paper-server/src/main/java/org/bukkit/craftbukkit/map/RenderData.java
index 256a131781..503a31b4ef 100644
--- a/paper-server/src/main/java/org/bukkit/craftbukkit/map/RenderData.java
+++ b/paper-server/src/main/java/org/bukkit/craftbukkit/map/RenderData.java
@@ -5,7 +5,7 @@ import org.bukkit.map.MapCursor;
 
 public class RenderData {
 
-    public final byte[] buffer;
+    public byte[] buffer;
     public final ArrayList<MapCursor> cursors;
 
     public RenderData() {