Implement APIs for per world view and simulation distances

By: md_5 <git@md-5.net>

paper-server/nms-patches/net/minecraft/server/level/ChunkMapDistance.patch

@@ -1,5 +1,14 @@
 --- a/net/minecraft/server/level/ChunkMapDistance.java
 +++ b/net/minecraft/server/level/ChunkMapDistance.java
+@@ -55,7 +55,7 @@
+     final LongSet ticketsToRelease = new LongOpenHashSet();
+     final Executor mainThreadExecutor;
+     private long ticketTickCounter;
+-    private int simulationDistance = 10;
++    public int simulationDistance = 10;
+ 
+     protected ChunkMapDistance(Executor executor, Executor executor1) {
+         Objects.requireNonNull(executor1);
 @@ -122,10 +122,25 @@
          }
  

paper-server/nms-patches/net/minecraft/server/level/PlayerChunkMap.patch

@@ -1,22 +1,23 @@
 --- a/net/minecraft/server/level/PlayerChunkMap.java
 +++ b/net/minecraft/server/level/PlayerChunkMap.java
-@@ -101,6 +101,12 @@
+@@ -101,6 +101,10 @@
  import org.apache.commons.lang3.mutable.MutableBoolean;
  import org.slf4j.Logger;
  
 +// CraftBukkit start
-+import net.minecraft.world.level.levelgen.GeneratorSettings;
 +import org.bukkit.craftbukkit.generator.CustomChunkGenerator;
-+import org.bukkit.entity.Player;
 +// CraftBukkit end
 +
  public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.d {
  
      private static final byte CHUNK_TYPE_REPLACEABLE = -1;
-@@ -143,6 +149,27 @@
+@@ -141,7 +145,28 @@
+     private final Long2ByteMap chunkTypeCache;
+     private final Long2LongMap chunkSaveCooldowns;
      private final Queue<Runnable> unloadQueue;
-     private int serverViewDistance;
+-    private int serverViewDistance;
- 
++    public int serverViewDistance;
++
 +    // CraftBukkit start - recursion-safe executor for Chunk loadCallback() and unloadCallback()
 +    public final CallbackExecutor callbackExecutor = new CallbackExecutor();
 +    public static final class CallbackExecutor implements java.util.concurrent.Executor, Runnable {
@@ -37,11 +38,10 @@
 +        }
 +    };
 +    // CraftBukkit end
-+
+ 
      public PlayerChunkMap(WorldServer worldserver, Convertable.ConversionSession convertable_conversionsession, DataFixer datafixer, StructureTemplateManager structuretemplatemanager, Executor executor, IAsyncTaskHandler<Runnable> iasynctaskhandler, ILightAccess ilightaccess, ChunkGenerator chunkgenerator, WorldLoadListener worldloadlistener, ChunkStatusUpdateListener chunkstatusupdatelistener, Supplier<WorldPersistentData> supplier, int i, boolean flag) {
          super(convertable_conversionsession.getDimensionPath(worldserver.dimension()).resolve("region"), datafixer, flag);
-         this.visibleChunkMap = this.updatingChunkMap.clone();
+@@ -161,6 +186,11 @@
-@@ -161,6 +188,11 @@
          this.storageName = path.getFileName().toString();
          this.level = worldserver;
          this.generator = chunkgenerator;
@@ -53,7 +53,7 @@
          IRegistryCustom iregistrycustom = worldserver.registryAccess();
          long j = worldserver.getSeed();
  
-@@ -332,9 +364,12 @@
+@@ -332,9 +362,12 @@
              CompletableFuture<List<Either<IChunkAccess, PlayerChunk.Failure>>> completablefuture1 = SystemUtils.sequence(list);
              CompletableFuture<Either<List<IChunkAccess>, PlayerChunk.Failure>> completablefuture2 = completablefuture1.thenApply((list2) -> {
                  List<IChunkAccess> list3 = Lists.newArrayList();
@@ -68,7 +68,7 @@
                      final Either<IChunkAccess, PlayerChunk.Failure> either = (Either) iterator.next();
  
                      if (either == null) {
-@@ -540,7 +575,7 @@
+@@ -540,7 +573,7 @@
  
      private void scheduleUnload(long i, PlayerChunk playerchunk) {
          CompletableFuture<IChunkAccess> completablefuture = playerchunk.getChunkToSave();
@@ -77,7 +77,7 @@
              CompletableFuture<IChunkAccess> completablefuture1 = playerchunk.getChunkToSave();
  
              if (completablefuture1 != completablefuture) {
-@@ -631,9 +666,9 @@
+@@ -631,9 +664,9 @@
                  ProtoChunk protochunk = ChunkRegionLoader.read(this.level, this.poiManager, chunkcoordintpair, (NBTTagCompound) optional.get());
  
                  this.markPosition(chunkcoordintpair, protochunk.getStatus().getChunkType());
@@ -89,7 +89,7 @@
              }
          }, this.mainThreadExecutor).exceptionallyAsync((throwable) -> {
              return this.handleChunkLoadFailure(throwable, chunkcoordintpair);
-@@ -748,7 +783,21 @@
+@@ -748,7 +781,21 @@
  
      private static void postLoadProtoChunk(WorldServer worldserver, List<NBTTagCompound> list) {
          if (!list.isEmpty()) {
@@ -112,7 +112,7 @@
          }
  
      }
-@@ -860,7 +909,7 @@
+@@ -860,7 +907,7 @@
          if (!playerchunk.wasAccessibleSinceLastSave()) {
              return false;
          } else {
@@ -121,7 +121,7 @@
  
              if (!(ichunkaccess instanceof ProtoChunkExtension) && !(ichunkaccess instanceof Chunk)) {
                  return false;
-@@ -1017,7 +1066,8 @@
+@@ -1017,7 +1064,8 @@
                  return ichunkaccess instanceof Chunk ? Optional.of((Chunk) ichunkaccess) : Optional.empty();
              });
  
@@ -131,7 +131,7 @@
                  return chunk.getBlockEntities().size();
              }).orElse(0), tickingtracker.getTicketDebugString(i), tickingtracker.getLevel(i), optional1.map((chunk) -> {
                  return chunk.getBlockTicks().count();
-@@ -1030,7 +1080,7 @@
+@@ -1030,7 +1078,7 @@
  
      private static String printFuture(CompletableFuture<Either<Chunk, PlayerChunk.Failure>> completablefuture) {
          try {
@@ -140,7 +140,7 @@
  
              return either != null ? (String) either.map((chunk) -> {
                  return "done";
-@@ -1046,12 +1096,14 @@
+@@ -1046,12 +1094,14 @@
  
      private CompletableFuture<Optional<NBTTagCompound>> readChunk(ChunkCoordIntPair chunkcoordintpair) {
          return this.read(chunkcoordintpair).thenApplyAsync((optional) -> {
@@ -158,7 +158,7 @@
      }
  
      boolean anyPlayerCloseEnoughForSpawning(ChunkCoordIntPair chunkcoordintpair) {
-@@ -1460,7 +1512,7 @@
+@@ -1460,7 +1510,7 @@
          public final Set<ServerPlayerConnection> seenBy = Sets.newIdentityHashSet();
  
          public EntityTracker(Entity entity, int i, int j, boolean flag) {
@@ -167,7 +167,7 @@
              this.entity = entity;
              this.range = i;
              this.lastSectionPos = SectionPosition.of((EntityAccess) entity);
-@@ -1520,6 +1572,11 @@
+@@ -1520,6 +1570,11 @@
                  double d2 = d0 * d0;
                  boolean flag = d1 <= d2 && this.entity.broadcastToPlayer(entityplayer) && PlayerChunkMap.this.isChunkTracked(entityplayer, this.entity.chunkPosition().x, this.entity.chunkPosition().z);
  

paper-server/src/main/java/org/bukkit/craftbukkit/CraftWorld.java

@@ -1032,6 +1032,16 @@ public class CraftWorld extends CraftRegionAccessor implements World {
         return Difficulty.getByValue(this.getHandle().getDifficulty().ordinal());
     }
 
+    @Override
+    public int getViewDistance() {
+        return world.getChunkSource().chunkMap.serverViewDistance;
+    }
+
+    @Override
+    public int getSimulationDistance() {
+        return world.getChunkSource().chunkMap.getDistanceManager().simulationDistance;
+    }
+
     public BlockMetadataStore getBlockMetadata() {
         return blockMetadata;
     }