Provide E/TE/Chunk count stat methods

Provides counts without the ineffeciency of using .getEntities().size()
which creates copy of the collections.

paper-server/patches/sources/net/minecraft/world/level/Level.java.patch

@@ -57,6 +57,15 @@
  public abstract class Level implements LevelAccessor, AutoCloseable {
  
      public static final Codec<ResourceKey<Level>> RESOURCE_KEY_CODEC = ResourceKey.codec(Registries.DIMENSION);
+@@ -94,7 +117,7 @@
+     public static final int TICKS_PER_DAY = 24000;
+     public static final int MAX_ENTITY_SPAWN_Y = 20000000;
+     public static final int MIN_ENTITY_SPAWN_Y = -20000000;
+-    protected final List<TickingBlockEntity> blockEntityTickers = Lists.newArrayList();
++    public final List<TickingBlockEntity> blockEntityTickers = Lists.newArrayList(); // Paper - public
+     protected final NeighborUpdater neighborUpdater;
+     private final List<TickingBlockEntity> pendingBlockEntityTickers = Lists.newArrayList();
+     private boolean tickingBlockEntities;
 @@ -121,23 +144,74 @@
      private final DamageSources damageSources;
      private long subTickCount;
@@ -306,7 +315,7 @@
          if (this.isOutsideBuildHeight(pos)) {
              return false;
          } else if (!this.isClientSide && this.isDebug()) {
-@@ -214,45 +400,124 @@
+@@ -214,44 +400,123 @@
          } else {
              LevelChunk chunk = this.getChunkAt(pos);
              Block block = state.getBlock();
@@ -390,10 +399,10 @@
 +                // CraftBukkit end
 +
                  return true;
-             }
-         }
-     }
- 
++            }
++        }
++    }
++
 +    // CraftBukkit start - Split off from above in order to directly send client and physic updates
 +    public void notifyAndUpdatePhysics(BlockPos blockposition, LevelChunk chunk, BlockState oldBlock, BlockState newBlock, BlockState actualBlock, int i, int j) {
 +        BlockState iblockdata = newBlock;
@@ -406,7 +415,7 @@
 +
 +            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
 +                this.sendBlockUpdated(blockposition, iblockdata1, iblockdata, i);
-+            }
+             }
 +
 +            if ((i & 1) != 0) {
 +                this.blockUpdated(blockposition, iblockdata1.getBlock());
@@ -439,13 +448,12 @@
 +                this.onBlockStateChange(blockposition, iblockdata1, iblockdata2);
 +            }
 +            // CraftBukkit end
-+        }
-+    }
+         }
+     }
 +    // CraftBukkit end
-+
+ 
      public void onBlockStateChange(BlockPos pos, BlockState oldBlock, BlockState newBlock) {}
  
-     @Override
 @@ -340,10 +605,18 @@
  
      @Override

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

@@ -169,6 +169,48 @@ public class CraftWorld extends CraftRegionAccessor implements World {
     private final CraftPersistentDataContainer persistentDataContainer = new CraftPersistentDataContainer(CraftWorld.DATA_TYPE_REGISTRY);
     private net.kyori.adventure.pointer.Pointers adventure$pointers; // Paper - implement pointers
 
+    // Paper start - Provide fast information methods
+    @Override
+    public int getEntityCount() {
+        int ret = 0;
+        for (net.minecraft.world.entity.Entity entity : world.getEntities().getAll()) {
+            if (entity.isChunkLoaded()) {
+                ++ret;
+            }
+        }
+        return ret;
+    }
+
+    @Override
+    public int getTileEntityCount() {
+        // We don't use the full world tile entity list, so we must iterate chunks
+        int size = 0;
+        for (ChunkHolder playerchunk : ca.spottedleaf.moonrise.common.util.ChunkSystem.getVisibleChunkHolders(this.world)) {
+            net.minecraft.world.level.chunk.LevelChunk chunk = playerchunk.getTickingChunk();
+            if (chunk == null) {
+                continue;
+            }
+            size += chunk.blockEntities.size();
+        }
+        return size;
+    }
+
+    @Override
+    public int getTickableTileEntityCount() {
+        return world.blockEntityTickers.size();
+    }
+
+    @Override
+    public int getChunkCount() {
+        return this.world.getChunkSource().getFullChunksCount();
+    }
+
+    @Override
+    public int getPlayerCount() {
+        return world.players().size();
+    }
+    // Paper end
+
     private static final Random rand = new Random();
 
     public CraftWorld(ServerLevel world, ChunkGenerator gen, BiomeProvider biomeProvider, Environment env) {