Finish chunk tick iteration optimisation port from Moonrise

5 files changed, 98 insertions, 403 deletions

diff --git a/patches/server/0988-Moonrise-optimisation-patches.patch b/patches/server/0988-Moonrise-optimisation-patches.patch
index 93f61b991b..b3cb82cd6e 100644
--- a/patches/server/0988-Moonrise-optimisation-patches.patch
+++ b/patches/server/0988-Moonrise-optimisation-patches.patch
@@ -25105,7 +25105,7 @@ index 3dc1daa3c6a04d3ff1a2353773b465fc380994a2..3575782f13a7f3c52e64dc5046803305
      }
  }
 diff --git a/src/main/java/net/minecraft/server/level/ServerChunkCache.java b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
-index 60f678c26fb5144386d8697ddfd5b6d841563b6f..9aec513f05b10e78579f79ccda6acf285f13222e 100644
+index 60f678c26fb5144386d8697ddfd5b6d841563b6f..17fafa62f21e505f9f77cf486f7f766a404f7c31 100644
 --- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
 +++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
 @@ -46,7 +46,7 @@ import net.minecraft.world.level.levelgen.structure.templatesystem.StructureTemp
@@ -25117,7 +25117,7 @@ index 60f678c26fb5144386d8697ddfd5b6d841563b6f..9aec513f05b10e78579f79ccda6acf28
  
      public static final org.slf4j.Logger LOGGER = com.mojang.logging.LogUtils.getLogger(); // Paper
      private static final List<ChunkStatus> CHUNK_STATUSES = ChunkStatus.getStatusList();
-@@ -71,6 +71,61 @@ public class ServerChunkCache extends ChunkSource {
+@@ -71,6 +71,62 @@ public class ServerChunkCache extends ChunkSource {
      private final ca.spottedleaf.concurrentutil.map.ConcurrentLong2ReferenceChainedHashTable<net.minecraft.world.level.chunk.LevelChunk> fullChunks = new ca.spottedleaf.concurrentutil.map.ConcurrentLong2ReferenceChainedHashTable<>();
      long chunkFutureAwaitCounter;
      // Paper end
@@ -25176,10 +25176,11 @@ index 60f678c26fb5144386d8697ddfd5b6d841563b6f..9aec513f05b10e78579f79ccda6acf28
 +        return load ? this.syncLoad(chunkX, chunkZ, toStatus) : null;
 +    }
 +    // Paper end - rewrite chunk system
++    private ServerChunkCache.ChunkAndHolder[] iterationCopy; // Paper - 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;
-@@ -97,13 +152,7 @@ public class ServerChunkCache extends ChunkSource {
+@@ -97,13 +153,7 @@ public class ServerChunkCache extends ChunkSource {
      }
      // CraftBukkit end
      // Paper start
@@ -25194,7 +25195,7 @@ index 60f678c26fb5144386d8697ddfd5b6d841563b6f..9aec513f05b10e78579f79ccda6acf28
  
      @Nullable
      public ChunkAccess getChunkAtImmediately(int x, int z) {
-@@ -174,63 +223,25 @@ public class ServerChunkCache extends ChunkSource {
+@@ -174,63 +224,25 @@ public class ServerChunkCache extends ChunkSource {
      @Nullable
      @Override
      public ChunkAccess getChunk(int x, int z, ChunkStatus leastStatus, boolean create) {
@@ -25210,13 +25211,13 @@ index 60f678c26fb5144386d8697ddfd5b6d841563b6f..9aec513f05b10e78579f79ccda6acf28
 -            }
 -            // Paper end - Perf: Optimise getChunkAt calls for loaded chunks
 -            ProfilerFiller gameprofilerfiller = this.level.getProfiler();
+-
+-            gameprofilerfiller.incrementCounter("getChunk");
+-            long k = ChunkPos.asLong(x, z);
 +        // 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];
@@ -25268,7 +25269,7 @@ index 60f678c26fb5144386d8697ddfd5b6d841563b6f..9aec513f05b10e78579f79ccda6acf28
      }
  
      private void clearCache() {
-@@ -261,56 +272,59 @@ public class ServerChunkCache extends ChunkSource {
+@@ -261,56 +273,59 @@ public class ServerChunkCache extends ChunkSource {
      }
  
      private CompletableFuture<ChunkResult<ChunkAccess>> getChunkFutureMainThread(int chunkX, int chunkZ, ChunkStatus leastStatus, boolean create) {
@@ -25364,7 +25365,7 @@ index 60f678c26fb5144386d8697ddfd5b6d841563b6f..9aec513f05b10e78579f79ccda6acf28
      }
  
      @Override
-@@ -323,16 +337,7 @@ public class ServerChunkCache extends ChunkSource {
+@@ -323,16 +338,7 @@ public class ServerChunkCache extends ChunkSource {
      }
  
      public boolean runDistanceManagerUpdates() { // Paper - public
@@ -25382,7 +25383,7 @@ index 60f678c26fb5144386d8697ddfd5b6d841563b6f..9aec513f05b10e78579f79ccda6acf28
      }
  
      // Paper start
-@@ -342,13 +347,14 @@ public class ServerChunkCache extends ChunkSource {
+@@ -342,13 +348,14 @@ public class ServerChunkCache extends ChunkSource {
      // Paper end
  
      public boolean isPositionTicking(long pos) {
@@ -25401,7 +25402,7 @@ index 60f678c26fb5144386d8697ddfd5b6d841563b6f..9aec513f05b10e78579f79ccda6acf28
          try (co.aikar.timings.Timing timed = level.timings.chunkSaveData.startTiming()) { // Paper - Timings
          this.chunkMap.saveAllChunks(flush);
          } // Paper - Timings
-@@ -361,12 +367,7 @@ public class ServerChunkCache extends ChunkSource {
+@@ -361,12 +368,7 @@ public class ServerChunkCache extends ChunkSource {
      }
  
      public void close(boolean save) throws IOException {
@@ -25415,7 +25416,7 @@ index 60f678c26fb5144386d8697ddfd5b6d841563b6f..9aec513f05b10e78579f79ccda6acf28
      }
  
      // CraftBukkit start - modelled on below
-@@ -394,6 +395,7 @@ public class ServerChunkCache extends ChunkSource {
+@@ -394,6 +396,7 @@ public class ServerChunkCache extends ChunkSource {
          this.level.getProfiler().popPush("chunks");
          if (tickChunks) {
              this.level.timings.chunks.startTiming(); // Paper - timings
@@ -25423,7 +25424,7 @@ index 60f678c26fb5144386d8697ddfd5b6d841563b6f..9aec513f05b10e78579f79ccda6acf28
              this.tickChunks();
              this.level.timings.chunks.stopTiming(); // Paper - timings
              this.chunkMap.tick();
-@@ -408,6 +410,7 @@ public class ServerChunkCache extends ChunkSource {
+@@ -408,6 +411,7 @@ public class ServerChunkCache extends ChunkSource {
      }
  
      private void tickChunks() {
@@ -25431,7 +25432,45 @@ index 60f678c26fb5144386d8697ddfd5b6d841563b6f..9aec513f05b10e78579f79ccda6acf28
          long i = this.level.getGameTime();
          long j = i - this.lastInhabitedUpdate;
  
-@@ -460,14 +463,19 @@ public class ServerChunkCache extends ChunkSource {
+@@ -417,18 +421,29 @@ public class ServerChunkCache extends ChunkSource {
+ 
+             gameprofilerfiller.push("pollingChunks");
+             gameprofilerfiller.push("filteringLoadedChunks");
+-            List<ServerChunkCache.ChunkAndHolder> list = Lists.newArrayListWithCapacity(this.chunkMap.size());
+-            Iterator iterator = this.chunkMap.getChunks().iterator();
+-            if (this.level.getServer().tickRateManager().runsNormally()) this.level.timings.chunkTicks.startTiming(); // Paper
++            // Paper start - chunk tick iteration optimisations
++            List<ServerChunkCache.ChunkAndHolder> list;
++            {
++                final ca.spottedleaf.moonrise.common.list.ReferenceList<net.minecraft.server.level.ServerChunkCache.ChunkAndHolder> tickingChunks =
++                    ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel) this.level).moonrise$getTickingChunks();
+ 
+-            while (iterator.hasNext()) {
+-                ChunkHolder playerchunk = (ChunkHolder) iterator.next();
+-                LevelChunk chunk = playerchunk.getTickingChunk();
++                final ServerChunkCache.ChunkAndHolder[] raw = tickingChunks.getRawDataUnchecked();
++                final int size = tickingChunks.size();
+ 
+-                if (chunk != null) {
+-                    list.add(new ServerChunkCache.ChunkAndHolder(chunk, playerchunk));
++                if (this.iterationCopy == null || this.iterationCopy.length < size) {
++                    this.iterationCopy = new ServerChunkCache.ChunkAndHolder[raw.length];
+                 }
++                System.arraycopy(raw, 0, this.iterationCopy, 0, size);
++
++                list = it.unimi.dsi.fastutil.objects.ObjectArrayList.wrap(
++                    this.iterationCopy, size
++                );
+             }
++            // Paper end - chunk tick iteration optimisations
++            Iterator iterator = null; // Paper - chunk tick iteration optimisations
++            if (this.level.getServer().tickRateManager().runsNormally()) this.level.timings.chunkTicks.startTiming(); // Paper
++
++            // Paper - chunk tick iteration optimisations
+ 
+             if (this.level.tickRateManager().runsNormally()) {
+                 gameprofilerfiller.popPush("naturalSpawnCount");
+@@ -460,14 +475,19 @@ public class ServerChunkCache extends ChunkSource {
                      LevelChunk chunk1 = chunkproviderserver_a.chunk;
                      ChunkPos chunkcoordintpair = chunk1.getPos();
  
@@ -25453,7 +25492,35 @@ index 60f678c26fb5144386d8697ddfd5b6d841563b6f..9aec513f05b10e78579f79ccda6acf28
                          }
                      }
                  }
-@@ -493,11 +501,12 @@ public class ServerChunkCache extends ChunkSource {
+@@ -482,22 +502,35 @@ public class ServerChunkCache extends ChunkSource {
+             }
+ 
+             gameprofilerfiller.popPush("broadcast");
+-            list.forEach((chunkproviderserver_a1) -> {
+-                this.level.timings.broadcastChunkUpdates.startTiming(); // Paper - timing
+-                chunkproviderserver_a1.holder.broadcastChanges(chunkproviderserver_a1.chunk);
+-                this.level.timings.broadcastChunkUpdates.stopTiming(); // Paper - timing
+-            });
++            // Paper start - chunk tick iteration optimisations
++            this.level.timings.broadcastChunkUpdates.startTiming(); // Paper - timing
++            {
++                final it.unimi.dsi.fastutil.objects.ObjectArrayList<net.minecraft.server.level.ServerChunkCache.ChunkAndHolder> chunks = (it.unimi.dsi.fastutil.objects.ObjectArrayList<net.minecraft.server.level.ServerChunkCache.ChunkAndHolder>)list;
++                final ServerChunkCache.ChunkAndHolder[] raw = chunks.elements();
++                final int size = chunks.size();
++
++                Objects.checkFromToIndex(0, size, raw.length);
++                for (int idx = 0; idx < size; ++idx) {
++                    final ServerChunkCache.ChunkAndHolder holder = raw[idx];
++                    raw[idx] = null;
++
++                    holder.holder().broadcastChanges(holder.chunk());
++                }
++            }
++            this.level.timings.broadcastChunkUpdates.stopTiming(); // Paper - timing
++            // Paper end - chunk tick iteration optimisations
+             gameprofilerfiller.pop();
+             gameprofilerfiller.pop();
+         }
      }
  
      private void getFullChunk(long pos, Consumer<LevelChunk> chunkConsumer) {
@@ -25470,7 +25537,7 @@ index 60f678c26fb5144386d8697ddfd5b6d841563b6f..9aec513f05b10e78579f79ccda6acf28
  
      }
  
-@@ -591,6 +600,12 @@ public class ServerChunkCache extends ChunkSource {
+@@ -591,6 +624,12 @@ public class ServerChunkCache extends ChunkSource {
          this.chunkMap.setServerViewDistance(watchDistance);
      }
  
@@ -25483,7 +25550,7 @@ index 60f678c26fb5144386d8697ddfd5b6d841563b6f..9aec513f05b10e78579f79ccda6acf28
      public void setSimulationDistance(int simulationDistance) {
          this.distanceManager.updateSimulationDistance(simulationDistance);
      }
-@@ -669,21 +684,19 @@ public class ServerChunkCache extends ChunkSource {
+@@ -669,21 +708,19 @@ public class ServerChunkCache extends ChunkSource {
          @Override
          // CraftBukkit start - process pending Chunk loadCallback() and unloadCallback() after each run task
          public boolean pollTask() {
diff --git a/patches/server/0998-Optional-per-player-mob-spawns.patch b/patches/server/0998-Optional-per-player-mob-spawns.patch
index a5b1729654..b13e13f0b2 100644
--- a/patches/server/0998-Optional-per-player-mob-spawns.patch
+++ b/patches/server/0998-Optional-per-player-mob-spawns.patch
@@ -37,10 +37,10 @@ index edb36dee707433d4f9419aef6ac6cc0bec5f285e..c282566ee45d79b4fb3297989e054c80
      // Paper end
  
 diff --git a/src/main/java/net/minecraft/server/level/ServerChunkCache.java b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
-index 9aec513f05b10e78579f79ccda6acf285f13222e..96a03770d47c47e07615815bcc3d474d6cd7711b 100644
+index 17fafa62f21e505f9f77cf486f7f766a404f7c31..2ed9a088d0fd56043d161909ce8e0df683a6413a 100644
 --- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
 +++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
-@@ -437,7 +437,19 @@ public class ServerChunkCache extends ChunkSource implements ca.spottedleaf.moon
+@@ -449,14 +449,26 @@ public class ServerChunkCache extends ChunkSource implements ca.spottedleaf.moon
                  gameprofilerfiller.popPush("naturalSpawnCount");
                  this.level.timings.countNaturalMobs.startTiming(); // Paper - timings
                  int k = this.distanceManager.getNaturalSpawnChunkCount();
@@ -61,6 +61,14 @@ index 9aec513f05b10e78579f79ccda6acf285f13222e..96a03770d47c47e07615815bcc3d474d
                  this.level.timings.countNaturalMobs.stopTiming(); // Paper - timings
  
                  this.lastSpawnState = spawnercreature_d;
+                 gameprofilerfiller.popPush("spawnAndTick");
+                 boolean flag = this.level.getGameRules().getBoolean(GameRules.RULE_DOMOBSPAWNING) && !this.level.players().isEmpty(); // CraftBukkit
+ 
+-                Util.shuffle(list, this.level.random);
++                if (!this.level.paperConfig().entities.spawning.perPlayerMobSpawns) Util.shuffle(list, this.level.random); // Paper - per player mob spawns - do not need this when per-player is enabled
+                 // Paper start - PlayerNaturallySpawnCreaturesEvent
+                 int chunkRange = level.spigotConfig.mobSpawnRange;
+                 chunkRange = (chunkRange > level.spigotConfig.viewDistance) ? (byte) level.spigotConfig.viewDistance : chunkRange;
 diff --git a/src/main/java/net/minecraft/server/level/ServerPlayer.java b/src/main/java/net/minecraft/server/level/ServerPlayer.java
 index fd61e10fd3151bf8cc206a93d4ede22a7c681dbf..23ddb7735623e502eda2b7b3029c6597f4b0f9a0 100644
 --- a/src/main/java/net/minecraft/server/level/ServerPlayer.java
diff --git a/patches/server/1002-Improve-cancelling-PreCreatureSpawnEvent-with-per-pl.patch b/patches/server/1002-Improve-cancelling-PreCreatureSpawnEvent-with-per-pl.patch
index e670998b87..f8dc0458f9 100644
--- a/patches/server/1002-Improve-cancelling-PreCreatureSpawnEvent-with-per-pl.patch
+++ b/patches/server/1002-Improve-cancelling-PreCreatureSpawnEvent-with-per-pl.patch
@@ -37,10 +37,10 @@ index c282566ee45d79b4fb3297989e054c803873a294..dc64227e3b0d7855ef8870935aa437b7
      }
      // Paper end
 diff --git a/src/main/java/net/minecraft/server/level/ServerChunkCache.java b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
-index 96a03770d47c47e07615815bcc3d474d6cd7711b..5f195875564822f422127462fbbeea5df4a4e1cb 100644
+index 2ed9a088d0fd56043d161909ce8e0df683a6413a..cdb9160244cc69acd36ac9afcfe109a15ab2ab58 100644
 --- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
 +++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
-@@ -443,7 +443,17 @@ public class ServerChunkCache extends ChunkSource implements ca.spottedleaf.moon
+@@ -455,7 +455,17 @@ public class ServerChunkCache extends ChunkSource implements ca.spottedleaf.moon
                  if ((this.spawnFriendlies || this.spawnEnemies) && this.level.paperConfig().entities.spawning.perPlayerMobSpawns) { // don't count mobs when animals and monsters are disabled
                      // re-set mob counts
                      for (ServerPlayer player : this.level.players) {
diff --git a/patches/server/1036-Write-SavedData-IO-async.patch b/patches/server/1036-Write-SavedData-IO-async.patch
index 8f31373c74..f92c991a18 100644
--- a/patches/server/1036-Write-SavedData-IO-async.patch
+++ b/patches/server/1036-Write-SavedData-IO-async.patch
@@ -6,10 +6,10 @@ Subject: [PATCH] Write SavedData IO async
 Co-Authored-By: Shane Freeder <[email protected]>
 
 diff --git a/src/main/java/net/minecraft/server/level/ServerChunkCache.java b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
-index 5f195875564822f422127462fbbeea5df4a4e1cb..5149f7a5f0ee8620df582dcf26151e5842463cae 100644
+index cdb9160244cc69acd36ac9afcfe109a15ab2ab58..8a0b00d645e4cf2ca96ec7e8ebc6ef726a0ab8b0 100644
 --- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
 +++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
-@@ -368,6 +368,13 @@ public class ServerChunkCache extends ChunkSource implements ca.spottedleaf.moon
+@@ -369,6 +369,13 @@ public class ServerChunkCache extends ChunkSource implements ca.spottedleaf.moon
  
      public void close(boolean save) throws IOException {
          ((ca.spottedleaf.moonrise.patches.chunk_system.level.ChunkSystemServerLevel)this.level).moonrise$getChunkTaskScheduler().chunkHolderManager.close(save, true); // Paper - rewrite chunk system
diff --git a/patches/unapplied/server/1034-Optimise-chunk-tick-iteration.patch b/patches/unapplied/server/1034-Optimise-chunk-tick-iteration.patch
deleted file mode 100644
index bc67b755cd..0000000000
--- a/patches/unapplied/server/1034-Optimise-chunk-tick-iteration.patch
+++ /dev/null
@@ -1,380 +0,0 @@
-From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
-From: Spottedleaf <[email protected]>
-Date: Sat, 23 Sep 2023 21:36:36 -0700
-Subject: [PATCH] Optimise chunk tick iteration
-
-When per-player mob spawning is enabled we do not need to randomly
-shuffle the chunk list. Additionally, we can use the NearbyPlayers
-class to quickly retrieve nearby players instead of possible
-searching all players on the server.
-
-diff --git a/src/main/java/io/papermc/paper/util/player/NearbyPlayers.java b/src/main/java/io/papermc/paper/util/player/NearbyPlayers.java
-index c3ce8a42dddd76b7189ad5685b23f9d9f8ccadb3..f164256d59b761264876ca0c85f812d101bfd5de 100644
---- a/src/main/java/io/papermc/paper/util/player/NearbyPlayers.java
-+++ b/src/main/java/io/papermc/paper/util/player/NearbyPlayers.java
-@@ -17,7 +17,8 @@ public final class NearbyPlayers {
-         GENERAL_SMALL,
-         GENERAL_REALLY_SMALL,
-         TICK_VIEW_DISTANCE,
--        VIEW_DISTANCE;
-+        VIEW_DISTANCE, // Paper - optimise chunk iteration
-+        SPAWN_RANGE, // Paper - optimise chunk iteration
-     }
- 
-     private static final NearbyMapType[] MOB_TYPES = NearbyMapType.values();
-@@ -26,10 +27,12 @@ public final class NearbyPlayers {
-     private static final int GENERAL_AREA_VIEW_DISTANCE = 33;
-     private static final int GENERAL_SMALL_VIEW_DISTANCE = 10;
-     private static final int GENERAL_REALLY_SMALL_VIEW_DISTANCE = 3;
-+    private static final int SPAWN_RANGE_VIEW_DISTANCE = net.minecraft.server.level.DistanceManager.MOB_SPAWN_RANGE; // Paper - optimise chunk iteration
- 
-     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);
-+    public static final int SPAWN_RANGE_VIEW_DISTANCE_BLOCKS = (SPAWN_RANGE_VIEW_DISTANCE << 4); // Paper - optimise chunk iteration
- 
-     private final ServerLevel world;
-     private final Reference2ReferenceOpenHashMap<ServerPlayer, TrackedPlayer[]> players = new Reference2ReferenceOpenHashMap<>();
-@@ -80,6 +83,7 @@ public final class NearbyPlayers {
-         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.getLoadViewDistance(player));
-+        players[NearbyMapType.SPAWN_RANGE.ordinal()].update(chunk.x, chunk.z, SPAWN_RANGE_VIEW_DISTANCE); // Paper - optimise chunk iteration
-     }
- 
-     public TrackedChunk getChunk(final ChunkPos pos) {
-diff --git a/src/main/java/net/minecraft/server/level/ChunkHolder.java b/src/main/java/net/minecraft/server/level/ChunkHolder.java
-index 13d15a135dd0373bef4a5ac9ffb56dbbf53353a0..472b9494f8a34a8ba90d6a2936b0db7530a229ad 100644
---- a/src/main/java/net/minecraft/server/level/ChunkHolder.java
-+++ b/src/main/java/net/minecraft/server/level/ChunkHolder.java
-@@ -77,11 +77,19 @@ public class ChunkHolder {
- 
-     // Paper start
-     public void onChunkAdd() {
--
-+        // Paper start - optimise chunk tick iteration
-+        if (this.needsBroadcastChanges()) {
-+            this.chunkMap.needsChangeBroadcasting.add(this);
-+        }
-+        // Paper end - optimise chunk tick iteration
-     }
- 
-     public void onChunkRemove() {
--
-+        // Paper start - optimise chunk tick iteration
-+        if (this.needsBroadcastChanges()) {
-+            this.chunkMap.needsChangeBroadcasting.remove(this);
-+        }
-+        // Paper end - optimise chunk tick iteration
-     }
-     // Paper end
- 
-@@ -216,7 +224,7 @@ public class ChunkHolder {
- 
-             if (i < 0 || i >= this.changedBlocksPerSection.length) return; // CraftBukkit - SPIGOT-6086, SPIGOT-6296
-             if (this.changedBlocksPerSection[i] == null) {
--                this.hasChangedSections = true;
-+                this.hasChangedSections = true; this.addToBroadcastMap(); // Paper - optimise chunk tick iteration
-                 this.changedBlocksPerSection[i] = new ShortOpenHashSet();
-             }
- 
-@@ -236,6 +244,7 @@ public class ChunkHolder {
-                 int k = this.lightEngine.getMaxLightSection();
- 
-                 if (y >= j && y <= k) {
-+                    this.addToBroadcastMap(); // Paper - optimise chunk tick iteration
-                     int l = y - j;
- 
-                     if (lightType == LightLayer.SKY) {
-@@ -254,9 +263,19 @@ public class ChunkHolder {
-         this.broadcast(this.getPlayers(onChunkViewEdge), packet); // Paper - rewrite chunk system
-     }
-     // Paper end - starlight
-+    // Paper start - optimise chunk tick iteration
-+    public final boolean needsBroadcastChanges() {
-+        return this.hasChangedSections || !this.skyChangedLightSectionFilter.isEmpty() || !this.blockChangedLightSectionFilter.isEmpty();
-+    }
-+
-+    private void addToBroadcastMap() {
-+        io.papermc.paper.util.TickThread.ensureTickThread(this.chunkMap.level, this.pos, "Asynchronous ChunkHolder update is not allowed");
-+        this.chunkMap.needsChangeBroadcasting.add(this);
-+    }
-+    // Paper end - optimise chunk tick iteration
- 
-     public void broadcastChanges(LevelChunk chunk) {
--        if (this.hasChangedSections || !this.skyChangedLightSectionFilter.isEmpty() || !this.blockChangedLightSectionFilter.isEmpty()) {
-+        if (this.needsBroadcastChanges()) { // Paper - optimise chunk tick iteration; moved into above, other logic needs to call
-             Level world = chunk.getLevel();
-             List list;
- 
-diff --git a/src/main/java/net/minecraft/server/level/ChunkMap.java b/src/main/java/net/minecraft/server/level/ChunkMap.java
-index 48f7997e8a20f5a5a77516cbde990d0aacc2078a..dbe9df1e1973db133f7c8516256697ef7c968137 100644
---- a/src/main/java/net/minecraft/server/level/ChunkMap.java
-+++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
-@@ -194,6 +194,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
-             this.playerEntityTrackerTrackMaps[i].remove(player);
-         }
-         // Paper end - use distance map to optimise tracker
-+        this.playerMobSpawnMap.remove(player); // Paper - optimise chunk tick iteration
-     }
- 
-     void updateMaps(ServerPlayer player) {
-@@ -243,6 +244,10 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
-     }
-     public final io.papermc.paper.util.player.NearbyPlayers nearbyPlayers;
-     // Paper end
-+    // Paper start - optimise chunk tick iteration
-+    public final it.unimi.dsi.fastutil.objects.ReferenceOpenHashSet<ChunkHolder> needsChangeBroadcasting = new it.unimi.dsi.fastutil.objects.ReferenceOpenHashSet<>();
-+    public final com.destroystokyo.paper.util.misc.PlayerAreaMap playerMobSpawnMap = new com.destroystokyo.paper.util.misc.PlayerAreaMap(this.pooledLinkedPlayerHashSets);
-+    // Paper end - optimise chunk tick iteration
- 
-     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);
-@@ -411,7 +416,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
-     }
-     // Paper end - Optional per player mob spawns
- 
--    private static double euclideanDistanceSquared(ChunkPos pos, Entity entity) {
-+    public static double euclideanDistanceSquared(ChunkPos pos, Entity entity) { // Paper - optimise chunk iteration; public
-         double d0 = (double) SectionPos.sectionToBlockCoord(pos.x, 8);
-         double d1 = (double) SectionPos.sectionToBlockCoord(pos.z, 8);
-         double d2 = d0 - entity.getX();
-diff --git a/src/main/java/net/minecraft/server/level/DistanceManager.java b/src/main/java/net/minecraft/server/level/DistanceManager.java
-index ed5154e41ca858f4d6b4d1c276c66831c038d2a6..cdb3c2cde5d9133ef60cf96d91762e6a7c8aeb4a 100644
---- a/src/main/java/net/minecraft/server/level/DistanceManager.java
-+++ b/src/main/java/net/minecraft/server/level/DistanceManager.java
-@@ -49,7 +49,7 @@ public abstract class DistanceManager {
-     private static final int INITIAL_TICKET_LIST_CAPACITY = 4;
-     final Long2ObjectMap<ObjectSet<ServerPlayer>> playersPerChunk = new Long2ObjectOpenHashMap();
-     // Paper - rewrite chunk system
--    private final DistanceManager.FixedPlayerDistanceChunkTracker naturalSpawnChunkCounter = new DistanceManager.FixedPlayerDistanceChunkTracker(8);
-+    public static final int MOB_SPAWN_RANGE = 8; //private final DistanceManager.FixedPlayerDistanceChunkTracker naturalSpawnChunkCounter = new DistanceManager.FixedPlayerDistanceChunkTracker(8); // Paper - optimise chunk tick iteration
-     // Paper - rewrite chunk system
-     private final ChunkMap chunkMap; // Paper
- 
-@@ -135,7 +135,7 @@ public abstract class DistanceManager {
-         long i = chunkcoordintpair.toLong();
- 
-         // Paper - no longer used
--        this.naturalSpawnChunkCounter.update(i, 0, true);
-+        //this.naturalSpawnChunkCounter.update(i, 0, true); // Paper - optimise chunk tick iteration
-         //this.playerTicketManager.update(i, 0, true); // Paper - no longer used
-         //this.tickingTicketsTracker.addTicket(TicketType.PLAYER, chunkcoordintpair, this.getPlayerTicketLevel(), chunkcoordintpair); // Paper - no longer used
-     }
-@@ -149,7 +149,7 @@ 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.naturalSpawnChunkCounter.update(i, Integer.MAX_VALUE, false); // Paper - optimise chunk tick iteration
-             //this.playerTicketManager.update(i, Integer.MAX_VALUE, false); // Paper - no longer used
-             //this.tickingTicketsTracker.removeTicket(TicketType.PLAYER, chunkcoordintpair, this.getPlayerTicketLevel(), chunkcoordintpair); // Paper - no longer used
-         }
-@@ -191,13 +191,11 @@ public abstract class DistanceManager {
-     }
- 
-     public int getNaturalSpawnChunkCount() {
--        this.naturalSpawnChunkCounter.runAllUpdates();
--        return this.naturalSpawnChunkCounter.chunks.size();
-+        return this.chunkMap.playerMobSpawnMap.size(); // Paper - optimise chunk tick iteration
-     }
- 
-     public boolean hasPlayersNearby(long chunkPos) {
--        this.naturalSpawnChunkCounter.runAllUpdates();
--        return this.naturalSpawnChunkCounter.chunks.containsKey(chunkPos);
-+        return this.chunkMap.playerMobSpawnMap.getObjectsInRange(chunkPos) != null; // Paper - optimise chunk tick iteration
-     }
- 
-     public String getDebugStatus() {
-diff --git a/src/main/java/net/minecraft/server/level/ServerChunkCache.java b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
-index 01577dbb16ff6abc9edcf897f7fadaad14350184..e2c67c011503c9c37b9d637c0268717baac13e32 100644
---- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
-+++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
-@@ -499,18 +499,10 @@ public class ServerChunkCache extends ChunkSource {
- 
-             gameprofilerfiller.push("pollingChunks");
-             gameprofilerfiller.push("filteringLoadedChunks");
--            List<ServerChunkCache.ChunkAndHolder> list = Lists.newArrayListWithCapacity(this.chunkMap.size());
--            Iterator iterator = this.chunkMap.getChunks().iterator();
-+            // Paper - optimise chunk tick iteration
-             if (this.level.getServer().tickRateManager().runsNormally()) this.level.timings.chunkTicks.startTiming(); // Paper
- 
--            while (iterator.hasNext()) {
--                ChunkHolder playerchunk = (ChunkHolder) iterator.next();
--                LevelChunk chunk = playerchunk.getTickingChunk();
--
--                if (chunk != null) {
--                    list.add(new ServerChunkCache.ChunkAndHolder(chunk, playerchunk));
--                }
--            }
-+            // Paper - optimise chunk tick iteration
- 
-             if (this.level.tickRateManager().runsNormally()) {
-                 gameprofilerfiller.popPush("naturalSpawnCount");
-@@ -545,38 +537,109 @@ public class ServerChunkCache extends ChunkSource {
-                 gameprofilerfiller.popPush("spawnAndTick");
-                 boolean flag = this.level.getGameRules().getBoolean(GameRules.RULE_DOMOBSPAWNING) && !this.level.players().isEmpty(); // CraftBukkit
- 
--                Util.shuffle(list, this.level.random);
--                // Paper start - PlayerNaturallySpawnCreaturesEvent
--                int chunkRange = level.spigotConfig.mobSpawnRange;
--                chunkRange = (chunkRange > level.spigotConfig.viewDistance) ? (byte) level.spigotConfig.viewDistance : chunkRange;
--                chunkRange = Math.min(chunkRange, 8);
--                for (ServerPlayer entityPlayer : this.level.players()) {
--                    entityPlayer.playerNaturallySpawnedEvent = new com.destroystokyo.paper.event.entity.PlayerNaturallySpawnCreaturesEvent(entityPlayer.getBukkitEntity(), (byte) chunkRange);
--                    entityPlayer.playerNaturallySpawnedEvent.callEvent();
-+                // Paper start - optimise chunk tick iteration
-+                ChunkMap playerChunkMap = this.chunkMap;
-+                for (ServerPlayer player : this.level.players) {
-+                    if (!player.affectsSpawning || player.isSpectator()) {
-+                        playerChunkMap.playerMobSpawnMap.remove(player);
-+                        player.playerNaturallySpawnedEvent = null;
-+                        player.lastEntitySpawnRadiusSquared = -1.0;
-+                        continue;
-+                    }
-+
-+                    int viewDistance = io.papermc.paper.chunk.system.ChunkSystem.getTickViewDistance(player);
-+
-+                    // copied and modified from isOutisdeRange
-+                    int chunkRange = (int)level.spigotConfig.mobSpawnRange;
-+                    chunkRange = (chunkRange > viewDistance) ? viewDistance : chunkRange;
-+                    chunkRange = (chunkRange > DistanceManager.MOB_SPAWN_RANGE) ? DistanceManager.MOB_SPAWN_RANGE : chunkRange;
-+
-+                    com.destroystokyo.paper.event.entity.PlayerNaturallySpawnCreaturesEvent event = new com.destroystokyo.paper.event.entity.PlayerNaturallySpawnCreaturesEvent(player.getBukkitEntity(), (byte)chunkRange);
-+                    event.callEvent();
-+                    if (event.isCancelled() || event.getSpawnRadius() < 0) {
-+                        playerChunkMap.playerMobSpawnMap.remove(player);
-+                        player.playerNaturallySpawnedEvent = null;
-+                        player.lastEntitySpawnRadiusSquared = -1.0;
-+                        continue;
-+                    }
-+
-+                    int range = Math.min(event.getSpawnRadius(), DistanceManager.MOB_SPAWN_RANGE); // limit to max spawn range
-+                    int chunkX = io.papermc.paper.util.CoordinateUtils.getChunkCoordinate(player.getX());
-+                    int chunkZ = io.papermc.paper.util.CoordinateUtils.getChunkCoordinate(player.getZ());
-+
-+                    playerChunkMap.playerMobSpawnMap.addOrUpdate(player, chunkX, chunkZ, range);
-+                    player.lastEntitySpawnRadiusSquared = (double)((range << 4) * (range << 4)); // used in anyPlayerCloseEnoughForSpawning
-+                    player.playerNaturallySpawnedEvent = event;
-                 }
--                // Paper end - PlayerNaturallySpawnCreaturesEvent
-+                // Paper end - optimise chunk tick iteration
-                 int l = this.level.getGameRules().getInt(GameRules.RULE_RANDOMTICKING);
-                 boolean flag1 = this.level.ticksPerSpawnCategory.getLong(org.bukkit.entity.SpawnCategory.ANIMAL) != 0L && this.level.getLevelData().getGameTime() % this.level.ticksPerSpawnCategory.getLong(org.bukkit.entity.SpawnCategory.ANIMAL) == 0L; // CraftBukkit
--                Iterator iterator1 = list.iterator();
-+                // Paper - optimise chunk tick iteration
- 
-                 int chunksTicked = 0; // Paper
--                while (iterator1.hasNext()) {
--                    ServerChunkCache.ChunkAndHolder chunkproviderserver_a = (ServerChunkCache.ChunkAndHolder) iterator1.next();
--                    LevelChunk chunk1 = chunkproviderserver_a.chunk;
-+                // Paper start - optimise chunk tick iteration
-+                io.papermc.paper.util.player.NearbyPlayers nearbyPlayers = this.chunkMap.getNearbyPlayers(); // Paper - optimise chunk tick iteration
-+                Iterator<LevelChunk> chunkIterator;
-+                if (this.level.paperConfig().entities.spawning.perPlayerMobSpawns) {
-+                    chunkIterator = this.tickingChunks.iterator();
-+                } else {
-+                    chunkIterator = this.tickingChunks.unsafeIterator();
-+                    List<LevelChunk> shuffled = Lists.newArrayListWithCapacity(this.tickingChunks.size());
-+                    while (chunkIterator.hasNext()) {
-+                        shuffled.add(chunkIterator.next());
-+                    }
-+                    Util.shuffle(shuffled, this.level.random);
-+                    chunkIterator = shuffled.iterator();
-+                }
-+                try {
-+                // Paper end - optimise chunk tick iteration
-+                while (chunkIterator.hasNext()) {
-+                    LevelChunk chunk1 = chunkIterator.next();
-+                    // Paper end - optimise chunk tick iteration
-                     ChunkPos chunkcoordintpair = chunk1.getPos();
- 
--                    if (this.level.isNaturalSpawningAllowed(chunkcoordintpair) && this.chunkMap.anyPlayerCloseEnoughForSpawning(chunkcoordintpair)) {
-+                    // Paper start - optimise chunk tick iteration
-+                    com.destroystokyo.paper.util.maplist.ReferenceList<ServerPlayer> playersNearby
-+                        = nearbyPlayers.getPlayers(chunkcoordintpair, io.papermc.paper.util.player.NearbyPlayers.NearbyMapType.SPAWN_RANGE);
-+                    if (playersNearby == null) {
-+                        continue;
-+                    }
-+                    Object[] rawData = playersNearby.getRawData();
-+                    boolean spawn = false;
-+                    boolean tick = false;
-+                    for (int itr = 0, len = playersNearby.size(); itr < len; ++itr) {
-+                        ServerPlayer player = (ServerPlayer)rawData[itr];
-+                        if (player.isSpectator()) {
-+                            continue;
-+                        }
-+
-+                        double distance = ChunkMap.euclideanDistanceSquared(chunkcoordintpair, player);
-+                        spawn |= player.lastEntitySpawnRadiusSquared >= distance;
-+                        tick |= ((double)io.papermc.paper.util.player.NearbyPlayers.SPAWN_RANGE_VIEW_DISTANCE_BLOCKS) * ((double)io.papermc.paper.util.player.NearbyPlayers.SPAWN_RANGE_VIEW_DISTANCE_BLOCKS) >= distance;
-+                        if (spawn & tick) {
-+                            break;
-+                        }
-+                    }
-+                    if (tick && chunk1.chunkStatus.isOrAfter(net.minecraft.server.level.FullChunkStatus.ENTITY_TICKING)) {
-+                        // Paper end - optimise chunk tick iteration
-                         chunk1.incrementInhabitedTime(j);
--                        if (flag && (this.spawnEnemies || this.spawnFriendlies) && this.level.getWorldBorder().isWithinBounds(chunkcoordintpair) && this.chunkMap.anyPlayerCloseEnoughForSpawning(chunkcoordintpair, true)) { // Spigot
-+                        if (spawn && flag && (this.spawnEnemies || this.spawnFriendlies) && this.level.getWorldBorder().isWithinBounds(chunkcoordintpair)) { // Spigot // Paper - optimise chunk tick iteration
-                             NaturalSpawner.spawnForChunk(this.level, chunk1, spawnercreature_d, this.spawnFriendlies, this.spawnEnemies, flag1);
-                         }
- 
--                        if (this.level.shouldTickBlocksAt(chunkcoordintpair.toLong())) {
-+                        if (true || this.level.shouldTickBlocksAt(chunkcoordintpair.toLong())) { // Paper - optimise chunk tick iteration
-                             this.level.tickChunk(chunk1, l);
-                             if ((chunksTicked++ & 1) == 0) net.minecraft.server.MinecraftServer.getServer().executeMidTickTasks(); // Paper
-                         }
-                     }
-                 }
-+                // Paper start - optimise chunk tick iteration
-+                } finally {
-+                    if (chunkIterator instanceof io.papermc.paper.util.maplist.IteratorSafeOrderedReferenceSet.Iterator safeIterator) {
-+                        safeIterator.finishedIterating();
-+                    }
-+                }
-+                // Paper end - optimise chunk tick iteration
-                 this.level.timings.chunkTicks.stopTiming(); // Paper
- 
-                 gameprofilerfiller.popPush("customSpawners");
-@@ -588,11 +651,23 @@ public class ServerChunkCache extends ChunkSource {
-             }
- 
-             gameprofilerfiller.popPush("broadcast");
--            list.forEach((chunkproviderserver_a1) -> {
-+            // Paper - optimise chunk tick iteration
-                 this.level.timings.broadcastChunkUpdates.startTiming(); // Paper - timing
--                chunkproviderserver_a1.holder.broadcastChanges(chunkproviderserver_a1.chunk);
-+            // Paper start - optimise chunk tick iteration
-+            if (!this.chunkMap.needsChangeBroadcasting.isEmpty()) {
-+                it.unimi.dsi.fastutil.objects.ReferenceOpenHashSet<ChunkHolder> copy = this.chunkMap.needsChangeBroadcasting.clone();
-+                this.chunkMap.needsChangeBroadcasting.clear();
-+                for (ChunkHolder holder : copy) {
-+                    holder.broadcastChanges(holder.getFullChunkNowUnchecked()); // LevelChunks are NEVER unloaded
-+                    if (holder.needsBroadcastChanges()) {
-+                        // I DON'T want to KNOW what DUMB plugins might be doing.
-+                        this.chunkMap.needsChangeBroadcasting.add(holder);
-+                    }
-+                }
-+            }
-+            // Paper end - optimise chunk tick iteration
-                 this.level.timings.broadcastChunkUpdates.stopTiming(); // Paper - timing
--            });
-+            // Paper - optimise chunk tick iteration
-             gameprofilerfiller.pop();
-             gameprofilerfiller.pop();
-         }
-diff --git a/src/main/java/net/minecraft/server/level/ServerPlayer.java b/src/main/java/net/minecraft/server/level/ServerPlayer.java
-index 09a80b6816e50ea0d733725c59164520136308d6..6a4637eef14cbd84bbe26ef16f004b8f93367a3d 100644
---- a/src/main/java/net/minecraft/server/level/ServerPlayer.java
-+++ b/src/main/java/net/minecraft/server/level/ServerPlayer.java
-@@ -342,6 +342,9 @@ public class ServerPlayer extends Player {
-         });
-     }
-     // Paper end - replace player chunk loader
-+    // Paper start - optimise chunk tick iteration
-+    public double lastEntitySpawnRadiusSquared = -1.0;
-+    // Paper end - optimise chunk tick iteration
- 
-     public ServerPlayer(MinecraftServer server, ServerLevel world, GameProfile profile, ClientInformation clientOptions) {
-         super(world, world.getSharedSpawnPos(), world.getSharedSpawnAngle(), profile);