SparklyPaperMC/patches/server/0025-Optimise-chunk-tick-iteration.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
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 0048077dedd19adc6c5a88e7d916d88a71662115..358efd39ae73f0a8a5c25d116af48c3e56167a16 100644
--- a/src/main/java/net/minecraft/server/level/ChunkHolder.java
+++ b/src/main/java/net/minecraft/server/level/ChunkHolder.java
@@ -51,11 +51,19 @@ public class ChunkHolder extends GenerationChunkHolder implements ca.spottedleaf
 
     // 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
 
@@ -264,7 +272,7 @@ public class ChunkHolder extends GenerationChunkHolder implements ca.spottedleaf
 
             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();
             }
 
@@ -284,6 +292,7 @@ public class ChunkHolder extends GenerationChunkHolder implements ca.spottedleaf
                 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) {
@@ -297,8 +306,19 @@ public class ChunkHolder extends GenerationChunkHolder implements ca.spottedleaf
         }
     }
 
+    // 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 3bb88e49fa4513011a082f06d592e70e759fd2ae..26aab541e157b3dafbbffbeab9bcc1dbf13c13c2 100644
--- a/src/main/java/net/minecraft/server/level/ChunkMap.java
+++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
@@ -182,6 +182,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         int chunkZ = io.papermc.paper.util.MCUtil.getChunkCoordinate(player.getZ());
         // Note: players need to be explicitly added to distance maps before they can be updated
         this.nearbyPlayers.removePlayer(player);
+        this.playerMobSpawnMap.remove(player); // Paper - optimise chunk tick iteration
     }
 
     void updateMaps(ServerPlayer player) {
@@ -222,6 +223,10 @@ 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);
@@ -335,7 +340,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         return this.randomState;
     }
 
-    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 71abe25cfb73af3857cbc85980aa32d0201aab62..51c5901efbe4b5e6789aa9b7edbe973bd3dd1a6f 100644
--- a/src/main/java/net/minecraft/server/level/DistanceManager.java
+++ b/src/main/java/net/minecraft/server/level/DistanceManager.java
@@ -43,7 +43,7 @@ public abstract class DistanceManager implements ca.spottedleaf.moonrise.patches
     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 long ticketTickCounter;
     // Paper - rewrite chunk system
@@ -143,7 +143,7 @@ public abstract class DistanceManager implements ca.spottedleaf.moonrise.patches
         ((ObjectSet) this.playersPerChunk.computeIfAbsent(i, (j) -> {
             return new ObjectOpenHashSet();
         })).add(player);
-        this.naturalSpawnChunkCounter.update(i, 0, true);
+        //this.naturalSpawnChunkCounter.update(i, 0, true); // Paper - optimise chunk tick iteration
         // Paper - rewrite chunk system
     }
 
@@ -156,7 +156,7 @@ public abstract class DistanceManager implements ca.spottedleaf.moonrise.patches
         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
             // Paper - rewrite chunk system
         }
 
@@ -194,13 +194,11 @@ public abstract class DistanceManager implements ca.spottedleaf.moonrise.patches
     }
 
     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 f3c5c66baf5e4d87d43c6e790923e22383211666..9ae1a0d7a0b36eea43f85e0a0cdc2296aef2e655 100644
--- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
+++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
@@ -524,18 +524,10 @@ public class ServerChunkCache extends ChunkSource implements ca.spottedleaf.moon
 
             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");
@@ -570,36 +562,107 @@ public class ServerChunkCache extends ChunkSource implements ca.spottedleaf.moon
                 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
 
-                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.getFullStatus().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);
                         }
                     }
                 }
+                // 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");
@@ -611,11 +674,23 @@ public class ServerChunkCache extends ChunkSource implements ca.spottedleaf.moon
             }
 
             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 2cd3e99fe31b074c8051fc69a2b6201745bd05a6..f60ebe355c968f35c05c64149baa507869f1f78f 100644
--- a/src/main/java/net/minecraft/server/level/ServerPlayer.java
+++ b/src/main/java/net/minecraft/server/level/ServerPlayer.java
@@ -332,8 +332,10 @@ public class ServerPlayer extends net.minecraft.world.entity.player.Player imple
     }
     // Paper end - rewrite chunk system
     public boolean hasTickedAtLeastOnceInNewWorld = false; // SparklyPaper - parallel world ticking (fixes bug in DreamResourceReset where the inventory is opened AFTER the player has changed worlds, if you click with the quick tp torch in a chest, because the inventory is opened AFTER the player has teleported)
-
-    public ServerPlayer(MinecraftServer server, ServerLevel world, GameProfile profile, ClientInformation clientOptions) {
+    // 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);
         this.chatVisibility = ChatVisiblity.FULL;
         this.canChatColor = true;