Paper/patches/server/0685-Optimize-anyPlayerCloseEnoughForSpawning-to-use-dist.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Tue, 5 May 2020 20:40:53 -0700
Subject: [PATCH] Optimize anyPlayerCloseEnoughForSpawning to use distance maps

Use a distance map to find the players in range quickly

diff --git a/src/main/java/net/minecraft/server/level/ChunkHolder.java b/src/main/java/net/minecraft/server/level/ChunkHolder.java
index c5389e7f3665c06e487dfde3200b7e229694fbd2..4164204ba80f68a768de0ed1721c6447b972a631 100644
--- a/src/main/java/net/minecraft/server/level/ChunkHolder.java
+++ b/src/main/java/net/minecraft/server/level/ChunkHolder.java
@@ -79,16 +79,29 @@ public class ChunkHolder {
 
     // Paper start
     public void onChunkAdd() {
-
+        // Paper start - optimise anyPlayerCloseEnoughForSpawning
+        long key = io.papermc.paper.util.MCUtil.getCoordinateKey(this.pos);
+        this.playersInMobSpawnRange = this.chunkMap.playerMobSpawnMap.getObjectsInRange(key);
+        this.playersInChunkTickRange = this.chunkMap.playerChunkTickRangeMap.getObjectsInRange(key);
+        // Paper end - optimise anyPlayerCloseEnoughForSpawning
     }
 
     public void onChunkRemove() {
-
+        // Paper start - optimise anyPlayerCloseEnoughForSpawning
+        this.playersInMobSpawnRange = null;
+        this.playersInChunkTickRange = null;
+        // Paper end - optimise anyPlayerCloseEnoughForSpawning
     }
     // Paper end
 
     public final io.papermc.paper.chunk.system.scheduling.NewChunkHolder newChunkHolder; // Paper - rewrite chunk system
 
+    // Paper start - optimise anyPlayerCloseEnoughForSpawning
+    // cached here to avoid a map lookup
+    com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> playersInMobSpawnRange;
+    com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> playersInChunkTickRange;
+    // Paper end - optimise anyPlayerCloseEnoughForSpawning
+
     // Paper start - replace player chunk loader
     private final com.destroystokyo.paper.util.maplist.ReferenceList<ServerPlayer> playersSentChunkTo = new com.destroystokyo.paper.util.maplist.ReferenceList<>();
 
diff --git a/src/main/java/net/minecraft/server/level/ChunkMap.java b/src/main/java/net/minecraft/server/level/ChunkMap.java
index 93dea79180ebaef3ffb6abffd47f0026a91406cd..4e65e1d2d1538366f554d94bff31ab74c2e8a225 100644
--- a/src/main/java/net/minecraft/server/level/ChunkMap.java
+++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
@@ -174,12 +174,24 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         return net.minecraft.server.MinecraftServer.getServer().getScaledTrackingDistance(vanilla);
     }
     // Paper end - use distance map to optimise tracker
+    // Paper start - optimise ChunkMap#anyPlayerCloseEnoughForSpawning
+    // A note about the naming used here:
+    // Previously, mojang used a "spawn range" of 8 for controlling both ticking and
+    // mob spawn range. However, spigot makes the spawn range configurable by
+    // checking if the chunk is in the tick range (8) and the spawn range
+    // obviously this means a spawn range > 8 cannot be implemented
+
+    // these maps are named after spigot's uses
+    public final com.destroystokyo.paper.util.misc.PlayerAreaMap playerMobSpawnMap; // this map is absent from updateMaps since it's controlled at the start of the chunkproviderserver tick
+    public final com.destroystokyo.paper.util.misc.PlayerAreaMap playerChunkTickRangeMap;
+    // Paper end - optimise ChunkMap#anyPlayerCloseEnoughForSpawning
 
     void addPlayerToDistanceMaps(ServerPlayer player) {
         this.level.playerChunkLoader.addPlayer(player); // Paper - replace chunk loader
         int chunkX = MCUtil.getChunkCoordinate(player.getX());
         int chunkZ = MCUtil.getChunkCoordinate(player.getZ());
         // Note: players need to be explicitly added to distance maps before they can be updated
+        this.playerChunkTickRangeMap.add(player, chunkX, chunkZ, DistanceManager.MOB_SPAWN_RANGE); // Paper - optimise ChunkMap#anyPlayerCloseEnoughForSpawning
         // Paper start - per player mob spawning
         if (this.playerMobDistanceMap != null) {
             this.playerMobDistanceMap.add(player, chunkX, chunkZ, io.papermc.paper.chunk.system.ChunkSystem.getTickViewDistance(player));
@@ -198,6 +210,10 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
     void removePlayerFromDistanceMaps(ServerPlayer player) {
         this.level.playerChunkLoader.removePlayer(player); // Paper - replace chunk loader
 
+        // Paper start - optimise ChunkMap#anyPlayerCloseEnoughForSpawning
+        this.playerMobSpawnMap.remove(player);
+        this.playerChunkTickRangeMap.remove(player);
+        // Paper end - optimise ChunkMap#anyPlayerCloseEnoughForSpawning
         // Paper start - per player mob spawning
         if (this.playerMobDistanceMap != null) {
             this.playerMobDistanceMap.remove(player);
@@ -215,6 +231,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         int chunkZ = MCUtil.getChunkCoordinate(player.getZ());
         // Note: players need to be explicitly added to distance maps before they can be updated
         this.level.playerChunkLoader.updatePlayer(player); // Paper - replace chunk loader
+        this.playerChunkTickRangeMap.update(player, chunkX, chunkZ, DistanceManager.MOB_SPAWN_RANGE); // Paper - optimise ChunkMap#anyPlayerCloseEnoughForSpawning
         // Paper start - per player mob spawning
         if (this.playerMobDistanceMap != null) {
             this.playerMobDistanceMap.update(player, chunkX, chunkZ, io.papermc.paper.chunk.system.ChunkSystem.getTickViewDistance(player));
@@ -353,6 +370,38 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
             this.playerEntityTrackerTrackMaps[ordinal] = new com.destroystokyo.paper.util.misc.PlayerAreaMap(this.pooledLinkedPlayerHashSets);
         }
         // Paper end - use distance map to optimise entity tracker
+        // Paper start - optimise ChunkMap#anyPlayerCloseEnoughForSpawning
+        this.playerChunkTickRangeMap = new com.destroystokyo.paper.util.misc.PlayerAreaMap(this.pooledLinkedPlayerHashSets,
+            (ServerPlayer player, int rangeX, int rangeZ, int currPosX, int currPosZ, int prevPosX, int prevPosZ,
+             com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> newState) -> {
+                ChunkHolder playerChunk = ChunkMap.this.getUpdatingChunkIfPresent(MCUtil.getCoordinateKey(rangeX, rangeZ));
+                if (playerChunk != null) {
+                    playerChunk.playersInChunkTickRange = newState;
+                }
+            },
+            (ServerPlayer player, int rangeX, int rangeZ, int currPosX, int currPosZ, int prevPosX, int prevPosZ,
+             com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> newState) -> {
+                ChunkHolder playerChunk = ChunkMap.this.getUpdatingChunkIfPresent(MCUtil.getCoordinateKey(rangeX, rangeZ));
+                if (playerChunk != null) {
+                    playerChunk.playersInChunkTickRange = newState;
+                }
+            });
+        this.playerMobSpawnMap = new com.destroystokyo.paper.util.misc.PlayerAreaMap(this.pooledLinkedPlayerHashSets,
+            (ServerPlayer player, int rangeX, int rangeZ, int currPosX, int currPosZ, int prevPosX, int prevPosZ,
+             com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> newState) -> {
+                ChunkHolder playerChunk = ChunkMap.this.getUpdatingChunkIfPresent(MCUtil.getCoordinateKey(rangeX, rangeZ));
+                if (playerChunk != null) {
+                    playerChunk.playersInMobSpawnRange = newState;
+                }
+            },
+            (ServerPlayer player, int rangeX, int rangeZ, int currPosX, int currPosZ, int prevPosX, int prevPosZ,
+             com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> newState) -> {
+                ChunkHolder playerChunk = ChunkMap.this.getUpdatingChunkIfPresent(MCUtil.getCoordinateKey(rangeX, rangeZ));
+                if (playerChunk != null) {
+                    playerChunk.playersInMobSpawnRange = newState;
+                }
+            });
+        // Paper end - optimise ChunkMap#anyPlayerCloseEnoughForSpawning
     }
 
     protected ChunkGenerator generator() {
@@ -927,43 +976,48 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         return this.anyPlayerCloseEnoughForSpawning(pos, false);
     }
 
-    boolean anyPlayerCloseEnoughForSpawning(ChunkPos chunkcoordintpair, boolean reducedRange) {
-        int chunkRange = level.spigotConfig.mobSpawnRange;
-        chunkRange = (chunkRange > level.spigotConfig.viewDistance) ? (byte) level.spigotConfig.viewDistance : chunkRange;
-        chunkRange = (chunkRange > 8) ? 8 : chunkRange;
-
-        final int finalChunkRange = chunkRange; // Paper for lambda below
-        //double blockRange = (reducedRange) ? Math.pow(chunkRange << 4, 2) : 16384.0D; // Paper - use from event
-        double blockRange = 16384.0D; // Paper
-        // Spigot end
-        long i = chunkcoordintpair.toLong();
+    // Paper start - optimise anyPlayerCloseEnoughForSpawning
+    final boolean anyPlayerCloseEnoughForSpawning(ChunkPos chunkcoordintpair, boolean reducedRange) {
+        return this.anyPlayerCloseEnoughForSpawning(this.getUpdatingChunkIfPresent(chunkcoordintpair.toLong()), chunkcoordintpair, reducedRange);
+    }
 
-        if (!this.distanceManager.hasPlayersNearby(i)) {
+    final boolean anyPlayerCloseEnoughForSpawning(ChunkHolder playerchunk, ChunkPos chunkcoordintpair, boolean reducedRange) {
+        // this function is so hot that removing the map lookup call can have an order of magnitude impact on its performance
+        // tested and confirmed via System.nanoTime()
+        com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> playersInRange = reducedRange ? playerchunk.playersInMobSpawnRange : playerchunk.playersInChunkTickRange;
+        if (playersInRange == null) {
             return false;
-        } else {
-            Iterator iterator = this.playerMap.getPlayers(i).iterator();
-
-            ServerPlayer entityplayer;
+        }
+        Object[] backingSet = playersInRange.getBackingSet();
 
-            do {
-                if (!iterator.hasNext()) {
-                    return false;
+        if (reducedRange) {
+            for (int i = 0, len = backingSet.length; i < len; ++i) {
+                Object raw = backingSet[i];
+                if (!(raw instanceof ServerPlayer player)) {
+                    continue;
                 }
-
-                entityplayer = (ServerPlayer) iterator.next();
-                // Paper start - add PlayerNaturallySpawnCreaturesEvent
-                com.destroystokyo.paper.event.entity.PlayerNaturallySpawnCreaturesEvent event;
-                blockRange = 16384.0D;
-                if (reducedRange) {
-                    event = entityplayer.playerNaturallySpawnedEvent;
-                    if (event == null || event.isCancelled()) return false;
-                    blockRange = (double) ((event.getSpawnRadius() << 4) * (event.getSpawnRadius() << 4));
+                // don't check spectator and whatnot, already handled by mob spawn map update
+                if (euclideanDistanceSquared(chunkcoordintpair, player) < player.lastEntitySpawnRadiusSquared) {
+                    return true; // in range
                 }
-                // Paper end
-            } while (!this.playerIsCloseEnoughForSpawning(entityplayer, chunkcoordintpair, blockRange)); // Spigot
-
-            return true;
+            }
+        } else {
+            final double range = (DistanceManager.MOB_SPAWN_RANGE * 16) * (DistanceManager.MOB_SPAWN_RANGE * 16);
+            // before spigot, mob spawn range was actually mob spawn range + tick range, but it was split
+            for (int i = 0, len = backingSet.length; i < len; ++i) {
+                Object raw = backingSet[i];
+                if (!(raw instanceof ServerPlayer player)) {
+                    continue;
+                }
+                // don't check spectator and whatnot, already handled by mob spawn map update
+                if (euclideanDistanceSquared(chunkcoordintpair, player) < range) {
+                    return true; // in range
+                }
+            }
         }
+        // no players in range
+        return false;
+        // Paper end - optimise anyPlayerCloseEnoughForSpawning
     }
 
     public List<ServerPlayer> getPlayersCloseForSpawning(ChunkPos pos) {
diff --git a/src/main/java/net/minecraft/server/level/DistanceManager.java b/src/main/java/net/minecraft/server/level/DistanceManager.java
index 0a926afa06a5e37cf2650afa1b5099a2a9ffa659..ae4a4710ba07614be42cdcbf52cee04cfa08466b 100644
--- a/src/main/java/net/minecraft/server/level/DistanceManager.java
+++ b/src/main/java/net/minecraft/server/level/DistanceManager.java
@@ -50,7 +50,7 @@ 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 - no longer used
     // Paper - rewrite chunk system
     private final ChunkMap chunkMap; // Paper
 
@@ -136,7 +136,7 @@ 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 - no longer used
         //this.playerTicketManager.update(i, 0, true); // Paper - no longer used
         //this.tickingTicketsTracker.addTicket(TicketType.PLAYER, chunkcoordintpair, this.getPlayerTicketLevel(), chunkcoordintpair); // Paper - no longer used
     }
@@ -150,7 +150,7 @@ 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 - no longer used
             //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
         }
@@ -192,13 +192,17 @@ public abstract class DistanceManager {
     }
 
     public int getNaturalSpawnChunkCount() {
-        this.naturalSpawnChunkCounter.runAllUpdates();
-        return this.naturalSpawnChunkCounter.chunks.size();
+        // Paper start - use distance map to implement
+        // note: this is the spawn chunk count
+        return this.chunkMap.playerChunkTickRangeMap.size();
+        // Paper end - use distance map to implement
     }
 
     public boolean hasPlayersNearby(long chunkPos) {
-        this.naturalSpawnChunkCounter.runAllUpdates();
-        return this.naturalSpawnChunkCounter.chunks.containsKey(chunkPos);
+        // Paper start - use distance map to implement
+        // note: this is the is spawn chunk method
+        return this.chunkMap.playerChunkTickRangeMap.getObjectsInRange(chunkPos) != null;
+        // Paper end - use distance map to implement
     }
 
     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 3f5d572994bc8b3f1e106105dc0bb202ad005b8c..5c5fe2087a7617324ab8e18389e3ffa9ac413026 100644
--- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
+++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
@@ -517,6 +517,37 @@ public class ServerChunkCache extends ChunkSource {
         if (flag) {
             this.chunkMap.tick();
         } else {
+            // Paper start - optimize isOutisdeRange
+            ChunkMap playerChunkMap = this.chunkMap;
+            for (ServerPlayer player : this.level.players) {
+                if (!player.affectsSpawning || player.isSpectator()) {
+                    playerChunkMap.playerMobSpawnMap.remove(player);
+                    continue;
+                }
+
+                int viewDistance = this.chunkMap.getEffectiveViewDistance();
+
+                // copied and modified from isOutisdeRange
+                int chunkRange = level.spigotConfig.mobSpawnRange;
+                chunkRange = (chunkRange > viewDistance) ? (byte)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.playerChunkTickRangeMap.getLastViewDistance(player) == -1) {
+                    playerChunkMap.playerMobSpawnMap.remove(player);
+                    continue;
+                }
+
+                int range = Math.min(event.getSpawnRadius(), 32); // limit to max view distance
+                int chunkX = io.papermc.paper.util.MCUtil.getChunkCoordinate(player.getX());
+                int chunkZ = io.papermc.paper.util.MCUtil.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 - optimize isOutisdeRange
             LevelData worlddata = this.level.getLevelData();
             ProfilerFiller gameprofilerfiller = this.level.getProfiler();
 
@@ -560,15 +591,7 @@ public class ServerChunkCache extends ChunkSource {
             boolean flag2 = this.level.getGameRules().getBoolean(GameRules.RULE_DOMOBSPAWNING) && !this.level.players().isEmpty(); // CraftBukkit
 
             Collections.shuffle(list);
-            // Paper start - call player naturally spawn event
-            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 end
+            // Paper - moved natural spawn event up
             Iterator iterator1 = list.iterator();
 
             while (iterator1.hasNext()) {
@@ -576,9 +599,9 @@ public class ServerChunkCache extends ChunkSource {
                 LevelChunk chunk1 = chunkproviderserver_a.chunk;
                 ChunkPos chunkcoordintpair = chunk1.getPos();
 
-                if (this.level.isNaturalSpawningAllowed(chunkcoordintpair) && this.chunkMap.anyPlayerCloseEnoughForSpawning(chunkcoordintpair)) {
+                if (this.level.isNaturalSpawningAllowed(chunkcoordintpair) && this.chunkMap.anyPlayerCloseEnoughForSpawning(chunkproviderserver_a.holder, chunkcoordintpair, false)) { // Paper - optimise anyPlayerCloseEnoughForSpawning
                     chunk1.incrementInhabitedTime(j);
-                    if (flag2 && (this.spawnEnemies || this.spawnFriendlies) && this.level.getWorldBorder().isWithinBounds(chunkcoordintpair) && this.chunkMap.anyPlayerCloseEnoughForSpawning(chunkcoordintpair, true)) { // Spigot
+                    if (flag2 && (this.spawnEnemies || this.spawnFriendlies) && this.level.getWorldBorder().isWithinBounds(chunkcoordintpair) && this.chunkMap.anyPlayerCloseEnoughForSpawning(chunkproviderserver_a.holder, chunkcoordintpair, true)) { // Spigot // Paper - optimise anyPlayerCloseEnoughForSpawning
                         NaturalSpawner.spawnForChunk(this.level, chunk1, spawnercreature_d, this.spawnFriendlies, this.spawnEnemies, flag1);
                     }
 
diff --git a/src/main/java/net/minecraft/server/level/ServerPlayer.java b/src/main/java/net/minecraft/server/level/ServerPlayer.java
index 1511d45eb61e72e73bc17cfe03fbb6c22f9dd128..7b8e06fc7e2d422ba0e996d6de3f769e995cc6e5 100644
--- a/src/main/java/net/minecraft/server/level/ServerPlayer.java
+++ b/src/main/java/net/minecraft/server/level/ServerPlayer.java
@@ -273,6 +273,7 @@ public class ServerPlayer extends Player {
     public Integer clientViewDistance;
     // CraftBukkit end
     public boolean isRealPlayer; // Paper
+    public double lastEntitySpawnRadiusSquared; // Paper - optimise isOutsideRange, this field is in blocks
     public final com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> cachedSingleHashSet; // Paper
     public PlayerNaturallySpawnCreaturesEvent playerNaturallySpawnedEvent; // Paper
     public org.bukkit.event.player.PlayerQuitEvent.QuitReason quitReason = null; // Paper - there are a lot of changes to do if we change all methods leading to the event