Paper/patches/server-remapped/0467-Use-distance-map-to-optimise-entity-tracker.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Tue, 5 May 2020 20:18:05 -0700
Subject: [PATCH] Use distance map to optimise entity tracker

Use the distance map to find candidate players for tracking.

diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index e5ad635a480d32e7a10ee92c65cfc18a98beafad..74f393ffa2ae2d0e25b3f0b674cef7a987e985d3 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -1652,6 +1652,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
         }
     }
 
+    public final int applyTrackingRangeScale(int value) { return this.getScaledTrackingDistance(value); } // Paper - OBFHELPER
     public int getScaledTrackingDistance(int initialDistance) {
         return initialDistance;
     }
diff --git a/src/main/java/net/minecraft/server/level/ChunkMap.java b/src/main/java/net/minecraft/server/level/ChunkMap.java
index 6c7af93cead523830d32b007cc69b313e59abef1..41147be189f764c2346cf015890a148f9730bc0f 100644
--- a/src/main/java/net/minecraft/server/level/ChunkMap.java
+++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
@@ -61,6 +61,7 @@ import net.minecraft.network.protocol.game.ClientboundSetEntityLinkPacket;
 import net.minecraft.network.protocol.game.ClientboundSetPassengersPacket;
 import net.minecraft.network.protocol.game.DebugPackets;
 import net.minecraft.server.MCUtil;
+import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.level.progress.ChunkProgressListener;
 import net.minecraft.util.CsvOutput;
 import net.minecraft.util.Mth;
@@ -193,21 +194,55 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
 
     // Paper start - distance maps
     private final com.destroystokyo.paper.util.misc.PooledLinkedHashSets<ServerPlayer> pooledLinkedPlayerHashSets = new com.destroystokyo.paper.util.misc.PooledLinkedHashSets<>();
+    // Paper start - use distance map to optimise tracker
+    public static boolean isLegacyTrackingEntity(Entity entity) {
+        return entity.isLegacyTrackingEntity;
+    }
+
+    // inlined EnumMap, TrackingRange.TrackingRangeType
+    static final org.spigotmc.TrackingRange.TrackingRangeType[] TRACKING_RANGE_TYPES = org.spigotmc.TrackingRange.TrackingRangeType.values();
+    public final com.destroystokyo.paper.util.misc.PlayerAreaMap[] playerEntityTrackerTrackMaps;
+    final int[] entityTrackerTrackRanges;
+
+    private int convertSpigotRangeToVanilla(final int vanilla) {
+        return MinecraftServer.getServer().applyTrackingRangeScale(vanilla);
+    }
+    // Paper end - use distance map to optimise tracker
 
     void addPlayerToDistanceMaps(ServerPlayer player) {
         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
+        // Paper start - use distance map to optimise entity tracker
+        for (int i = 0, len = TRACKING_RANGE_TYPES.length; i < len; ++i) {
+            com.destroystokyo.paper.util.misc.PlayerAreaMap trackMap = this.playerEntityTrackerTrackMaps[i];
+            int trackRange = this.entityTrackerTrackRanges[i];
+
+            trackMap.add(player, chunkX, chunkZ, Math.min(trackRange, this.getEffectiveViewDistance()));
+        }
+        // Paper end - use distance map to optimise entity tracker
     }
 
     void removePlayerFromDistanceMaps(ServerPlayer player) {
-
+        // Paper start - use distance map to optimise tracker
+        for (int i = 0, len = TRACKING_RANGE_TYPES.length; i < len; ++i) {
+            this.playerEntityTrackerTrackMaps[i].remove(player);
+        }
+        // Paper end - use distance map to optimise tracker
     }
 
     void updateMaps(ServerPlayer player) {
         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
+        // Paper start - use distance map to optimise entity tracker
+        for (int i = 0, len = TRACKING_RANGE_TYPES.length; i < len; ++i) {
+            com.destroystokyo.paper.util.misc.PlayerAreaMap trackMap = this.playerEntityTrackerTrackMaps[i];
+            int trackRange = this.entityTrackerTrackRanges[i];
+
+            trackMap.update(player, chunkX, chunkZ, Math.min(trackRange, this.getEffectiveViewDistance()));
+        }
+        // Paper end - use distance map to optimise entity tracker
     }
     // Paper end
 
@@ -244,6 +279,45 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         this.poiManager = new PoiManager(new File(this.storageFolder, "poi"), dataFixer, flag, this.level); // Paper
         this.setViewDistance(i);
         this.playerMobDistanceMap = this.level.paperConfig.perPlayerMobSpawns ? new com.destroystokyo.paper.util.PlayerMobDistanceMap() : null; // Paper
+        // Paper start - use distance map to optimise entity tracker
+        this.playerEntityTrackerTrackMaps = new com.destroystokyo.paper.util.misc.PlayerAreaMap[TRACKING_RANGE_TYPES.length];
+        this.entityTrackerTrackRanges = new int[TRACKING_RANGE_TYPES.length];
+
+        org.spigotmc.SpigotWorldConfig spigotWorldConfig = this.level.spigotConfig;
+
+        for (int ordinal = 0, len = TRACKING_RANGE_TYPES.length; ordinal < len; ++ordinal) {
+            org.spigotmc.TrackingRange.TrackingRangeType trackingRangeType = TRACKING_RANGE_TYPES[ordinal];
+            int configuredSpigotValue;
+            switch (trackingRangeType) {
+                case PLAYER:
+                    configuredSpigotValue = spigotWorldConfig.playerTrackingRange;
+                    break;
+                case ANIMAL:
+                    configuredSpigotValue = spigotWorldConfig.animalTrackingRange;
+                    break;
+                case MONSTER:
+                    configuredSpigotValue = spigotWorldConfig.monsterTrackingRange;
+                    break;
+                case MISC:
+                    configuredSpigotValue = spigotWorldConfig.miscTrackingRange;
+                    break;
+                case OTHER:
+                    configuredSpigotValue = spigotWorldConfig.otherTrackingRange;
+                    break;
+                case ENDERDRAGON:
+                    configuredSpigotValue = EntityType.ENDER_DRAGON.clientTrackingRange() * 16;
+                    break;
+                default:
+                    throw new IllegalStateException("Missing case for enum " + trackingRangeType);
+            }
+            configuredSpigotValue = convertSpigotRangeToVanilla(configuredSpigotValue);
+
+            int trackRange = (configuredSpigotValue >>> 4) + ((configuredSpigotValue & 15) != 0 ? 1 : 0);
+            this.entityTrackerTrackRanges[ordinal] = trackRange;
+
+            this.playerEntityTrackerTrackMaps[ordinal] = new com.destroystokyo.paper.util.misc.PlayerAreaMap(this.pooledLinkedPlayerHashSets);
+        }
+        // Paper end - use distance map to optimise entity tracker
     }
 
     public void updatePlayerMobTypeMap(Entity entity) {
@@ -1490,17 +1564,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
     }
 
     public void move(ServerPlayer player) {
-        ObjectIterator objectiterator = this.entityMap.values().iterator();
-
-        while (objectiterator.hasNext()) {
-            ChunkMap.TrackedEntity playerchunkmap_entitytracker = (ChunkMap.TrackedEntity) objectiterator.next();
-
-            if (playerchunkmap_entitytracker.entity == player) {
-                playerchunkmap_entitytracker.updatePlayers(this.level.players());
-            } else {
-                playerchunkmap_entitytracker.updatePlayer(player);
-            }
-        }
+        // Paper - delay this logic for the entity tracker tick, no need to duplicate it
 
         int i = Mth.floor(player.getX()) >> 4;
         int j = Mth.floor(player.getZ()) >> 4;
@@ -1616,7 +1680,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
 
                 entity.tracker = playerchunkmap_entitytracker; // Paper - Fast access to tracker
                 this.entityMap.put(entity.getId(), playerchunkmap_entitytracker);
-                playerchunkmap_entitytracker.updatePlayers(this.level.players());
+                playerchunkmap_entitytracker.updatePlayers(entity.getPlayersInTrackRange()); // Paper - don't search all players
                 if (entity instanceof ServerPlayer) {
                     ServerPlayer entityplayer = (ServerPlayer) entity;
 
@@ -1659,7 +1723,37 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         entity.tracker = null; // Paper - We're no longer tracked
     }
 
+    // Paper start - optimised tracker
+    private final void processTrackQueue() {
+        this.level.timings.tracker1.startTiming();
+        try {
+            for (TrackedEntity tracker : this.entityMap.values()) {
+                // update tracker entry
+                tracker.updatePlayers(tracker.entity.getPlayersInTrackRange());
+            }
+        } finally {
+            this.level.timings.tracker1.stopTiming();
+        }
+
+
+        this.level.timings.tracker2.startTiming();
+        try {
+            for (TrackedEntity tracker : this.entityMap.values()) {
+                tracker.serverEntity.tick();
+            }
+        } finally {
+            this.level.timings.tracker2.stopTiming();
+        }
+    }
+    // Paper end - optimised tracker
+
     protected void tick() {
+        // Paper start - optimized tracker
+        if (true) {
+            this.processTrackQueue();
+            return;
+        }
+        // Paper end - optimized tracker
         List<ServerPlayer> list = Lists.newArrayList();
         List<ServerPlayer> list1 = this.level.players();
 
@@ -1728,23 +1822,31 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         DebugPackets.sendPoiPacketsForChunk(this.level, chunk.getPos());
         List<Entity> list = Lists.newArrayList();
         List<Entity> list1 = Lists.newArrayList();
-        ObjectIterator objectiterator = this.entityMap.values().iterator();
+        // Paper start - optimise entity tracker
+        // use the chunk entity list, not the whole trackedEntities map...
+        Entity[] entities = chunk.entities.getRawData();
+        for (int i = 0, size = chunk.entities.size(); i < size; ++i) {
+            Entity entity = entities[i];
+            if (entity == player) {
+                continue;
+            }
+            ChunkMap.TrackedEntity tracker = this.entityMap.get(entity.getId());
+            if (tracker != null) { // dumb plugins... move on...
+                tracker.updatePlayer(player);
+            }
 
-        while (objectiterator.hasNext()) {
-            ChunkMap.TrackedEntity playerchunkmap_entitytracker = (ChunkMap.TrackedEntity) objectiterator.next();
-            Entity entity = playerchunkmap_entitytracker.entity;
+            // keep the vanilla logic here - this is REQUIRED or else passengers and their vehicles disappear!
+            // (and god knows what the leash thing is)
 
-            if (entity != player && entity.xChunk == chunk.getPos().x && entity.zChunk == chunk.getPos().z) {
-                playerchunkmap_entitytracker.updatePlayer(player);
-                if (entity instanceof Mob && ((Mob) entity).getLeashHolder() != null) {
-                    list.add(entity);
-                }
+            if (entity instanceof Mob && ((Mob)entity).getLeashHolder() != null) {
+                list.add(entity);
+            }
 
-                if (!entity.getPassengers().isEmpty()) {
-                    list1.add(entity);
-                }
+            if (!entity.getPassengers().isEmpty()) {
+                list1.add(entity);
             }
         }
+        // Paper end - optimise entity tracker
 
         Iterator iterator;
         Entity entity1;
@@ -1782,7 +1884,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
 
     public class TrackedEntity {
 
-        private final ServerEntity serverEntity;
+        final ServerEntity serverEntity; // Paper - private -> package private
         private final Entity entity;
         private final int range;
         private SectionPos lastSectionPos;
@@ -1799,6 +1901,42 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
             this.lastSectionPos = SectionPos.of(entity);
         }
 
+        // Paper start - use distance map to optimise tracker
+        com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> lastTrackerCandidates;
+
+        final void updatePlayers(com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> newTrackerCandidates) {
+            com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> oldTrackerCandidates = this.lastTrackerCandidates;
+            this.lastTrackerCandidates = newTrackerCandidates;
+
+            if (newTrackerCandidates != null) {
+                Object[] rawData = newTrackerCandidates.getBackingSet();
+                for (int i = 0, len = rawData.length; i < len; ++i) {
+                    Object raw = rawData[i];
+                    if (!(raw instanceof ServerPlayer)) {
+                        continue;
+                    }
+                    ServerPlayer player = (ServerPlayer)raw;
+                    this.updatePlayer(player);
+                }
+            }
+
+            if (oldTrackerCandidates == newTrackerCandidates) {
+                // this is likely the case.
+                // means there has been no range changes, so we can just use the above for tracking.
+                return;
+            }
+
+            // stuff could have been removed, so we need to check the trackedPlayers set
+            // for players that were removed
+
+            for (ServerPlayer player : this.seenBy.toArray(new ServerPlayer[0])) { // avoid CME
+                if (newTrackerCandidates == null || !newTrackerCandidates.contains(player)) {
+                    this.updatePlayer(player);
+                }
+            }
+        }
+        // Paper end - use distance map to optimise tracker
+
         public boolean equals(Object object) {
             return object instanceof ChunkMap.TrackedEntity ? ((ChunkMap.TrackedEntity) object).entity.getId() == this.entity.getId() : false;
         }
@@ -1899,7 +2037,7 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
                 int j = entity.getType().clientTrackingRange() * 16;
                 j = org.spigotmc.TrackingRange.getEntityTrackingRange(entity, j); // Paper
 
-                if (j > i) {
+                if (j < i) { // Paper - we need the lowest range thanks to the fact that our tracker doesn't account for passenger logic
                     i = j;
                 }
             }
diff --git a/src/main/java/net/minecraft/server/level/ServerEntity.java b/src/main/java/net/minecraft/server/level/ServerEntity.java
index 1609ab94c86e964421f996d4d46aef30f8b8e696..d797873db52ba265ac4478f9f3c6344badd4739e 100644
--- a/src/main/java/net/minecraft/server/level/ServerEntity.java
+++ b/src/main/java/net/minecraft/server/level/ServerEntity.java
@@ -100,6 +100,7 @@ public class ServerEntity {
         this.wasOnGround = entity.isOnGround();
     }
 
+    public final void tick() { this.sendChanges(); } // Paper - OBFHELPER
     public void sendChanges() {
         List<Entity> list = this.entity.getPassengers();
 
diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
index 2b48c4a2b512c42bed2c767db90a28898c74286a..d9bb00752ac81b2171d3ad25fd84904467a18e3b 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -46,6 +46,7 @@ import net.minecraft.network.syncher.EntityDataSerializers;
 import net.minecraft.network.syncher.SynchedEntityData;
 import net.minecraft.resources.ResourceKey;
 import net.minecraft.resources.ResourceLocation;
+import net.minecraft.server.MCUtil;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.level.ChunkMap;
 import net.minecraft.server.level.ServerLevel;
@@ -294,6 +295,21 @@ public abstract class Entity implements Nameable, CommandSource, net.minecraft.s
     }
     // CraftBukkit end
 
+    // Paper start - optimise entity tracking
+    final org.spigotmc.TrackingRange.TrackingRangeType trackingRangeType = org.spigotmc.TrackingRange.getTrackingRangeType(this);
+
+    public boolean isLegacyTrackingEntity = false;
+
+    public final void setLegacyTrackingEntity(final boolean isLegacyTrackingEntity) {
+        this.isLegacyTrackingEntity = isLegacyTrackingEntity;
+    }
+
+    public final com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<ServerPlayer> getPlayersInTrackRange() {
+        return ((ServerLevel)this.level).getChunkSource().chunkMap.playerEntityTrackerTrackMaps[this.trackingRangeType.ordinal()]
+            .getObjectsInRange(MCUtil.getCoordinateKey(this));
+    }
+    // Paper end - optimise entity tracking
+
     public Entity(EntityType<?> type, Level world) {
         this.id = Entity.ENTITY_COUNTER.incrementAndGet();
         this.passengers = Lists.newArrayList();
diff --git a/src/main/java/org/spigotmc/TrackingRange.java b/src/main/java/org/spigotmc/TrackingRange.java
index b03fa9024c7f0238e1379f6ae4486db5300a70e9..7b6011be849ecffdd791d439f70ae5dffc96f264 100644
--- a/src/main/java/org/spigotmc/TrackingRange.java
+++ b/src/main/java/org/spigotmc/TrackingRange.java
@@ -20,6 +20,7 @@ public class TrackingRange
      */
     public static int getEntityTrackingRange(Entity entity, int defaultRange)
     {
+        if (entity instanceof net.minecraft.world.entity.boss.enderdragon.EnderDragon) return defaultRange; // Paper - enderdragon is exempt
         SpigotWorldConfig config = entity.level.spigotConfig;
         if ( entity instanceof ServerPlayer )
         {
@@ -43,8 +44,48 @@ public class TrackingRange
             return config.miscTrackingRange;
         } else
         {
-            if (entity instanceof net.minecraft.world.entity.boss.enderdragon.EnderDragon) return ((net.minecraft.server.level.ServerLevel)(entity.getCommandSenderWorld())).getChunkSource().chunkMap.getLoadViewDistance(); // Paper - enderdragon is exempt
             return config.otherTrackingRange;
         }
     }
+
+    // Paper start - optimise entity tracking
+    // copied from above, TODO check on update
+    public static TrackingRangeType getTrackingRangeType(Entity entity)
+    {
+        if (entity instanceof net.minecraft.world.entity.boss.enderdragon.EnderDragon) return TrackingRangeType.ENDERDRAGON; // Paper - enderdragon is exempt
+        if ( entity instanceof ServerPlayer )
+        {
+            return TrackingRangeType.PLAYER;
+            // Paper start - Simplify and set water mobs to animal tracking range
+        }
+        switch (entity.activationType) {
+            case RAIDER:
+            case MONSTER:
+            case FLYING_MONSTER:
+                return TrackingRangeType.MONSTER;
+            case WATER:
+            case VILLAGER:
+            case ANIMAL:
+                return TrackingRangeType.ANIMAL;
+            case MISC:
+        }
+        if ( entity instanceof ItemFrame || entity instanceof Painting || entity instanceof ItemEntity || entity instanceof ExperienceOrb )
+        // Paper end
+        {
+            return TrackingRangeType.MISC;
+        } else
+        {
+            return TrackingRangeType.OTHER;
+        }
+    }
+
+    public static enum TrackingRangeType {
+        PLAYER,
+        ANIMAL,
+        MONSTER,
+        MISC,
+        OTHER,
+        ENDERDRAGON;
+    }
+    // Paper end - optimise entity tracking
 }