Paper/patches/server/0432-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/level/ChunkMap.java b/src/main/java/net/minecraft/server/level/ChunkMap.java
index c643919e17081c85717b0b00c227b914d7abcc0a..9ce330be998f3392288d8eb0386a48237ff3a880 100644
--- a/src/main/java/net/minecraft/server/level/ChunkMap.java
+++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
@@ -63,6 +63,7 @@ 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.server.network.ServerPlayerConnection;
 import net.minecraft.util.CsvOutput;
@@ -226,11 +227,33 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
     public final com.destroystokyo.paper.util.misc.PlayerAreaMap playerViewDistanceTickMap;
     public final com.destroystokyo.paper.util.misc.PlayerAreaMap playerViewDistanceNoTickMap;
     // Paper end - no-tick view distance
+    // 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().getScaledTrackingDistance(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
         // Paper start - no-tick view distance
         int effectiveTickViewDistance = this.getEffectiveViewDistance();
         int effectiveNoTickViewDistance = Math.max(this.getEffectiveNoTickViewDistance(), effectiveTickViewDistance);
@@ -247,7 +270,11 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
     }
 
     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
         // Paper start - no-tick view distance
         this.playerViewDistanceBroadcastMap.remove(player);
         this.playerViewDistanceTickMap.remove(player);
@@ -259,6 +286,14 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         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 start - no-tick view distance
         int effectiveTickViewDistance = this.getEffectiveViewDistance();
         int effectiveNoTickViewDistance = Math.max(this.getEffectiveNoTickViewDistance(), effectiveTickViewDistance);
@@ -310,6 +345,45 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
         this.poiManager = new PoiManager(new File(this.storageFolder, "poi"), dataFixer, dsync, world);
         this.setViewDistance(viewDistance);
         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
         // Paper start - no-tick view distance
         this.setNoTickViewDistance(this.level.paperConfig.noTickViewDistance);
         this.playerViewDistanceTickMap = new com.destroystokyo.paper.util.misc.PlayerAreaMap(this.pooledLinkedPlayerHashSets,
@@ -1464,17 +1538,7 @@ 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 = SectionPos.blockToSectionCoord(player.getBlockX());
         int j = SectionPos.blockToSectionCoord(player.getBlockZ());
@@ -1629,7 +1693,7 @@ 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;
 
@@ -1673,7 +1737,37 @@ 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.sendChanges();
+            }
+        } 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();
 
@@ -1782,23 +1876,31 @@ Sections go from 0..16. Now whenever a section is not empty, it can potentially
         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.chunkPosition().equals(chunk.getPos())) {
-                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;
@@ -1877,6 +1979,42 @@ Sections go from 0..16. Now whenever a section is not empty, it can potentially
             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 (ServerPlayerConnection conn : this.seenBy.toArray(new ServerPlayerConnection[0])) { // avoid CME
+                if (newTrackerCandidates == null || !newTrackerCandidates.contains(conn)) {
+                    this.updatePlayer(conn.getPlayer());
+                }
+            }
+        }
+        // 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;
         }
@@ -1962,7 +2100,7 @@ Sections go from 0..16. Now whenever a section is not empty, it can potentially
                 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/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
index 677124d720105e9bda9d05a1fcc46ce10f44539d..fe4b09f82d36e5d7e109c86e8f4c003e92ba4e9d 100644
--- a/src/main/java/net/minecraft/world/entity/Entity.java
+++ b/src/main/java/net/minecraft/world/entity/Entity.java
@@ -50,6 +50,7 @@ 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.ServerLevel;
 import net.minecraft.server.level.ServerPlayer;
@@ -343,6 +344,21 @@ public abstract class Entity implements Nameable, EntityAccess, CommandSource, n
     }
     // 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 = ImmutableList.of();
diff --git a/src/main/java/org/spigotmc/TrackingRange.java b/src/main/java/org/spigotmc/TrackingRange.java
index 24b1dfcf91d36947c87e9e5c2524317f8775ba95..e5bcbfe175a697e04886d04543e1278b7e83a184 100644
--- a/src/main/java/org/spigotmc/TrackingRange.java
+++ b/src/main/java/org/spigotmc/TrackingRange.java
@@ -24,6 +24,7 @@ public class TrackingRange
         {
             return 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 )
         {
@@ -47,8 +48,48 @@ 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
 }