Paper/Spigot-Server-Patches/0502-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/Entity.java b/src/main/java/net/minecraft/server/Entity.java
index 6dea557fa32fd44674bf01e2f7429c9691c315b8..c005734f835fd07b121fdb885d981e55f8be81b4 100644
--- a/src/main/java/net/minecraft/server/Entity.java
+++ b/src/main/java/net/minecraft/server/Entity.java
@@ -245,6 +245,21 @@ public abstract class Entity implements INamableTileEntity, ICommandListener, Ke
     }
     // Paper end
 
+    // Paper start - optimise entity tracking
+    final org.spigotmc.TrackingRange.TrackingRangeType trackingRangeType = org.spigotmc.TrackingRange.getTrackingRangeType(this);
+
+    boolean isLegacyTrackingEntity = false;
+
+    public final void setLegacyTrackingEntity(final boolean isLegacyTrackingEntity) {
+        this.isLegacyTrackingEntity = isLegacyTrackingEntity;
+    }
+
+    final com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<EntityPlayer> getPlayersInTrackRange() {
+        return ((WorldServer)this.world).getChunkProvider().playerChunkMap.playerEntityTrackerTrackMaps[this.trackingRangeType.ordinal()]
+            .getObjectsInRange(MCUtil.getCoordinateKey(this));
+    }
+    // Paper end - optimise entity tracking
+
     public Entity(EntityTypes<?> entitytypes, World world) {
         this.id = Entity.entityCount.incrementAndGet();
         this.passengers = Lists.newArrayList();
diff --git a/src/main/java/net/minecraft/server/EntityTrackerEntry.java b/src/main/java/net/minecraft/server/EntityTrackerEntry.java
index 3a88c9a67062eb73ad8257ea786efca7e7e99f65..6d3b34ead9cc95dcc1152dffa8c6c4a8c7f1d58b 100644
--- a/src/main/java/net/minecraft/server/EntityTrackerEntry.java
+++ b/src/main/java/net/minecraft/server/EntityTrackerEntry.java
@@ -70,6 +70,7 @@ public class EntityTrackerEntry {
         this.r = entity.onGround;
     }
 
+    public final void tick() { this.a(); } // Paper - OBFHELPER
     public void a() {
         List<Entity> list = this.tracker.getPassengers();
 
diff --git a/src/main/java/net/minecraft/server/PlayerChunkMap.java b/src/main/java/net/minecraft/server/PlayerChunkMap.java
index bdf835397aa691c41280f65a7785e777791b2891..3d31f00a22233bd885496d7aac34eb2b634c40e8 100644
--- a/src/main/java/net/minecraft/server/PlayerChunkMap.java
+++ b/src/main/java/net/minecraft/server/PlayerChunkMap.java
@@ -120,21 +120,51 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.d {
 
     // Paper start - distance maps
     private final com.destroystokyo.paper.util.misc.PooledLinkedHashSets<EntityPlayer> 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();
+    final com.destroystokyo.paper.util.misc.PlayerAreaMap[] playerEntityTrackerTrackMaps;
+    final int[] entityTrackerTrackRanges;
+    // Paper end - use distance map to optimise tracker
 
     void addPlayerToDistanceMaps(EntityPlayer player) {
         int chunkX = MCUtil.getChunkCoordinate(player.locX());
         int chunkZ = MCUtil.getChunkCoordinate(player.locZ());
         // 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(EntityPlayer 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(EntityPlayer player) {
         int chunkX = MCUtil.getChunkCoordinate(player.locX());
         int chunkZ = MCUtil.getChunkCoordinate(player.locZ());
         // 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
     }
 
 
@@ -172,6 +202,44 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.d {
         this.m = new VillagePlace(new File(this.w, "poi"), datafixer, this.world); // Paper
         this.setViewDistance(i);
         this.playerMobDistanceMap = this.world.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.world.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 = 10 * 16; // default is 10 chunk range // TODO check on update
+                    break;
+                default:
+                    throw new IllegalStateException("Missing case for enum " + trackingRangeType);
+            }
+
+            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) {
@@ -1423,17 +1491,7 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.d {
     }
 
     public void movePlayer(EntityPlayer entityplayer) {
-        ObjectIterator objectiterator = this.trackedEntities.values().iterator();
-
-        while (objectiterator.hasNext()) {
-            PlayerChunkMap.EntityTracker playerchunkmap_entitytracker = (PlayerChunkMap.EntityTracker) objectiterator.next();
-
-            if (playerchunkmap_entitytracker.tracker == entityplayer) {
-                playerchunkmap_entitytracker.track(this.world.getPlayers());
-            } else {
-                playerchunkmap_entitytracker.updatePlayer(entityplayer);
-            }
-        }
+        // Paper - delay this logic for the entity tracker tick, no need to duplicate it
 
         int i = MathHelper.floor(entityplayer.locX()) >> 4;
         int j = MathHelper.floor(entityplayer.locZ()) >> 4;
@@ -1550,7 +1608,7 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.d {
 
                     entity.tracker = playerchunkmap_entitytracker; // Paper - Fast access to tracker
                     this.trackedEntities.put(entity.getId(), playerchunkmap_entitytracker);
-                    playerchunkmap_entitytracker.track(this.world.getPlayers());
+                    playerchunkmap_entitytracker.updatePlayers(entity.getPlayersInTrackRange()); // Paper - don't search all players
                     if (entity instanceof EntityPlayer) {
                         EntityPlayer entityplayer = (EntityPlayer) entity;
 
@@ -1594,7 +1652,37 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.d {
         entity.tracker = null; // Paper - We're no longer tracked
     }
 
+    // Paper start - optimised tracker
+    private final void processTrackQueue() {
+        this.world.timings.tracker1.startTiming();
+        try {
+            for (EntityTracker tracker : this.trackedEntities.values()) {
+                // update tracker entry
+                tracker.updatePlayers(tracker.tracker.getPlayersInTrackRange());
+            }
+        } finally {
+            this.world.timings.tracker1.stopTiming();
+        }
+
+
+        this.world.timings.tracker2.startTiming();
+        try {
+            for (EntityTracker tracker : this.trackedEntities.values()) {
+                tracker.trackerEntry.tick();
+            }
+        } finally {
+            this.world.timings.tracker2.stopTiming();
+        }
+    }
+    // Paper end - optimised tracker
+
     protected void g() {
+        // Paper start - optimized tracker
+        if (true) {
+            this.processTrackQueue();
+            return;
+        }
+        // Paper end - optimized tracker
         List<EntityPlayer> list = Lists.newArrayList();
         List<EntityPlayer> list1 = this.world.getPlayers();
 
@@ -1662,23 +1750,31 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.d {
         PacketDebug.a(this.world, chunk.getPos());
         List<Entity> list = Lists.newArrayList();
         List<Entity> list1 = Lists.newArrayList();
-        ObjectIterator objectiterator = this.trackedEntities.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 == entityplayer) {
+                continue;
+            }
+            PlayerChunkMap.EntityTracker tracker = this.trackedEntities.get(entity.getId());
+            if (tracker != null) { // dumb plugins... move on...
+                tracker.updatePlayer(entityplayer);
+            }
 
-        while (objectiterator.hasNext()) {
-            PlayerChunkMap.EntityTracker playerchunkmap_entitytracker = (PlayerChunkMap.EntityTracker) objectiterator.next();
-            Entity entity = playerchunkmap_entitytracker.tracker;
+            // 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 != entityplayer && entity.chunkX == chunk.getPos().x && entity.chunkZ == chunk.getPos().z) {
-                playerchunkmap_entitytracker.updatePlayer(entityplayer);
-                if (entity instanceof EntityInsentient && ((EntityInsentient) entity).getLeashHolder() != null) {
-                    list.add(entity);
-                }
+            if (entity instanceof EntityInsentient && ((EntityInsentient)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;
@@ -1716,7 +1812,7 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.d {
 
     public class EntityTracker {
 
-        private final EntityTrackerEntry trackerEntry;
+        final EntityTrackerEntry trackerEntry; // Paper - private -> package private
         private final Entity tracker;
         private final int trackingDistance;
         private SectionPosition e;
@@ -1733,6 +1829,42 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.d {
             this.e = SectionPosition.a(entity);
         }
 
+        // Paper start - use distance map to optimise tracker
+        com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<EntityPlayer> lastTrackerCandidates;
+
+        final void updatePlayers(com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<EntityPlayer> newTrackerCandidates) {
+            com.destroystokyo.paper.util.misc.PooledLinkedHashSets.PooledObjectLinkedOpenHashSet<EntityPlayer> 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 EntityPlayer)) {
+                        continue;
+                    }
+                    EntityPlayer player = (EntityPlayer)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 (EntityPlayer player : this.trackedPlayers.toArray(new EntityPlayer[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 PlayerChunkMap.EntityTracker ? ((PlayerChunkMap.EntityTracker) object).tracker.getId() == this.tracker.getId() : false;
         }
@@ -1829,7 +1961,7 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.d {
                 int j = entity.getEntityType().getChunkRange() * 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/org/spigotmc/TrackingRange.java b/src/main/java/org/spigotmc/TrackingRange.java
index 765bdaf9b525a989ec8d37a2fe856dcfcbd06782..43b5ed8e396e5312f7de1f160f596f58baead28a 100644
--- a/src/main/java/org/spigotmc/TrackingRange.java
+++ b/src/main/java/org/spigotmc/TrackingRange.java
@@ -49,4 +49,43 @@ public class TrackingRange
             return config.otherTrackingRange;
         }
     }
+
+    // Paper start - optimise entity tracking
+    // copied from above, TODO check on update
+    public static TrackingRangeType getTrackingRangeType(Entity entity)
+    {
+        if ( entity instanceof EntityPlayer )
+        {
+            return TrackingRangeType.PLAYER;
+            // Paper start - Simplify and set water mobs to animal tracking range
+        }
+        switch (entity.activationType) {
+            case RAIDER:
+            case MONSTER:
+                return TrackingRangeType.MONSTER;
+            case WATER:
+            case ANIMAL:
+                return TrackingRangeType.ANIMAL;
+            case MISC:
+        }
+        if ( entity instanceof EntityItemFrame || entity instanceof EntityPainting || entity instanceof EntityItem || entity instanceof EntityExperienceOrb )
+        // Paper end
+        {
+            return TrackingRangeType.MISC;
+        } else
+        {
+            if (entity instanceof EntityEnderDragon) return TrackingRangeType.ENDERDRAGON; // Paper - enderdragon is exempt
+            return TrackingRangeType.OTHER;
+        }
+    }
+
+    public static enum TrackingRangeType {
+        PLAYER,
+        ANIMAL,
+        MONSTER,
+        MISC,
+        OTHER,
+        ENDERDRAGON;
+    }
+    // Paper end - optimise entity tracking
 }