Paper/Spigot-Server-Patches/0333-Add-entity-count-cache.patch

From 5b101db469123c2f92ff82fc04a8b77274296bcf Mon Sep 17 00:00:00 2001
From: Colin Godsey <crgodsey@gmail.com>
Date: Wed, 8 Aug 2018 10:10:06 -0600
Subject: [PATCH] Add entity count cache


diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index d6b56d685..3d973deb7 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -1034,6 +1034,14 @@ public abstract class MinecraftServer implements IAsyncTaskHandler, IMojangStati
                 }
                 // CraftBukkit end */
 
+                /*
+                 * Paper - clear count cache every once in a while.
+                 * Cache can never be entirely trusted because
+                 * an entity may become persistent or not
+                 * during its lifetime.
+                 */
+                if (this.ticks % 600 == 0) worldserver.clearEntityCountCache();
+
                 this.methodProfiler.a("tick");
 
                 CrashReport crashreport;
diff --git a/src/main/java/net/minecraft/server/SpawnerCreature.java b/src/main/java/net/minecraft/server/SpawnerCreature.java
index f525fd1b4..494759a1c 100644
--- a/src/main/java/net/minecraft/server/SpawnerCreature.java
+++ b/src/main/java/net/minecraft/server/SpawnerCreature.java
@@ -113,7 +113,7 @@ public final class SpawnerCreature {
                 // CraftBukkit end
 
                 if ((!enumcreaturetype.c() || flag1) && (enumcreaturetype.c() || flag) && (!enumcreaturetype.d() || flag2)) {
-                    k = worldserver.a(enumcreaturetype.a());
+                    k = worldserver.getCreatureCount(enumcreaturetype); // Paper - entity count cache
                     int l1 = limit * i / b; // CraftBukkit - use per-world limits
 
                     if (k <= l1) {
diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index 004c3ec47..baf73a411 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -1,28 +1,20 @@
 	package net.minecraft.server;
 
-import co.aikar.timings.Timings;
 import com.destroystokyo.paper.event.server.ServerExceptionEvent;
 import com.destroystokyo.paper.exception.ServerInternalException;
 import com.google.common.base.MoreObjects;
 import com.google.common.collect.Lists;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Random;
-import java.util.UUID;
+
+import java.util.*;
 
 import java.util.function.Function;
 import java.util.function.Predicate;
-import java.util.function.Supplier;
 import javax.annotation.Nullable;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
 // CraftBukkit start
 import com.google.common.collect.Maps;
-import java.util.HashMap; // Paper
-import java.util.Map;
 import org.bukkit.Bukkit;
 import org.bukkit.block.BlockState;
 import org.bukkit.craftbukkit.CraftServer;
@@ -30,16 +22,11 @@ import org.bukkit.craftbukkit.CraftWorld;
 import org.bukkit.craftbukkit.block.CraftBlockState;
 import org.bukkit.craftbukkit.block.data.CraftBlockData;
 import org.bukkit.craftbukkit.event.CraftEventFactory;
-import org.bukkit.craftbukkit.util.CraftMagicNumbers;
-import org.bukkit.craftbukkit.util.LongHashSet; // Paper
-import org.bukkit.entity.Player;
-import org.bukkit.event.block.BlockCanBuildEvent;
 import org.bukkit.event.block.BlockPhysicsEvent;
 import org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason;
 import org.bukkit.generator.ChunkGenerator;
 // CraftBukkit end
 // Paper start
-import java.util.Set;
 import com.google.common.collect.Sets;
 // Paper end
 public abstract class World implements GeneratorAccess, IIBlockAccess, AutoCloseable {
@@ -50,10 +37,41 @@ public abstract class World implements GeneratorAccess, IIBlockAccess, AutoClose
     // Spigot start - guard entity list from removals
     public final List<Entity> entityList = new java.util.ArrayList<Entity>()
     {
+        // Paper start - entity count cache
+        @Override
+        public boolean addAll(Collection<? extends Entity> c) {
+            for (Entity e : c) {
+                updateEntityCount(e, true);
+            }
+
+            return super.addAll(c);
+        }
+
+        @Override
+        public boolean removeAll(Collection<?> c) {
+            for (Object e : c) {
+                if (e instanceof Entity) {
+                    updateEntityCount((Entity)e, false);
+                }
+            }
+
+            return super.removeAll(c);
+        }
+
+        @Override
+        public boolean add(Entity e) {
+            updateEntityCount(e, true);
+
+            return super.add(e);
+        }
+
+        // Paper end
+
         @Override
         public Entity remove(int index)
         {
             guard();
+            updateEntityCount(get(index), false); // Paper
             return super.remove( index );
         }
 
@@ -61,6 +79,7 @@ public abstract class World implements GeneratorAccess, IIBlockAccess, AutoClose
         public boolean remove(Object o)
         {
             guard();
+            if (o instanceof Entity) updateEntityCount((Entity)o, false); // Paper
             return super.remove( o );
         }
 
@@ -82,6 +101,7 @@ public abstract class World implements GeneratorAccess, IIBlockAccess, AutoClose
     public final Map<String, EntityHuman> playersByName = Maps.newHashMap(); // Paper - World EntityHuman Lookup Optimizations
     public final List<Entity> k = Lists.newArrayList();
     protected final IntHashMap<Entity> entitiesById = new IntHashMap();
+    private Map<EnumCreatureType, Integer> countCache = new EnumMap(EnumCreatureType.class); // Paper - entity count cache
     private final long G = 16777215L;
     private int H; public int getSkylightSubtracted() { return this.H; } public void setSkylightSubtracted(int value) { this.H = value;} // Paper - OBFHELPER
     protected int m = (new Random()).nextInt();
@@ -2439,6 +2459,7 @@ public abstract class World implements GeneratorAccess, IIBlockAccess, AutoClose
 
     }
 
+    public int getEntityCount(Class<?> oclass) { return a(oclass); } // Paper - OBFHELPER
     public int a(Class<?> oclass) {
         int i = 0;
         Iterator iterator = this.entityList.iterator();
@@ -2464,6 +2485,61 @@ public abstract class World implements GeneratorAccess, IIBlockAccess, AutoClose
         return i;
     }
 
+    // Paper start - entity count cache
+    public int getCreatureCount(EnumCreatureType typ) {
+        Integer count = countCache.get(typ);
+
+        if (count == null) {
+            count = getEntityCount(typ.a());
+
+            countCache.put(typ, count);
+        }
+
+        return count;
+    }
+
+    void clearEntityCountCache() {
+        countCache.clear();
+    }
+
+    protected void updateEntityCount(EnumCreatureType typ, boolean incr) {
+        Integer countObject = countCache.get(typ);
+
+        if (countObject == null) return;
+
+        int count = countObject;
+
+        if (incr) count++;
+        else count--;
+
+        if (count < 0) {
+            e.warn("Entity count cache has gone negative");
+            count = 0;
+        }
+
+        countCache.put(typ, count);
+    }
+
+    protected void updateEntityCount(Entity entity, boolean incr) {
+        if (entity == null || !(entity instanceof IAnimal)) return;
+
+        if (entity instanceof EntityInsentient) {
+            EntityInsentient entityinsentient = (EntityInsentient) entity;
+            if (entityinsentient.isTypeNotPersistent() && entityinsentient.isPersistent()) {
+                return;
+            }
+        }
+
+        Class<?> clazz = entity.getClass();
+
+        for (EnumCreatureType typ : EnumCreatureType.values()) {
+            if (typ.a().isAssignableFrom(clazz)) {
+                updateEntityCount(typ, incr);
+            }
+        }
+    }
+    // Paper end
+
     public void addChunkEntities(Collection<Entity> collection) { a(collection); } // Paper - OBFHELPER
     public void a(Collection<Entity> collection) {
         org.spigotmc.AsyncCatcher.catchOp( "entity world add"); // Spigot
-- 
2.15.2 (Apple Git-101.1)