Paper/Spigot-Server-Patches/0034-Optimize-TileEntity-Ticking.patch

From 6e7a139066c3fd9fa5274045d80aede527b636ab Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sun, 24 Aug 2014 21:35:11 -0400
Subject: [PATCH] Optimize TileEntity Ticking

Re-organizes the servers TileEntity Tick List to be bucketed based on their tick interval.

We now will not even store a Tile Entity that is known to not have any tick function
(half of them), skipping time spent iterating them and checking if they are valid
and in a loaded chunk. In other words, a lot of "meta" time wasted on tile entities
that would never do anything anyways.

Then by reducing chests to 1 in 20 ticks, we cut out 95% of isLoaded checks and findPlayer
calls on chests, and 100% of the checks for Signs, the 2 most popular Tile Entities.

This cuts out a massive amount of checks revolving around TileEntity ticking.
Servers with large amounts of TileEntities should see significant improvement.

Finally, this then spreads out the ticking of reduced-rate TileEntities so that they
do not all tick on the same tick, distributing the load of some TileEntities like Chest.

diff --git a/src/main/java/net/minecraft/server/TileEntity.java b/src/main/java/net/minecraft/server/TileEntity.java
index 3c5ec6f..27fedeb 100644
--- a/src/main/java/net/minecraft/server/TileEntity.java
+++ b/src/main/java/net/minecraft/server/TileEntity.java
@@ -56,6 +56,12 @@ public class TileEntity {
             }
         }
     }
+
+    // Optimized TileEntity Tick changes
+    private static int tileEntityCounter = 0;
+    public boolean isAdded = false;
+    public int tileId = tileEntityCounter++;
+
     // Spigot end
 
     public TileEntity() {}
diff --git a/src/main/java/net/minecraft/server/TileEntityBeacon.java b/src/main/java/net/minecraft/server/TileEntityBeacon.java
index 09313ea..198f908 100644
--- a/src/main/java/net/minecraft/server/TileEntityBeacon.java
+++ b/src/main/java/net/minecraft/server/TileEntityBeacon.java
@@ -45,7 +45,7 @@ public class TileEntityBeacon extends TileEntity implements IInventory {
     public TileEntityBeacon() {}
 
     public void h() {
-        if (this.world.getTime() % 80L == 0L) {
+        if (true || this.world.getTime() % 80L == 0L) { // PaperSpigot - controlled by Improved Tick handling
             this.y();
             this.x();
         }
diff --git a/src/main/java/net/minecraft/server/TileEntityChest.java b/src/main/java/net/minecraft/server/TileEntityChest.java
index c900caf..e27716b 100644
--- a/src/main/java/net/minecraft/server/TileEntityChest.java
+++ b/src/main/java/net/minecraft/server/TileEntityChest.java
@@ -255,7 +255,7 @@ public class TileEntityChest extends TileEntity implements IInventory {
         ++this.ticks;
         float f;
 
-        if (!this.world.isStatic && this.o != 0 && (this.ticks + this.x + this.y + this.z) % 200 == 0) {
+        if (!this.world.isStatic && this.o != 0 && (this.ticks + this.x + this.y + this.z) % 10 == 0) { // PaperSpigot Reduced 200 -> 10 interval due to reduced tick rate from Improved Tick Handling
             this.o = 0;
             f = 5.0F;
             List list = this.world.a(EntityHuman.class, AxisAlignedBB.a((double) ((float) this.x - f), (double) ((float) this.y - f), (double) ((float) this.z - f), (double) ((float) (this.x + 1) + f), (double) ((float) (this.y + 1) + f), (double) ((float) (this.z + 1) + f)));
diff --git a/src/main/java/net/minecraft/server/TileEntityEnderChest.java b/src/main/java/net/minecraft/server/TileEntityEnderChest.java
index b205ab7..d76a2b2 100644
--- a/src/main/java/net/minecraft/server/TileEntityEnderChest.java
+++ b/src/main/java/net/minecraft/server/TileEntityEnderChest.java
@@ -11,7 +11,7 @@ public class TileEntityEnderChest extends TileEntity {
 
     public void h() {
         super.h();
-        if (++this.k % 20 * 4 == 0) {
+        if (++this.k % 4 == 0) { // PaperSpigot Reduced (20 * 4) -> 4 interval due to reduced tick rate from Improved Tick Handling
             this.world.playBlockAction(this.x, this.y, this.z, Blocks.ENDER_CHEST, 1, this.j);
         }
 
diff --git a/src/main/java/net/minecraft/server/TileEntityLightDetector.java b/src/main/java/net/minecraft/server/TileEntityLightDetector.java
index 143cffb..de33df0 100644
--- a/src/main/java/net/minecraft/server/TileEntityLightDetector.java
+++ b/src/main/java/net/minecraft/server/TileEntityLightDetector.java
@@ -5,7 +5,7 @@ public class TileEntityLightDetector extends TileEntity {
     public TileEntityLightDetector() {}
 
     public void h() {
-        if (this.world != null && !this.world.isStatic && this.world.getTime() % 20L == 0L) {
+        if (this.world != null && !this.world.isStatic /*&& this.world.getTime() % 20L == 0L*/) { // PaperSpigot - interval controlled by Improved Tick Handling
             this.h = this.q();
             if (this.h instanceof BlockDaylightDetector) {
                 ((BlockDaylightDetector) this.h).e(this.world, this.x, this.y, this.z);
diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index 33c228b..3bf2af0 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -58,7 +58,7 @@ public abstract class World implements IBlockAccess {
     };
     // Spigot end
     protected List f = new ArrayList();
-    public Set tileEntityList = new HashSet(); // CraftBukkit - ArrayList -> HashSet
+    public Set tileEntityList = new org.spigotmc.WorldTileEntityList(this); // CraftBukkit - ArrayList -> HashSet
     private List a = new ArrayList();
     private List b = new ArrayList();
     public List players = new ArrayList();
diff --git a/src/main/java/org/spigotmc/WorldTileEntityList.java b/src/main/java/org/spigotmc/WorldTileEntityList.java
new file mode 100644
index 0000000..4e6b762
--- /dev/null
+++ b/src/main/java/org/spigotmc/WorldTileEntityList.java
@@ -0,0 +1,174 @@
+package org.spigotmc;
+
+import com.google.common.collect.ArrayListMultimap;
+import com.google.common.collect.Maps;
+import com.google.common.collect.Multimap;
+import net.minecraft.server.*;
+import net.minecraft.util.gnu.trove.map.hash.TObjectIntHashMap;
+
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Map;
+
+public class WorldTileEntityList extends HashSet<TileEntity> {
+    private static final TObjectIntHashMap<Class<? extends TileEntity>> tileEntityTickIntervals =
+        new TObjectIntHashMap<Class<? extends TileEntity>>() {{
+            // Use -1 for no ticking
+            // These TE's have empty tick methods, doing nothing. Never bother ticking them.
+            for (Class<? extends TileEntity> ignored : new Class[]{
+                TileEntityChest.class, // PaperSpigot - Don't tick chests either
+                TileEntityEnderChest.class, // PaperSpigot - Don't tick chests either
+                TileEntityRecordPlayer.class,
+                TileEntityDispenser.class,
+                TileEntityDropper.class,
+                TileEntitySign.class,
+                TileEntityNote.class,
+                TileEntityEnderPortal.class,
+                TileEntityCommand.class,
+                TileEntitySkull.class,
+                TileEntityComparator.class,
+                TileEntityFlowerPot.class
+            }) {
+                put(ignored, -1);
+            }
+
+            // does findPlayer lookup, so this helps performance to slow down
+            put(TileEntityEnchantTable.class, 20);
+
+            // Slow things down that players won't notice due to craftbukkit "wall time" patches.
+            // These need to be investigated further before they can be safely used here
+            //put(TileEntityFurnace.class, 20);
+            //put(TileEntityBrewingStand.class, 10);
+
+            // Vanilla controlled values - These are checks already done in vanilla, so don't tick on ticks we know
+            // won't do anything anyways
+            put(TileEntityBeacon.class, 80);
+            put(TileEntityLightDetector.class, 20);
+        }};
+    private static int getInterval(Class<? extends TileEntity> cls) {
+        int tickInterval = tileEntityTickIntervals.get(cls);
+        return tickInterval != 0 ? tickInterval : 1;
+    }
+
+    private static int getBucketId(TileEntity entity, Integer interval) {
+        return entity.tileId % interval;
+    }
+
+    private final Map<Integer, Multimap<Integer, TileEntity>> tickList = Maps.newHashMap();
+    private final WorldServer world;
+
+    public WorldTileEntityList(World world) {
+        this.world = (WorldServer) world;
+    }
+
+
+    private Multimap<Integer, TileEntity> getBucket(int interval) {
+        Multimap<Integer, TileEntity> intervalBucket = tickList.get(interval);
+        if (intervalBucket == null) {
+            intervalBucket = ArrayListMultimap.create();
+            tickList.put(interval, intervalBucket);
+        }
+        return intervalBucket;
+    }
+
+    /**
+     * Adds the TileEntity to the tick list only if it is expected to tick
+     */
+    @Override
+    public boolean add(TileEntity entity) {
+        if (entity.isAdded) {
+            return false;
+        }
+
+        int interval = getInterval(entity.getClass());
+        if (interval > 0) {
+            entity.isAdded = true;
+            int bucket = getBucketId(entity, interval);
+            Multimap<Integer, TileEntity> typeBucket = getBucket(interval);
+            return typeBucket.put(bucket, entity);
+        }
+        return false;
+    }
+
+    @Override
+    public boolean remove(Object o) {
+        if (!(o instanceof TileEntity)) {
+            return false;
+        }
+        TileEntity entity = (TileEntity) o;
+        if (!entity.isAdded) {
+            return false;
+        }
+        entity.isAdded = false;
+        int interval = getInterval(entity.getClass());
+        int bucket = getBucketId(entity, interval);
+        Multimap<Integer, TileEntity> typeBucket = getBucket(interval);
+        return typeBucket.remove(bucket, entity);
+    }
+
+    @Override
+    public Iterator iterator() {
+        return new WorldTileEntityIterator();
+    }
+
+    @Override
+    public boolean contains(Object o) {
+        return o instanceof TileEntity && ((TileEntity) o).isAdded;
+    }
+
+    private class WorldTileEntityIterator implements Iterator<TileEntity> {
+        private final Iterator<Map.Entry<Integer, Multimap<Integer, TileEntity>>> intervalIterator;
+        private Map.Entry<Integer, Multimap<Integer, TileEntity>> intervalMap = null;
+        private Iterator<TileEntity> listIterator = null;
+
+        protected WorldTileEntityIterator() {
+            intervalIterator = tickList.entrySet().iterator();
+            nextInterval();
+        }
+
+        private boolean nextInterval() {
+            listIterator = null;
+            if (intervalIterator.hasNext()) {
+                intervalMap = intervalIterator.next();
+
+                final Integer interval = intervalMap.getKey();
+                final Multimap<Integer, TileEntity> buckets = intervalMap.getValue();
+
+                int bucket = (int) (world.getTime() % interval);
+
+                if (!buckets.isEmpty() && buckets.containsKey(bucket)) {
+                    final Collection<TileEntity> tileList = buckets.get(bucket);
+
+                    if (tileList != null && !tileList.isEmpty()) {
+                        listIterator = tileList.iterator();
+                        return true;
+                    }
+                }
+            }
+
+            return false;
+
+        }
+
+        @Override
+        public boolean hasNext() {
+            do {
+                if (listIterator != null && listIterator.hasNext()) {
+                    return true;
+                }
+            } while (nextInterval());
+            return false;
+        }
+
+        @Override
+        public TileEntity next() {
+            return listIterator.next();
+        }
+
+        @Override
+        public void remove() {
+            listIterator.remove();
+        }
+    }
+}
-- 
1.9.1