PaperMC/CraftBukkit-Patches/0026-Optimize-getTileEntities-performance.patch

From c0bce5effec9fed2726650b37ca5ef37f005e2c4 Mon Sep 17 00:00:00 2001
From: Mike Primm <mike@primmhome.com>
Date: Wed, 20 Feb 2013 23:07:53 -0500
Subject: [PATCH] Optimize getTileEntities performance

Avoid traversing tile entities for every loaded chunk
---
 src/main/java/net/minecraft/server/WorldServer.java | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/src/main/java/net/minecraft/server/WorldServer.java b/src/main/java/net/minecraft/server/WorldServer.java
index 6cb3e24..8f0050a 100644
--- a/src/main/java/net/minecraft/server/WorldServer.java
+++ b/src/main/java/net/minecraft/server/WorldServer.java
@@ -616,17 +616,20 @@ public class WorldServer extends World implements org.bukkit.BlockChangeDelegate
 
     public List getTileEntities(int i, int j, int k, int l, int i1, int j1) {
         ArrayList arraylist = new ArrayList();
-        // CraftBukkit start - use iterator
-        Iterator iterator = this.tileEntityList.iterator();
-
-        while (iterator.hasNext()) {
-            TileEntity tileentity = (TileEntity) iterator.next();
-            // CraftBukkit end
-
-            if (tileentity.x >= i && tileentity.y >= j && tileentity.z >= k && tileentity.x < l && tileentity.y < i1 && tileentity.z < j1) {
-                arraylist.add(tileentity);
+        // Spigot start - check in chunks: usually just from one
+        for (int cx = (i >> 4); cx <= ((l - 1) >> 4); cx++) {
+            for (int cz = (k >> 4); cz <= ((j1 - 1) >> 4); cz++) {
+                Chunk c = getChunkAt(cx, cz);
+                if (c == null) continue;
+                for (Object te : c.tileEntities.values()) {
+                    TileEntity tileentity = (TileEntity) te;
+                    if ((tileentity.x >= i) && (tileentity.y >= j) && (tileentity.z >= k) && (tileentity.x < l) && (tileentity.y < i1) && (tileentity.z < j1)) {
+                        arraylist.add(tileentity);
+                    }
+                }
             }
         }
+        // Spigot end
 
         return arraylist;
     }
-- 
1.8.1-rc2