From 005dac3ad5e821f19272ed003a8b4df9aac6e56f Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Wed, 30 Mar 2016 02:13:24 -0400
Subject: [PATCH] Use FastUtil Int HashMap for DataWatcher

For DataWatcher, swap out plain Integer key HashMap for a Int2ObjectOpenHashMap

These collections are super fast as seen
http://java-performance.info/hashmap-overview-jdk-fastutil-goldman-sachs-hppc-koloboke-trove-january-2015/

diff --git a/src/main/java/net/minecraft/server/DataWatcher.java b/src/main/java/net/minecraft/server/DataWatcher.java
index f1c62ec..68a0565 100644
--- a/src/main/java/net/minecraft/server/DataWatcher.java
+++ b/src/main/java/net/minecraft/server/DataWatcher.java
@@ -11,13 +11,14 @@ import java.util.List;
 import java.util.Map;
 import java.util.concurrent.locks.ReadWriteLock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
+import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap; // Paper
 import org.apache.commons.lang3.ObjectUtils;
 
 public class DataWatcher {
 
     private static final Map<Class<? extends Entity>, Integer> a = Maps.newHashMap();
     private final Entity b;
-    private final Map<Integer, DataWatcher.Item<?>> c = Maps.newHashMap();
+    private final Map<Integer, DataWatcher.Item<?>> c = new Int2ObjectOpenHashMap<>(); // Paper
     private final ReadWriteLock d = new ReentrantReadWriteLock();
     private boolean e = true;
     private boolean f;
-- 
2.8.0