PaperMC/patches/server/0251-Optimize-MappedRegistry.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sun, 26 Aug 2018 20:49:50 -0400
Subject: [PATCH] Optimize MappedRegistry

Use larger initial sizes to increase bucket capacity on the BiMap

BiMap.get was seen to be using a good bit of CPU time.

diff --git a/src/main/java/net/minecraft/core/MappedRegistry.java b/src/main/java/net/minecraft/core/MappedRegistry.java
index 3b9eb0d19623a8a8e60f785edfd2faadba54ce84..0ae87b1ee3373a7eead633fa2a85d64f8d88bcaf 100644
--- a/src/main/java/net/minecraft/core/MappedRegistry.java
+++ b/src/main/java/net/minecraft/core/MappedRegistry.java
@@ -38,12 +38,10 @@ public class MappedRegistry<T> extends WritableRegistry<T> {
 
     protected static final Logger LOGGER = LogManager.getLogger();
     private final ObjectList<T> byId = new ObjectArrayList(256);
-    private final Object2IntMap<T> toId = (Object2IntMap) Util.make(new Object2IntOpenCustomHashMap(Util.identityStrategy()), (object2intopencustomhashmap) -> {
-        object2intopencustomhashmap.defaultReturnValue(-1);
-    });
-    private final BiMap<ResourceLocation, T> storage = HashBiMap.create();
-    private final BiMap<ResourceKey<T>, T> keyStorage = HashBiMap.create();
-    private final Map<T, Lifecycle> lifecycles = Maps.newIdentityHashMap();
+    private final it.unimi.dsi.fastutil.objects.Reference2IntOpenHashMap<T> toId = new it.unimi.dsi.fastutil.objects.Reference2IntOpenHashMap<T>(2048);// Paper - use bigger expected size to reduce collisions and direct intent for FastUtil to be identity map
+    private final BiMap<ResourceLocation, T> storage = HashBiMap.create(2048); // Paper - use bigger expected size to reduce collisions
+    private final BiMap<ResourceKey<T>, T> keyStorage = HashBiMap.create(2048); // Paper - use bigger expected size to reduce collisions
+    private final Map<T, Lifecycle> lifecycles = new java.util.IdentityHashMap<>(2048); // Paper - use bigger expected size to reduce collisions
     private Lifecycle elementsLifecycle;
     @Nullable
     protected Object[] randomCache;
@@ -52,6 +50,7 @@ public class MappedRegistry<T> extends WritableRegistry<T> {
     public MappedRegistry(ResourceKey<? extends Registry<T>> key, Lifecycle lifecycle) {
         super(key, lifecycle);
         this.elementsLifecycle = lifecycle;
+        this.toId.defaultReturnValue(-1); // Paper
     }
 
     public static <T> MapCodec<MappedRegistry.RegistryEntry<T>> withNameAndId(ResourceKey<? extends Registry<T>> key, MapCodec<T> entryCodec) {