PaperMC/patches/server/0245-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 33990e4f9b5e7e3d8080c80f639b81b7f798c859..6ef235aa9ea8ea2baec335f99f8368dbfc55a10e 100644
--- a/src/main/java/net/minecraft/core/MappedRegistry.java
+++ b/src/main/java/net/minecraft/core/MappedRegistry.java
@@ -35,13 +35,11 @@ public class MappedRegistry<T> implements WritableRegistry<T> {
     private static final Logger LOGGER = LogUtils.getLogger();
     final ResourceKey<? extends Registry<T>> key;
     private final ObjectList<Holder.Reference<T>> byId = new ObjectArrayList<>(256);
-    private final Reference2IntMap<T> toId = Util.make(new Reference2IntOpenHashMap<>(), (map) -> {
-        map.defaultReturnValue(-1);
-    });
-    private final Map<ResourceLocation, Holder.Reference<T>> byLocation = new HashMap<>();
-    private final Map<ResourceKey<T>, Holder.Reference<T>> byKey = new HashMap<>();
-    private final Map<T, Holder.Reference<T>> byValue = new IdentityHashMap<>();
-    private final Map<T, Lifecycle> lifecycles = new IdentityHashMap<>();
+    private final Reference2IntMap<T> toId = new Reference2IntOpenHashMap<T>(2048);// Paper - use bigger expected size to reduce collisions and direct intent for FastUtil to be identity map
+    private final Map<ResourceLocation, Holder.Reference<T>> byLocation = new HashMap<>(2048); // Paper - use bigger expected size to reduce collisions
+    private final Map<ResourceKey<T>, Holder.Reference<T>> byKey = new HashMap<>(2048); // Paper - use bigger expected size to reduce collisions
+    private final Map<T, Holder.Reference<T>> byValue = new IdentityHashMap<>(2048); // Paper - use bigger expected size to reduce collisions
+    private final Map<T, Lifecycle> lifecycles = new IdentityHashMap<>(2048); // Paper - use bigger expected size to reduce collisions
     private Lifecycle registryLifecycle;
     private volatile Map<TagKey<T>, HolderSet.Named<T>> tags = new IdentityHashMap<>();
     private boolean frozen;
@@ -87,6 +85,7 @@ public class MappedRegistry<T> implements WritableRegistry<T> {
     }
 
     public MappedRegistry(ResourceKey<? extends Registry<T>> key, Lifecycle lifecycle, boolean intrusive) {
+        this.toId.defaultReturnValue(-1); // Paper
         this.key = key;
         this.registryLifecycle = lifecycle;
         if (intrusive) {