From 6d92bd624a75098dfeae5b99362e4fd0e13df989 Mon Sep 17 00:00:00 2001
From: Alfie Cleveland <alfeh@me.com>
Date: Fri, 19 Aug 2016 01:52:56 +0100
Subject: [PATCH] Optimise BlockStateEnum hashCode and equals


diff --git a/src/main/java/net/minecraft/server/BlockStateEnum.java b/src/main/java/net/minecraft/server/BlockStateEnum.java
index 73623a21c5..9d8a03be8d 100644
--- a/src/main/java/net/minecraft/server/BlockStateEnum.java
+++ b/src/main/java/net/minecraft/server/BlockStateEnum.java
@@ -8,6 +8,7 @@ import java.util.Arrays;
 import java.util.Collection;
 import java.util.Map;
 import java.util.Optional;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
@@ -15,11 +16,17 @@ public class BlockStateEnum<T extends Enum<T> & INamable> extends BlockState<T>
     private final ImmutableSet<T> a;
     private final Map<String, T> b = Maps.newHashMap();
 
+    // Paper start - BlockStateEnum is a singleton, so we can use our own hashCode
+    private static AtomicInteger hashId = new AtomicInteger(1);
+    private int hashCode;
+    // Paper end
+
     protected BlockStateEnum(String s, Class<T> oclass, Collection<T> collection) {
         super(s, oclass);
         this.a = ImmutableSet.copyOf(collection);
 
-        for(Enum oenum : collection) {
+        this.hashCode = hashId.getAndIncrement() * 61; // Paper
+        for(T oenum : collection) { // Paper - decompile fix
             String s1 = ((INamable)oenum).getName();
             if (this.b.containsKey(s1)) {
                 throw new IllegalArgumentException("Multiple values have the same name '" + s1 + "'");
@@ -42,22 +49,14 @@ public class BlockStateEnum<T extends Enum<T> & INamable> extends BlockState<T>
         return ((INamable)oenum).getName();
     }
 
+    @Override // Paper start - override equals as BlockStateEnum is a singleton
     public boolean equals(Object object) {
-        if (this == object) {
-            return true;
-        } else if (object instanceof BlockStateEnum && super.equals(object)) {
-            BlockStateEnum blockstateenum1 = (BlockStateEnum)object;
-            return this.a.equals(blockstateenum1.a) && this.b.equals(blockstateenum1.b);
-        } else {
-            return false;
-        }
+       return this == object;
+        // Paper end - override equals as BlockStateEnum is a singleton
     }
 
     public int c() {
-        int i = super.c();
-        i = 31 * i + this.a.hashCode();
-        i = 31 * i + this.b.hashCode();
-        return i;
+        return hashCode; // Paper - hashCode method is final, but we can do this here
     }
 
     public static <T extends Enum<T> & INamable> BlockStateEnum<T> of(String s, Class<T> oclass) {
-- 
2.18.0