From 6cd1c78e821326bfd011a8a7b3f2394bb383268d Mon Sep 17 00:00:00 2001
From: Nassim Jahnke <nassim@njahnke.dev>
Date: Fri, 7 Aug 2026 14:04:28 +0200
Subject: [PATCH] Use identity/enum maps for material maps

---
 .../org/bukkit/craftbukkit/block/CraftBlockStates.java |  3 ++-
 .../org/bukkit/craftbukkit/util/CraftMagicNumbers.java | 10 ++++++----
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/paper-server/src/main/java/org/bukkit/craftbukkit/block/CraftBlockStates.java b/paper-server/src/main/java/org/bukkit/craftbukkit/block/CraftBlockStates.java
index 6dcfe2cea0..063a4ad33d 100644
--- a/paper-server/src/main/java/org/bukkit/craftbukkit/block/CraftBlockStates.java
+++ b/paper-server/src/main/java/org/bukkit/craftbukkit/block/CraftBlockStates.java
@@ -2,6 +2,7 @@ package org.bukkit.craftbukkit.block;
 
 import com.google.common.base.Preconditions;
 import java.util.HashMap;
+import java.util.IdentityHashMap;
 import java.util.Map;
 import java.util.function.BiFunction;
 import javax.annotation.Nullable;
@@ -69,7 +70,7 @@ public final class CraftBlockStates {
         }
     }
 
-    private static final Map<Material, BlockStateFactory<?>> FACTORIES = new HashMap<>();
+    private static final Map<Material, BlockStateFactory<?>> FACTORIES = new IdentityHashMap<>();
     private static final BlockStateFactory<?> DEFAULT_FACTORY = new BlockStateFactory<>(CraftBlockState.class) {
         @Override
         public CraftBlockState createBlockState(World world, BlockPos pos, net.minecraft.world.level.block.state.BlockState state, BlockEntity blockEntity) {
diff --git a/paper-server/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java b/paper-server/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
index 051466ae23..80317dc41f 100644
--- a/paper-server/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
+++ b/paper-server/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
@@ -26,8 +26,10 @@ import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
+import java.util.EnumMap;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.IdentityHashMap;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
@@ -134,10 +136,10 @@ public final class CraftMagicNumbers implements UnsafeValues {
     }
 
     // ========================================================================
-    private static final Map<Block, Material> BLOCK_MATERIAL = new HashMap<>();
-    private static final Map<Item, Material> ITEM_MATERIAL = new HashMap<>();
-    private static final Map<Material, Item> MATERIAL_ITEM = new HashMap<>();
-    private static final Map<Material, Block> MATERIAL_BLOCK = new HashMap<>();
+    private static final Map<Block, Material> BLOCK_MATERIAL = new IdentityHashMap<>();
+    private static final Map<Item, Material> ITEM_MATERIAL = new IdentityHashMap<>();
+    private static final Map<Material, Item> MATERIAL_ITEM = new EnumMap<>(Material.class);
+    private static final Map<Material, Block> MATERIAL_BLOCK = new EnumMap<>(Material.class);
 
     static {
         for (Block block : BuiltInRegistries.BLOCK) {