PaperMC/patches/server/0904-Cache-map-ids-on-item-frames.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Warrior <50800980+Warriorrrr@users.noreply.github.com>
Date: Mon, 7 Aug 2023 12:58:28 +0200
Subject: [PATCH] Cache map ids on item frames


diff --git a/src/main/java/net/minecraft/server/level/ServerEntity.java b/src/main/java/net/minecraft/server/level/ServerEntity.java
index 888cbfaf49aa6d1d1b8cc87cf411a1dd53fbe89d..c2a4fde17673a2bc3133aa0c68608c3da75d5cc5 100644
--- a/src/main/java/net/minecraft/server/level/ServerEntity.java
+++ b/src/main/java/net/minecraft/server/level/ServerEntity.java
@@ -118,7 +118,7 @@ public class ServerEntity {
                 ItemStack itemstack = entityitemframe.getItem();
 
                 if (this.level.paperConfig().maps.itemFrameCursorUpdateInterval > 0 && this.tickCount % this.level.paperConfig().maps.itemFrameCursorUpdateInterval == 0 && itemstack.getItem() instanceof MapItem) { // CraftBukkit - Moved this.tickCounter % 10 logic here so item frames do not enter the other blocks // Paper - Make item frame map cursor update interval configurable
-                    Integer integer = MapItem.getMapId(itemstack);
+                    Integer integer = entityitemframe.cachedMapId; // Paper - Perf: Cache map ids on item frames
                     MapItemSavedData worldmap = MapItem.getSavedData(integer, this.level);
 
                     if (worldmap != null) {
diff --git a/src/main/java/net/minecraft/world/entity/decoration/ItemFrame.java b/src/main/java/net/minecraft/world/entity/decoration/ItemFrame.java
index e875196824ef9618a52ca3f172f202d5584990df..c34701f95580e4cf45fe086115563127432a28c5 100644
--- a/src/main/java/net/minecraft/world/entity/decoration/ItemFrame.java
+++ b/src/main/java/net/minecraft/world/entity/decoration/ItemFrame.java
@@ -50,6 +50,7 @@ public class ItemFrame extends HangingEntity {
     public static final int NUM_ROTATIONS = 8;
     public float dropChance;
     public boolean fixed;
+    public Integer cachedMapId; // Paper - Perf: Cache map ids on item frames
 
     public ItemFrame(EntityType<? extends ItemFrame> type, Level world) {
         super(type, world);
@@ -388,6 +389,7 @@ public class ItemFrame extends HangingEntity {
     }
 
     private void onItemChanged(ItemStack stack) {
+        this.cachedMapId = MapItem.getMapId(stack); // Paper - Perf: Cache map ids on item frames
         if (!stack.isEmpty() && stack.getFrame() != this) {
             stack.setEntityRepresentation(this);
         }