From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: MrPowerGamerBR <git@mrpowergamerbr.com>
Date: Sat, 18 Nov 2023 21:04:53 -0300
Subject: [PATCH] Avoid unnecessary ItemFrame#getItem() calls

When ticking a item frame, on each tick, it checks if the item on the item frame is a map and, if it is, it adds the map to be carried by the entity player

However, the "getItem()" call is a bit expensive, especially because this is only really used if the item in the item frame is a map

We can avoid this call by checking if the "cachedMapId" is not null

diff --git a/src/main/java/net/minecraft/server/level/ServerEntity.java b/src/main/java/net/minecraft/server/level/ServerEntity.java
index aedf24ba0d64de855a59869052cbc2704e7dc134..f49585cfd485eed504e91887599ff25c3238c8fd 100644
--- a/src/main/java/net/minecraft/server/level/ServerEntity.java
+++ b/src/main/java/net/minecraft/server/level/ServerEntity.java
@@ -115,13 +115,14 @@ public class ServerEntity {
             ItemFrame entityitemframe = (ItemFrame) entity;
 
             if (true || this.tickCount % 10 == 0) { // CraftBukkit - Moved below, should always enter this block
-                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
+                if (this.level.paperConfig().maps.itemFrameCursorUpdateInterval > 0 && this.tickCount % this.level.paperConfig().maps.itemFrameCursorUpdateInterval == 0 && entityitemframe.cachedMapId != null) { // 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 // SparklyPaper - avoid unnecessary ItemFrame#getItem() calls
                     Integer integer = entityitemframe.cachedMapId; // Paper
                     MapItemSavedData worldmap = MapItem.getSavedData(integer, this.level);
 
                     if (worldmap != null) {
+                        // SparklyPaper start - avoid unnecessary ItemFrame#getItem() calls
+                        ItemStack itemstack = entityitemframe.getItem();
+                        if (itemstack.getItem() instanceof MapItem) { // fail-safe, what if the cached map ID is present but the item isn't a MapItem? (this should NEVER happen but, who knows)
                         Iterator<ServerPlayerConnection> iterator = this.trackedPlayers.iterator(); // CraftBukkit
 
                         while (iterator.hasNext()) {
@@ -134,6 +135,7 @@ public class ServerEntity {
                                 entityplayer.connection.send(packet);
                             }
                         }
+                        } // SparklyPaper end
                     }
                 }
 
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 759ecd79534a7706f7d4a63eb9dacbefcfe54674..07739c3d74074b2668466250f944dfbe22d4dc86 100644
--- a/src/main/java/net/minecraft/world/entity/decoration/ItemFrame.java
+++ b/src/main/java/net/minecraft/world/entity/decoration/ItemFrame.java
@@ -50,7 +50,8 @@ public class ItemFrame extends HangingEntity {
     public static final int NUM_ROTATIONS = 8;
     public float dropChance;
     public boolean fixed;
-    public Integer cachedMapId; // Paper
+    @Nullable // SparklyPaper - avoid unnecessary ItemFrame#getItem() calls
+    public Integer cachedMapId = null; // Paper // SparklyPaper - avoid unnecessary ItemFrame#getItem() calls
 
     public ItemFrame(EntityType<? extends ItemFrame> type, Level world) {
         super(type, world);