From d0badaff2fdf04edf104e78702414937df7af010 Mon Sep 17 00:00:00 2001
From: Alfie Cleveland <alfeh@me.com>
Date: Fri, 25 Nov 2016 13:22:40 +0000
Subject: [PATCH] Optimise removeQueue


diff --git a/src/main/java/net/minecraft/server/EntityPlayer.java b/src/main/java/net/minecraft/server/EntityPlayer.java
index 5610c539a..ecdfd306b 100644
--- a/src/main/java/net/minecraft/server/EntityPlayer.java
+++ b/src/main/java/net/minecraft/server/EntityPlayer.java
@@ -4,7 +4,9 @@ import com.google.common.collect.Lists;
 import com.mojang.authlib.GameProfile;
 import com.mojang.datafixers.util.Either;
 import io.netty.util.concurrent.Future;
+import java.util.ArrayDeque; // Paper
 import java.util.Collection;
+import java.util.Deque; // Paper
 import java.util.Iterator;
 import java.util.List;
 import java.util.OptionalInt;
@@ -40,7 +42,7 @@ public class EntityPlayer extends EntityHuman implements ICrafting {
     public PlayerConnection playerConnection;
     public final MinecraftServer server;
     public final PlayerInteractManager playerInteractManager;
-    public final List<Integer> removeQueue = Lists.newLinkedList();
+    public final Deque<Integer> removeQueue = new ArrayDeque<>(); // Paper
     private final AdvancementDataPlayer advancementDataPlayer;
     private final ServerStatisticManager serverStatisticManager;
     private float lastHealthScored = Float.MIN_VALUE;
@@ -364,13 +366,20 @@ public class EntityPlayer extends EntityHuman implements ICrafting {
         while (!this.removeQueue.isEmpty()) {
             int i = Math.min(this.removeQueue.size(), Integer.MAX_VALUE);
             int[] aint = new int[i];
-            Iterator<Integer> iterator = this.removeQueue.iterator();
+            //Iterator<Integer> iterator = this.removeQueue.iterator(); // Paper
             int j = 0;
 
-            while (iterator.hasNext() && j < i) {
+            // Paper start
+            /* while (iterator.hasNext() && j < i) {
                 aint[j++] = (Integer) iterator.next();
                 iterator.remove();
+            } */
+
+            Integer integer;
+            while (j < i && (integer = this.removeQueue.poll()) != null) {
+                aint[j++] = integer.intValue();
             }
+            // Paper end
 
             this.playerConnection.sendPacket(new PacketPlayOutEntityDestroy(aint));
         }
@@ -1298,7 +1307,14 @@ public class EntityPlayer extends EntityHuman implements ICrafting {
         this.lastHealthSent = -1.0F;
         this.lastFoodSent = -1;
         // this.recipeBook.a((RecipeBook) entityplayer.recipeBook); // CraftBukkit
-        this.removeQueue.addAll(entityplayer.removeQueue);
+        // Paper start - Optimize remove queue - vanilla copies player objects, but CB doesn't. This method currently only
+        // Applies to the same player, so we need to not duplicate our removal queue. The rest of this method does "resetting"
+        // type logic so it does need to be called, maybe? This is silly.
+        //this.removeQueue.addAll(entityplayer.removeQueue);
+        if (this.removeQueue != entityplayer.removeQueue) {
+            this.removeQueue.addAll(entityplayer.removeQueue);
+        }
+        // Paper end
         this.cp = entityplayer.cp;
         this.cu = entityplayer.cu;
         this.setShoulderEntityLeft(entityplayer.getShoulderEntityLeft());
-- 
2.21.0