Paper/Spigot-Server-Patches/0379-Performance-improvement-for-Chunk.getEntities.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: wea_ondara <wea_ondara@alpenblock.net>
Date: Thu, 10 Oct 2019 11:29:42 +0200
Subject: [PATCH] Performance improvement for Chunk.getEntities

This patch aims to reduce performance cost used by collecting the
entities of a chunk. Previously the entitySlices were copied into an
extra array with List.toArray() with is a costly and unneccessary
operation. This patch will reduce the load of plugins which for example
implement custom moblimits and depend on Chunk.getEntities().

diff --git a/src/main/java/org/bukkit/craftbukkit/CraftChunk.java b/src/main/java/org/bukkit/craftbukkit/CraftChunk.java
index f09e783e38bbe4d8e825abf77884b9cb307bcce4..531d5e41dfbfbfe8da0676207f6325a0bca97a9a 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftChunk.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftChunk.java
@@ -117,14 +117,14 @@ public class CraftChunk implements Chunk {
         Entity[] entities = new Entity[count];
 
         for (int i = 0; i < 16; i++) {
-
-            for (Object obj : chunk.entitySlices[i].toArray()) {
-                if (!(obj instanceof net.minecraft.server.Entity)) {
+            // Paper start - speed up (was with chunk.entitySlices[i].toArray() and cast checks which costs a lot of performance if called often)
+            for (net.minecraft.server.Entity entity : chunk.entitySlices[i]) {
+                if (entity == null) {
                     continue;
                 }
-
-                entities[index++] = ((net.minecraft.server.Entity) obj).getBukkitEntity();
+                entities[index++] = entity.getBukkitEntity();
             }
+            // Paper end
         }
 
         return entities;