From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Sun, 20 Sep 2020 16:10:49 -0700
Subject: [PATCH] Make sure inlined getChunkAt has inlined logic for loaded
 chunks

Tux did some profiling some time ago and showed that the
previous getChunkAt method which had inlined logic for loaded
chunks did get inlined, but the standard CPS.getChunkAt
method was not inlined.

diff --git a/src/main/java/net/minecraft/world/level/Level.java b/src/main/java/net/minecraft/world/level/Level.java
index 2069cad866a3fd2ed5512fa8fc6dc2ef8bc9758e..7718db906ed1b97f1b55a891c2ea3b59ac1307fb 100644
--- a/src/main/java/net/minecraft/world/level/Level.java
+++ b/src/main/java/net/minecraft/world/level/Level.java
@@ -458,6 +458,15 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
 
     @Override
     public final LevelChunk getChunk(int chunkX, int chunkZ) { // Paper - final to help inline
+        // Paper start - Perf: make sure loaded chunks get the inlined variant of this function
+        net.minecraft.server.level.ServerChunkCache cps = ((ServerLevel)this).getChunkSource();
+        if (cps.mainThread == Thread.currentThread()) {
+            LevelChunk ifLoaded = cps.getChunkAtIfLoadedMainThread(chunkX, chunkZ);
+            if (ifLoaded != null) {
+                return ifLoaded;
+            }
+        }
+        // Paper end - Perf: make sure loaded chunks get the inlined variant of this function
         return (LevelChunk) this.getChunk(chunkX, chunkZ, ChunkStatus.FULL, true); // Paper - avoid a method jump
     }