From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: bluelhf <ilari.suhonen@gmail.com>
Date: Wed, 21 Sep 2022 23:05:55 +0200
Subject: [PATCH] StarlightPR Improve performance of ThreadedLevelLightEngine

Taken from https://github.com/PaperMC/Starlight/pull/160

diff --git a/src/main/java/ca/spottedleaf/starlight/common/light/StarLightInterface.java b/src/main/java/ca/spottedleaf/starlight/common/light/StarLightInterface.java
index ef8dcbb6bbc0769e9ccfdadb05e6a46c070eda98..9a5fa60cb8156fe254a123e237d957ccb82f7195 100644
--- a/src/main/java/ca/spottedleaf/starlight/common/light/StarLightInterface.java
+++ b/src/main/java/ca/spottedleaf/starlight/common/light/StarLightInterface.java
@@ -5,6 +5,7 @@ import ca.spottedleaf.starlight.common.util.WorldUtil;
 import it.unimi.dsi.fastutil.longs.Long2ObjectLinkedOpenHashMap;
 import it.unimi.dsi.fastutil.shorts.ShortCollection;
 import it.unimi.dsi.fastutil.shorts.ShortOpenHashSet;
+import it.unimi.dsi.fastutil.objects.ObjectOpenHashSet;
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.SectionPos;
 import net.minecraft.server.level.ServerChunkCache;
@@ -21,7 +22,6 @@ import net.minecraft.world.level.lighting.LayerLightEventListener;
 import net.minecraft.world.level.lighting.LevelLightEngine;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.concurrent.CompletableFuture;
@@ -647,7 +647,7 @@ public final class StarLightInterface {
 
         protected static final class ChunkTasks {
 
-            public final Set<BlockPos> changedPositions = new HashSet<>();
+            public final Set<BlockPos> changedPositions = new ObjectOpenHashSet<>();
             public Boolean[] changedSectionSet;
             public ShortOpenHashSet queuedEdgeChecksSky;
             public ShortOpenHashSet queuedEdgeChecksBlock;
diff --git a/src/main/java/net/minecraft/server/level/ThreadedLevelLightEngine.java b/src/main/java/net/minecraft/server/level/ThreadedLevelLightEngine.java
index b57bffce30154b196b879209c1ce559d0b82456e..937a8a24c912f25725dc17ded0fed3ca63a11b96 100644
--- a/src/main/java/net/minecraft/server/level/ThreadedLevelLightEngine.java
+++ b/src/main/java/net/minecraft/server/level/ThreadedLevelLightEngine.java
@@ -285,9 +285,7 @@ public class ThreadedLevelLightEngine extends LevelLightEngine implements AutoCl
             for (int dz = -1; dz <= 1; ++dz) {
                 ChunkHolder neighbour = world.getChunkSource().chunkMap.getUpdatingChunkIfPresent(CoordinateUtils.getChunkKey(dx + chunkX, dz + chunkZ));
                 if (neighbour != null) {
-                    neighbour.chunkToSave = neighbour.chunkToSave.thenCombine(updateFuture, (final ChunkAccess curr, final Void ignore) -> {
-                        return curr;
-                    });
+                    neighbour.chunkToSave = updateFuture.thenCompose(v -> neighbour.chunkToSave);
                 }
             }
         }