From c630ddd10b4711ffcd5318829821fb44f48294df Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Wed, 29 Aug 2018 21:59:22 -0400
Subject: [PATCH] Optimize getChunkIfLoaded type calls

Uses optimized check to avoid major locks and large method.

Will improve inlining across many hot methods.

Improve getBrightness to not do double chunk map lookups.

diff --git a/src/main/java/net/minecraft/server/ChunkProviderServer.java b/src/main/java/net/minecraft/server/ChunkProviderServer.java
index 41926a361b..186cfda7e4 100644
--- a/src/main/java/net/minecraft/server/ChunkProviderServer.java
+++ b/src/main/java/net/minecraft/server/ChunkProviderServer.java
@@ -379,7 +379,7 @@ public class ChunkProviderServer implements IChunkProvider {
                     continue;
                 }
 
-                Chunk neighbor = this.getChunkAt(chunk.locX + x, chunk.locZ + z, false, false);
+                Chunk neighbor = this.chunks.get(chunk.chunkKey); // Paper
                 if (neighbor != null) {
                     neighbor.setNeighborUnloaded(-x, -z);
                     chunk.setNeighborUnloaded(x, z);
diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index 14f419deb8..630ebfb37c 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -162,7 +162,7 @@ public abstract class World implements IEntityAccess, GeneratorAccess, IIBlockAc
     }
 
     public Chunk getChunkIfLoaded(int x, int z) {
-        return ((ChunkProviderServer) this.chunkProvider).getChunkAt(x, z, false, false);
+        return ((ChunkProviderServer) this.chunkProvider).chunks.get(ChunkCoordIntPair.a(x, z)); // Paper - optimize getChunkIfLoaded
     }
 
     protected World(IDataManager idatamanager, @Nullable PersistentCollection persistentcollection, WorldData worlddata, WorldProvider worldprovider, MethodProfiler methodprofiler, boolean flag, ChunkGenerator gen, org.bukkit.World.Environment env) {
@@ -724,7 +724,8 @@ public abstract class World implements IEntityAccess, GeneratorAccess, IIBlockAc
             blockposition = new BlockPosition(blockposition.getX(), 0, blockposition.getZ());
         }
 
-        return !blockposition.isValidLocation() ? enumskyblock.c : (!this.isLoaded(blockposition) ? enumskyblock.c : this.getChunkAtWorldCoords(blockposition).getBrightness(enumskyblock, blockposition)); // Paper
+        Chunk chunk; // Paper
+        return !blockposition.isValidLocation() ? enumskyblock.c : ((chunk = this.getChunkIfLoaded(blockposition)) == null ? enumskyblock.c : chunk.getBrightness(enumskyblock, blockposition)); // Paper - optimize ifChunkLoaded
     }
 
     public void a(EnumSkyBlock enumskyblock, BlockPosition blockposition, int i) {
@@ -1959,7 +1960,7 @@ public abstract class World implements IEntityAccess, GeneratorAccess, IIBlockAc
         if (blockposition.isInvalidYLocation()) { // Paper
             return false;
         } else {
-            Chunk chunk = this.chunkProvider.getChunkAt(blockposition.getX() >> 4, blockposition.getZ() >> 4, false, false);
+            Chunk chunk = this.getChunkIfLoaded(blockposition.getX() >> 4, blockposition.getZ() >> 4); // Paper - optimize ifLoaded
 
             return chunk != null && !chunk.isEmpty();
         }
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
index 72eb8ed4f4..7e52859c1d 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
@@ -218,7 +218,7 @@ public class CraftWorld implements World {
             return false;
         }
 
-        net.minecraft.server.Chunk chunk = world.getChunkProvider().getChunkAt(x, z, false, false);
+        net.minecraft.server.Chunk chunk = world.getChunkIfLoaded(x, z); // Paper - optimize ifLaoded
         if (chunk != null) {
             world.getChunkProvider().unload(chunk);
         }
@@ -237,7 +237,7 @@ public class CraftWorld implements World {
 
     private boolean unloadChunk0(int x, int z, boolean save) {
         Boolean result = MCUtil.ensureMain("Unload Chunk", () -> { // Paper - Ensure never async
-        net.minecraft.server.Chunk chunk = world.getChunkProvider().getChunkAt(x, z, false, false);
+        net.minecraft.server.Chunk chunk = world.getChunkIfLoaded(x, z); // Paper - optimize ifLoaded
         if (chunk == null) {
             return true;
         }
-- 
2.21.0