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.

Spigot-Server-Patches/0355-Optimize-getChunkIfLoaded-type-calls.patch

@@ -0,0 +1,81 @@
+From b8345560939d63b8f8e221f468aaf9792c61152a 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 96d49b469a..c0ec896eea 100644
+--- a/src/main/java/net/minecraft/server/ChunkProviderServer.java
++++ b/src/main/java/net/minecraft/server/ChunkProviderServer.java
+@@ -381,7 +381,7 @@ 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 49809372d8..0437cfdd55 100644
+--- a/src/main/java/net/minecraft/server/World.java
++++ b/src/main/java/net/minecraft/server/World.java
+@@ -165,7 +165,7 @@ 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) {
+@@ -715,7 +715,8 @@ 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) {
+@@ -2017,7 +2018,7 @@ 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 1ccf2a7609..d9766447de 100644
+--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
++++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+@@ -227,7 +227,7 @@ public class CraftWorld implements World {
+             return false;
+         }
+ 
+-        net.minecraft.server.Chunk chunk = world.getChunkProviderServer().getChunkAt(x, z, false, false);
++        net.minecraft.server.Chunk chunk = world.getChunkIfLoaded(x, z); // Paper - optimize ifLaoded
+         if (chunk != null) {
+             world.getChunkProviderServer().unload(chunk);
+         }
+@@ -246,7 +246,7 @@ 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.getChunkProviderServer().getChunkAt(x, z, false, false);
++        net.minecraft.server.Chunk chunk = world.getChunkIfLoaded(x, z); // Paper - optimize ifLoaded
+         if (chunk == null) {
+             return true;
+         }
+-- 
+2.18.0
+