From 3ce3d501a6fc62dc396aaec8eaff30c4a469b405 Mon Sep 17 00:00:00 2001
From: mezz <tehgeek@gmail.com>
Date: Wed, 9 Aug 2017 17:51:22 -0500
Subject: [PATCH] Fix MC-117075: TE Unload Lag Spike


diff --git a/src/main/java/net/minecraft/server/Chunk.java b/src/main/java/net/minecraft/server/Chunk.java
index ed595955..228792fa 100644
--- a/src/main/java/net/minecraft/server/Chunk.java
+++ b/src/main/java/net/minecraft/server/Chunk.java
@@ -823,6 +823,9 @@ public class Chunk {
 
     public void removeEntities() {
         this.j = false;
+        // Paper start - Fix MC-117075: TE Unload Lag Spike
+        this.world.markTileEntitiesForRemoval(this);
+        /*
         Iterator iterator = this.tileEntities.values().iterator();
 
         while (iterator.hasNext()) {
@@ -842,6 +845,8 @@ public class Chunk {
 
             this.world.b(tileentity);
         }
+        */
+        // Paper end
 
         List[] aentityslice = this.entitySlices; // Spigot
         int i = aentityslice.length;
diff --git a/src/main/java/net/minecraft/server/ChunkCoordIntPair.java b/src/main/java/net/minecraft/server/ChunkCoordIntPair.java
index 23944088..e8d1a1c6 100644
--- a/src/main/java/net/minecraft/server/ChunkCoordIntPair.java
+++ b/src/main/java/net/minecraft/server/ChunkCoordIntPair.java
@@ -15,6 +15,7 @@ public class ChunkCoordIntPair {
         this.z = blockposition.getZ() >> 4;
     }
 
+    public static long asLong(int x, int z) { return a(x, z); } // Paper - OBFHELPER
     public static long a(int i, int j) {
         return (long) i & 4294967295L | ((long) j & 4294967295L) << 32;
     }
diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index 12938b9f..7e0ba4b2 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -147,6 +147,7 @@ public abstract class World implements IBlockAccess {
     private org.spigotmc.TickLimiter tileLimiter;
     private int tileTickPosition;
     public final Map<Explosion.CacheKey, Float> explosionDensityCache = new HashMap<>(); // Paper - Optimize explosions
+    private it.unimi.dsi.fastutil.longs.LongCollection tileEntitiesChunkToBeRemoved = new it.unimi.dsi.fastutil.longs.LongOpenHashSet(); // Paper - Fix MC-117075: TE Unload Lag Spike
 
     public CraftWorld getWorld() {
         return this.world;
@@ -1581,6 +1582,7 @@ public abstract class World implements IBlockAccess {
             this.tileEntityListUnload.clear();
         }
         // CraftBukkit end
+        this.removeTileEntitiesForRemovedChunks(); // Paper - Fix MC-117075: TE Unload Lag Spike
 
         // Spigot start
         // Iterator iterator = this.tileEntityListTick.iterator();
@@ -3261,4 +3263,36 @@ public abstract class World implements IBlockAccess {
     public BlockPosition a(String s, BlockPosition blockposition, boolean flag) {
         return null;
     }
+
+    // Paper start - Fix MC-117075: TE Unload Lag Spike
+    public void markTileEntitiesForRemoval(Chunk chunk) {
+        if (!chunk.getTileEntities().isEmpty()) {
+            long pos = net.minecraft.server.ChunkCoordIntPair.asLong(chunk.locX, chunk.locZ);
+            this.tileEntitiesChunkToBeRemoved.add(pos);
+        }
+    }
+
+    private void removeTileEntitiesForRemovedChunks() {
+        if (!this.tileEntitiesChunkToBeRemoved.isEmpty()) {
+            java.util.function.Predicate<TileEntity> isInChunk = (tileEntity) -> {
+                BlockPosition tilePos = tileEntity.getPosition();
+                long tileChunkPos = net.minecraft.server.ChunkCoordIntPair.asLong(tilePos.getX() >> 4, tilePos.getZ() >> 4);
+                final boolean willRemove = this.tileEntitiesChunkToBeRemoved.contains(tileChunkPos);
+                // Brought over from Chunk#removeEntities
+                if (willRemove && tileEntity instanceof IInventory) {
+                    for (org.bukkit.entity.HumanEntity human : Lists.newArrayList(((IInventory) tileEntity).getViewers())) {
+                        if (human instanceof org.bukkit.craftbukkit.entity.CraftHumanEntity) {
+                            ((org.bukkit.craftbukkit.entity.CraftHumanEntity) human).getHandle().closeInventory();
+                        }
+                    }
+                }
+
+                return willRemove;
+            };
+
+            this.tileEntityListTick.removeIf(isInChunk);
+            this.tileEntitiesChunkToBeRemoved.clear();
+        }
+    }
+    // Paper end
 }
-- 
2.13.4