PaperMC/Spigot-Server-Patches/0180-API-to-get-a-BlockState-without-a-snapshot.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Mon, 6 Nov 2017 21:08:22 -0500
Subject: [PATCH] API to get a BlockState without a snapshot

This allows you to get a BlockState without creating a snapshot, operating
on the real tile entity.

This is useful for where performance is needed

also Avoid NPE during CraftBlockEntityState load if could not get TE

If Tile Entity was null, correct Sign to return empty lines instead of null

diff --git a/src/main/java/net/minecraft/server/TileEntity.java b/src/main/java/net/minecraft/server/TileEntity.java
index 5e5bb5aaa3d8f4e8f4b00ba8bee059ec79f82b43..2b06c95b4fac97513e706ef073fdd7418e1f092c 100644
--- a/src/main/java/net/minecraft/server/TileEntity.java
+++ b/src/main/java/net/minecraft/server/TileEntity.java
@@ -231,7 +231,12 @@ public abstract class TileEntity implements KeyedObject { // Paper
     }
 
     // CraftBukkit start - add method
+    // Paper start
     public InventoryHolder getOwner() {
+        return getOwner(true);
+    }
+    public InventoryHolder getOwner(boolean useSnapshot) {
+        // Paper end
         if (world == null) return null;
         // Spigot start
         org.bukkit.block.Block block = world.getWorld().getBlockAt(position.getX(), position.getY(), position.getZ());
@@ -240,7 +245,7 @@ public abstract class TileEntity implements KeyedObject { // Paper
             return null;
         }
         // Spigot end
-        org.bukkit.block.BlockState state = block.getState();
+        org.bukkit.block.BlockState state = block.getState(useSnapshot); // Paper
         if (state instanceof InventoryHolder) return (InventoryHolder) state;
         return null;
     }
diff --git a/src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java b/src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java
index 606a89a905396a020a3497aa293f64a04c693c7b..12b8d544566888dc77bc2c8748d78f09c4bb3b76 100644
--- a/src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java
+++ b/src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java
@@ -308,6 +308,20 @@ public class CraftBlock implements Block {
 
     @Override
     public BlockState getState() {
+        // Paper start - allow disabling the use of snapshots
+        return getState(true);
+    }
+    public BlockState getState(boolean useSnapshot) {
+        boolean prev = CraftBlockEntityState.DISABLE_SNAPSHOT;
+        CraftBlockEntityState.DISABLE_SNAPSHOT = !useSnapshot;
+        try {
+            return getState0();
+        } finally {
+            CraftBlockEntityState.DISABLE_SNAPSHOT = prev;
+        }
+    }
+    public BlockState getState0() {
+        // Paper end
         Material material = getType();
 
         switch (material) {
diff --git a/src/main/java/org/bukkit/craftbukkit/block/CraftBlockEntityState.java b/src/main/java/org/bukkit/craftbukkit/block/CraftBlockEntityState.java
index 26cc40e57f5b73b9c32859bff37c4a3d94904c56..feeae1a9eb309ae4101783b191bb2bffe9aeb7d3 100644
--- a/src/main/java/org/bukkit/craftbukkit/block/CraftBlockEntityState.java
+++ b/src/main/java/org/bukkit/craftbukkit/block/CraftBlockEntityState.java
@@ -26,20 +26,40 @@ public class CraftBlockEntityState<T extends TileEntity> extends CraftBlockState
         this.tileEntity = tileEntityClass.cast(world.getHandle().getTileEntity(this.getPosition()));
         Preconditions.checkState(this.tileEntity != null, "Tile is null, asynchronous access? " + block);
 
+        // Paper start
+        this.snapshotDisabled = DISABLE_SNAPSHOT;
+        if (DISABLE_SNAPSHOT) {
+            this.snapshot = this.tileEntity;
+        } else {
+            this.snapshot = this.createSnapshot(this.tileEntity);
+        }
         // copy tile entity data:
-        this.snapshot = this.createSnapshot(tileEntity);
-        this.load(snapshot);
+        if(this.snapshot != null) {
+            this.load(this.snapshot);
+        }
+        // Paper end
     }
 
+    public final boolean snapshotDisabled; // Paper
+    public static boolean DISABLE_SNAPSHOT = false; // Paper
+
     public CraftBlockEntityState(Material material, T tileEntity) {
         super(material);
 
         this.tileEntityClass = (Class<T>) tileEntity.getClass();
         this.tileEntity = tileEntity;
-
+        // Paper start
+        this.snapshotDisabled = DISABLE_SNAPSHOT;
+        if (DISABLE_SNAPSHOT) {
+            this.snapshot = this.tileEntity;
+        } else {
+            this.snapshot = this.createSnapshot(this.tileEntity);
+        }
         // copy tile entity data:
-        this.snapshot = this.createSnapshot(tileEntity);
-        this.load(snapshot);
+        if(this.snapshot != null) {
+            this.load(this.snapshot);
+        }
+        // Paper end
     }
 
     private T createSnapshot(T tileEntity) {
diff --git a/src/main/java/org/bukkit/craftbukkit/block/CraftSign.java b/src/main/java/org/bukkit/craftbukkit/block/CraftSign.java
index 15022ada0c2fd0f4302b45c55f46d0fdd3bfd57f..af15656cc4b4c1e9da4fc8a5bfffa95eb6caf903 100644
--- a/src/main/java/org/bukkit/craftbukkit/block/CraftSign.java
+++ b/src/main/java/org/bukkit/craftbukkit/block/CraftSign.java
@@ -17,10 +17,12 @@ public class CraftSign extends CraftBlockEntityState<TileEntitySign> implements
 
     public CraftSign(final Block block) {
         super(block, TileEntitySign.class);
+        if (lines == null) { lines = new String[]{"", "", "", ""}; } // Paper
     }
 
     public CraftSign(final Material material, final TileEntitySign te) {
         super(material, te);
+        if (lines == null) { lines = new String[]{"", "", "", ""}; } // Paper
     }
 
     @Override