Paper/Spigot-Server-Patches/0183-API-to-get-a-BlockState-without-a-snapshot.patch

From e1c64c1bb29a3243a08d22459101f338e858ee41 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 630b2791..95827924 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 eb0201eb..1354d949 100644
--- a/src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java
+++ b/src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java
@@ -311,6 +311,20 @@ 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 17d80b5c..f6401e2c 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 15022ada..af15656c 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
-- 
2.25.1.windows.1