Paper/Spigot-Server-Patches/0182-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 630b279158f26902ebdcc6e5c810b189ce49c910..958279249fdadfe5c2808d2a046636f06c3bd500 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 5c1c4d5837bb65bc0509c7cb5a9d7f9a72dfe444..ef81c1d3a9679b0e65b453431de3cd0216f05bb6 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 17d80b5c6e512e0c582b05c92bb795b004ba27c2..f6401e2cde9d56547cee7f8d9e4b2a58764ee895 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