Paper/Spigot-Server-Patches/0178-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/world/level/block/entity/TileEntity.java b/src/main/java/net/minecraft/world/level/block/entity/TileEntity.java
index 9b44ca96669ce423e5649f11743226dfdd9ce746..48daa039ffa8ccb7b6f3ca47bdc56394addf9254 100644
--- a/src/main/java/net/minecraft/world/level/block/entity/TileEntity.java
+++ b/src/main/java/net/minecraft/world/level/block/entity/TileEntity.java
@@ -47,6 +47,7 @@ public abstract class TileEntity implements net.minecraft.server.KeyedObject { /
     public TileEntity(TileEntityTypes<?> tileentitytypes) {
         this.position = BlockPosition.ZERO;
         this.tileType = tileentitytypes;
+        persistentDataContainer = new CraftPersistentDataContainer(DATA_TYPE_REGISTRY); // Paper - always init
     }
 
     // Paper start
@@ -95,7 +96,7 @@ public abstract class TileEntity implements net.minecraft.server.KeyedObject { /
     public void load(IBlockData iblockdata, NBTTagCompound nbttagcompound) {
         this.position = new BlockPosition(nbttagcompound.getInt("x"), nbttagcompound.getInt("y"), nbttagcompound.getInt("z"));
         // CraftBukkit start - read container
-        this.persistentDataContainer = new CraftPersistentDataContainer(DATA_TYPE_REGISTRY);
+        this.persistentDataContainer.clear(); // Paper - clear instead of reinit
 
         net.minecraft.nbt.NBTBase persistentDataTag = nbttagcompound.get("PublicBukkitValues");
         if (persistentDataTag instanceof NBTTagCompound) {
@@ -245,7 +246,12 @@ public abstract class TileEntity implements net.minecraft.server.KeyedObject { /
     }
 
     // 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());
@@ -254,7 +260,7 @@ public abstract class TileEntity implements net.minecraft.server.KeyedObject { /
             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 255aac0803b436434bc00822f3698c4f3ba7e0ac..8a6d8f21937ce7e2ac4623a3083421ed5ef9aa63 100644
--- a/src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java
+++ b/src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java
@@ -316,6 +316,20 @@ 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 dcf3f9265b0b00a7bbb9ff428e10da3c198ba08a..2f0b48869077c27d0cacea81a99c9e34ff59c684 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? %s", 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/persistence/CraftPersistentDataContainer.java b/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataContainer.java
index f342feee4e2274cdc51fef6caace52cc31eefb18..a4c888236bf09a25f234831a041ca5a4a2c972ef 100644
--- a/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataContainer.java
+++ b/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataContainer.java
@@ -155,4 +155,10 @@ public final class CraftPersistentDataContainer implements PersistentDataContain
     public Map<String, Object> serialize() {
         return (Map<String, Object>) CraftNBTTagConfigSerializer.serialize(toTagCompound());
     }
+
+    // Paper start
+    public void clear() {
+        this.customDataTags.clear();
+    }
+    // Paper end
 }