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

paper-server/patches/sources/net/minecraft/world/level/block/entity/BlockEntity.java.patch

@@ -19,14 +19,22 @@
      private static final Logger LOGGER = LogUtils.getLogger();
      private final BlockEntityType<?> type;
      @Nullable
-@@ -74,8 +84,17 @@
+@@ -43,6 +53,7 @@
+         this.worldPosition = pos.immutable();
+         this.validateBlockState(state);
+         this.blockState = state;
++        this.persistentDataContainer = new CraftPersistentDataContainer(DATA_TYPE_REGISTRY); // Paper - always init
+     }
+ 
+     private void validateBlockState(BlockState state) {
+@@ -74,8 +85,17 @@
          return this.level != null;
      }
  
 -    protected void loadAdditional(CompoundTag nbt, HolderLookup.Provider registries) {}
 +    // CraftBukkit start - read container
 +    protected void loadAdditional(CompoundTag nbt, HolderLookup.Provider registries) {
-+        this.persistentDataContainer = new CraftPersistentDataContainer(BlockEntity.DATA_TYPE_REGISTRY);
++        this.persistentDataContainer.clear(); // Paper - clear instead of init
  
 +        net.minecraft.nbt.Tag persistentDataTag = nbt.get("PublicBukkitValues");
 +        if (persistentDataTag instanceof CompoundTag) {
@@ -38,7 +46,7 @@
      public final void loadWithComponents(CompoundTag nbt, HolderLookup.Provider registries) {
          this.loadAdditional(nbt, registries);
          BlockEntity.ComponentHelper.COMPONENTS_CODEC.parse(registries.createSerializationContext(NbtOps.INSTANCE), nbt).resultOrPartial((s) -> {
-@@ -114,6 +133,11 @@
+@@ -114,6 +134,11 @@
          }).ifPresent((nbtbase) -> {
              nbttagcompound.merge((CompoundTag) nbtbase);
          });
@@ -50,7 +58,7 @@
          return nbttagcompound;
      }
  
-@@ -234,7 +258,12 @@
+@@ -234,7 +259,12 @@
      public void fillCrashReportCategory(CrashReportCategory crashReportSection) {
          crashReportSection.setDetail("Name", this::getNameForReporting);
          if (this.level != null) {
@@ -64,7 +72,7 @@
              CrashReportCategory.populateBlockDetails(crashReportSection, this.level, this.worldPosition, this.level.getBlockState(this.worldPosition));
          }
      }
-@@ -263,13 +292,19 @@
+@@ -263,13 +293,19 @@
      }
  
      public final void applyComponents(DataComponentMap defaultComponents, DataComponentPatch components) {
@@ -86,7 +94,7 @@
              @Nullable
              @Override
              public <T> T get(DataComponentType<T> type) {
-@@ -284,9 +319,13 @@
+@@ -284,9 +320,13 @@
              }
          });
          Objects.requireNonNull(set);
@@ -101,14 +109,21 @@
      }
  
      protected void collectImplicitComponents(DataComponentMap.Builder builder) {}
-@@ -321,6 +360,15 @@
+@@ -321,6 +361,22 @@
          }
      }
  
 +    // CraftBukkit start - add method
 +    public InventoryHolder getOwner() {
++        // Paper start
++        return getOwner(true);
++    }
++    public InventoryHolder getOwner(boolean useSnapshot) {
++        // Paper end
 +        if (this.level == null) return null;
-+        org.bukkit.block.BlockState state = this.level.getWorld().getBlockAt(this.worldPosition.getX(), this.worldPosition.getY(), this.worldPosition.getZ()).getState();
++        org.bukkit.block.Block block = this.level.getWorld().getBlockAt(this.worldPosition.getX(), this.worldPosition.getY(), this.worldPosition.getZ());
++        if (block.getType() == org.bukkit.Material.AIR) return null;
++        org.bukkit.block.BlockState state = block.getState(useSnapshot); // Paper
 +        if (state instanceof InventoryHolder) return (InventoryHolder) state;
 +        return null;
 +    }

paper-server/src/main/java/org/bukkit/craftbukkit/block/CraftBlock.java

@@ -328,6 +328,13 @@ public class CraftBlock implements Block {
         return CraftBlockStates.getBlockState(this);
     }
 
+    // Paper start
+    @Override
+    public BlockState getState(boolean useSnapshot) {
+        return CraftBlockStates.getBlockState(this, useSnapshot);
+    }
+    // Paper end
+
     @Override
     public Biome getBiome() {
         return this.getWorld().getBiome(this.getX(), this.getY(), this.getZ());

paper-server/src/main/java/org/bukkit/craftbukkit/block/CraftBlockEntityState.java

@@ -24,15 +24,26 @@ public class CraftBlockEntityState<T extends BlockEntity> extends CraftBlockStat
 
     private final T tileEntity;
     private final T snapshot;
+    public boolean snapshotDisabled; // Paper
+    public static boolean DISABLE_SNAPSHOT = false; // Paper
 
     public CraftBlockEntityState(World world, T tileEntity) {
         super(world, tileEntity.getBlockPos(), tileEntity.getBlockState());
 
         this.tileEntity = tileEntity;
 
+        // Paper start
+        this.snapshotDisabled = DISABLE_SNAPSHOT;
+        if (DISABLE_SNAPSHOT) {
+            this.snapshot = this.tileEntity;
+        } else {
+            this.snapshot = this.createSnapshot(tileEntity);
+        }
         // copy tile entity data:
-        this.snapshot = this.createSnapshot(tileEntity);
-        this.load(this.snapshot);
+        if (this.snapshot != null) {
+            this.load(this.snapshot);
+        }
+        // Paper end
     }
 
     protected CraftBlockEntityState(CraftBlockEntityState<T> state, Location location) {
@@ -184,4 +195,11 @@ public class CraftBlockEntityState<T extends BlockEntity> extends CraftBlockStat
     public CraftBlockEntityState<T> copy(Location location) {
         return new CraftBlockEntityState<>(this, location);
     }
+
+    // Paper start
+    @Override
+    public boolean isSnapshot() {
+        return !this.snapshotDisabled;
+    }
+    // Paper end
 }

paper-server/src/main/java/org/bukkit/craftbukkit/block/CraftBlockStates.java

@@ -393,15 +393,30 @@ public final class CraftBlockStates {
     }
 
     public static BlockState getBlockState(Block block) {
+        // Paper start
+        return CraftBlockStates.getBlockState(block, true);
+    }
+    public static BlockState getBlockState(Block block, boolean useSnapshot) {
+        // Paper end
         Preconditions.checkNotNull(block, "block is null");
         CraftBlock craftBlock = (CraftBlock) block;
         CraftWorld world = (CraftWorld) block.getWorld();
         BlockPos blockPosition = craftBlock.getPosition();
         net.minecraft.world.level.block.state.BlockState blockData = craftBlock.getNMS();
         BlockEntity tileEntity = craftBlock.getHandle().getBlockEntity(blockPosition);
+        // Paper start - block state snapshots
+        boolean prev = CraftBlockEntityState.DISABLE_SNAPSHOT;
+        CraftBlockEntityState.DISABLE_SNAPSHOT = !useSnapshot;
+        try {
+        // Paper end
         CraftBlockState blockState = CraftBlockStates.getBlockState(world, blockPosition, blockData, tileEntity);
         blockState.setWorldHandle(craftBlock.getHandle()); // Inject the block's generator access
         return blockState;
+        // Paper start
+        } finally {
+            CraftBlockEntityState.DISABLE_SNAPSHOT = prev;
+        }
+        // Paper end
     }
 
     @Deprecated

paper-server/src/main/java/org/bukkit/craftbukkit/persistence/CraftPersistentDataContainer.java

@@ -177,4 +177,10 @@ public class CraftPersistentDataContainer implements PersistentDataContainer {
     public String serialize() {
         return CraftNBTTagConfigSerializer.serialize(this.toTagCompound());
     }
+
+    // Paper start
+    public void clear() {
+        this.customDataTags.clear();
+    }
+    // Paper end
 }