Tiles no longer store their NBT at runtime

This is a significant breaking change for anything utilizing Tiles as they now do not store their NBT at runtime anymore.
This is another step in the process of ridding PocketMine-MP of runtime NBT.

It can be noticed that all tiles are now using class fields to store properties instead of NBT, which is much faster, uses less memory and is also more concise when written in code.

Highlights:
- Tile->namedtag has been removed.
- Tile->saveNBT() now accepts a CompoundTag() parameter. Typically it's expected that this will be fed a newly-created CompoundTag (this part may be improved in the future).
- New internal methods Tile->readSaveData() and Tile->writeSaveData() have been added. Instead of overriding __construct() and saveNBT() to load and save properties from NBT, you should now implement these methods instead.

This is not final and will see further changes before it's done.

src/pocketmine/level/format/io/leveldb/LevelDB.php

@@ -456,8 +456,8 @@ class LevelDB extends BaseLevelProvider{
 		$tiles = [];
 		foreach($chunk->getTiles() as $tile){
 			if(!$tile->isClosed()){
-				$tile->saveNBT();
+				$tile->saveNBT($tileTag = new CompoundTag());
-				$tiles[] = $tile->namedtag;
+				$tiles[] = $tileTag;
 			}
 		}
 		$this->writeTags($tiles, $index . self::TAG_BLOCK_ENTITY);

src/pocketmine/level/format/io/region/Anvil.php

@@ -75,8 +75,8 @@ class Anvil extends McRegion{
 
 		$tiles = [];
 		foreach($chunk->getTiles() as $tile){
-			$tile->saveNBT();
+			$tile->saveNBT($tileTag = new CompoundTag());
-			$tiles[] = $tile->namedtag;
+			$tiles[] = $tileTag;
 		}
 
 		$nbt->setTag(new ListTag("TileEntities", $tiles, NBT::TAG_Compound));

src/pocketmine/level/format/io/region/McRegion.php

@@ -94,8 +94,8 @@ class McRegion extends BaseLevelProvider{
 
 		$tiles = [];
 		foreach($chunk->getTiles() as $tile){
-			$tile->saveNBT();
+			$tile->saveNBT($tileTag = new CompoundTag());
-			$tiles[] = $tile->namedtag;
+			$tiles[] = $tileTag;
 		}
 
 		$nbt->setTag(new ListTag("TileEntities", $tiles, NBT::TAG_Compound));

src/pocketmine/tile/Banner.php

@@ -24,7 +24,6 @@ declare(strict_types=1);
 namespace pocketmine\tile;
 
 use pocketmine\item\Item;
-use pocketmine\level\Level;
 use pocketmine\math\Vector3;
 use pocketmine\nbt\tag\CompoundTag;
 use pocketmine\nbt\tag\IntTag;
@@ -107,19 +106,16 @@ class Banner extends Spawnable implements Nameable{
 	 */
 	private $patterns;
 
-	public function __construct(Level $level, CompoundTag $nbt){
+	protected function readSaveData(CompoundTag $nbt) : void{
 		$this->baseColor = $nbt->getInt(self::TAG_BASE, self::COLOR_BLACK, true);
 		$this->patterns = $nbt->getListTag(self::TAG_PATTERNS) ?? new ListTag(self::TAG_PATTERNS);
-		$nbt->removeTag(self::TAG_BASE, self::TAG_PATTERNS);
 		$this->loadName($nbt);
-		parent::__construct($level, $nbt);
 	}
 
-	public function saveNBT() : void{
+	protected function writeSaveData(CompoundTag $nbt) : void{
-		parent::saveNBT();
+		$nbt->setInt(self::TAG_BASE, $this->baseColor);
-		$this->namedtag->setInt(self::TAG_BASE, $this->baseColor);
+		$nbt->setTag($this->patterns);
-		$this->namedtag->setTag($this->patterns);
+		$this->saveName($nbt);
-		$this->saveName($this->namedtag);
 	}
 
 	public function addAdditionalSpawnData(CompoundTag $nbt) : void{

src/pocketmine/tile/Bed.php

@@ -25,7 +25,6 @@ namespace pocketmine\tile;
 
 
 use pocketmine\item\Item;
-use pocketmine\level\Level;
 use pocketmine\math\Vector3;
 use pocketmine\nbt\tag\CompoundTag;
 use pocketmine\Player;
@@ -35,13 +34,6 @@ class Bed extends Spawnable{
 	/** @var int */
 	private $color = 14; //default to old red
 
-	public function __construct(Level $level, CompoundTag $nbt){
-		$this->color = $nbt->getByte(self::TAG_COLOR, 14, true);
-		$nbt->removeTag(self::TAG_COLOR);
-
-		parent::__construct($level, $nbt);
-	}
-
 	public function getColor() : int{
 		return $this->color;
 	}
@@ -51,13 +43,16 @@ class Bed extends Spawnable{
 		$this->onChanged();
 	}
 
-	public function addAdditionalSpawnData(CompoundTag $nbt) : void{
+	protected function readSaveData(CompoundTag $nbt) : void{
+		$this->color = $nbt->getByte(self::TAG_COLOR, 14, true);
+	}
+
+	protected function writeSaveData(CompoundTag $nbt) : void{
 		$nbt->setByte(self::TAG_COLOR, $this->color);
 	}
 
-	public function saveNBT() : void{
+	public function addAdditionalSpawnData(CompoundTag $nbt) : void{
-		parent::saveNBT();
+		$nbt->setByte(self::TAG_COLOR, $this->color);
-		$this->namedtag->setByte(self::TAG_COLOR, $this->color);
 	}
 
 	protected static function createAdditionalNBT(CompoundTag $nbt, Vector3 $pos, ?int $face = null, ?Item $item = null, ?Player $player = null) : void{

src/pocketmine/tile/Chest.php

@@ -26,7 +26,6 @@ namespace pocketmine\tile;
 use pocketmine\inventory\ChestInventory;
 use pocketmine\inventory\DoubleChestInventory;
 use pocketmine\inventory\InventoryHolder;
-use pocketmine\level\Level;
 use pocketmine\nbt\tag\CompoundTag;
 use pocketmine\nbt\tag\IntTag;
 
@@ -50,19 +49,26 @@ class Chest extends Spawnable implements InventoryHolder, Container, Nameable{
 	/** @var int|null */
 	private $pairZ;
 
-	public function __construct(Level $level, CompoundTag $nbt){
+	protected function readSaveData(CompoundTag $nbt) : void{
 		if($nbt->hasTag(self::TAG_PAIRX, IntTag::class) and $nbt->hasTag(self::TAG_PAIRZ, IntTag::class)){
 			$this->pairX = $nbt->getInt(self::TAG_PAIRX);
 			$this->pairZ = $nbt->getInt(self::TAG_PAIRZ);
 		}
-		$nbt->removeTag(self::TAG_PAIRX, self::TAG_PAIRZ);
 		$this->loadName($nbt);
 
-		parent::__construct($level, $nbt);
-
 		$this->inventory = new ChestInventory($this);
-		$this->loadItems($this->namedtag);
+		$this->loadItems($nbt);
+	}
 
+	protected function writeSaveData(CompoundTag $nbt) : void{
+		if($this->isPaired()){
+			$nbt->setInt(self::TAG_PAIRX, $this->pairX);
+			$nbt->setInt(self::TAG_PAIRZ, $this->pairZ);
+		}else{
+			$nbt->removeTag(self::TAG_PAIRX, self::TAG_PAIRZ);
+		}
+		$this->saveName($nbt);
+		$this->saveItems($nbt);
 	}
 
 	public function close() : void{
@@ -81,18 +87,6 @@ class Chest extends Spawnable implements InventoryHolder, Container, Nameable{
 		}
 	}
 
-	public function saveNBT() : void{
-		parent::saveNBT();
-		if($this->isPaired()){
-			$this->namedtag->setInt(self::TAG_PAIRX, $this->pairX);
-			$this->namedtag->setInt(self::TAG_PAIRZ, $this->pairZ);
-		}else{
-			$this->namedtag->removeTag(self::TAG_PAIRX, self::TAG_PAIRZ);
-		}
-		$this->saveItems($this->namedtag);
-		$this->saveName($this->namedtag);
-	}
-
 	/**
 	 * @return ChestInventory|DoubleChestInventory
 	 */

src/pocketmine/tile/EnchantTable.php

@@ -23,20 +23,10 @@ declare(strict_types=1);
 
 namespace pocketmine\tile;
 
-use pocketmine\level\Level;
-use pocketmine\nbt\tag\CompoundTag;
-
 class EnchantTable extends Spawnable implements Nameable{
-	use NameableTrait;
+	use NameableTrait{
-
+		loadName as readSaveData;
-	public function __construct(Level $level, CompoundTag $nbt){
+		saveName as writeSaveData;
-		$this->loadName($nbt);
-		parent::__construct($level, $nbt);
-	}
-
-	public function saveNBT() : void{
-		parent::saveNBT();
-		$this->saveName($this->namedtag);
 	}
 
 	/**

src/pocketmine/tile/EnderChest.php

@@ -27,6 +27,14 @@ use pocketmine\nbt\tag\CompoundTag;
 
 class EnderChest extends Spawnable{
 
+	protected function readSaveData(CompoundTag $nbt) : void{
+
+	}
+
+	protected function writeSaveData(CompoundTag $nbt) : void{
+
+	}
+
 	public function addAdditionalSpawnData(CompoundTag $nbt) : void{
 
 	}

src/pocketmine/tile/FlowerPot.php

@@ -25,7 +25,6 @@ namespace pocketmine\tile;
 
 use pocketmine\item\Item;
 use pocketmine\item\ItemFactory;
-use pocketmine\level\Level;
 use pocketmine\nbt\tag\CompoundTag;
 
 class FlowerPot extends Spawnable{
@@ -35,17 +34,13 @@ class FlowerPot extends Spawnable{
 	/** @var Item */
 	private $item;
 
-	public function __construct(Level $level, CompoundTag $nbt){
+	protected function readSaveData(CompoundTag $nbt) : void{
-		//TODO: check PC format
 		$this->item = ItemFactory::get($nbt->getShort(self::TAG_ITEM, 0, true), $nbt->getInt(self::TAG_ITEM_DATA, 0, true), 1);
-		$nbt->removeTag(self::TAG_ITEM, self::TAG_ITEM_DATA);
-
-		parent::__construct($level, $nbt);
 	}
 
-	public function saveNBT() : void{
+	protected function writeSaveData(CompoundTag $nbt) : void{
-		$this->namedtag->setShort(self::TAG_ITEM, $this->item->getId());
+		$nbt->setShort(self::TAG_ITEM, $this->item->getId());
-		$this->namedtag->setInt(self::TAG_ITEM_DATA, $this->item->getDamage());
+		$nbt->setInt(self::TAG_ITEM_DATA, $this->item->getDamage());
 	}
 
 	public function canAddItem(Item $item) : bool{

src/pocketmine/tile/Furnace.php

@@ -56,6 +56,13 @@ class Furnace extends Spawnable implements InventoryHolder, Container, Nameable{
 	private $maxTime;
 
 	public function __construct(Level $level, CompoundTag $nbt){
+		parent::__construct($level, $nbt);
+		if($this->burnTime > 0){
+			$this->scheduleUpdate();
+		}
+	}
+
+	protected function readSaveData(CompoundTag $nbt) : void{
 		$this->burnTime = max(0, $nbt->getShort(self::TAG_BURN_TIME, 0, true));
 
 		$this->cookTime = $nbt->getShort(self::TAG_COOK_TIME, 0, true);
@@ -70,14 +77,16 @@ class Furnace extends Spawnable implements InventoryHolder, Container, Nameable{
 
 		$this->loadName($nbt);
 
-		parent::__construct($level, $nbt);
 		$this->inventory = new FurnaceInventory($this);
-		$this->loadItems($this->namedtag);
+		$this->loadItems($nbt);
+	}
 
-
+	protected function writeSaveData(CompoundTag $nbt) : void{
-		if($this->burnTime > 0){
+		$nbt->setShort(self::TAG_BURN_TIME, $this->burnTime);
-			$this->scheduleUpdate();
+		$nbt->setShort(self::TAG_COOK_TIME, $this->cookTime);
-		}
+		$nbt->setShort(self::TAG_MAX_TIME, $this->maxTime);
+		$this->saveName($nbt);
+		$this->saveItems($nbt);
 	}
 
 	/**
@@ -96,16 +105,6 @@ class Furnace extends Spawnable implements InventoryHolder, Container, Nameable{
 		}
 	}
 
-	public function saveNBT() : void{
-		parent::saveNBT();
-		$this->namedtag->setShort(self::TAG_BURN_TIME, $this->burnTime);
-		$this->namedtag->setShort(self::TAG_COOK_TIME, $this->cookTime);
-		$this->namedtag->setShort(self::TAG_MAX_TIME, $this->maxTime);
-
-		$this->saveItems($this->namedtag);
-		$this->saveName($this->namedtag);
-	}
-
 	/**
 	 * @return FurnaceInventory
 	 */

src/pocketmine/tile/ItemFrame.php

@@ -25,7 +25,6 @@ namespace pocketmine\tile;
 
 use pocketmine\item\Item;
 use pocketmine\item\ItemFactory;
-use pocketmine\level\Level;
 use pocketmine\nbt\tag\CompoundTag;
 
 class ItemFrame extends Spawnable{
@@ -40,7 +39,7 @@ class ItemFrame extends Spawnable{
 	/** @var float */
 	private $itemDropChance;
 
-	public function __construct(Level $level, CompoundTag $nbt){
+	protected function readSaveData(CompoundTag $nbt) : void{
 		if(($itemTag = $nbt->getCompoundTag(self::TAG_ITEM)) !== null){
 			$this->item = Item::nbtDeserialize($itemTag);
 		}else{
@@ -48,16 +47,12 @@ class ItemFrame extends Spawnable{
 		}
 		$this->itemRotation = $nbt->getByte(self::TAG_ITEM_ROTATION, 0, true);
 		$this->itemDropChance = $nbt->getFloat(self::TAG_ITEM_DROP_CHANCE, 1.0, true);
-		$nbt->removeTag(self::TAG_ITEM, self::TAG_ITEM_ROTATION, self::TAG_ITEM_DROP_CHANCE);
-
-		parent::__construct($level, $nbt);
 	}
 
-	public function saveNBT() : void{
+	protected function writeSaveData(CompoundTag $nbt) : void{
-		parent::saveNBT();
+		$nbt->setFloat(self::TAG_ITEM_DROP_CHANCE, $this->itemDropChance);
-		$this->namedtag->setFloat(self::TAG_ITEM_DROP_CHANCE, $this->itemDropChance);
+		$nbt->setByte(self::TAG_ITEM_ROTATION, $this->itemRotation);
-		$this->namedtag->setByte(self::TAG_ITEM_ROTATION, $this->itemRotation);
+		$nbt->setTag($this->item->nbtSerialize(-1, self::TAG_ITEM));
-		$this->namedtag->setTag($this->item->nbtSerialize(-1, self::TAG_ITEM));
 	}
 
 	public function hasItem() : bool{

src/pocketmine/tile/Sign.php

@@ -24,7 +24,6 @@ declare(strict_types=1);
 namespace pocketmine\tile;
 
 use pocketmine\event\block\SignChangeEvent;
-use pocketmine\level\Level;
 use pocketmine\nbt\tag\CompoundTag;
 use pocketmine\nbt\tag\StringTag;
 use pocketmine\Player;
@@ -37,7 +36,7 @@ class Sign extends Spawnable{
 	/** @var string[] */
 	protected $text = ["", "", "", ""];
 
-	public function __construct(Level $level, CompoundTag $nbt){
+	protected function readSaveData(CompoundTag $nbt) : void{
 		if($nbt->hasTag(self::TAG_TEXT_BLOB, StringTag::class)){ //MCPE 1.2 save format
 			$this->text = array_pad(explode("\n", $nbt->getString(self::TAG_TEXT_BLOB)), 4, "");
 			assert(count($this->text) === 4, "Too many lines!");
@@ -51,17 +50,14 @@ class Sign extends Spawnable{
 				}
 			}
 		}
-
-		parent::__construct($level, $nbt);
 	}
 
-	public function saveNBT() : void{
+	protected function writeSaveData(CompoundTag $nbt) : void{
-		parent::saveNBT();
+		$nbt->setString(self::TAG_TEXT_BLOB, implode("\n", $this->text));
-		$this->namedtag->setString(self::TAG_TEXT_BLOB, implode("\n", $this->text));
 
 		for($i = 1; $i <= 4; ++$i){ //Backwards-compatibility
 			$textKey = sprintf(self::TAG_TEXT_LINE, $i);
-			$this->namedtag->setString($textKey, $this->getLine($i - 1));
+			$nbt->setString($textKey, $this->getLine($i - 1));
 		}
 	}
 

src/pocketmine/tile/Skull.php

@@ -24,7 +24,6 @@ declare(strict_types=1);
 namespace pocketmine\tile;
 
 use pocketmine\item\Item;
-use pocketmine\level\Level;
 use pocketmine\math\Vector3;
 use pocketmine\nbt\tag\CompoundTag;
 use pocketmine\Player;
@@ -47,17 +46,14 @@ class Skull extends Spawnable{
 	/** @var int */
 	private $skullRotation;
 
-	public function __construct(Level $level, CompoundTag $nbt){
+	protected function readSaveData(CompoundTag $nbt) : void{
 		$this->skullType = $nbt->getByte(self::TAG_SKULL_TYPE, self::TYPE_SKELETON, true);
 		$this->skullRotation = $nbt->getByte(self::TAG_ROT, 0, true);
-		$nbt->removeTag(self::TAG_SKULL_TYPE, self::TAG_ROT);
-		parent::__construct($level, $nbt);
 	}
 
-	public function saveNBT() : void{
+	protected function writeSaveData(CompoundTag $nbt) : void{
-		parent::saveNBT();
+		$nbt->setByte(self::TAG_SKULL_TYPE, $this->skullType);
-		$this->namedtag->setByte(self::TAG_SKULL_TYPE, $this->skullType);
+		$nbt->setByte(self::TAG_ROT, $this->skullRotation);
-		$this->namedtag->setByte(self::TAG_ROT, $this->skullRotation);
 	}
 
 	public function setType(int $type){

src/pocketmine/tile/Tile.php

@@ -74,8 +74,6 @@ abstract class Tile extends Position{
 	public $id;
 	/** @var bool */
 	public $closed = false;
-	/** @var CompoundTag */
-	public $namedtag;
 	/** @var Server */
 	protected $server;
 	/** @var TimingsHandler */
@@ -155,12 +153,12 @@ abstract class Tile extends Position{
 	public function __construct(Level $level, CompoundTag $nbt){
 		$this->timings = Timings::getTileEntityTimings($this);
 
-		$this->namedtag = $nbt;
 		$this->server = $level->getServer();
 		$this->name = "";
 		$this->id = Tile::$tileCount++;
 
-		parent::__construct($this->namedtag->getInt(self::TAG_X), $this->namedtag->getInt(self::TAG_Y), $this->namedtag->getInt(self::TAG_Z), $level);
+		parent::__construct($nbt->getInt(self::TAG_X), $nbt->getInt(self::TAG_Y), $nbt->getInt(self::TAG_Z), $level);
+		$this->readSaveData($nbt);
 
 		$this->getLevel()->addTile($this);
 	}
@@ -169,26 +167,31 @@ abstract class Tile extends Position{
 		return $this->id;
 	}
 
-	public function saveNBT() : void{
+	/**
-		$this->namedtag->setString(self::TAG_ID, static::getSaveId());
+	 * Reads additional data from the CompoundTag on tile creation.
-		$this->namedtag->setInt(self::TAG_X, $this->x);
+	 *
-		$this->namedtag->setInt(self::TAG_Y, $this->y);
+	 * @param CompoundTag $nbt
-		$this->namedtag->setInt(self::TAG_Z, $this->z);
+	 */
-	}
+	abstract protected function readSaveData(CompoundTag $nbt) : void;
 
-	public function getNBT() : CompoundTag{
+	/**
-		return $this->namedtag;
+	 * Writes additional save data to a CompoundTag, not including generic things like ID and coordinates.
+	 *
+	 * @param CompoundTag $nbt
+	 */
+	abstract protected function writeSaveData(CompoundTag $nbt) : void;
+
+	public function saveNBT(CompoundTag $nbt) : void{
+		$nbt->setString(self::TAG_ID, static::getSaveId());
+		$nbt->setInt(self::TAG_X, $this->x);
+		$nbt->setInt(self::TAG_Y, $this->y);
+		$nbt->setInt(self::TAG_Z, $this->z);
+		$this->writeSaveData($nbt);
 	}
 
 	public function getCleanedNBT() : ?CompoundTag{
-		$this->saveNBT();
+		$this->writeSaveData($tag = new CompoundTag());
-		$tag = clone $this->namedtag;
+		return $tag->getCount() > 0 ? $tag : null;
-		$tag->removeTag(self::TAG_X, self::TAG_Y, self::TAG_Z, self::TAG_ID);
-		if($tag->getCount() > 0){
-			return $tag;
-		}else{
-			return null;
-		}
 	}
 
 	/**
@@ -270,8 +273,6 @@ abstract class Tile extends Position{
 				$this->level->removeTile($this);
 				$this->setLevel(null);
 			}
-
-			$this->namedtag = null;
 		}
 	}