From be2d134994d53a8b63e6d2643173c0f27d909d9f Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <odigiman@gmail.com>
Date: Wed, 11 Oct 2017 16:09:08 +0100
Subject: [PATCH] Added API to allow flagging an entity not to be saved to disk
 when its chunk is saved (#1452)

---
 src/pocketmine/Player.php                     |  8 ++++
 src/pocketmine/entity/Entity.php              | 21 ++++++++++
 .../level/format/io/leveldb/LevelDB.php       | 40 +++++++++++--------
 .../level/format/io/region/Anvil.php          |  2 +-
 .../level/format/io/region/McRegion.php       |  2 +-
 .../level/format/io/region/PMAnvil.php        |  2 +-
 6 files changed, 55 insertions(+), 20 deletions(-)

diff --git a/src/pocketmine/Player.php b/src/pocketmine/Player.php
index 5e7b9dd506..a91e432047 100644
--- a/src/pocketmine/Player.php
+++ b/src/pocketmine/Player.php
@@ -3415,6 +3415,14 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 		return [];
 	}
 
+	public function canSaveWithChunk() : bool{
+		return false;
+	}
+
+	public function setCanSaveWithChunk(bool $value) : void{
+		throw new \BadMethodCallException("Players can't be saved with chunks");
+	}
+
 	/**
 	 * Handles player data saving
 	 *
diff --git a/src/pocketmine/entity/Entity.php b/src/pocketmine/entity/Entity.php
index 4be957e29e..e1744243e3 100644
--- a/src/pocketmine/entity/Entity.php
+++ b/src/pocketmine/entity/Entity.php
@@ -337,6 +337,9 @@ abstract class Entity extends Location implements Metadatable{
 	/** @var bool */
 	protected $isStatic = false;
 
+	/** @var bool */
+	private $savedWithChunk = true;
+
 	/** @var bool */
 	public $isCollided = false;
 	/** @var bool */
@@ -764,6 +767,24 @@ abstract class Entity extends Location implements Metadatable{
 		return false;
 	}
 
+	/**
+	 * Returns whether this entity will be saved when its chunk is unloaded.
+	 * @return bool
+	 */
+	public function canSaveWithChunk() : bool{
+		return $this->savedWithChunk;
+	}
+
+	/**
+	 * Sets whether this entity will be saved when its chunk is unloaded. This can be used to prevent the entity being
+	 * saved to disk.
+	 *
+	 * @param bool $value
+	 */
+	public function setCanSaveWithChunk(bool $value) : void{
+		$this->savedWithChunk = $value;
+	}
+
 	/**
 	 * Returns the short save name
 	 *
diff --git a/src/pocketmine/level/format/io/leveldb/LevelDB.php b/src/pocketmine/level/format/io/leveldb/LevelDB.php
index d0c4340367..eea526e71a 100644
--- a/src/pocketmine/level/format/io/leveldb/LevelDB.php
+++ b/src/pocketmine/level/format/io/leveldb/LevelDB.php
@@ -509,32 +509,38 @@ class LevelDB extends BaseLevelProvider{
 		//TODO: use this properly
 		$this->db->put($index . self::TAG_STATE_FINALISATION, chr(self::FINALISATION_DONE));
 
-		$this->writeTags($chunk->getTiles(), $index . self::TAG_BLOCK_ENTITY);
-		$this->writeTags(array_filter($chunk->getEntities(), function(Entity $entity) : bool{
-				return !($entity instanceof Player);
-		}), $index . self::TAG_ENTITY);
+		/** @var CompoundTag[] $tiles */
+		$tiles = [];
+		foreach($chunk->getTiles() as $tile){
+			if(!$tile->isClosed()){
+				$tile->saveNBT();
+				$tiles[] = $tile->namedtag;
+			}
+		}
+		$this->writeTags($tiles, $index . self::TAG_BLOCK_ENTITY);
+
+		/** @var CompoundTag[] $entities */
+		$entities = [];
+		foreach($chunk->getEntities() as $entity){
+			if($entity->canSaveWithChunk() and !$entity->isClosed()){
+				$entity->saveNBT();
+				$entities[] = $entity->namedtag;
+			}
+		}
+		$this->writeTags($entities, $index . self::TAG_ENTITY);
 
 		$this->db->delete($index . self::TAG_DATA_2D_LEGACY);
 		$this->db->delete($index . self::TAG_LEGACY_TERRAIN);
 	}
 
 	/**
-	 * @param Entity[]|Tile[] $targets
-	 * @param string          $index
+	 * @param CompoundTag[] $targets
+	 * @param string        $index
 	 */
 	private function writeTags(array $targets, string $index){
-		$nbt = new NBT(NBT::LITTLE_ENDIAN);
-		$out = [];
-		/** @var Entity|Tile $target */
-		foreach($targets as $target){
-			if(!$target->isClosed()){
-				$target->saveNBT();
-				$out[] = $target->namedtag;
-			}
-		}
-
 		if(!empty($targets)){
-			$nbt->setData($out);
+			$nbt = new NBT(NBT::LITTLE_ENDIAN);
+			$nbt->setData($targets);
 			$this->db->put($index, $nbt->write());
 		}else{
 			$this->db->delete($index);
diff --git a/src/pocketmine/level/format/io/region/Anvil.php b/src/pocketmine/level/format/io/region/Anvil.php
index a9d83741e3..7536f3f334 100644
--- a/src/pocketmine/level/format/io/region/Anvil.php
+++ b/src/pocketmine/level/format/io/region/Anvil.php
@@ -70,7 +70,7 @@ class Anvil extends McRegion{
 		$entities = [];
 
 		foreach($chunk->getEntities() as $entity){
-			if(!($entity instanceof Player) and !$entity->isClosed()){
+			if($entity->canSaveWithChunk() and !$entity->isClosed()){
 				$entity->saveNBT();
 				$entities[] = $entity->namedtag;
 			}
diff --git a/src/pocketmine/level/format/io/region/McRegion.php b/src/pocketmine/level/format/io/region/McRegion.php
index b3c7391080..df2394542b 100644
--- a/src/pocketmine/level/format/io/region/McRegion.php
+++ b/src/pocketmine/level/format/io/region/McRegion.php
@@ -89,7 +89,7 @@ class McRegion extends BaseLevelProvider{
 		$entities = [];
 
 		foreach($chunk->getEntities() as $entity){
-			if(!($entity instanceof Player) and !$entity->isClosed()){
+			if($entity->canSaveWithChunk() and !$entity->isClosed()){
 				$entity->saveNBT();
 				$entities[] = $entity->namedtag;
 			}
diff --git a/src/pocketmine/level/format/io/region/PMAnvil.php b/src/pocketmine/level/format/io/region/PMAnvil.php
index b6fe2728b0..9a8a2951a3 100644
--- a/src/pocketmine/level/format/io/region/PMAnvil.php
+++ b/src/pocketmine/level/format/io/region/PMAnvil.php
@@ -74,7 +74,7 @@ class PMAnvil extends Anvil{
 		$entities = [];
 
 		foreach($chunk->getEntities() as $entity){
-			if(!($entity instanceof Player) and !$entity->isClosed()){
+			if($entity->canSaveWithChunk() and !$entity->isClosed()){
 				$entity->saveNBT();
 				$entities[] = $entity->namedtag;
 			}