LevelProvider: Remove cyclic dependency between Level and LevelProvider

This will now allow LevelProviders to be constructed on threads.

src/pocketmine/level/Level.php

@@ -343,7 +343,7 @@ class Level implements ChunkManager, Metadatable{
 		/** @var LevelProvider $provider */
 
 		if(is_subclass_of($provider, LevelProvider::class, true)){
-			$this->provider = new $provider($this, $path);
+			$this->provider = new $provider($path);
 		}else{
 			throw new LevelException("Provider is not a subclass of LevelProvider");
 		}
@@ -2546,7 +2546,7 @@ class Level implements ChunkManager, Metadatable{
 				}
 				$this->timings->syncChunkSendPrepareTimer->startTiming();
 
-				$chunk = $this->provider->getChunk($x, $z, false);
+				$chunk = $this->provider->getChunk($x, $z);
 				if(!($chunk instanceof Chunk)){
 					throw new ChunkException("Invalid Chunk sent");
 				}
@@ -2686,7 +2686,13 @@ class Level implements ChunkManager, Metadatable{
 
 		$this->cancelUnloadChunkRequest($x, $z);
 
-		$chunk = $this->provider->getChunk($x, $z, $generate);
+		$this->timings->syncChunkLoadDataTimer->startTiming();
+
+		$this->provider->loadChunk($x, $z, $generate);
+		$chunk = $this->provider->getChunk($x, $z);
+
+		$this->timings->syncChunkLoadDataTimer->stopTiming();
+
 		if($chunk === null){
 			if($generate){
 				throw new \InvalidStateException("Could not create new Chunk");

src/pocketmine/level/format/io/BaseLevelProvider.php

@@ -33,8 +33,6 @@ use pocketmine\nbt\tag\CompoundTag;
 use pocketmine\nbt\tag\StringTag;
 
 abstract class BaseLevelProvider implements LevelProvider{
-	/** @var Level */
-	protected $level;
 	/** @var string */
 	protected $path;
 	/** @var CompoundTag */
@@ -42,8 +40,7 @@ abstract class BaseLevelProvider implements LevelProvider{
 	/** @var Chunk[] */
 	protected $chunks = [];
 
-	public function __construct(Level $level, string $path){
+	public function __construct(string $path){
-		$this->level = $level;
 		$this->path = $path;
 		if(!file_exists($this->path)){
 			mkdir($this->path, 0777, true);
@@ -120,15 +117,8 @@ abstract class BaseLevelProvider implements LevelProvider{
 		file_put_contents($this->getPath() . "level.dat", $buffer);
 	}
 
-	public function getChunk(int $chunkX, int $chunkZ, bool $create = false){
+	public function getChunk(int $chunkX, int $chunkZ){
-		$index = Level::chunkHash($chunkX, $chunkZ);
+		return $this->chunks[Level::chunkHash($chunkX, $chunkZ)] ?? null;
-		if(isset($this->chunks[$index])){
-			return $this->chunks[$index];
-		}else{
-			$this->loadChunk($chunkX, $chunkZ, $create);
-
-			return $this->chunks[$index] ?? null;
-		}
 	}
 
 	public function isChunkLoaded(int $chunkX, int $chunkZ) : bool{
@@ -145,12 +135,10 @@ abstract class BaseLevelProvider implements LevelProvider{
 			return true;
 		}
 
-		$this->level->timings->syncChunkLoadDataTimer->startTiming();
 		$chunk = $this->readChunk($chunkX, $chunkZ);
 		if($chunk === null and $create){
 			$chunk = new Chunk($chunkX, $chunkZ);
 		}
-		$this->level->timings->syncChunkLoadDataTimer->stopTiming();
 
 		if($chunk !== null){
 			$this->chunks[$index] = $chunk;

src/pocketmine/level/format/io/LevelProvider.php

@@ -24,16 +24,14 @@ declare(strict_types=1);
 namespace pocketmine\level\format\io;
 
 use pocketmine\level\format\Chunk;
-use pocketmine\level\Level;
 use pocketmine\math\Vector3;
 
 interface LevelProvider{
 
 	/**
-	 * @param Level  $level
 	 * @param string $path
 	 */
-	public function __construct(Level $level, string $path);
+	public function __construct(string $path);
 
 	/**
 	 * Returns the full provider name, like "anvil" or "mcregion", will be used to find the correct format.
@@ -91,13 +89,12 @@ interface LevelProvider{
 	 * Gets the Chunk object
 	 * This method must be implemented by all the level formats.
 	 *
-	 * @param int  $chunkX
+	 * @param int $chunkX
-	 * @param int  $chunkZ
+	 * @param int $chunkZ
-	 * @param bool $create
 	 *
 	 * @return Chunk|null
 	 */
-	public function getChunk(int $chunkX, int $chunkZ, bool $create = false);
+	public function getChunk(int $chunkX, int $chunkZ);
 
 	/**
 	 * @param int   $chunkX

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

@@ -87,10 +87,9 @@ class LevelDB extends BaseLevelProvider{
 		}
 	}
 
-	public function __construct(Level $level, string $path){
+	public function __construct(string $path){
 		self::checkForLevelDBExtension();
 
-		$this->level = $level;
 		$this->path = $path;
 		if(!file_exists($this->path)){
 			mkdir($this->path, 0777, true);
@@ -530,6 +529,5 @@ class LevelDB extends BaseLevelProvider{
 	public function close(){
 		$this->unloadChunks();
 		$this->db->close();
-		$this->level = null;
 	}
 }

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

@@ -355,7 +355,6 @@ class McRegion extends BaseLevelProvider{
 			$region->close();
 			unset($this->regions[$index]);
 		}
-		$this->level = null;
 	}
 
 	protected function readChunk(int $chunkX, int $chunkZ) : ?Chunk{