LevelProvider: added calculateChunkCount()

this will be used to provide progress information to the user during world conversion.

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

@@ -111,4 +111,10 @@ interface LevelProvider{
 	 */
 	public function getAllChunks() : \Generator;
 
+	/**
+	 * Returns the number of chunks in the provider. Used for world conversion time estimations.
+	 *
+	 * @return int
+	 */
+	public function calculateChunkCount() : int;
 }

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

@@ -373,4 +373,14 @@ class LevelDB extends BaseLevelProvider{
 			}
 		}
 	}
+
+	public function calculateChunkCount() : int{
+		$count = 0;
+		foreach($this->db->getIterator() as $key => $_){
+			if(strlen($key) === 9 and substr($key, -1) === self::TAG_VERSION){
+				$count++;
+			}
+		}
+		return $count;
+	}
 }

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

@@ -208,8 +208,8 @@ abstract class RegionLevelProvider extends BaseLevelProvider{
 		$this->getRegion($regionX, $regionZ)->writeChunk($chunkX & 0x1f, $chunkZ & 0x1f, $this->serializeChunk($chunk));
 	}
 
-	public function getAllChunks() : \Generator{
-		$iterator = new \RegexIterator(
+	private function createRegionIterator() : \RegexIterator{
+		return new \RegexIterator(
 			new \FilesystemIterator(
 				$this->path . '/region/',
 				\FilesystemIterator::CURRENT_AS_PATHNAME | \FilesystemIterator::SKIP_DOTS | \FilesystemIterator::UNIX_PATHS
@@ -217,6 +217,10 @@ abstract class RegionLevelProvider extends BaseLevelProvider{
 			'/\/r\.(-?\d+)\.(-?\d+)\.' . static::getRegionFileExtension() . '$/',
 			\RegexIterator::GET_MATCH
 		);
+	}
+
+	public function getAllChunks() : \Generator{
+		$iterator = $this->createRegionIterator();
 
 		foreach($iterator as $region){
 			$rX = ((int) $region[1]) << 5;
@@ -232,4 +236,13 @@ abstract class RegionLevelProvider extends BaseLevelProvider{
 			}
 		}
 	}
+
+	public function calculateChunkCount() : int{
+		$count = 0;
+		foreach($this->createRegionIterator() as $region){
+			$this->loadRegion((int) $region[1], (int) $region[2]);
+			$count += $this->getRegion((int) $region[1], (int) $region[2])->calculateChunkCount();
+		}
+		return $count;
+	}
 }

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

@@ -289,4 +289,14 @@ class RegionLoader{
 	public function getFilePath() : string{
 		return $this->filePath;
 	}
+
+	public function calculateChunkCount() : int{
+		$count = 0;
+		for($i = 0; $i < 1024; ++$i){
+			if($this->isChunkGenerated($i)){
+				$count++;
+			}
+		}
+		return $count;
+	}
 }