public static function getDirectorySize($dir) {
		if (is_dir($dir)) {
			$totalSize = 0;
			$iterator = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($dir));
			foreach($iterator as $file) {
				$totalSize += $file->getSize();
			}
			return $totalSize;
		}
		return false;
	}