public function getSize( $pattern = NULL, $unit = NULL, $precision = NULL )
	{
		$size	= 0;
		foreach( $this->getFileList( $pattern ) as $entry )
			$size	+= $entry->getSize();
		if( $unit )
			$size	= Alg_UnitFormater::formatBytes( $size, $precision );
		return $size;
	}