Diag::formatSize

private function formatSize($size, $precision = 2)
{
	$suffix = array('b', 'Kb', 'Mb', 'Gb', 'Tb');
	$pos = 0;
	while($size >= 1024 && $pos < 4)
	{
		$size /= 1024;
		$pos++;
	}

	return round($size, $precision) . ' ' . $suffix[$pos];
}