/**
* Generates a weak fingerprint based on some attributes of the file (does not require to read the whole file)
*
* @param FileSystemIterator $file File object
*
* @return string Weak fingerprint
*/
protected function generateWeakFingerprint($file)
{
$parts = array($file->getSize(), $file->getCTime(), $file->getOwner(), $file->getMTime());
return implode('_', $parts);
}
