US Patent 9244928 Systems and methods for directory snapshot

A system and method creates a directory snapshot. The method includes retrieving a group of filenames from a directory, splitting the group of filenames into a first plurality of filenames and a second plurality of filenames, and storing the first plurality of filenames into a first temporary snapshot file and storing the second plurality of filenames into a second temporary snapshot file. The filenames in the first and second temporary snapshot files are sorted based on the same heuristic and a sorted linked list that includes a filename listed first in the first temporary snapshot file and a filename listed first in the second temporary snapshot file is created. A first filename from the sorted linked list is saved to a result directory snapshot file.