freezer.utils.checksum module

class freezer.utils.checksum.CheckSum(path, hasher_type='sha256', blocksize=1048576, exclude='', ignorelinks=False)

Bases: object

Checksum a file or directory with sha256 or md5 algorithms.

This is used by backup and restore jobs to check for backup consistency.

• parameters::

  param path

  the path to the file or directory to checksum

  type path

  string

  param hasher_type

  the hashing algorithm to use for checksum

  type hasher_type

  string

  param hasher

  hasher object for the specified hasher_type

  type hasher

  hashlib object

  param blocksize

  the max. size of block to read when hashing a file

  type blocksize

  integer

  param exclude

  pattern of files to exclude

  type exclude

  string

  param checksum

  final result for checksum computing

  type checksum

  string

  param real_checksum

  checksum without filename appended if unique file

  type real_checksum

  string

  param count

  number of files checksummed

  type count

  int

compare(checksum)

Compute the checksum for the object path and compare with the given checksum. :return: boolean

compute()

Compute the checksum for the given path. If a single file is provided, the result is its checksum concatenated with its name. If a directory is provided, the result is the checksum of the checksum concatenation for each file. :return: string

get_files_hashes_in_path()

Walk the files in path computing the checksum for each one and updates the concatenation checksum for the final result

get_hash(filepath)

Open filename and calculate its hash. Append the hash to the previous result and stores the checksum for this concatenation :param filepath: path to file :type filepath: string :return: string containing the hash of the given file

hashes = []

hashfile(afile)

Checksum a single file with the chosen algorithm. The file is read in chunks of self.blocksize. :return: string

hashstring(string)

Returns

the hash for a given string

set_hasher(hasher_type)

Sets the hasher from hashlib according to the chosen hasher_type. Also sets the size of the expected output