How to use the securesystemslib.formats.NAME_SCHEMA.check_match function in securesystemslib

Th metadata files (e.g., 'root.json', 'targets.json') for the top- level
      roles are read from disk and stored in dictionaries.  In addition, the
      key and roledb modules are populated with 'repository_name' entries.

    
      None.
    """

    # Do the arguments have the correct format?
    # These checks ensure the arguments have the appropriate
    # number of objects and object types and that all dict
    # keys are properly named.
    # Raise 'securesystemslib.exceptions.FormatError' if there is a mistmatch.
    securesystemslib.formats.NAME_SCHEMA.check_match(repository_name)
    tuf.formats.MIRRORDICT_SCHEMA.check_match(repository_mirrors)

    # Save the validated arguments.
    self.repository_name = repository_name
    self.mirrors = repository_mirrors

    # Store the trusted metadata read from disk.
    self.metadata = {}

    # Store the currently trusted/verified metadata.
    self.metadata['current'] = {}

    # Store the previously trusted/verified metadata.
    self.metadata['previous'] = {}

    # Store the version numbers of roles available on the repository.  The dict

securesystemslib.exceptions.FormatError, if 'repository_name' is improperly
    formatted.

    securesystemslib.exceptions.InvalidNameError, if 'repository_name' does not
    exist in the role database.

  
    None.

  
    A list of rolenames.
  """

  # Does 'repository_name' have the correct format?  Raise
  # 'securesystemslib.exceptions.FormatError' if it is improperly formatted.
  securesystemslib.formats.NAME_SCHEMA.check_match(repository_name)

  global _roledb_dict
  global _dirty_roles

  if repository_name not in _roledb_dict or repository_name not in _dirty_roles:
    raise securesystemslib.exceptions.InvalidNameError('Repository name does'
      ' not' ' exist: ' + repository_name)

  return list(_roledb_dict[repository_name].keys())

None.

  
    A timestamp metadata object, conformant to 'tuf.formats.TIMESTAMP_SCHEMA'.
  """

  # Do the arguments have the correct format?
  # This check ensures arguments have the appropriate number of objects and
  # object types, and that all dict keys are properly named.
  # Raise 'securesystemslib.exceptions.FormatError' if the check fails.
  securesystemslib.formats.PATH_SCHEMA.check_match(snapshot_filename)
  tuf.formats.METADATAVERSION_SCHEMA.check_match(version)
  securesystemslib.formats.ISO8601_DATETIME_SCHEMA.check_match(expiration_date)
  securesystemslib.formats.NAME_SCHEMA.check_match(repository_name)

  # Retrieve the versioninfo of the Snapshot metadata file.
  snapshot_fileinfo = {}
  length, hashes = securesystemslib.util.get_file_details(snapshot_filename)
  snapshot_version = get_metadata_versioninfo('snapshot', repository_name)
  snapshot_fileinfo[SNAPSHOT_FILENAME] = \
    tuf.formats.make_fileinfo(length, hashes, version=snapshot_version['version'])

  # We previously saved the versioninfo of the compressed versions of
  # 'snapshot.json' in 'versioninfo'.  Since version numbers are now stored,
  # the version numbers of compressed roles do not change and can thus be
  # excluded.

  # Generate the timestamp metadata object.
  timestamp_metadata = tuf.formats.TimestampFile.make_metadata(version,
      expiration_date, snapshot_fileinfo)

securesystemslib.exceptions.FormatError, if 'repository_name' does not have
    the correct format.

    securesystemslib.exceptions.InvalidNameError, if 'repository_name' does not
    exist in the role database.

  
    None.

  
    None.
  """

  # Do the arguments have the correct format?  If not, raise
  # 'securesystemslib.exceptions.FormatError'
  securesystemslib.formats.NAME_SCHEMA.check_match(repository_name)
  securesystemslib.formats.BOOLEAN_SCHEMA.check_match(clear_all)

  global _roledb_dict
  global _dirty_roles

  if repository_name not in _roledb_dict or repository_name not in _dirty_roles:
    raise securesystemslib.exceptions.InvalidNameError('Repository name does not'
      ' exist: ' + repository_name)

  if clear_all:
    _roledb_dict = {}
    _roledb_dict['default'] = {}
    _dirty_roles = {}
    _dirty_roles['default'] = set()
    return

tuf.exceptions.UnknownRoleError, if 'rolename' cannot be found
    in the role database.

    securesystemslib.exceptions.InvalidNameError, if 'rolename' is incorrectly
    formatted, or 'repository_name' does not exist in the role database.

  
    None.

  
    A threshold integer value.
  """

  # Raise 'securesystemslib.exceptions.FormatError' if 'repository_name' is
  # improperly formatted.
  securesystemslib.formats.NAME_SCHEMA.check_match(repository_name)

  # Raises securesystemslib.exceptions.FormatError,
  # tuf.exceptions.UnknownRoleError, or
  # securesystemslib.exceptions.InvalidNameError.
  _check_rolename(rolename, repository_name)

  global _roledb_dict
  global _dirty_roles

  roleinfo = _roledb_dict[repository_name][rolename]

  return roleinfo['threshold']

securesystemslib.exceptions.FormatError, if 'repository_name' is improperly formatted.

    securesystemslib.exceptions.InvalidNameError, if 'repository_name' does not exist in the key
    database.

  
    The keydb key database is reset.

  
    None.
  """

  # Do the arguments have the correct format?  Raise 'securesystemslib.exceptions.FormatError' if
  # 'repository_name' is improperly formatted.
  securesystemslib.formats.NAME_SCHEMA.check_match(repository_name)
  securesystemslib.formats.BOOLEAN_SCHEMA.check_match(clear_all)

  global _keydb_dict

  if clear_all:
    _keydb_dict = {}
    _keydb_dict['default'] = {}

  if repository_name not in _keydb_dict:
    raise securesystemslib.exceptions.InvalidNameError('Repository name does not exist:'
      ' ' + repr(repository_name))

  _keydb_dict[repository_name] = {}

The 'metadata_directory' and 'targets_directory'  directories are created
    if they do not exist.

  
    A 'tuf.developer_tool.Project' object.
  """

  # Does 'metadata_directory' have the correct format?
  # Ensure the arguments have the appropriate number of objects and object
  # types, and that all dict keys are properly named.
  # Raise 'securesystemslib.exceptions.FormatError' if there is a mismatch.
  securesystemslib.formats.PATH_SCHEMA.check_match(metadata_directory)

  # Do the same for the location in the repo and the project name, we must
  # ensure they are valid pathnames.
  securesystemslib.formats.NAME_SCHEMA.check_match(project_name)
  securesystemslib.formats.PATH_SCHEMA.check_match(location_in_repository)
  securesystemslib.formats.NAME_SCHEMA.check_match(repository_name)

  # for the targets directory we do the same, but first, let's find out what
  # layout the user needs, layout_type is a variable that is usually set to
  # 1, which means "flat" (i.e. the cfg file is where the metadata folder is
  # located), with a two, the cfg file goes to the "metadata" folder, and a
  # new metadata folder is created inside the tree, to separate targets and
  # metadata.
  layout_type = 'flat'
  if targets_directory is None:
    targets_directory = os.path.join(metadata_directory, TARGETS_DIRECTORY_NAME)
    metadata_directory = \
        os.path.join(metadata_directory, METADATA_DIRECTORY_NAME)
    layout_type = 'repo-like'

None.

  
    A signable object conformant to 'tuf.formats.SIGNABLE_SCHEMA'.
  """

  # Do the arguments have the correct format?
  # This check ensures arguments have the appropriate number of objects and
  # object types, and that all dict keys are properly named.
  # Raise 'securesystemslib.exceptions.FormatError' if the check fails.
  tuf.formats.ANYROLE_SCHEMA.check_match(metadata_object)
  securesystemslib.formats.KEYIDS_SCHEMA.check_match(keyids)
  securesystemslib.formats.PATH_SCHEMA.check_match(filename)
  securesystemslib.formats.NAME_SCHEMA.check_match(repository_name)

  # Make sure the metadata is in 'signable' format.  That is,
  # it contains a 'signatures' field containing the result
  # of signing the 'signed' field of 'metadata' with each
  # keyid of 'keyids'.
  signable = tuf.formats.make_signable(metadata_object)

  # Sign the metadata with each keyid in 'keyids'.  'signable' should have
  # zero signatures (metadata_object contained none).
  for keyid in keyids:

    # Load the signing key.
    key = tuf.keydb.get_key(keyid, repository_name=repository_name)
    # Generate the signature using the appropriate signing method.
    if key['keytype'] in SUPPORTED_KEY_TYPES:
      if 'private' in key['keyval']:

not be removed, so 'repository_name' cannot be 'default'.

  
    securesystemslib.exceptions.FormatError, if 'repository_name' is improperly formatted.

    securesystemslib.exceptions.InvalidNameError, if 'repository_name' is 'default'.

  
    None.

  
    None.
  """

  # Is 'repository_name' properly formatted?  Raise 'securesystemslib.exceptions.FormatError' if not.
  securesystemslib.formats.NAME_SCHEMA.check_match(repository_name)

  if repository_name not in _keydb_dict:
    logger.warn('Repository name does not exist: ' + repr(repository_name))
    return

  if repository_name == 'default':
    raise securesystemslib.exceptions.InvalidNameError('Cannot remove the default repository:'
      ' ' + repr(repository_name))

  del _keydb_dict[repository_name]