def digest(self, path=os.curdir, hasher=utils.DEFAULT_HASHER):
"""
Compute the digest of the file. Returns the hex digest of the
file; to retrieve the digest in other forms, pass an explicit
hasher or tuple of hashers.
:param path: An optional path to a subelement of this
directory.
:param hasher: The string name of the desired hash algorithm,
or a digester object as returned by one of the
hashers present in ``hashlib``, or a tuple of
such objects. If not given, defaults to
``utils.DEFAULT_HASHER``.
:returns: The digest of the file, in hex. If a tuple of
hashers was passed for ``hasher``, then the first
hasher will be returned.
"""
# Set up the hasher, first
if not hasher:
raise ValueError('a hasher must be specified')
elif isinstance(hasher, six.string_types):
hasher = (utils.get_hasher(hasher)(),)
elif not isinstance(hasher, tuple):
hasher = (hasher,)
# Open the desired file and digest it
with self.open(path) as f:
return utils.digest(f, hasher)
def test_basic(self):
fo = io.BytesIO(six.b("12345678901234"))
digesters = [
mock.Mock(**{'hexdigest.return_value': 'd16e57'}),
mock.Mock(),
mock.Mock(),
]
result = utils.digest(fo, digesters)
self.assertEqual(result, 'd16e57')
for i, digester in enumerate(digesters):
digester.update.assert_has_calls([
mock.call(six.b('1234')),
mock.call(six.b('5678')),
mock.call(six.b('9012')),
mock.call(six.b('34')),
])
self.assertEqual(digester.update.call_count, 4)
if i == 0:
digester.hexdigest.assert_called_once_with()
else:
self.assertFalse(digester.hexdigest.called)
def tar(self, filename, start=os.curdir, compression=utils.unset,
hasher=None):
"""
Create a tar file with the given filename.
:param filename: The filename of the tar file to create. If
``compression`` is not given, it will be
inferred from the filename. The appropriate
extensions will be added to the filename, if
necessary. If a compression extension on the
filename does not match the specified
compression, a ``ValueError`` will be raised.
:param start: The directory from which to start the tar
process. If not given, starts from the current
directory and includes all files in the
directory. If it is a parent of the current
directory, only the current directory will be
included in the tarball. A ``ValueError`` will
be raised if the tar process cannot start from
the given location.
:param compression: If given, specifies the compression to
use. The ``filename`` will be modified to
include the appropriate extension. A
``ValueError`` will be raised if the given
compression is not supported or if a
compression was inferred from the
filename.
:param hasher: If given, requests that a hash of the resulting
tar file be computed. May be a ``True`` value
to use the default hasher; a string to specify
a hasher; or a tuple of hashers.
:returns: The final filename that was created. If ``hasher``
was specified, a tuple will be returned, with the
second element consisting of the hex digest of the
tar file.
"""
# If the filename is a FSEntry, use its path
if isinstance(filename, FSEntry):
filename = filename.path
# Parse the file name and set the compression
filename = tarname.TarFileName(utils.abspath(filename, cwd=self.path))
if compression is not utils.unset:
filename.compression = compression
# Determine the starting location and file list
start = self._rel(start, False)
filelist = None
rel_path = utils.RelPath(start, self.name)
if rel_path.parents and rel_path.remainder:
raise ValueError("cannot start tar-ing from '%s'" % rel_path)
elif not rel_path.parents and not rel_path.remainder:
start = self.path
elif rel_path.parents:
start = os.path.normpath(
os.path.join(self.path, [os.pardir] * rel_path.parents))
filelist = [os.path.join(*rel_path.path_list[-rel_path.parents:])]
start = self.tree._full(start)
if filelist is None:
filelist = os.listdir(start)
# OK, let's build the tarball
tar = tarfile.open(str(filename), 'w:%s' % filename.compression or '')
try:
with utils.workdir(start):
for fname in filelist:
try:
tar.add(fname)
except Exception:
pass
finally:
tar.close()
# Begin building the result
result = str(filename)
# If a hash was requested, generate it
if hasher:
# Select the hasher(s)
if hasher is True:
hasher = (utils.get_hasher(utils.DEFAULT_HASHER)(),)
elif isinstance(hasher, six.string_types):
hasher = (utils.get_hasher(hasher)(),)
elif not isinstance(hasher, tuple):
hasher = (hasher,)
# Open the file
with open(result) as f:
result = (result, utils.digest(f, hasher))
return result
