forked from varia/varia.website
214 lines
7.2 KiB
Python
214 lines
7.2 KiB
Python
"""Utilities for extracting common archive formats"""
|
|
|
|
import zipfile
|
|
import tarfile
|
|
import os
|
|
import shutil
|
|
import posixpath
|
|
import contextlib
|
|
from distutils.errors import DistutilsError
|
|
|
|
from ._path import ensure_directory
|
|
|
|
__all__ = [
|
|
"unpack_archive", "unpack_zipfile", "unpack_tarfile", "default_filter",
|
|
"UnrecognizedFormat", "extraction_drivers", "unpack_directory",
|
|
]
|
|
|
|
|
|
class UnrecognizedFormat(DistutilsError):
|
|
"""Couldn't recognize the archive type"""
|
|
|
|
|
|
def default_filter(src, dst):
|
|
"""The default progress/filter callback; returns True for all files"""
|
|
return dst
|
|
|
|
|
|
def unpack_archive(
|
|
filename, extract_dir, progress_filter=default_filter,
|
|
drivers=None):
|
|
"""Unpack `filename` to `extract_dir`, or raise ``UnrecognizedFormat``
|
|
|
|
`progress_filter` is a function taking two arguments: a source path
|
|
internal to the archive ('/'-separated), and a filesystem path where it
|
|
will be extracted. The callback must return the desired extract path
|
|
(which may be the same as the one passed in), or else ``None`` to skip
|
|
that file or directory. The callback can thus be used to report on the
|
|
progress of the extraction, as well as to filter the items extracted or
|
|
alter their extraction paths.
|
|
|
|
`drivers`, if supplied, must be a non-empty sequence of functions with the
|
|
same signature as this function (minus the `drivers` argument), that raise
|
|
``UnrecognizedFormat`` if they do not support extracting the designated
|
|
archive type. The `drivers` are tried in sequence until one is found that
|
|
does not raise an error, or until all are exhausted (in which case
|
|
``UnrecognizedFormat`` is raised). If you do not supply a sequence of
|
|
drivers, the module's ``extraction_drivers`` constant will be used, which
|
|
means that ``unpack_zipfile`` and ``unpack_tarfile`` will be tried, in that
|
|
order.
|
|
"""
|
|
for driver in drivers or extraction_drivers:
|
|
try:
|
|
driver(filename, extract_dir, progress_filter)
|
|
except UnrecognizedFormat:
|
|
continue
|
|
else:
|
|
return
|
|
else:
|
|
raise UnrecognizedFormat(
|
|
"Not a recognized archive type: %s" % filename
|
|
)
|
|
|
|
|
|
def unpack_directory(filename, extract_dir, progress_filter=default_filter):
|
|
""""Unpack" a directory, using the same interface as for archives
|
|
|
|
Raises ``UnrecognizedFormat`` if `filename` is not a directory
|
|
"""
|
|
if not os.path.isdir(filename):
|
|
raise UnrecognizedFormat("%s is not a directory" % filename)
|
|
|
|
paths = {
|
|
filename: ('', extract_dir),
|
|
}
|
|
for base, dirs, files in os.walk(filename):
|
|
src, dst = paths[base]
|
|
for d in dirs:
|
|
paths[os.path.join(base, d)] = src + d + '/', os.path.join(dst, d)
|
|
for f in files:
|
|
target = os.path.join(dst, f)
|
|
target = progress_filter(src + f, target)
|
|
if not target:
|
|
# skip non-files
|
|
continue
|
|
ensure_directory(target)
|
|
f = os.path.join(base, f)
|
|
shutil.copyfile(f, target)
|
|
shutil.copystat(f, target)
|
|
|
|
|
|
def unpack_zipfile(filename, extract_dir, progress_filter=default_filter):
|
|
"""Unpack zip `filename` to `extract_dir`
|
|
|
|
Raises ``UnrecognizedFormat`` if `filename` is not a zipfile (as determined
|
|
by ``zipfile.is_zipfile()``). See ``unpack_archive()`` for an explanation
|
|
of the `progress_filter` argument.
|
|
"""
|
|
|
|
if not zipfile.is_zipfile(filename):
|
|
raise UnrecognizedFormat("%s is not a zip file" % (filename,))
|
|
|
|
with zipfile.ZipFile(filename) as z:
|
|
_unpack_zipfile_obj(z, extract_dir, progress_filter)
|
|
|
|
|
|
def _unpack_zipfile_obj(zipfile_obj, extract_dir, progress_filter=default_filter):
|
|
"""Internal/private API used by other parts of setuptools.
|
|
Similar to ``unpack_zipfile``, but receives an already opened :obj:`zipfile.ZipFile`
|
|
object instead of a filename.
|
|
"""
|
|
for info in zipfile_obj.infolist():
|
|
name = info.filename
|
|
|
|
# don't extract absolute paths or ones with .. in them
|
|
if name.startswith('/') or '..' in name.split('/'):
|
|
continue
|
|
|
|
target = os.path.join(extract_dir, *name.split('/'))
|
|
target = progress_filter(name, target)
|
|
if not target:
|
|
continue
|
|
if name.endswith('/'):
|
|
# directory
|
|
ensure_directory(target)
|
|
else:
|
|
# file
|
|
ensure_directory(target)
|
|
data = zipfile_obj.read(info.filename)
|
|
with open(target, 'wb') as f:
|
|
f.write(data)
|
|
unix_attributes = info.external_attr >> 16
|
|
if unix_attributes:
|
|
os.chmod(target, unix_attributes)
|
|
|
|
|
|
def _resolve_tar_file_or_dir(tar_obj, tar_member_obj):
|
|
"""Resolve any links and extract link targets as normal files."""
|
|
while tar_member_obj is not None and (
|
|
tar_member_obj.islnk() or tar_member_obj.issym()):
|
|
linkpath = tar_member_obj.linkname
|
|
if tar_member_obj.issym():
|
|
base = posixpath.dirname(tar_member_obj.name)
|
|
linkpath = posixpath.join(base, linkpath)
|
|
linkpath = posixpath.normpath(linkpath)
|
|
tar_member_obj = tar_obj._getmember(linkpath)
|
|
|
|
is_file_or_dir = (
|
|
tar_member_obj is not None and
|
|
(tar_member_obj.isfile() or tar_member_obj.isdir())
|
|
)
|
|
if is_file_or_dir:
|
|
return tar_member_obj
|
|
|
|
raise LookupError('Got unknown file type')
|
|
|
|
|
|
def _iter_open_tar(tar_obj, extract_dir, progress_filter):
|
|
"""Emit member-destination pairs from a tar archive."""
|
|
# don't do any chowning!
|
|
tar_obj.chown = lambda *args: None
|
|
|
|
with contextlib.closing(tar_obj):
|
|
for member in tar_obj:
|
|
name = member.name
|
|
# don't extract absolute paths or ones with .. in them
|
|
if name.startswith('/') or '..' in name.split('/'):
|
|
continue
|
|
|
|
prelim_dst = os.path.join(extract_dir, *name.split('/'))
|
|
|
|
try:
|
|
member = _resolve_tar_file_or_dir(tar_obj, member)
|
|
except LookupError:
|
|
continue
|
|
|
|
final_dst = progress_filter(name, prelim_dst)
|
|
if not final_dst:
|
|
continue
|
|
|
|
if final_dst.endswith(os.sep):
|
|
final_dst = final_dst[:-1]
|
|
|
|
yield member, final_dst
|
|
|
|
|
|
def unpack_tarfile(filename, extract_dir, progress_filter=default_filter):
|
|
"""Unpack tar/tar.gz/tar.bz2 `filename` to `extract_dir`
|
|
|
|
Raises ``UnrecognizedFormat`` if `filename` is not a tarfile (as determined
|
|
by ``tarfile.open()``). See ``unpack_archive()`` for an explanation
|
|
of the `progress_filter` argument.
|
|
"""
|
|
try:
|
|
tarobj = tarfile.open(filename)
|
|
except tarfile.TarError as e:
|
|
raise UnrecognizedFormat(
|
|
"%s is not a compressed or uncompressed tar file" % (filename,)
|
|
) from e
|
|
|
|
for member, final_dst in _iter_open_tar(
|
|
tarobj, extract_dir, progress_filter,
|
|
):
|
|
try:
|
|
# XXX Ugh
|
|
tarobj._extract_member(member, final_dst)
|
|
except tarfile.ExtractError:
|
|
# chown/chmod/mkfifo/mknode/makedev failed
|
|
pass
|
|
|
|
return True
|
|
|
|
|
|
extraction_drivers = unpack_directory, unpack_zipfile, unpack_tarfile
|