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"""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
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