#
# Copyright (C) 2017 Codethink Limited
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library. If not, see .
#
# Authors:
# Jonathan Maw
"""
tar - stage files from tar archives
===================================
**Host dependencies:**
* lzip (for .tar.lz files)
**Usage:**
.. code:: yaml
# Specify the tar source kind
kind: tar
# Specify the tar url. Using an alias defined in your project
# configuration is encouraged. 'bst track' will update the
# sha256sum in 'ref' to the downloaded file's sha256sum.
url: upstream:foo.tar
# Specify the ref. It's a sha256sum of the file you download.
ref: 6c9f6f68a131ec6381da82f2bff978083ed7f4f7991d931bfa767b7965ebc94b
# Specify a glob pattern to indicate the base directory to extract
# from the tarball. The first matching directory will be used.
#
# Note that this is '*' by default since most standard release
# tarballs contain a self named subdirectory at the root which
# contains the files one normally wants to extract to build.
#
# To extract the root of the tarball directly, this can be set
# to an empty string.
base-dir: '*'
See :ref:`built-in functionality doumentation ` for
details on common configuration options for sources.
"""
import os
import tarfile
from contextlib import contextmanager
from tempfile import TemporaryFile
from buildstream import SourceError
from buildstream import utils
from buildstream import DownloadableFileSource
class TarSource(DownloadableFileSource):
# pylint: disable=attribute-defined-outside-init
def configure(self, node):
super().configure(node)
# url in DownloadableFileSource is private, so we read it again
original_url = self.node_get_member(node, str, 'url')
self.url = self.translate_url(original_url)
self.base_dir = self.node_get_member(node, str, 'base-dir', '*') or None
self.node_validate(node, DownloadableFileSource.COMMON_CONFIG_KEYS + ['base-dir'])
def preflight(self):
self.host_lzip = None
if self.url.endswith('.lz'):
self.host_lzip = utils.get_host_tool('lzip')
def get_unique_key(self):
return super().get_unique_key() + [self.base_dir]
@contextmanager
def _run_lzip(self):
assert self.host_lzip
with TemporaryFile() as lzip_stdout:
with open(self.get_mirror_file(), 'r') as lzip_file:
self.call([self.host_lzip, '-d'],
stdin=lzip_file,
stdout=lzip_stdout)
lzip_stdout.seek(0, 0)
yield lzip_stdout
@contextmanager
def _get_tar(self):
if self.url.endswith('.lz'):
with self._run_lzip() as lzip_dec:
with tarfile.open(fileobj=lzip_dec, mode='r:') as tar:
yield tar
else:
with tarfile.open(self.get_mirror_file()) as tar:
yield tar
def stage(self, directory):
try:
with self._get_tar() as tar:
base_dir = None
if self.base_dir:
base_dir = self._find_base_dir(tar, self.base_dir)
if base_dir:
tar.extractall(path=directory, members=self._extract_members(tar, base_dir))
else:
tar.extractall(path=directory)
except (tarfile.TarError, OSError) as e:
raise SourceError("{}: Error staging source: {}".format(self, e)) from e
# Override and translate which filenames to extract
def _extract_members(self, tar, base_dir):
if not base_dir.endswith(os.sep):
base_dir = base_dir + os.sep
L = len(base_dir)
for member in tar.getmembers():
# First, ensure that a member never starts with `./`
if member.path.startswith('./'):
member.path = member.path[2:]
# Now extract only the paths which match the normalized path
if member.path.startswith(base_dir):
# If it's got a link name, give it the same treatment, we
# need the link targets to match up with what we are staging
#
# NOTE: Its possible this is not perfect, we may need to
# consider links which point outside of the chosen
# base directory.
#
if member.type == tarfile.LNKTYPE:
member.linkname = member.linkname[L:]
member.path = member.path[L:]
yield member
# We want to iterate over all paths of a tarball, but getmembers()
# is not enough because some tarballs simply do not contain the leading
# directory paths for the archived files.
def _list_tar_paths(self, tar):
visited = {}
for member in tar.getmembers():
# Remove any possible leading './', offer more consistent behavior
# across tarballs encoded with or without a leading '.'
member_name = member.name.lstrip('./')
if not member.isdir():
# Loop over the components of a path, for a path of a/b/c/d
# we will first visit 'a', then 'a/b' and then 'a/b/c', excluding
# the final component
components = member_name.split('/')
for i in range(len(components) - 1):
dir_component = '/'.join([components[j] for j in range(i + 1)])
if dir_component not in visited:
visited[dir_component] = True
try:
# Dont yield directory members which actually do
# exist in the archive
_ = tar.getmember(dir_component)
except KeyError:
if dir_component != '.':
yield dir_component
continue
# Avoid considering the '.' directory, if any is included in the archive
# this is to avoid the default 'base-dir: *' value behaving differently
# depending on whether the tarball was encoded with a leading '.' or not
elif member_name == '.':
continue
yield member_name
def _find_base_dir(self, tar, pattern):
paths = self._list_tar_paths(tar)
matches = sorted(list(utils.glob(paths, pattern)))
if not matches:
raise SourceError("{}: Could not find base directory matching pattern: {}".format(self, pattern))
return matches[0]
def setup():
return TarSource