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# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
import hashlib
import os
import shutil
import stat
import sys
import tempfile
from io import BytesIO
from urllib.request import urlopen
from mozpack.macpkg import Pbzx, uncpio, unxar
def unpack_sdk(url, sha256, extract_prefix, out_dir="."):
with tempfile.TemporaryFile() as pkg:
hash = hashlib.sha256()
with urlopen(url) as fh:
# Equivalent to shutil.copyfileobj, but computes sha256 at the same time.
while True:
buf = fh.read(1024 * 1024)
if not buf:
break
hash.update(buf)
pkg.write(buf)
digest = hash.hexdigest()
if digest != sha256:
raise Exception(f"(actual) {digest} != (expected) {sha256}")
pkg.seek(0, os.SEEK_SET)
for name, content in unxar(pkg):
if name in ("Payload", "Content"):
extract_payload(content, extract_prefix, out_dir)
def extract_payload(fileobj, extract_prefix, out_dir="."):
hardlinks = {}
for path, st, content in uncpio(Pbzx(fileobj)):
# When there are hardlinks, normally a cpio stream is supposed to
# contain the data for all of them, but, even with compression, that
# can be a waste of space, so in some cpio streams (*cough* *cough*,
# Apple's, e.g. in Xcode), the files after the first one have dummy
# data.
# As we may be filtering the first file out (if it doesn't match
# extract_prefix), we need to keep its data around (we're not going
# to be able to rewind).
# We could do something fancy in the case where the first file is not
# filtered out, but in practice, it's not worth the extra complexity.
if stat.S_ISREG(st.mode) and st.nlink > 1:
key = (st.dev, st.ino)
hardlink = hardlinks.get(key)
if hardlink:
hardlink[0] -= 1
if hardlink[0] == 0:
del hardlinks[key]
else:
hardlink = hardlinks[key] = [st.nlink - 1, BytesIO(content.read())]
content = hardlink[1]
content.seek(0)
if not path:
continue
path = path.decode()
if not path.startswith(extract_prefix):
continue
path = os.path.join(out_dir, path[len(extract_prefix) :].lstrip("/"))
if stat.S_ISDIR(st.mode):
os.makedirs(path, exist_ok=True)
else:
parent = os.path.dirname(path)
if parent:
os.makedirs(parent, exist_ok=True)
if stat.S_ISLNK(st.mode):
os.symlink(content.read(), path)
elif stat.S_ISREG(st.mode):
with open(path, "wb") as out:
shutil.copyfileobj(content, out)
else:
raise Exception(f"File mode {st.mode:o} is not supported")
if __name__ == "__main__":
unpack_sdk(*sys.argv[1:])
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