# Copyright 2019 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
import struct
import sys
import zipfile
from util
import build_utils
_FIXED_ZIP_HEADER_LEN =
30
def _PatchedDecodeExtra(self):
# Try to decode the extra field.
extra = self.extra
unpack = struct.unpack
while len(extra) >=
4:
tp, ln = unpack(
'<HH', extra[:
4])
if tp ==
1:
if ln >=
24:
counts = unpack(
'<QQQ', extra[
4:
28])
elif ln ==
16:
counts = unpack(
'<QQ', extra[
4:
20])
elif ln ==
8:
counts = unpack(
'<Q', extra[
4:
12])
elif ln ==
0:
counts = ()
else:
raise RuntimeError(
"Corrupt extra field %s" % (ln, ))
idx =
0
# ZIP64 extension (large files and/or large archives)
if self.file_size
in (
0xffffffffffffffff,
0xffffffff):
self.file_size = counts[idx]
idx +=
1
if self.compress_size ==
0xffffffff:
self.compress_size = counts[idx]
idx +=
1
if self.header_offset ==
0xffffffff:
self.header_offset = counts[idx]
idx +=
1
extra = extra[ln +
4:]
def ApplyZipFileZipAlignFix():
"""Fix zipfile.ZipFile() to be able to open zipaligned .zip files.
Android
's zip alignment uses not-quite-valid zip headers to perform alignment.
Python <
3.
4 crashes when trying to load them.
https://bugs.python.org/issue14315
"""
if sys.version_info < (
3,
4):
zipfile.ZipInfo._decodeExtra = (
# pylint: disable=protected-access
_PatchedDecodeExtra)
def _SetAlignment(zip_obj, zip_info, alignment):
"""Sets a ZipInfo's extra field such that the file will be aligned.
Args:
zip_obj: The ZipFile object that
is being written.
zip_info: The ZipInfo object about to be written.
alignment: The amount of alignment (e.g.
4,
or 4*
1024).
"""
cur_offset = zip_obj.fp.tell()
header_size = _FIXED_ZIP_HEADER_LEN + len(zip_info.filename)
padding_needed = (alignment - (
(cur_offset + header_size) % alignment)) % alignment
# Python writes |extra| to both the local file header and the central
# directory's file header. Android's zipalign tool writes only to the
# local file header, so there is more overhead in using python to align.
zip_info.extra = b
'\0' * padding_needed
def AddToZipHermetic(zip_file,
zip_path,
src_path=
None,
data=
None,
compress=
None,
alignment=
None):
"""Same as build_utils.AddToZipHermetic(), but with alignment.
Args:
alignment:
If set, align the data of the entry to this many bytes.
"""
zipinfo = build_utils.HermeticZipInfo(filename=zip_path)
if alignment:
_SetAlignment(zip_file, zipinfo, alignment)
build_utils.AddToZipHermetic(
zip_file, zipinfo, src_path=src_path, data=data, compress=compress)
