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# 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.
"""
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)