Stowage/cpython
2
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-12-08 06:10:17 +00:00
Code Issues Projects Releases Packages Wiki Activity

Fix and optimize _scan_data_descriptor_no_sig

Browse source
This commit is contained in:
Danny Lin 2025-06-01 11:14:19 +08:00
parent 8067b0c489
commit 92d3a9c418
1 changed files with 8 additions and 10 deletions
Download patch file Download diff file Expand all files Collapse all files

18
Lib/zipfile/__init__.py
View file

@ -1712,30 +1712,28 @@ def _scan_data_descriptor_no_sig(self, fp, offset, end_offset, zip64, chunk_size
dd_fmt = '<LQQ' if zip64 else '<LLL'
dd_size = struct.calcsize(dd_fmt)
base = offset
pos = offset
remainder = b''
while base < end_offset:
fp.seek(base)
chunk = remainder + fp.read(min(chunk_size, end_offset - base))
if not chunk:
break
fp.seek(offset)
while pos < end_offset:
chunk = remainder + fp.read(min(chunk_size, end_offset - pos))
scan_limit = len(chunk) - dd_size + 1
delta = pos - len(remainder) - offset
mv = memoryview(chunk)
for i in range(scan_limit):
for i in range(len(chunk) - dd_size + 1):
dd = mv[i:i + dd_size]
try:
crc, compress_size, file_size = struct.unpack(dd_fmt, dd)
except struct.error:
continue
if (base + i) - offset != compress_size:
if delta + i != compress_size:
continue
return crc, compress_size, file_size, dd_size
remainder = chunk[-(dd_size - 1):]
base += scan_limit
pos += chunk_size
return None