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Issue #14099: ZipFile.open() no longer reopen the underlying file. Objects 

returned by ZipFile.open() can now operate independently of the ZipFile even
if the ZipFile was created by passing in a file-like object as the first
argument to the constructor.
This commit is contained in:
Serhiy Storchaka 2014-12-03 09:14:36 +02:00
parent 4954f9fcab 1ad088f3ea
commit f4adbae927
4 changed files with 166 additions and 73 deletions
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10
Doc/library/zipfile.rst
View File

@ -219,14 +219,8 @@ ZipFile Objects
.. note::
If the ZipFile was created by passing in a file-like object as the first
argument to the constructor, then the object returned by :meth:`.open` shares the
ZipFile's file pointer. Under these circumstances, the object returned by
:meth:`.open` should not be used after any additional operations are performed
on the ZipFile object. If the ZipFile was created by passing in a string (the
filename) as the first argument to the constructor, then :meth:`.open` will
create a new file object that will be held by the ZipExtFile, allowing it to
operate independently of the ZipFile.
Objects returned by :meth:`.open` can operate independently of the
ZipFile.
.. note::

121
Lib/test/test_zipfile.py
View File

@ -1,3 +1,4 @@
import contextlib
import io
import os
import sys
@ -25,6 +26,9 @@ SMALL_TEST_DATA = [('_ziptest1', '1q2w3e4r5t'),
('ziptest2dir/ziptest3dir/_ziptest3', 'azsxdcfvgb'),
('ziptest2dir/ziptest3dir/ziptest4dir/_ziptest3', '6y7u8i9o0p')]
def getrandbytes(size):
return getrandbits(8 * size).to_bytes(size, 'little')
def get_files(test):
yield TESTFN2
with TemporaryFile() as f:
@ -289,7 +293,7 @@ class AbstractTestsWithSourceFile:
# than requested.
for test_size in (1, 4095, 4096, 4097, 16384):
file_size = test_size + 1
junk = getrandbits(8 * file_size).to_bytes(file_size, 'little')
junk = getrandbytes(file_size)
with zipfile.ZipFile(io.BytesIO(), "w", self.compression) as zipf:
zipf.writestr('foo', junk)
with zipf.open('foo', 'r') as fp:
@ -1666,46 +1670,111 @@ class LzmaTestsWithRandomBinaryFiles(AbstractTestsWithRandomBinaryFiles,
@requires_zlib
class TestsWithMultipleOpens(unittest.TestCase):
def setUp(self):
@classmethod
def setUpClass(cls):
cls.data1 = b'111' + getrandbytes(10000)
cls.data2 = b'222' + getrandbytes(10000)
def make_test_archive(self, f):
# Create the ZIP archive
with zipfile.ZipFile(TESTFN2, "w", zipfile.ZIP_DEFLATED) as zipfp:
zipfp.writestr('ones', '1'*FIXEDTEST_SIZE)
zipfp.writestr('twos', '2'*FIXEDTEST_SIZE)
with zipfile.ZipFile(f, "w", zipfile.ZIP_DEFLATED) as zipfp:
zipfp.writestr('ones', self.data1)
zipfp.writestr('twos', self.data2)
def test_same_file(self):
# Verify that (when the ZipFile is in control of creating file objects)
# multiple open() calls can be made without interfering with each other.
with zipfile.ZipFile(TESTFN2, mode="r") as zipf:
with zipf.open('ones') as zopen1, zipf.open('ones') as zopen2:
data1 = zopen1.read(500)
data2 = zopen2.read(500)
data1 += zopen1.read(500)
data2 += zopen2.read(500)
self.assertEqual(data1, data2)
for f in get_files(self):
self.make_test_archive(f)
with zipfile.ZipFile(f, mode="r") as zipf:
with zipf.open('ones') as zopen1, zipf.open('ones') as zopen2:
data1 = zopen1.read(500)
data2 = zopen2.read(500)
data1 += zopen1.read()
data2 += zopen2.read()
self.assertEqual(data1, data2)
self.assertEqual(data1, self.data1)
def test_different_file(self):
# Verify that (when the ZipFile is in control of creating file objects)
# multiple open() calls can be made without interfering with each other.
with zipfile.ZipFile(TESTFN2, mode="r") as zipf:
with zipf.open('ones') as zopen1, zipf.open('twos') as zopen2:
data1 = zopen1.read(500)
data2 = zopen2.read(500)
data1 += zopen1.read(500)
data2 += zopen2.read(500)
self.assertEqual(data1, b'1'*FIXEDTEST_SIZE)
self.assertEqual(data2, b'2'*FIXEDTEST_SIZE)
for f in get_files(self):
self.make_test_archive(f)
with zipfile.ZipFile(f, mode="r") as zipf:
with zipf.open('ones') as zopen1, zipf.open('twos') as zopen2:
data1 = zopen1.read(500)
data2 = zopen2.read(500)
data1 += zopen1.read()
data2 += zopen2.read()
self.assertEqual(data1, self.data1)
self.assertEqual(data2, self.data2)
def test_interleaved(self):
# Verify that (when the ZipFile is in control of creating file objects)
# multiple open() calls can be made without interfering with each other.
with zipfile.ZipFile(TESTFN2, mode="r") as zipf:
with zipf.open('ones') as zopen1, zipf.open('twos') as zopen2:
for f in get_files(self):
self.make_test_archive(f)
with zipfile.ZipFile(f, mode="r") as zipf:
with zipf.open('ones') as zopen1, zipf.open('twos') as zopen2:
data1 = zopen1.read(500)
data2 = zopen2.read(500)
data1 += zopen1.read()
data2 += zopen2.read()
self.assertEqual(data1, self.data1)
self.assertEqual(data2, self.data2)
def test_read_after_close(self):
for f in get_files(self):
self.make_test_archive(f)
with contextlib.ExitStack() as stack:
with zipfile.ZipFile(f, 'r') as zipf:
zopen1 = stack.enter_context(zipf.open('ones'))
zopen2 = stack.enter_context(zipf.open('twos'))
data1 = zopen1.read(500)
data2 = zopen2.read(500)
data1 += zopen1.read(500)
data2 += zopen2.read(500)
self.assertEqual(data1, b'1'*FIXEDTEST_SIZE)
self.assertEqual(data2, b'2'*FIXEDTEST_SIZE)
data1 += zopen1.read()
data2 += zopen2.read()
self.assertEqual(data1, self.data1)
self.assertEqual(data2, self.data2)
def test_read_after_write(self):
for f in get_files(self):
with zipfile.ZipFile(f, 'w', zipfile.ZIP_DEFLATED) as zipf:
zipf.writestr('ones', self.data1)
zipf.writestr('twos', self.data2)
with zipf.open('ones') as zopen1:
data1 = zopen1.read(500)
self.assertEqual(data1, self.data1[:500])
with zipfile.ZipFile(f, 'r') as zipf:
data1 = zipf.read('ones')
data2 = zipf.read('twos')
self.assertEqual(data1, self.data1)
self.assertEqual(data2, self.data2)
def test_write_after_read(self):
for f in get_files(self):
with zipfile.ZipFile(f, "w", zipfile.ZIP_DEFLATED) as zipf:
zipf.writestr('ones', self.data1)
with zipf.open('ones') as zopen1:
zopen1.read(500)
zipf.writestr('twos', self.data2)
with zipfile.ZipFile(f, 'r') as zipf:
data1 = zipf.read('ones')
data2 = zipf.read('twos')
self.assertEqual(data1, self.data1)
self.assertEqual(data2, self.data2)
def test_many_opens(self):
# Verify that read() and open() promptly close the file descriptor,
# and don't rely on the garbage collector to free resources.
self.make_test_archive(TESTFN2)
with zipfile.ZipFile(TESTFN2, mode="r") as zipf:
for x in range(100):
zipf.read('ones')
with zipf.open('ones') as zopen1:
pass
with open(os.devnull) as f:
self.assertLess(f.fileno(), 100)
def tearDown(self):
unlink(TESTFN2)

103
Lib/zipfile.py
View File

@ -646,6 +646,25 @@ def _get_decompressor(compress_type):
raise NotImplementedError("compression type %d" % (compress_type,))
class _SharedFile:
def __init__(self, file, pos, close):
self._file = file
self._pos = pos
self._close = close
def read(self, n=-1):
self._file.seek(self._pos)
data = self._file.read(n)
self._pos = self._file.tell()
return data
def close(self):
if self._file is not None:
fileobj = self._file
self._file = None
self._close(fileobj)
class ZipExtFile(io.BufferedIOBase):
"""File-like object for reading an archive member.
Is returned by ZipFile.open().
@ -945,7 +964,7 @@ class ZipFile:
self.NameToInfo = {} # Find file info given name
self.filelist = [] # List of ZipInfo instances for archive
self.compression = compression # Method of compression
self.mode = key = mode.replace('b', '')[0]
self.mode = mode
self.pwd = None
self._comment = b''
@ -954,28 +973,33 @@ class ZipFile:
# No, it's a filename
self._filePassed = 0
self.filename = file
modeDict = {'r' : 'rb', 'w': 'wb', 'a' : 'r+b'}
try:
self.fp = io.open(file, modeDict[mode])
except OSError:
if mode == 'a':
mode = key = 'w'
self.fp = io.open(file, modeDict[mode])
else:
modeDict = {'r' : 'rb', 'w': 'w+b', 'a' : 'r+b',
'r+b': 'w+b', 'w+b': 'wb'}
filemode = modeDict[mode]
while True:
try:
self.fp = io.open(file, filemode)
except OSError:
if filemode in modeDict:
filemode = modeDict[filemode]
continue
raise
break
else:
self._filePassed = 1
self.fp = file
self.filename = getattr(file, 'name', None)
self._fileRefCnt = 1
try:
if key == 'r':
if mode == 'r':
self._RealGetContents()
elif key == 'w':
elif mode == 'w':
# set the modified flag so central directory gets written
# even if no files are added to the archive
self._didModify = True
elif key == 'a':
self.start_dir = 0
elif mode == 'a':
try:
# See if file is a zip file
self._RealGetContents()
@ -988,13 +1012,13 @@ class ZipFile:
# set the modified flag so central directory gets written
# even if no files are added to the archive
self._didModify = True
self.start_dir = self.fp.tell()
else:
raise RuntimeError('Mode must be "r", "w" or "a"')
except:
fp = self.fp
self.fp = None
if not self._filePassed:
fp.close()
self._fpclose(fp)
raise
def __enter__(self):
@ -1181,23 +1205,17 @@ class ZipFile:
raise RuntimeError(
"Attempt to read ZIP archive that was already closed")
# Only open a new file for instances where we were not
# given a file object in the constructor
if self._filePassed:
zef_file = self.fp
# Make sure we have an info object
if isinstance(name, ZipInfo):
# 'name' is already an info object
zinfo = name
else:
zef_file = io.open(self.filename, 'rb')
# Get info object for name
zinfo = self.getinfo(name)
self._fileRefCnt += 1
zef_file = _SharedFile(self.fp, zinfo.header_offset, self._fpclose)
try:
# Make sure we have an info object
if isinstance(name, ZipInfo):
# 'name' is already an info object
zinfo = name
else:
# Get info object for name
zinfo = self.getinfo(name)
zef_file.seek(zinfo.header_offset, 0)
# Skip the file header:
fheader = zef_file.read(sizeFileHeader)
if len(fheader) != sizeFileHeader:
@ -1256,11 +1274,9 @@ class ZipFile:
if h[11] != check_byte:
raise RuntimeError("Bad password for file", name)
return ZipExtFile(zef_file, mode, zinfo, zd,
close_fileobj=not self._filePassed)
return ZipExtFile(zef_file, mode, zinfo, zd, True)
except:
if not self._filePassed:
zef_file.close()
zef_file.close()
raise
def extract(self, member, path=None, pwd=None):
@ -1394,6 +1410,7 @@ class ZipFile:
zinfo.file_size = st.st_size
zinfo.flag_bits = 0x00
self.fp.seek(self.start_dir, 0)
zinfo.header_offset = self.fp.tell() # Start of header bytes
if zinfo.compress_type == ZIP_LZMA:
# Compressed data includes an end-of-stream (EOS) marker
@ -1410,6 +1427,7 @@ class ZipFile:
self.filelist.append(zinfo)
self.NameToInfo[zinfo.filename] = zinfo
self.fp.write(zinfo.FileHeader(False))
self.start_dir = self.fp.tell()
return
cmpr = _get_compressor(zinfo.compress_type)
@ -1448,10 +1466,10 @@ class ZipFile:
raise RuntimeError('Compressed size larger than uncompressed size')
# Seek backwards and write file header (which will now include
# correct CRC and file sizes)
position = self.fp.tell() # Preserve current position in file
self.start_dir = self.fp.tell() # Preserve current position in file
self.fp.seek(zinfo.header_offset, 0)
self.fp.write(zinfo.FileHeader(zip64))
self.fp.seek(position, 0)
self.fp.seek(self.start_dir, 0)
self.filelist.append(zinfo)
self.NameToInfo[zinfo.filename] = zinfo
@ -1480,6 +1498,7 @@ class ZipFile:
"Attempt to write to ZIP archive that was already closed")
zinfo.file_size = len(data) # Uncompressed size
self.fp.seek(self.start_dir, 0)
zinfo.header_offset = self.fp.tell() # Start of header data
if compress_type is not None:
zinfo.compress_type = compress_type
@ -1508,6 +1527,7 @@ class ZipFile:
self.fp.write(struct.pack(fmt, zinfo.CRC, zinfo.compress_size,
zinfo.file_size))
self.fp.flush()
self.start_dir = self.fp.tell()
self.filelist.append(zinfo)
self.NameToInfo[zinfo.filename] = zinfo
@ -1523,7 +1543,7 @@ class ZipFile:
try:
if self.mode in ("w", "a") and self._didModify: # write ending records
pos1 = self.fp.tell()
self.fp.seek(self.start_dir, 0)
for zinfo in self.filelist: # write central directory
dt = zinfo.date_time
dosdate = (dt[0] - 1980) << 9 | dt[1] << 5 | dt[2]
@ -1589,8 +1609,8 @@ class ZipFile:
pos2 = self.fp.tell()
# Write end-of-zip-archive record
centDirCount = len(self.filelist)
centDirSize = pos2 - pos1
centDirOffset = pos1
centDirSize = pos2 - self.start_dir
centDirOffset = self.start_dir
requires_zip64 = None
if centDirCount > ZIP_FILECOUNT_LIMIT:
requires_zip64 = "Files count"
@ -1626,8 +1646,13 @@ class ZipFile:
finally:
fp = self.fp
self.fp = None
if not self._filePassed:
fp.close()
self._fpclose(fp)
def _fpclose(self, fp):
assert self._fileRefCnt > 0
self._fileRefCnt -= 1
if not self._fileRefCnt and not self._filePassed:
fp.close()
class PyZipFile(ZipFile):

5
Misc/NEWS
View File

@ -194,6 +194,11 @@ Core and Builtins
Library
-------
- Issue #14099: ZipFile.open() no longer reopen the underlying file. Objects
returned by ZipFile.open() can now operate independently of the ZipFile even
if the ZipFile was created by passing in a file-like object as the first
argument to the constructor.
- Issue #22966: Fix __pycache__ pyc file name clobber when pyc_compile is
asked to compile a source file containing multiple dots in the source file
name.