# or unsigned.
output.write(struct.pack("<L", value))
+def read32(input):
+ return struct.unpack("<I", input.read(4))[0]
+
def open(filename, mode="rb", compresslevel=9):
"""Shorthand for GzipFile(filename, mode, compresslevel).
self.crc = zlib.crc32("") & 0xffffffffL
self.size = 0
- def _read_exact(self, n):
- data = self.fileobj.read(n)
- while len(data) < n:
- b = self.fileobj.read(n - len(data))
- if not b:
- raise EOFError("Compressed file ended before the "
- "end-of-stream marker was reached")
- data += b
- return data
-
def _read_gzip_header(self):
magic = self.fileobj.read(2)
if magic != '\037\213':
raise IOError, 'Not a gzipped file'
-
- method, flag, self.mtime = struct.unpack("<BBIxx", self._read_exact(8))
+ method = ord( self.fileobj.read(1) )
if method != 8:
raise IOError, 'Unknown compression method'
+ flag = ord( self.fileobj.read(1) )
+ self.mtime = read32(self.fileobj)
+ # extraflag = self.fileobj.read(1)
+ # os = self.fileobj.read(1)
+ self.fileobj.read(2)
if flag & FEXTRA:
# Read & discard the extra field, if present
- extra_len, = struct.unpack("<H", self._read_exact(2))
- self._read_exact(extra_len)
+ xlen = ord(self.fileobj.read(1))
+ xlen = xlen + 256*ord(self.fileobj.read(1))
+ self.fileobj.read(xlen)
if flag & FNAME:
# Read and discard a null-terminated string containing the filename
while True:
if not s or s=='\000':
break
if flag & FHCRC:
- self._read_exact(2) # Read & discard the 16-bit header CRC
+ self.fileobj.read(2) # Read & discard the 16-bit header CRC
def write(self,data):
self._check_closed()
readsize = 1024
if size < 0: # get the whole thing
- while self._read(readsize):
- readsize = min(self.max_read_chunk, readsize * 2)
- size = self.extrasize
+ try:
+ while True:
+ self._read(readsize)
+ readsize = min(self.max_read_chunk, readsize * 2)
+ except EOFError:
+ size = self.extrasize
else: # just get some more of it
- while size > self.extrasize:
- if not self._read(readsize):
- if size > self.extrasize:
- size = self.extrasize
- break
- readsize = min(self.max_read_chunk, readsize * 2)
+ try:
+ while size > self.extrasize:
+ self._read(readsize)
+ readsize = min(self.max_read_chunk, readsize * 2)
+ except EOFError:
+ if size > self.extrasize:
+ size = self.extrasize
offset = self.offset - self.extrastart
chunk = self.extrabuf[offset: offset + size]
def _read(self, size=1024):
if self.fileobj is None:
- return False
+ raise EOFError, "Reached EOF"
if self._new_member:
# If the _new_member flag is set, we have to
pos = self.fileobj.tell() # Save current position
self.fileobj.seek(0, 2) # Seek to end of file
if pos == self.fileobj.tell():
- return False
+ raise EOFError, "Reached EOF"
else:
self.fileobj.seek( pos ) # Return to original position
if buf == "":
uncompress = self.decompress.flush()
- self.fileobj.seek(-len(self.decompress.unused_data), 1)
self._read_eof()
self._add_read_data( uncompress )
- return False
+ raise EOFError, 'Reached EOF'
uncompress = self.decompress.decompress(buf)
self._add_read_data( uncompress )
# so seek back to the start of the unused data, finish up
# this member, and read a new gzip header.
# (The number of bytes to seek back is the length of the unused
- # data)
- self.fileobj.seek(-len(self.decompress.unused_data), 1)
+ # data, minus 8 because _read_eof() will rewind a further 8 bytes)
+ self.fileobj.seek( -len(self.decompress.unused_data)+8, 1)
# Check the CRC and file size, and set the flag so we read
# a new member on the next call
self._read_eof()
self._new_member = True
- return True
def _add_read_data(self, data):
self.crc = zlib.crc32(data, self.crc) & 0xffffffffL
self.size = self.size + len(data)
def _read_eof(self):
- # We've read to the end of the file.
+ # We've read to the end of the file, so we have to rewind in order
+ # to reread the 8 bytes containing the CRC and the file size.
# We check the that the computed CRC and size of the
# uncompressed data matches the stored values. Note that the size
# stored is the true file size mod 2**32.
- crc32, isize = struct.unpack("<II", self._read_exact(8))
+ self.fileobj.seek(-8, 1)
+ crc32 = read32(self.fileobj)
+ isize = read32(self.fileobj) # may exceed 2GB
if crc32 != self.crc:
raise IOError("CRC check failed %s != %s" % (hex(crc32),
hex(self.crc)))
self.assertRaises(ValueError, f.readline)
self.assertRaises(ValueError, f.readlines)
- def test_read_truncated(self):
- # Drop the eos_magic field (6 bytes) and CRC (4 bytes).
- truncated = self.DATA[:-10]
- with open(self.filename, 'wb') as f:
- f.write(truncated)
- with BZ2File(self.filename) as f:
- self.assertRaises(EOFError, f.read)
- with BZ2File(self.filename) as f:
- self.assertEqual(f.read(len(self.TEXT)), self.TEXT)
- self.assertRaises(EOFError, f.read, 1)
- # Incomplete 4-byte file header, and block header of at least 146 bits.
- for i in range(22):
- with open(self.filename, 'wb') as f:
- f.write(truncated[:i])
- with BZ2File(self.filename) as f:
- self.assertRaises(EOFError, f.read, 1)
-
-
class BZ2CompressorTest(BaseTest):
def testCompress(self):
# "Test BZ2Compressor.compress()/flush()"
with gzip.GzipFile(fileobj=f, mode="w") as g:
self.assertEqual(g.name, "")
- def test_read_truncated(self):
- data = data1*50
- buf = io.BytesIO()
- with gzip.GzipFile(fileobj=buf, mode="w") as f:
- f.write(data)
- # Drop the CRC (4 bytes) and file size (4 bytes).
- truncated = buf.getvalue()[:-8]
- with gzip.GzipFile(fileobj=io.BytesIO(truncated)) as f:
- self.assertRaises(EOFError, f.read)
- with gzip.GzipFile(fileobj=io.BytesIO(truncated)) as f:
- self.assertEqual(f.read(len(data)), data)
- self.assertRaises(EOFError, f.read, 1)
- # Incomplete 10-byte header.
- for i in range(2, 10):
- with gzip.GzipFile(fileobj=io.BytesIO(truncated[:i])) as f:
- self.assertRaises(EOFError, f.read, 1)
-
def test_read_with_extra(self):
# Gzip data with an extra field
gzdata = (b'\x1f\x8b\x08\x04\xb2\x17cQ\x02\xff'
projects / thirdparty / Python / cpython.git / commitdiff
