--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/python-2.5.2/win32/Lib/gzip.py Fri Apr 03 17:19:34 2009 +0100
@@ -0,0 +1,490 @@
+"""Functions that read and write gzipped files.
+
+The user of the file doesn't have to worry about the compression,
+but random access is not allowed."""
+
+# based on Andrew Kuchling's minigzip.py distributed with the zlib module
+
+import struct, sys, time
+import zlib
+import __builtin__
+
+__all__ = ["GzipFile","open"]
+
+FTEXT, FHCRC, FEXTRA, FNAME, FCOMMENT = 1, 2, 4, 8, 16
+
+READ, WRITE = 1, 2
+
+def U32(i):
+ """Return i as an unsigned integer, assuming it fits in 32 bits.
+
+ If it's >= 2GB when viewed as a 32-bit unsigned int, return a long.
+ """
+ if i < 0:
+ i += 1L << 32
+ return i
+
+def LOWU32(i):
+ """Return the low-order 32 bits of an int, as a non-negative int."""
+ return i & 0xFFFFFFFFL
+
+def write32(output, value):
+ output.write(struct.pack("<l", value))
+
+def write32u(output, value):
+ # The L format writes the bit pattern correctly whether signed
+ # or unsigned.
+ output.write(struct.pack("<L", value))
+
+def read32(input):
+ return struct.unpack("<l", input.read(4))[0]
+
+def open(filename, mode="rb", compresslevel=9):
+ """Shorthand for GzipFile(filename, mode, compresslevel).
+
+ The filename argument is required; mode defaults to 'rb'
+ and compresslevel defaults to 9.
+
+ """
+ return GzipFile(filename, mode, compresslevel)
+
+class GzipFile:
+ """The GzipFile class simulates most of the methods of a file object with
+ the exception of the readinto() and truncate() methods.
+
+ """
+
+ myfileobj = None
+ max_read_chunk = 10 * 1024 * 1024 # 10Mb
+
+ def __init__(self, filename=None, mode=None,
+ compresslevel=9, fileobj=None):
+ """Constructor for the GzipFile class.
+
+ At least one of fileobj and filename must be given a
+ non-trivial value.
+
+ The new class instance is based on fileobj, which can be a regular
+ file, a StringIO object, or any other object which simulates a file.
+ It defaults to None, in which case filename is opened to provide
+ a file object.
+
+ When fileobj is not None, the filename argument is only used to be
+ included in the gzip file header, which may includes the original
+ filename of the uncompressed file. It defaults to the filename of
+ fileobj, if discernible; otherwise, it defaults to the empty string,
+ and in this case the original filename is not included in the header.
+
+ The mode argument can be any of 'r', 'rb', 'a', 'ab', 'w', or 'wb',
+ depending on whether the file will be read or written. The default
+ is the mode of fileobj if discernible; otherwise, the default is 'rb'.
+ Be aware that only the 'rb', 'ab', and 'wb' values should be used
+ for cross-platform portability.
+
+ The compresslevel argument is an integer from 1 to 9 controlling the
+ level of compression; 1 is fastest and produces the least compression,
+ and 9 is slowest and produces the most compression. The default is 9.
+
+ """
+
+ # guarantee the file is opened in binary mode on platforms
+ # that care about that sort of thing
+ if mode and 'b' not in mode:
+ mode += 'b'
+ if fileobj is None:
+ fileobj = self.myfileobj = __builtin__.open(filename, mode or 'rb')
+ if filename is None:
+ if hasattr(fileobj, 'name'): filename = fileobj.name
+ else: filename = ''
+ if mode is None:
+ if hasattr(fileobj, 'mode'): mode = fileobj.mode
+ else: mode = 'rb'
+
+ if mode[0:1] == 'r':
+ self.mode = READ
+ # Set flag indicating start of a new member
+ self._new_member = True
+ self.extrabuf = ""
+ self.extrasize = 0
+ self.filename = filename
+ # Starts small, scales exponentially
+ self.min_readsize = 100
+
+ elif mode[0:1] == 'w' or mode[0:1] == 'a':
+ self.mode = WRITE
+ self._init_write(filename)
+ self.compress = zlib.compressobj(compresslevel,
+ zlib.DEFLATED,
+ -zlib.MAX_WBITS,
+ zlib.DEF_MEM_LEVEL,
+ 0)
+ else:
+ raise IOError, "Mode " + mode + " not supported"
+
+ self.fileobj = fileobj
+ self.offset = 0
+
+ if self.mode == WRITE:
+ self._write_gzip_header()
+
+ def __repr__(self):
+ s = repr(self.fileobj)
+ return '<gzip ' + s[1:-1] + ' ' + hex(id(self)) + '>'
+
+ def _init_write(self, filename):
+ if filename[-3:] != '.gz':
+ filename = filename + '.gz'
+ self.filename = filename
+ self.crc = zlib.crc32("")
+ self.size = 0
+ self.writebuf = []
+ self.bufsize = 0
+
+ def _write_gzip_header(self):
+ self.fileobj.write('\037\213') # magic header
+ self.fileobj.write('\010') # compression method
+ fname = self.filename[:-3]
+ flags = 0
+ if fname:
+ flags = FNAME
+ self.fileobj.write(chr(flags))
+ write32u(self.fileobj, long(time.time()))
+ self.fileobj.write('\002')
+ self.fileobj.write('\377')
+ if fname:
+ self.fileobj.write(fname + '\000')
+
+ def _init_read(self):
+ self.crc = zlib.crc32("")
+ self.size = 0
+
+ def _read_gzip_header(self):
+ magic = self.fileobj.read(2)
+ if magic != '\037\213':
+ raise IOError, 'Not a gzipped file'
+ method = ord( self.fileobj.read(1) )
+ if method != 8:
+ raise IOError, 'Unknown compression method'
+ flag = ord( self.fileobj.read(1) )
+ # modtime = self.fileobj.read(4)
+ # extraflag = self.fileobj.read(1)
+ # os = self.fileobj.read(1)
+ self.fileobj.read(6)
+
+ if flag & FEXTRA:
+ # Read & discard the extra field, if present
+ 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:
+ s = self.fileobj.read(1)
+ if not s or s=='\000':
+ break
+ if flag & FCOMMENT:
+ # Read and discard a null-terminated string containing a comment
+ while True:
+ s = self.fileobj.read(1)
+ if not s or s=='\000':
+ break
+ if flag & FHCRC:
+ self.fileobj.read(2) # Read & discard the 16-bit header CRC
+
+
+ def write(self,data):
+ if self.mode != WRITE:
+ import errno
+ raise IOError(errno.EBADF, "write() on read-only GzipFile object")
+
+ if self.fileobj is None:
+ raise ValueError, "write() on closed GzipFile object"
+ if len(data) > 0:
+ self.size = self.size + len(data)
+ self.crc = zlib.crc32(data, self.crc)
+ self.fileobj.write( self.compress.compress(data) )
+ self.offset += len(data)
+
+ def read(self, size=-1):
+ if self.mode != READ:
+ import errno
+ raise IOError(errno.EBADF, "read() on write-only GzipFile object")
+
+ if self.extrasize <= 0 and self.fileobj is None:
+ return ''
+
+ readsize = 1024
+ if size < 0: # get the whole thing
+ 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
+ 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
+
+ chunk = self.extrabuf[:size]
+ self.extrabuf = self.extrabuf[size:]
+ self.extrasize = self.extrasize - size
+
+ self.offset += size
+ return chunk
+
+ def _unread(self, buf):
+ self.extrabuf = buf + self.extrabuf
+ self.extrasize = len(buf) + self.extrasize
+ self.offset -= len(buf)
+
+ def _read(self, size=1024):
+ if self.fileobj is None:
+ raise EOFError, "Reached EOF"
+
+ if self._new_member:
+ # If the _new_member flag is set, we have to
+ # jump to the next member, if there is one.
+ #
+ # First, check if we're at the end of the file;
+ # if so, it's time to stop; no more members to read.
+ pos = self.fileobj.tell() # Save current position
+ self.fileobj.seek(0, 2) # Seek to end of file
+ if pos == self.fileobj.tell():
+ raise EOFError, "Reached EOF"
+ else:
+ self.fileobj.seek( pos ) # Return to original position
+
+ self._init_read()
+ self._read_gzip_header()
+ self.decompress = zlib.decompressobj(-zlib.MAX_WBITS)
+ self._new_member = False
+
+ # Read a chunk of data from the file
+ buf = self.fileobj.read(size)
+
+ # If the EOF has been reached, flush the decompression object
+ # and mark this object as finished.
+
+ if buf == "":
+ uncompress = self.decompress.flush()
+ self._read_eof()
+ self._add_read_data( uncompress )
+ raise EOFError, 'Reached EOF'
+
+ uncompress = self.decompress.decompress(buf)
+ self._add_read_data( uncompress )
+
+ if self.decompress.unused_data != "":
+ # Ending case: we've come to the end of a member in the file,
+ # 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, 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
+
+ def _add_read_data(self, data):
+ self.crc = zlib.crc32(data, self.crc)
+ self.extrabuf = self.extrabuf + data
+ self.extrasize = self.extrasize + len(data)
+ self.size = self.size + len(data)
+
+ def _read_eof(self):
+ # 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.
+ self.fileobj.seek(-8, 1)
+ crc32 = read32(self.fileobj)
+ isize = U32(read32(self.fileobj)) # may exceed 2GB
+ if U32(crc32) != U32(self.crc):
+ raise IOError, "CRC check failed"
+ elif isize != LOWU32(self.size):
+ raise IOError, "Incorrect length of data produced"
+
+ def close(self):
+ if self.mode == WRITE:
+ self.fileobj.write(self.compress.flush())
+ # The native zlib crc is an unsigned 32-bit integer, but
+ # the Python wrapper implicitly casts that to a signed C
+ # long. So, on a 32-bit box self.crc may "look negative",
+ # while the same crc on a 64-bit box may "look positive".
+ # To avoid irksome warnings from the `struct` module, force
+ # it to look positive on all boxes.
+ write32u(self.fileobj, LOWU32(self.crc))
+ # self.size may exceed 2GB, or even 4GB
+ write32u(self.fileobj, LOWU32(self.size))
+ self.fileobj = None
+ elif self.mode == READ:
+ self.fileobj = None
+ if self.myfileobj:
+ self.myfileobj.close()
+ self.myfileobj = None
+
+ def __del__(self):
+ try:
+ if (self.myfileobj is None and
+ self.fileobj is None):
+ return
+ except AttributeError:
+ return
+ self.close()
+
+ def flush(self,zlib_mode=zlib.Z_SYNC_FLUSH):
+ if self.mode == WRITE:
+ # Ensure the compressor's buffer is flushed
+ self.fileobj.write(self.compress.flush(zlib_mode))
+ self.fileobj.flush()
+
+ def fileno(self):
+ """Invoke the underlying file object's fileno() method.
+
+ This will raise AttributeError if the underlying file object
+ doesn't support fileno().
+ """
+ return self.fileobj.fileno()
+
+ def isatty(self):
+ return False
+
+ def tell(self):
+ return self.offset
+
+ def rewind(self):
+ '''Return the uncompressed stream file position indicator to the
+ beginning of the file'''
+ if self.mode != READ:
+ raise IOError("Can't rewind in write mode")
+ self.fileobj.seek(0)
+ self._new_member = True
+ self.extrabuf = ""
+ self.extrasize = 0
+ self.offset = 0
+
+ def seek(self, offset):
+ if self.mode == WRITE:
+ if offset < self.offset:
+ raise IOError('Negative seek in write mode')
+ count = offset - self.offset
+ for i in range(count // 1024):
+ self.write(1024 * '\0')
+ self.write((count % 1024) * '\0')
+ elif self.mode == READ:
+ if offset < self.offset:
+ # for negative seek, rewind and do positive seek
+ self.rewind()
+ count = offset - self.offset
+ for i in range(count // 1024):
+ self.read(1024)
+ self.read(count % 1024)
+
+ def readline(self, size=-1):
+ if size < 0:
+ size = sys.maxint
+ readsize = self.min_readsize
+ else:
+ readsize = size
+ bufs = []
+ while size != 0:
+ c = self.read(readsize)
+ i = c.find('\n')
+
+ # We set i=size to break out of the loop under two
+ # conditions: 1) there's no newline, and the chunk is
+ # larger than size, or 2) there is a newline, but the
+ # resulting line would be longer than 'size'.
+ if (size <= i) or (i == -1 and len(c) > size):
+ i = size - 1
+
+ if i >= 0 or c == '':
+ bufs.append(c[:i + 1]) # Add portion of last chunk
+ self._unread(c[i + 1:]) # Push back rest of chunk
+ break
+
+ # Append chunk to list, decrease 'size',
+ bufs.append(c)
+ size = size - len(c)
+ readsize = min(size, readsize * 2)
+ if readsize > self.min_readsize:
+ self.min_readsize = min(readsize, self.min_readsize * 2, 512)
+ return ''.join(bufs) # Return resulting line
+
+ def readlines(self, sizehint=0):
+ # Negative numbers result in reading all the lines
+ if sizehint <= 0:
+ sizehint = sys.maxint
+ L = []
+ while sizehint > 0:
+ line = self.readline()
+ if line == "":
+ break
+ L.append(line)
+ sizehint = sizehint - len(line)
+
+ return L
+
+ def writelines(self, L):
+ for line in L:
+ self.write(line)
+
+ def __iter__(self):
+ return self
+
+ def next(self):
+ line = self.readline()
+ if line:
+ return line
+ else:
+ raise StopIteration
+
+
+def _test():
+ # Act like gzip; with -d, act like gunzip.
+ # The input file is not deleted, however, nor are any other gzip
+ # options or features supported.
+ args = sys.argv[1:]
+ decompress = args and args[0] == "-d"
+ if decompress:
+ args = args[1:]
+ if not args:
+ args = ["-"]
+ for arg in args:
+ if decompress:
+ if arg == "-":
+ f = GzipFile(filename="", mode="rb", fileobj=sys.stdin)
+ g = sys.stdout
+ else:
+ if arg[-3:] != ".gz":
+ print "filename doesn't end in .gz:", repr(arg)
+ continue
+ f = open(arg, "rb")
+ g = __builtin__.open(arg[:-3], "wb")
+ else:
+ if arg == "-":
+ f = sys.stdin
+ g = GzipFile(filename="", mode="wb", fileobj=sys.stdout)
+ else:
+ f = __builtin__.open(arg, "rb")
+ g = open(arg + ".gz", "wb")
+ while True:
+ chunk = f.read(1024)
+ if not chunk:
+ break
+ g.write(chunk)
+ if g is not sys.stdout:
+ g.close()
+ if f is not sys.stdin:
+ f.close()
+
+if __name__ == '__main__':
+ _test()