diff -r ffa851df0825 -r 2fb8b9db1c86 symbian-qemu-0.9.1-12/python-2.6.1/Lib/gzip.py --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/symbian-qemu-0.9.1-12/python-2.6.1/Lib/gzip.py Fri Jul 31 15:01:17 2009 +0100 @@ -0,0 +1,484 @@ +"""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 write32u(output, value): + # The L format writes the bit pattern correctly whether signed + # or unsigned. + output.write(struct.pack("' + + def _init_write(self, filename): + self.name = filename + self.crc = zlib.crc32("") & 0xffffffffL + 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.name + if fname.endswith(".gz"): + fname = fname[:-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("") & 0xffffffffL + 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) & 0xffffffffL + 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) & 0xffffffffL + 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 = read32(self.fileobj) # may exceed 2GB + if crc32 != self.crc: + raise IOError("CRC check failed %s != %s" % (hex(crc32), + hex(self.crc))) + elif isize != (self.size & 0xffffffffL): + raise IOError, "Incorrect length of data produced" + + def close(self): + if self.fileobj is None: + return + if self.mode == WRITE: + self.fileobj.write(self.compress.flush()) + write32u(self.fileobj, self.crc) + # self.size may exceed 2GB, or even 4GB + write32u(self.fileobj, self.size & 0xffffffffL) + 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, whence=0): + if whence: + if whence == 1: + offset = self.offset + offset + else: + raise ValueError('Seek from end not supported') + 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()