NNTPContent.py 文件源码

def crc32(self):
        """
        A little bit old-fashioned, but some encodings like yEnc require that
        a crc32 value be used.  This calculates it based on the file
        """
        # block size defined as 2**16
        block_size = 65536

        # The mask to apply to all CRC checking
        BIN_MASK = 0xffffffffL

        # Initialize
        _crc = 0

        if self.open(mode=NNTPFileMode.BINARY_RO):
            for chunk in iter(lambda: self.stream.read(block_size), b''):
                _crc = crc32(chunk, _crc)

            return format(_crc & BIN_MASK, '08x')

        return None