primitives.py 文件源码

def parse(cls, buff, offset):
        """
        Given a buffer and offset, returns the parsed value and new offset.

        Parses the ``size_primitive`` first to determine how many more bytes to
        consume to extract the value.
        """
        size, offset = cls.size_primitive.parse(buff, offset)
        if size == -1:
            return None, offset

        var_struct = struct.Struct("!%ds" % size)

        value = var_struct.unpack_from(buff, offset)[0]
        value = cls.parse_value(value)
        offset += var_struct.size

        return value, offset