def get_next_id(self):
        try:
            query = {'_id': 'last_id'}
            update = {'$inc': {'id': 1}}
            fn = self.db.internal.find_and_modify
            row = fn(query, update, upsert=True, new=True)
        except Exception as e:
            raise DatabaseException(e)
        return row['id']
def _genSeq(self):
        self.raw_sequence = random.getrandbits(64)
        parts = []
        while self.raw_sequence:
            parts.append(self.raw_sequence & limit)
            self.raw_sequence >>= 32

        self.sequence = struct.pack('<' + 'L'*len(parts), *parts)
        # struct.unpack('<LL', '\xb1l\x1c\xb1\x11"\x10\xf4')
        return 0