def size(self, destination):
        """
        Size of the queue for specified destination.

        @param destination: The queue destination (e.g. /queue/foo)
        @type destination: C{str}

        @return: The number of frames in specified queue.
        @rtype: C{int}
        """
        session = meta.Session()
        sel = select([func.count(model.frames_table.c.message_id)]).where(
            model.frames_table.c.destination == destination)
        result = session.execute(sel)
        first = result.fetchone()
        if not first:
            return 0
        else:
            return int(first[0])