Exemple #1
0
def _call(addr, context, msg_id, topic, msg, timeout=None):
    # timeout_response is how long we wait for a response
    timeout = timeout or CONF.rpc_response_timeout

    # The msg_id is used to track replies.
    msg_id = uuid.uuid4().hex

    # Replies always come into the reply service.
    reply_topic = "zmq_replies.%s" % CONF.rpc_zmq_host

    LOG.debug(_("Creating payload"))
    # Curry the original request into a reply method.
    mcontext = RpcContext.marshal(context)
    payload = {
        'method': '-reply',
        'args': {
            'msg_id': msg_id,
            'context': mcontext,
            'topic': reply_topic,
            'msg': [mcontext, msg]
        }
    }

    LOG.debug(_("Creating queue socket for reply waiter"))

    # Messages arriving async.
    # TODO(ewindisch): have reply consumer with dynamic subscription mgmt
    with Timeout(timeout, exception=rpc_common.Timeout):
        try:
            msg_waiter = ZmqSocket(
                "ipc://%s/zmq_topic_zmq_replies" % CONF.rpc_zmq_ipc_dir,
                zmq.SUB, subscribe=msg_id, bind=False
            )

            LOG.debug(_("Sending cast"))
            _cast(addr, context, msg_id, topic, payload)

            LOG.debug(_("Cast sent; Waiting reply"))
            # Blocks until receives reply
            msg = msg_waiter.recv()
            LOG.debug(_("Received message: %s"), msg)
            LOG.debug(_("Unpacking response"))
            responses = rpc_common.deserialize_msg(msg[-1])
        # ZMQError trumps the Timeout error.
        except zmq.ZMQError:
            raise RPCException("ZMQ Socket Error")
        finally:
            if 'msg_waiter' in vars():
                msg_waiter.close()

    # It seems we don't need to do all of the following,
    # but perhaps it would be useful for multicall?
    # One effect of this is that we're checking all
    # responses for Exceptions.
    for resp in responses:
        if isinstance(resp, types.DictType) and 'exc' in resp:
            raise rpc_common.deserialize_remote_exception(CONF, resp['exc'])

    return responses[-1]
Exemple #2
0
    def __call__(self, data):
        """The consume() callback will call this.  Store the result."""
        if data['failure']:
            failure = data['failure']
            self._result = rpc_common.deserialize_remote_exception(self._conf,
                                                                   failure)

        elif data.get('ending', False):
            self._got_ending = True
        else:
            self._result = data['result']