def __call__(self, data):
"""The consume() callback will call this. Store the result."""
self.msg_id_cache.check_duplicate_message(data)
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']
def _process_data(self, data):
result = None
self.msg_id_cache.check_duplicate_message(data)
if data['failure']:
failure = data['failure']
result = rpc_common.deserialize_remote_exception(
self._conf, failure)
elif data.get('ending', False):
self._got_ending = True
else:
result = data['result']
return result
def _call(addr, context, topic, msg, timeout=None, envelope=False):
# 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,
'topic': reply_topic,
# TODO(ewindisch): safe to remove mcontext in I.
'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.%s" %
(CONF.rpc_zmq_ipc_dir, CONF.rpc_zmq_host),
zmq.SUB,
subscribe=msg_id,
bind=False)
LOG.debug(_("Sending cast"))
_cast(addr, context, topic, payload, envelope)
LOG.debug(_("Cast sent; Waiting reply"))
# Blocks until receives reply
msg = msg_waiter.recv()
LOG.debug(_("Received message: %s"), msg)
LOG.debug(_("Unpacking response"))
if msg[2] == 'cast': # Legacy version
raw_msg = _deserialize(msg[-1])[-1]
elif msg[2] == 'impl_zmq_v2':
rpc_envelope = unflatten_envelope(msg[4:])
raw_msg = rpc_common.deserialize_msg(rpc_envelope)
else:
raise rpc_common.UnsupportedRpcEnvelopeVersion(
_("Unsupported or unknown ZMQ envelope returned."))
responses = raw_msg['args']['response']
# ZMQError trumps the Timeout error.
except zmq.ZMQError:
raise RPCException("ZMQ Socket Error")
except (IndexError, KeyError):
raise RPCException(_("RPC Message Invalid."))
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]