def __on_receive_rpc_request(self, ch, method, props, body):
self._logger.debug("received RPC req from exchange '%s' with routing key %s and correlation_id %s",
method.exchange, method.routing_key, props.correlation_id)
# the following frames are handled here:
# • RPC request messages
# - sent to empty exchange
# - routing_key is queue provided in _register_rpc_function
# sanity check
assert method.routing_key in self.__rpc_queue_map, \
"%s not a valid RPC queue" % (method.routing_key,)
# hand off the RPC request to the RPCWorker
req_body = serializer_utils.deserialize(body, props.content_type)
callback = None
if req_body['command'] in self.__rpc_queue_map[method.routing_key]:
callback = self.__rpc_queue_map[method.routing_key][req_body['command']]
self.__rpc_worker.add_request(
RPCRequest(
correlation_id = props.correlation_id,
content_type = props.content_type,
reply_to = props.reply_to,
callback = callback,
args = req_body['args']
)
)
else:
self._logger.error("command %s not configured for queue %s", req_body['command'], method.routing_key)
ch.basic_ack(delivery_tag = method.delivery_tag)
def __on_receive_packet(self, ch, method, props, body):
self._logger.debug("received packet from exchange '%s' with routing key %s and correlation_id %s",
method.exchange, method.routing_key, props.correlation_id)
frame = serializer_utils.deserialize(body, props.content_type)
# the following frames are handled here:
# • XBee "raw" frames
# - sent to exhange 'raw_xbee_frames'
# - routing_key is '<frame type>.<source addr>'
# • XBee reply frames in response to a command or data sent to a device
# - sent to empty exchange
# - routing_key is name of our private queue
# - have correlation_id matching a key in __pending_xb_requests
# differentiate replies from raw packets
if (props.correlation_id != None) and (method.routing_key == self.__queue_name):
# this is a reply
with self.__pending_xb_requests_lock:
if props.correlation_id in self.__pending_xb_requests:
req = self.__pending_xb_requests[props.correlation_id]
if not req.async:
self.finish_async_request(req, frame)
else:
self.handle_async_reply(req, frame)
else:
self._logger.error("got %s reply for unknown correlation %s: %s",
frame['id'], props.correlation_id, frame)
# this needs to get called every now and then
self.__reap_unfinished_requests()
else:
# standard raw packet; guaranteed to have a routing_key of the form
# <frame id>.<address>, where the address is one we're subscribed to
formatted_addr = method.routing_key.split('.')[1]
try:
self.handle_packet(formatted_addr, frame)
except:
self._logger.critical("exception handling packet", exc_info = True)
def __on_receive_rpc_response(self, channel, method, props, body):
# props.correlation_id is the request ticket
with self.__pending_requests_lock:
request = self.__pending_requests.pop(props.correlation_id)
try:
resp_data = serializer_utils.deserialize(body, props.content_type)
if "exception" in resp_data:
request.exception = resp_data["exception"]
else:
request.response = resp_data["result"]
except:
self._logger.error("exception unpickling", exc_info=True)
request.exception = sys.exc_info()[1]
request.event.set()
channel.basic_ack(delivery_tag=method.delivery_tag)
def __handle_xb_tx(self, chan, method, props, body):
## no need for a connection lock since we're running in the main
## thread, and there isn't any possibility for concurrent access
## to the connection for this thread
try:
# ack the message; there's nothing below that would be
# recoverable if the same message were received again
chan.basic_ack(delivery_tag = method.delivery_tag)
req = serializer_utils.deserialize(body, props.content_type)
self._logger.debug(
"TX method %s for dest %s with correlation ID %s",
req['method'], req['dest'], props.correlation_id
)
# mapping of frame id to message properties; used to direct the
# response
frame_id = self.__next_frame_id()
if props.headers == None:
props.headers = {}
if 'keep_alive' not in props.headers:
props.headers['keep_alive'] = False
with self.__correlation_lock:
self.__correlations[frame_id] = {
'props' : props,
'keep_alive' : bool(props.headers['keep_alive']),
'expiration' : time.time() + 120,
}
if req['method'] == 'send_remote_at':
# {'method' : 'send_remote_at',
# 'dest' : <addr>,
# 'command' : …,
# 'param_val' : …,
# }
self.xbee.remote_at(frame_id = frame_id,
dest_addr_long = parse_addr(req['dest']),
command = req['command'],
parameter = req['param_val'])
elif req['method'] == 'send_data':
# {'method' : 'send_data',
# 'dest' : <addr>,
# 'data' : …,
# }
self.xbee.zb_tx_request(
frame_id = frame_id,
dest_addr_long = parse_addr(req['dest']),
data = req['data']
)
self._logger.debug("XBee command sent and message ack'd")
except:
self._logger.error("failed processing XBee TX message",
exc_info = True)
