def receive_once(self):
"""
block until messages are read off of socket
@return: list of newly received messages
@rtype: [Msg]
@raise TransportException: if unable to receive message due to error
"""
sock = self.socket
if sock is None:
raise TransportException("connection not initialized")
b = self.read_buff
msg_queue = []
p = self.protocol
try:
sock.setblocking(1)
while not msg_queue and not self.done and not is_shutdown():
if b.tell() >= 4:
p.read_messages(b, msg_queue, sock)
if not msg_queue:
self.stat_bytes += recv_buff(sock, b, p.buff_size)
self.stat_num_msg += len(msg_queue) #STATS
# set the _connection_header field
for m in msg_queue:
m._connection_header = self.header
# #1852: keep track of last latched message
if self.is_latched and msg_queue:
self.latch = msg_queue[-1]
return msg_queue
except DeserializationError as e:
rospyerr(traceback.format_exc())
raise TransportException(
"receive_once[%s]: DeserializationError %s" %
(self.name, str(e)))
except TransportTerminated as e:
raise #reraise
except ServiceException as e:
raise
except Exception as e:
rospyerr(traceback.format_exc())
raise TransportException("receive_once[%s]: unexpected error %s" %
(self.name, str(e)))
return retval
self.latch = msg_queue[-1]
return msg_queue
except DeserializationError, e:
rospyerr(traceback.format_exc())
raise TransportException(
"receive_once[%s]: DeserializationError %s" %
(self.name, str(e)))
except TransportTerminated, e:
raise #reraise
except ServiceException, e:
raise
except Exception, e:
rospyerr(traceback.format_exc())
raise TransportException("receive_once[%s]: unexpected error %s" %
(self.name, str(e)))
return retval
def receive_loop(self, msgs_callback):
"""
Receive messages until shutdown
@param msgs_callback: callback to invoke for new messages received
@type msgs_callback: fn([msg])
"""
# - use assert here as this would be an internal error, aka bug
logger.debug("receive_loop for [%s]", self.name)
try:
try:
while not self.done and not is_shutdown():
msgs = self.receive_once()
if not self.done and not is_shutdown():
