def handle_control_message(self, socket):
"""Handle a control message on the given socket
Args:
socket(zmq.Socket): The socket to receive a message and reply on
"""
message_handlers = {
"status": self.status,
"configure": self.configure,
"request_configuration": self.request_configuration,
"request_version": self.version,
"shutdown": self.shutdown,
}
# The first message part is a channel ID
channel_id = socket.recv()
# The second message part is the IpcMessage
message = IpcMessage(from_str=socket.recv())
request_type = message.get_msg_val()
handler = message_handlers.get(request_type, None)
if handler is not None:
reply = handler(message)
else:
error = "Unknown request type: {}".format(request_type)
self._logger.error(error)
reply = self._construct_reply(
message.get_msg_val(), message.get_msg_id(), error
)
socket.send(channel_id, zmq.SNDMORE)
socket.send(reply.encode())
def _callback(self, msg):
# Handle the multi-part message
reply = IpcMessage(from_str=msg[0])
if 'request_configuration' in reply.get_msg_val():
self._update_configuration(reply.attrs)
if 'status' in reply.get_msg_val():
self._update_status(reply.attrs)
def process_frames(self):
self.frame_header = Struct('<LLQQL')
while self._run:
if (self.ready_channel.poll(100)):
ready_msg = self.ready_channel.recv()
ready_decoded = IpcMessage(from_str=ready_msg)
if ready_decoded.get_msg_type(
) == 'notify' and ready_decoded.get_msg_val() == 'frame_ready':
frame_number = ready_decoded.get_param('frame')
buffer_id = ready_decoded.get_param('buffer_id')
self.logger.debug(
"Got frame ready notification for frame %d buffer ID %d"
% (frame_number, buffer_id))
if not self.config.bypass_mode:
self.handle_frame(frame_number, buffer_id)
release_msg = IpcMessage(msg_type='notify',
msg_val='frame_release')
release_msg.set_param('frame', frame_number)
release_msg.set_param('buffer_id', buffer_id)
self.release_channel.send(release_msg.encode())
self.frames_received += 1
elif ready_decoded.get_msg_type(
) == 'notify' and ready_decoded.get_msg_val(
) == 'buffer_config':
shared_buffer_name = ready_decoded.get_param(
'shared_buffer_name')
self.logger.debug(
'Got shared buffer config notification with name %s' %
(shared_buffer_name))
else:
self.logger.error(
"Got unexpected message on ready notification channel: %s"
% (ready_decoded))
self.logger.info("Frame processing thread interrupted, terminating")
def handle_control_message(self, receiver):
"""Handle control message.
:param: receiver: ZeroMQ channel to receive message from
"""
channel_id = receiver.recv()
message_val = ""
message_id = 0
try:
message = IpcMessage(from_str=receiver.recv())
message_val = message.get_msg_val()
message_id = message.get_msg_id()
if message.get_msg_val() == 'status':
reply = self.handle_status_message(message_id)
elif message.get_msg_val() == 'request_configuration':
reply = self.handle_request_config_message(message_id)
elif message.get_msg_val() == 'request_version':
reply = self.handle_request_version_message(message_id)
elif message.get_msg_val() == 'configure':
self.logger.debug('handling control configure message')
self.logger.debug(message)
params = message.attrs['params']
reply = self.handle_configure_message(params, message_id)
else:
reply = IpcMessage(IpcMessage.NACK, message_val, id=message_id)
reply.set_param('error', 'Unknown message value type')
except Exception as err:
self.logger.error(
'Unexpected Exception handling control message: ' + str(err))
reply = IpcMessage(IpcMessage.NACK, message_val, id=message_id)
reply.set_param('error', 'Error processing control message')
receiver.send(channel_id, zmq.SNDMORE)
receiver.send(reply.encode())
def test_valid_ipc_msg_from_string():
# Instantiate a valid message from a JSON string
json_str = """
{\"msg_type\":\"cmd\",
\"msg_val\":\"status\",
\"timestamp\" : \"2015-01-27T15:26:01.123456\",
\"id\":322,
\"params\" : {
\"paramInt\" : 1234,
\"paramStr\" : \"testParam\",
\"paramDouble\" : 3.1415
}
}
"""
# Instantiate a valid message from the JSON string
the_msg = IpcMessage(from_str=json_str)
# Check the message is indeed valid
assert_true(the_msg.is_valid())
# Check that all attributes are as expected
assert_equals(the_msg.get_msg_type(), "cmd")
assert_equals(the_msg.get_msg_val(), "status")
assert_equals(the_msg.get_msg_timestamp(), "2015-01-27T15:26:01.123456")
assert_equals(the_msg.get_msg_id(), 322)
# Check that all parameters are as expected
assert_equals(the_msg.get_param("paramInt"), 1234)
assert_equals(the_msg.get_param("paramStr"), "testParam")
assert_equals(the_msg.get_param("paramDouble"), 3.1415)
# Check valid message throws an exception on missing parameter
with assert_raises(IpcMessageException) as cm:
missingParam = the_msg.get_param("missingParam")
ex = cm.exception
assert_equals(ex.msg, 'Missing parameter missingParam')
# Check valid message can fall back to default value if parameter missing
defaultParamValue = 90210
assert_equals(the_msg.get_param("missingParam", defaultParamValue), defaultParamValue)
def test_round_trip_from_empty_msg():
# Instantiate an empty message
the_msg = IpcMessage()
# Set the message type and value
msg_type = "cmd"
the_msg.set_msg_type(msg_type)
msg_val = "reset"
the_msg.set_msg_val(msg_val)
msg_id = 61616
the_msg.set_msg_id(msg_id)
# Define and set some parameters
paramInt1 = 1234;
paramInt2 = 901201;
paramInt3 = 4567;
paramStr = "paramString"
the_msg.set_param('paramInt1', paramInt1)
the_msg.set_param('paramInt2', paramInt2)
the_msg.set_param('paramInt3', paramInt3)
the_msg.set_param('paramStr', paramStr)
# Retrieve the encoded version
the_msg_encoded = the_msg.encode()
# Create another message from the encoded version
msg_from_encoded = IpcMessage(from_str=the_msg_encoded)
# Validate the contents of all attributes and parameters of the new message
assert_equal(msg_from_encoded.get_msg_type(), msg_type)
assert_equal(msg_from_encoded.get_msg_val(), msg_val)
assert_equal(msg_from_encoded.get_msg_timestamp(), the_msg.get_msg_timestamp())
assert_equal(msg_from_encoded.get_msg_id(), the_msg.get_msg_id())
assert_equal(msg_from_encoded.get_param('paramInt1'), paramInt1)
assert_equal(msg_from_encoded.get_param('paramInt2'), paramInt2)
assert_equal(msg_from_encoded.get_param('paramInt3'), paramInt3)
assert_equal(msg_from_encoded.get_param('paramStr'), paramStr)
def run_rep(self):
''' sends a request, waits for a reply, returns response '''
while True:
try:
client_address, request = self.socket.recv_multipart()
request = IpcMessage(from_str=request)
print("received request : %s from %s" %
(request, client_address.decode()))
# Get the alias device name used in the request
req_alias = request.get_param("DEVICE")
# get the address of the device
req_address = self.process_address(request)
# get the message value (CONFIG/STATUS/READ)
req_msg_val = request.get_msg_val()
req_device = None
req_config = None
reply_message = IpcMessage(msg_type="CMD", msg_val="NOTIFY")
# Find the device attached to that request address
for device in self.devices:
if req_address == device.get_addr():
req_device = device
if req_msg_val == "CONFIG":
req_config = request.get_param("CONFIG")
if req_config == "BLINK":
req_timeout = request.get_param("TIMEOUT")
req_rate = request.get_param("RATE")
req_device.set_config(req_config, req_timeout, req_rate)
reply_string = "Processed request from %s. %s at address %s blinked for %s seconds. \
Current status is %s." % (client_address.decode(),req_alias, req_address, req_timeout, req_device.get_config())
else:
req_device.set_config(req_config)
reply_string = "Processed Request from %s. Set %s at \
address %s to: %s." % (client_address.decode(),
req_alias, req_address, req_device.get_config())
if req_msg_val == "STATUS":
rep_status = req_device.get_status()
reply_string = "Processed Request from %s. Status of %s at \
address %s is: %s." % (client_address.decode(),
req_alias, req_address, rep_status)
if req_msg_val == "READ":
rep_value = req_device.get_data()
reply_string = "Processed Request from %s. Value of %s at \
address %s is: %s." % (client_address.decode(),
req_alias, req_address, rep_value)
reply_message.set_param("REPLY", reply_string)
# Encode the message for sending
reply_message = reply_message.encode()
# check if its unicode, if so covert to bytes
if isinstance(reply_message, unicode):
reply_message = cast_bytes(reply_message)
# send a multipart back to the client
self.socket.send_multipart([client_address, b"", reply_message,])
except IpcMessageException as err:
print("IPC MESSAGE Error Found %s: " % str(err))