def _connect(self):
_log.debug('connect to %s:%d', self.host, int(self.port))
self.client.connect(self.host, self.port)
self.adapter = MQTTornadoAdapter(self.client)
class MQTTTask(TornadoTask):
OPT_PREFIX = 'mqtt'
port = option(default=1883, help='Broker port')
host = option(default='localhost', help='Broker host address')
topic = option(default='/parameters', help='Parameters topic')
def __init__(self, *args, **kwargs):
super(MQTTTask, self).__init__(*args, **kwargs)
self.adapter = None
self.client = mqtt.Client()
self.client.on_connect = self._on_connect
self.client.on_disconnect = self._on_disconnect
def start(self):
_log.debug('start')
self.ioloop.add_callback(self._try_connect)
ParametersStore.change_listeners.add(self.param_changed)
def stop(self):
_log.debug('stop')
if self.adapter is not None:
self.adapter.stop()
#self.client.disconnect()
ParametersStore.change_listeners.remove(self.param_changed)
def _try_connect(self):
"""Attempt connection, if not schedule a reconnect after timeout """
_log.debug('try connecting to broker')
try:
self._connect()
except socket.error:
_log.warning('failed to connect')
self._schedule_reconnect()
def _connect(self):
_log.debug('connect to %s:%d', self.host, int(self.port))
self.client.connect(self.host, self.port)
self.adapter = MQTTornadoAdapter(self.client)
def _schedule_reconnect(self):
"""Schedule reconnection attempt"""
# reconnect after 10s
timeout = 10
_log.debug('reconnect after %d seconds', timeout)
loop = self.ioloop
_log.debug('reconnect at %d (now %d)',
loop.time() + timeout, loop.time())
loop.add_timeout(loop.time() + timeout, self._try_connect)
def _on_connect(self, client, userdata, flags, rc):
"""CONNACK received"""
_log.debug('connected: %s', mqtt.connack_string(rc))
_log.debug('flags: %s', flags)
self.adapter.poll_writes()
def _on_disconnect(self, client, userdata, rc):
"""DISCONNECT received"""
_log.debug('disconnected: %s', mqtt.connack_string(rc))
self.adapter.stop()
self.adapter = None
self._schedule_reconnect()
def param_changed(self, param):
_log.debug('param_changed %s', param)
self.ioloop.add_callback(self._publish_param, param)
def _publish_param(self, param):
as_json = ParameterCodec(as_set=True).encode(param)
_log.debug('publish to %s: %s', self.topic, as_json)
self.client.publish(self.topic, as_json)
