def setup_mqtt_conn(self, *args, **kwargs):
'''
Setup a mqtt connection and manage it.
For the available parameters, please check out
:py:class:`paho.mqtt.client.Client`
A var ``self._mqtt_c`` will be setup.
This call will block until the mqtt server connected.
'''
self._mqtt_c_lock = SimpleLock()
self._mqtt_c_lock.acquire()
client = mqtt.Client()
client.on_connect = self.mqtt_on_connect
client.on_disconnect = self.mqtt_on_disconnect
client.on_subscribe = self.mqtt_on_subscribe
client.connect(*args, **kwargs)
client.loop_start()
self._mqtt_c = client
if not self._mqtt_c_lock.acquire(timeout=10):
raise RuntimeError('Connect to mqtt server timeout')
del self._mqtt_c_lock
class MQTTConnMgrMixin(object):
'''
Connection Manager MQTT Mixin
.. todo::
- reconnect
'''
_mqtt_c = None
def __init__(self):
super(MQTTConnMgrMixin, self).__init__()
self.mqtt_connected = False
def __del__(self):
super(MQTTConnMgrMixin, self).__del__()
if self.mqtt_c is not None:
self.mqtt_c.disconnect()
self.mqtt_c.loop_stop()
@property
def mqtt_c(self):
'''
The ``paho.mqtt.client.Client`` instance
'''
if self._mqtt_c is None:
raise AttributeError(
'Please create client via ``setup_mqtt_conn`` first.')
return self._mqtt_c
def setup_mqtt_conn(self, *args, **kwargs):
'''
Setup a mqtt connection and manage it.
For the available parameters, please check out
:py:class:`paho.mqtt.client.Client`
A var ``self._mqtt_c`` will be setup.
This call will block until the mqtt server connected.
'''
self._mqtt_c_lock = SimpleLock()
self._mqtt_c_lock.acquire()
client = mqtt.Client()
client.on_connect = self.mqtt_on_connect
client.on_disconnect = self.mqtt_on_disconnect
client.on_subscribe = self.mqtt_on_subscribe
client.connect(*args, **kwargs)
client.loop_start()
self._mqtt_c = client
if not self._mqtt_c_lock.acquire(timeout=10):
raise RuntimeError('Connect to mqtt server timeout')
del self._mqtt_c_lock
def mqtt_on_connect(self, client, userdata, flags, rc):
'''
The MQTT client connect callback
'''
if rc != 0:
self._mqtt_c_lock.release()
msg = 'MQTT server connection refused, code {}'.format(rc)
log.error(msg)
raise IOError(msg)
log.info('Connect to mqtt server successfully')
self.mqtt_connected = True
self._mqtt_c_lock.release()
def mqtt_on_disconnect(self, client, userdata, rc):
'''
The MQTT client disconnect callback
'''
log.info('MQTT server disconnected')
self.mqtt_connected = False
def mqtt_on_subscribe(self, client, userdata, mid, granted_qos):
'''
:param mid: the message id returned by ``Client.subscribe``
'''
pass
def mqtt_sub(self, id_, feature, topic, qos=0):
'''
Subscribe to a mqtt topic.
:param id_: the ``UUID`` object
:param feature: the feature name, if feature name is ``_ctrl``, we will
setup the control channel.
:param topic: the mqtt topic, e.g: ``uuid/feature/i``.
:param qos: the mqtt qos level, should be 0, 1, 2
:param ctrl: control channel or not
:return: a function accept a *on message* callback.
This returned function also has following
function attributes:
:func.cb: the using callback will be stored here.
:func.client: the ``paho.mqtt.client.Client`` instance
:func.feature: the feature name related to the subscription
:func.id: the ``UUID`` object
:func.remove_callback: the function for unsubscribing topic
:func.topic: the mqtt topic
'''
def f(callback):
if f.cb is not None:
f.client.message_callback_remove(f.topic)
f.client.message_callback_add(f.topic, callback)
f.cb = callback
return callback
f.cb = None
f.client = self.mqtt_c
f.feature = feature
f.id = id_
f.topic = topic
f.remove_callback = partial(
self.mqtt_c.message_callback_remove, f.topic)
self.mqtt_c.subscribe(topic, qos=qos)
if feature != '_ctrl':
self.conns[id_].data[feature].i = f
else:
self.conns[id_].ctrl.sub = f
return f
def mqtt_pub(self, id_, feature, topic, qos=0):
'''
Add a publish function to ``self.conns``.
:param id_: the ``UUID`` object
:param feature: the feature name, if feature name is ``_ctrl``, we will
setup the control channel
:param ctrl: control channel or not
:type topic: str
:return: the ``publish`` function
'''
if feature != '_ctrl':
pub = partial(self.mqtt_c.publish, topic, qos=qos)
self.conns[id_].data[feature].o = pub
else:
pub = partial(mqtt_json_pub(self.mqtt_c.publish), topic, qos=qos)
self.conns[id_].ctrl.pub = pub
return pub
def mqtt_ctrl(self, id_, pub_topic, sub_topic, rev):
'''
:param id_: the ``UUID`` object
:param pub_topic:
:param sub_topic:
:param rev:
'''
pub = self.mqtt_pub(id_, '_ctrl', pub_topic)
sub = self.mqtt_sub(id_, '_ctrl', sub_topic)
self.conns[id_].ctrl.rev = rev
return pub, sub
