comparison lib/mqtt_client.py @ 1183:6561367aa60a

factor common mqtt code out of mqtt_graph_bridge Ignore-this: 21b54376d0b00f6709f1947c198cb4a8 darcs-hash:6d93c35ea6d305744693e3cb8366577b4183ca05
author drewp <drewp@bigasterisk.com>
date Wed, 12 Dec 2018 01:10:48 -0800
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1182:bd215f18e715 1183:6561367aa60a
1 from mqtt.client.factory import MQTTFactory
2 from twisted.application.internet import ClientService, backoffPolicy
3 from twisted.internet.defer import inlineCallbacks, Deferred
4 from twisted.internet.endpoints import clientFromString
5 import logging
6 from twisted.internet import reactor
7 from rx.concurrency import TwistedScheduler
8 from rx import Observable
9
10 log = logging.getLogger('mqtt_client')
11
12 class MQTTService(ClientService):
13
14 def __init__(self, endpoint, factory):
15 self.endpoint = endpoint
16 ClientService.__init__(self, endpoint, factory, retryPolicy=backoffPolicy())
17
18 def startService(self):
19 self.whenConnected().addCallback(self.connectToBroker)
20 ClientService.startService(self)
21
22 @inlineCallbacks
23 def connectToBroker(self, protocol):
24 self.protocol = protocol
25 self.protocol.onDisconnection = self.onDisconnection
26 # We are issuing 3 publish in a row
27 # if order matters, then set window size to 1
28 # Publish requests beyond window size are enqueued
29 self.protocol.setWindowSize(1)
30
31 try:
32 yield self.protocol.connect("TwistedMQTT-pub", keepalive=60)
33 except Exception as e:
34 log.error("Connecting to {broker} raised {excp!s}",
35 broker=self.endpoint, excp=e)
36 else:
37 log.info("Connected to {broker}".format(broker=self.endpoint))
38 if getattr(self, 'onMqttConnectionMade', False):
39 self.onMqttConnectionMade()
40
41 def onDisconnection(self, reason):
42 log.warn("Connection to broker lost: %r", reason)
43 self.whenConnected().addCallback(self.connectToBroker)
44
45 def publish(self, topic, msg):
46 def _logFailure(failure):
47 log.warn("publish failed: %s", failure.getErrorMessage())
48 return failure
49
50 return self.protocol.publish(topic=topic, qos=0, message=msg).addErrback(_logFailure)
51
52
53 class MqttClient(object):
54 def __init__(self, brokerHost='bang', brokerPort=1883):
55
56 #scheduler = TwistedScheduler(reactor)
57
58 factory = MQTTFactory(profile=MQTTFactory.PUBLISHER | MQTTFactory.SUBSCRIBER)
59 myEndpoint = clientFromString(reactor, 'tcp:%s:%s' % (brokerHost, brokerPort))
60 myEndpoint.__class__.__repr__ = lambda self: repr('%s:%s' % (self._host, self._port))
61 self.serv = MQTTService(myEndpoint, factory)
62 self.serv.startService()
63
64 def publish(self, topic, msg):
65 return self.serv.publish(topic, msg)
66
67 def subscribe(self, topic):
68 """returns rx.Observable of payload strings"""
69 # This is surely broken for multiple topics and subscriptions. Might not even
70 # work over a reconnect.
71
72 ret = Observable.create(self._observe_msgs)
73
74 self.serv.onMqttConnectionMade = lambda: self._resubscribe(topic)
75 if (hasattr(self.serv, 'protocol') and
76 self.serv.protocol.state ==self.serv.protocol.CONNECTED):
77 self._resubscribe(topic)
78 return ret
79
80 def _resubscribe(self, topic):
81 log.info('subscribing %r', topic)
82 self.serv.protocol.onPublish = self._onPublish
83 return self.serv.protocol.subscribe(topic, 2)
84
85 def _observe_msgs(self, observer):
86 self.obs = observer
87
88 def _onPublish(self, topic, payload, qos, dup, retain, msgId):
89 log.debug('received payload %r', payload)
90 self.obs.on_next(payload)