prepare application

src/MqttProcessor.py

@@ -0,0 +1,76 @@
+import threading
+import paho.mqtt.client as mqtt
+from AbstractNotificationReceiver import AbstractNotificationReceiver
+
+
+
+def mqttOnConnectCallback(client, userdata, flags, rc):
+    userdata.onConnect()
+
+def mqttOnMessageCallback(client, userdata, message):
+    userdata.onMessage(message.topic, message.payload)
+
+def mqttOnDisconnectCallback(client, userdata, rc):
+    userdata.onDisconnect(rc)
+
+class MqttProcessor(threading.Thread, AbstractNotificationReceiver):
+    def __init__(self, config, registers, queue):
+        super().__init__()
+        self.config = config
+        self.registers = registers
+        self.queue = queue
+        self.client = mqtt.Client(userdata=self)
+        self.subscriptions = []
+        self.topicRegisterMap ={}
+
+    def __processUpdatedRegisters(self, force=False):
+        # print("MqttProcessor.__updateSubscriptions")
+
+        subscribeTopics = [ r.subscribeTopic for r in self.registers if r.subscribeTopic]
+        # print("Topics: {0!s}".format(subscribeTopics))
+
+        for subscribeTopic in subscribeTopics:
+            if (subscribeTopic not in self.subscriptions) or force:
+                print("Subscribe to {0}".format(subscribeTopic))
+                self.client.subscribe(subscribeTopic)
+                self.subscriptions.append(subscribeTopic)
+
+        for subscription in self.subscriptions:
+            if (subscription not in subscribeTopics) and not force:
+                print("Unsubscribe from {0}".format(subscription))
+                self.client.unsubscribe(subscription)
+                self.subscriptions.remove(subscription)
+
+        self.topicRegisterMap = { r.subscribeTopic: r for r in self.registers if r.subscribeTopic }
+
+    def receiveNotification(self, arg):
+        print("MqttProcessor:registersChanged")
+        self.__processUpdatedRegisters()
+
+    def run(self):
+        # print("MqttProcessor.run")
+        self.client.on_message = mqttOnMessageCallback
+        self.client.on_connect = mqttOnConnectCallback
+        self.client.on_disconnect = mqttOnDisconnectCallback
+        if self.config.mqttLogin and self.config.mqttPassword:
+            self.client.username_pw_set(self.config.mqttLogin, self.config.mqttPassword)
+        self.client.connect(self.config.mqttBrokerHost, self.config.mqttBrokerPort)
+        self.client.loop_forever()
+
+    def onConnect(self):
+        # print("MqttProcessor.onConnect")
+        self.__processUpdatedRegisters(force=True)
+
+    def onDisconnect(self, rc):
+        print("Disconnected from MQTT broker: {0}".format(rc))
+
+    def onMessage(self, topic, payload):
+        # print("MqttProcessor.onMessage")
+        r = self.topicRegisterMap[topic]
+        # print("{0}: {1!s} -> {2!s}".format(topic, payload, r))
+        r.setCommand('w')
+        r.setValue(payload)
+        self.queue.put(r)
+
+
+