publish cache

src/pv_controller/MqttBase.py

@@ -25,6 +25,8 @@ class AbstractMqttPublisher(threading.Thread):
         logger.info(f"mqtt client id: {client_id}")
         self.client = mqtt.Client(client_id=client_id, userdata=self)
 
+        self.cache = {}
+
         # consider this flag in the localLoop
         self.killBill = False
         self.killEvent = threading.Event()
@@ -62,3 +64,10 @@ class AbstractMqttPublisher(threading.Thread):
     def onMessage(self, topic, payload):
         logger.warning("mqtt unexpected message received: {} -> {}".format(topic, str(payload)))
 
+    def publish_with_cache(self, topic, payload):
+        if topic in self.cache and self.cache[topic] == payload:
+            logger.debug(f"mqtt message unchanged, not publishing: {topic} -> {payload}")
+            return
+        self.cache[topic] = payload
+        self.client.publish(topic, payload)
+