introduce channel and dispatcher

main.go

@@ -5,13 +5,32 @@ import "fmt"
 import "os"
 import "os/signal"
 import "strings"
+// import "time"
 import MQTT "github.com/eclipse/paho.mqtt.golang"
 import "github.com/google/uuid"
 
 
+type Message struct {
+  topic string
+  payload []byte
+}
+
+var messageChannel chan Message
+
 
 func onMessageReceived(client MQTT.Client, message MQTT.Message) {
-  log.Printf("Message received, topic: %s, payload: %s\n", message.Topic(), message.Payload())
+  // log.Printf("Message received, topic: %s, payload: %s\n", message.Topic(), message.Payload())
+  m := Message { 
+    topic: message.Topic(), 
+    payload: message.Payload(),
+  }
+  select {
+  case messageChannel <- m:
+    {}
+    //log.Println("Message sent to channel")
+  default:
+    log.Println("Channel full, message lost")
+  }
 }
 
 func onConnectionLost(client MQTT.Client, error error) {
@@ -37,6 +56,15 @@ func onConnect(client MQTT.Client) {
   }
 }
 
+func dispatcher() {
+  for {
+    select {
+    case message := <- messageChannel:
+      log.Printf("Message arrived in dispatcher, topic: %s, payload: %s\n", message.topic, message.payload)
+    }
+  }
+}
+
 
 func main() {
   log.SetPrefix("UDI: ")
@@ -44,6 +72,9 @@ func main() {
 
   log.Println("UDI starting")
 
+  messageChannel = make(chan Message, 100)
+  go dispatcher()
+
   broker := os.Getenv("MQTT_BROKER")
   if broker == "" {
     log.Fatal("No broker given, set env var MQTT_BROKER")