func main() {
flag.Parse()
conn, ch := qutils.GetChannel(url)
defer conn.Close()
defer ch.Close()
dataQueue := qutils.GetQueue(*name, ch, false)
publishQueueName(ch)
discoveryQueue := qutils.GetQueue("", ch, true)
ch.QueueBind(
discoveryQueue.Name,
"",
qutils.SensorDiscoveryExchange,
false,
nil)
go listenForDiscoveryRequests(discoveryQueue.Name, ch)
dur, _ := time.ParseDuration(strconv.Itoa(1000/int(*freq)) + "ms")
signal := time.Tick(dur)
buf := new(bytes.Buffer)
enc := gob.NewEncoder(buf)
for range signal {
calcValue()
reading := dto.SensorMessage{
Name: *name,
Value: value,
Timestamp: time.Now(),
}
buf.Reset()
enc = gob.NewEncoder(buf)
enc.Encode(reading)
msg := amqp.Publishing{
Body: buf.Bytes(),
}
ch.Publish(
"", // exchange name
dataQueue.Name, // key string
false, // mandatory bool
false, // immediate bool
msg) // msg amqp.Publish
log.Printf("Reading sent. Value: %v\n", value)
}
}
func NewDatabaseConsumer(er EventRaiser) *DatabaseConsumer {
dc := DatabaseConsumer{
er: er,
}
dc.conn, dc.ch = qutils.GetChannel(url)
dc.queue = qutils.GetQueue(qutils.PersistReadingsQueue, dc.ch, false)
dc.er.AddListener("DataSourceDiscovered", func(eventData interface{}) {
dc.SubscribeToDataEvent(eventData.(string))
})
return &dc
}
func (ql *QueueListener) ListenForNewSource() {
q := qutils.GetQueue("", ql.ch, true)
ql.ch.QueueBind(
q.Name, // name string
"", // key string
"amq.fanout", // exchange string
false, //noWait bool
nil) // args amqp.Table
msgs, _ := ql.ch.Consume(
q.Name,
"",
true,
false,
false,
false,
nil)
ql.DiscoverSensors()
fmt.Println("listening for new sources")
for msg := range msgs {
fmt.Println("new source discovered")
ql.ea.PublishEvent("DataSourceDiscovered", string(msg.Body))
sourceChan, _ := ql.ch.Consume(
string(msg.Body),
"",
true,
false,
false,
false,
nil)
if ql.sources[string(msg.Body)] == nil {
ql.sources[string(msg.Body)] = sourceChan
go ql.AddListener(sourceChan)
}
}
}