Exemplo n.º 1
0
// run receives pubsub messages from Redis after establishing a connection.
// When a valid message is received it is broadcast to all connected websockets
func (rr *redisReceiver) run() {
	conn := rr.pool.Get()
	defer conn.Close()
	psc := redis.PubSubConn{conn}
	psc.Subscribe(CHANNEL)
	for {
		switch v := psc.Receive().(type) {
		case redis.Message:
			log.WithFields(log.Fields{
				"channel": v.Channel,
				"message": string(v.Data),
			}).Println("Redis Message Received")
			msg, err := validateMessage(v.Data)
			if err != nil {
				log.WithFields(log.Fields{
					"err":  err,
					"data": v.Data,
					"msg":  msg,
				}).Error("Error unmarshalling message from Redis")
				continue
			}
			rr.broadcast(v.Data)
		case redis.Subscription:
			log.WithFields(log.Fields{
				"channel": v.Channel,
				"kind":    v.Kind,
				"count":   v.Count,
			}).Println("Redis Subscription Received")
		case error:
			log.WithField("err", v).Errorf("Error while subscribed to Redis channel %s", CHANNEL)
		default:
			log.WithField("v", v).Println("Unknown Redis receive during subscription")
		}
	}
}
// Applications can receive pushed messages from one goroutine and manage subscriptions from another goroutine.
func ExamplePubSubConn() {
	c, err := dial()
	if err != nil {
		panic(err)
	}
	defer c.Close()
	var wg sync.WaitGroup
	wg.Add(2)

	psc := redis.PubSubConn{Conn: c}

	// This goroutine receives and prints pushed notifications from the server.
	// The goroutine exits when the connection is unsubscribed from all
	// channels or there is an error.
	go func() {
		defer wg.Done()
		for {
			switch n := psc.Receive().(type) {
			case redis.Message:
				fmt.Printf("Message: %s %s\n", n.Channel, n.Data)
			case redis.PMessage:
				fmt.Printf("PMessage: %s %s %s\n", n.Pattern, n.Channel, n.Data)
			case redis.Subscription:
				fmt.Printf("Subscription: %s %s %d\n", n.Kind, n.Channel, n.Count)
				if n.Count == 0 {
					return
				}
			case error:
				fmt.Printf("error: %v\n", n)
				return
			}
		}
	}()

	// This goroutine manages subscriptions for the connection.
	go func() {
		defer wg.Done()

		psc.Subscribe("example")
		psc.PSubscribe("p*")

		// The following function calls publish a message using another
		// connection to the Redis server.
		publish("example", "hello")
		publish("example", "world")
		publish("pexample", "foo")
		publish("pexample", "bar")

		// Unsubscribe from all connections. This will cause the receiving
		// goroutine to exit.
		psc.Unsubscribe()
		psc.PUnsubscribe()
	}()

	wg.Wait()

	// Output:
	// Subscription: subscribe example 1
	// Subscription: psubscribe p* 2
	// Message: example hello
	// Message: example world
	// PMessage: p* pexample foo
	// PMessage: p* pexample bar
	// Subscription: unsubscribe example 1
	// Subscription: punsubscribe p* 0
}
func expectPushed(t *testing.T, c redis.PubSubConn, message string, expected interface{}) {
	actual := c.Receive()
	if !reflect.DeepEqual(actual, expected) {
		t.Errorf("%s = %v, want %v", message, actual, expected)
	}
}