Golang nsq.DecodeMessage函數代碼示例

// exercise the basic operations of the V2 protocol
func TestBasicV2(t *testing.T) {
	log.SetOutput(ioutil.Discard)
	defer log.SetOutput(os.Stdout)

	options := NewNsqdOptions()
	options.clientTimeout = 60 * time.Second
	tcpAddr, _ := mustStartNSQd(options)
	defer nsqd.Exit()

	topicName := "test_v2" + strconv.Itoa(int(time.Now().Unix()))
	topic := nsqd.GetTopic(topicName)
	msg := nsq.NewMessage(<-nsqd.idChan, []byte("test body"))
	topic.PutMessage(msg)

	conn, err := mustConnectNSQd(tcpAddr)
	assert.Equal(t, err, nil)

	identify(t, conn)
	sub(t, conn, topicName, "ch")

	err = nsq.Ready(1).Write(conn)
	assert.Equal(t, err, nil)

	resp, err := nsq.ReadResponse(conn)
	assert.Equal(t, err, nil)
	frameType, data, err := nsq.UnpackResponse(resp)
	msgOut, _ := nsq.DecodeMessage(data)
	assert.Equal(t, frameType, nsq.FrameTypeMessage)
	assert.Equal(t, msgOut.Id, msg.Id)
	assert.Equal(t, msgOut.Body, msg.Body)
	assert.Equal(t, msgOut.Attempts, uint16(1))
}

// messagePump selects over the in-memory and backend queue and
// writes messages to every channel for this topic
func (t *Topic) messagePump() {
	var msg *nsq.Message
	var buf []byte
	var err error

	for {
		// do an extra check for exit before we select on all the memory/backend/exitChan
		// this solves the case where we are closed and something else is writing into
		// backend. we don't want to reverse that
		if atomic.LoadInt32(&t.exitFlag) == 1 {
			goto exit
		}

		select {
		case msg = <-t.memoryMsgChan:
		case buf = <-t.backend.ReadChan():
			msg, err = nsq.DecodeMessage(buf)
			if err != nil {
				log.Printf("ERROR: failed to decode message - %s", err.Error())
				continue
			}
		case <-t.exitChan:
			goto exit
		}

		t.RLock()
		// check if all the channels have been deleted
		if len(t.channelMap) == 0 {
			// put this message back on the queue
			// we need to background because we currently hold the lock
			go func() {
				t.PutMessage(msg)
			}()

			// reset the sync.Once
			t.messagePumpStarter = new(sync.Once)

			t.RUnlock()
			goto exit
		}

		for _, channel := range t.channelMap {
			// copy the message because each channel
			// needs a unique instance
			chanMsg := nsq.NewMessage(msg.Id, msg.Body)
			chanMsg.Timestamp = msg.Timestamp
			err := channel.PutMessage(chanMsg)
			if err != nil {
				log.Printf("TOPIC(%s) ERROR: failed to put msg(%s) to channel(%s) - %s", t.name, msg.Id, channel.name, err.Error())
			}
		}
		t.RUnlock()
	}

exit:
	log.Printf("TOPIC(%s): closing ... messagePump", t.name)
}

func subWorker(n int, workers int, tcpAddr string, topic string, channel string, rdyChan chan int, goChan chan int, id int) {
	conn, err := net.DialTimeout("tcp", tcpAddr, time.Second)
	if err != nil {
		panic(err.Error())
	}
	conn.Write(nsq.MagicV2)
	rw := bufio.NewReadWriter(bufio.NewReader(conn), bufio.NewWriter(conn))
	ci := make(map[string]interface{})
	ci["short_id"] = "test"
	ci["long_id"] = "test"
	cmd, _ := nsq.Identify(ci)
	cmd.Write(rw)
	nsq.Subscribe(topic, channel).Write(rw)
	rdyCount := int(math.Min(math.Max(float64(n/workers), 1), 2500))
	rdyChan <- 1
	<-goChan
	nsq.Ready(rdyCount).Write(rw)
	rw.Flush()
	nsq.ReadResponse(rw)
	nsq.ReadResponse(rw)
	num := n / workers
	numRdy := num/rdyCount - 1
	rdy := rdyCount
	for i := 0; i < num; i += 1 {
		resp, err := nsq.ReadResponse(rw)
		if err != nil {
			panic(err.Error())
		}
		frameType, data, err := nsq.UnpackResponse(resp)
		if err != nil {
			panic(err.Error())
		}
		if frameType == nsq.FrameTypeError {
			panic("got something else")
		}
		msg, err := nsq.DecodeMessage(data)
		if err != nil {
			panic(err.Error())
		}
		nsq.Finish(msg.Id).Write(rw)
		rdy--
		if rdy == 0 && numRdy > 0 {
			nsq.Ready(rdyCount).Write(rw)
			rdy = rdyCount
			numRdy--
			rw.Flush()
		}
	}
}

func TestMultipleConsumerV2(t *testing.T) {
	log.SetOutput(ioutil.Discard)
	defer log.SetOutput(os.Stdout)

	msgChan := make(chan *nsq.Message)

	options := NewNsqdOptions()
	options.clientTimeout = 60 * time.Second
	tcpAddr, _ := mustStartNSQd(options)
	defer nsqd.Exit()

	topicName := "test_multiple_v2" + strconv.Itoa(int(time.Now().Unix()))
	topic := nsqd.GetTopic(topicName)
	msg := nsq.NewMessage(<-nsqd.idChan, []byte("test body"))
	topic.GetChannel("ch1")
	topic.GetChannel("ch2")
	topic.PutMessage(msg)

	for _, i := range []string{"1", "2"} {
		conn, err := mustConnectNSQd(tcpAddr)
		assert.Equal(t, err, nil)

		identify(t, conn)
		sub(t, conn, topicName, "ch"+i)

		err = nsq.Ready(1).Write(conn)
		assert.Equal(t, err, nil)

		go func(c net.Conn) {
			resp, _ := nsq.ReadResponse(c)
			_, data, _ := nsq.UnpackResponse(resp)
			msg, _ := nsq.DecodeMessage(data)
			msgChan <- msg
		}(conn)
	}

	msgOut := <-msgChan
	assert.Equal(t, msgOut.Id, msg.Id)
	assert.Equal(t, msgOut.Body, msg.Body)
	assert.Equal(t, msgOut.Attempts, uint16(1))
	msgOut = <-msgChan
	assert.Equal(t, msgOut.Id, msg.Id)
	assert.Equal(t, msgOut.Body, msg.Body)
	assert.Equal(t, msgOut.Attempts, uint16(1))
}

// messagePump reads messages from either memory or backend and writes
// to the client output go channel
//
// it is also performs in-flight accounting and initiates the auto-requeue
// goroutine
func (c *Channel) messagePump() {
	var msg *nsq.Message
	var buf []byte
	var err error

	for {
		// do an extra check for closed exit before we select on all the memory/backend/exitChan
		// this solves the case where we are closed and something else is draining clientMsgChan into
		// backend. we don't want to reverse that
		if atomic.LoadInt32(&c.exitFlag) == 1 {
			goto exit
		}

		select {
		case msg = <-c.memoryMsgChan:
		case buf = <-c.backend.ReadChan():
			msg, err = nsq.DecodeMessage(buf)
			if err != nil {
				log.Printf("ERROR: failed to decode message - %s", err.Error())
				continue
			}
		case <-c.exitChan:
			goto exit
		}

		msg.Attempts++

		atomic.StoreInt32(&c.bufferedCount, 1)
		c.clientMsgChan <- msg
		atomic.StoreInt32(&c.bufferedCount, 0)
		// the client will call back to mark as in-flight w/ it's info
	}

exit:
	log.Printf("CHANNEL(%s): closing ... messagePump", c.name)
	close(c.clientMsgChan)
}

// messagePump selects over the in-memory and backend queue and
// writes messages to every channel for this topic
func (t *Topic) messagePump() {
	var msg *nsq.Message
	var buf []byte
	var err error
	var chans []*Channel
	var memoryMsgChan chan *nsq.Message
	var backendChan chan []byte

	t.RLock()
	for _, c := range t.channelMap {
		chans = append(chans, c)
	}
	t.RUnlock()

	if len(chans) > 0 {
		memoryMsgChan = t.memoryMsgChan
		backendChan = t.backend.ReadChan()
	}

	for {
		select {
		case msg = <-memoryMsgChan:
		case buf = <-backendChan:
			msg, err = nsq.DecodeMessage(buf)
			if err != nil {
				log.Printf("ERROR: failed to decode message - %s", err.Error())
				continue
			}
		case <-t.channelUpdateChan:
			chans = make([]*Channel, 0)
			t.RLock()
			for _, c := range t.channelMap {
				chans = append(chans, c)
			}
			t.RUnlock()
			if len(chans) == 0 {
				memoryMsgChan = nil
				backendChan = nil
			} else {
				memoryMsgChan = t.memoryMsgChan
				backendChan = t.backend.ReadChan()
			}
			continue
		case <-t.exitChan:
			goto exit
		}

		for i, channel := range chans {
			chanMsg := msg
			// copy the message because each channel
			// needs a unique instance but...
			// fastpath to avoid copy if its the first channel
			// (the topic already created the first copy)
			if i > 0 {
				chanMsg = nsq.NewMessage(msg.Id, msg.Body)
				chanMsg.Timestamp = msg.Timestamp
			}
			err := channel.PutMessage(chanMsg)
			if err != nil {
				log.Printf("TOPIC(%s) ERROR: failed to put msg(%s) to channel(%s) - %s", t.name, msg.Id, channel.name, err.Error())
			}
		}
	}

exit:
	log.Printf("TOPIC(%s): closing ... messagePump", t.name)
}

// messagePump selects over the in-memory and backend queue and
// writes messages to every channel for this topic
func (t *Topic) messagePump() {
	var msg *nsq.Message
	var buf []byte
	var err error
	var chans []*Channel

	t.RLock()
	for _, c := range t.channelMap {
		chans = append(chans, c)
	}
	t.RUnlock()

	for {
		select {
		case msg = <-t.memoryMsgChan:
		case buf = <-t.backend.ReadChan():
			msg, err = nsq.DecodeMessage(buf)
			if err != nil {
				log.Printf("ERROR: failed to decode message - %s", err.Error())
				continue
			}
		case <-t.channelUpdateChan:
			chans = chans[:0]
			t.RLock()
			for _, c := range t.channelMap {
				chans = append(chans, c)
			}
			t.RUnlock()
			continue
		case <-t.exitChan:
			goto exit
		}

		// check if all the channels have been deleted
		if len(chans) == 0 {
			// put this message back on the queue
			t.PutMessage(msg)
			// reset the sync.Once
			t.messagePumpStarter = new(sync.Once)
			goto exit
		}

		for i, channel := range chans {
			chanMsg := msg
			// copy the message because each channel
			// needs a unique instance but...
			// fastpath to avoid copy if its the first channel
			// (the topic already created the first copy)
			if i > 0 {
				chanMsg = nsq.NewMessage(msg.Id, msg.Body)
				chanMsg.Timestamp = msg.Timestamp
			}
			err := channel.PutMessage(chanMsg)
			if err != nil {
				log.Printf("TOPIC(%s) ERROR: failed to put msg(%s) to channel(%s) - %s", t.name, msg.Id, channel.name, err.Error())
			}
		}
	}

exit:
	log.Printf("TOPIC(%s): closing ... messagePump", t.name)
}

//.........這裏部分代碼省略.........
	conn, err := mustConnectNSQd(tcpAddr)
	assert.Equal(t, err, nil)

	hbi := int(options.maxHeartbeatInterval/time.Millisecond + 1)
	identifyHeartbeatInterval(t, conn, hbi, nsq.FrameTypeError, "E_BAD_BODY IDENTIFY heartbeat interval (300001) is invalid")
}

func TestPausing(t *testing.T) {
	log.SetOutput(ioutil.Discard)
	defer log.SetOutput(os.Stdout)

	topicName := "test_pause_v2" + strconv.Itoa(int(time.Now().Unix()))

	tcpAddr, _ := mustStartNSQd(NewNsqdOptions())
	defer nsqd.Exit()

	conn, err := mustConnectNSQd(tcpAddr)
	assert.Equal(t, err, nil)

	identify(t, conn)
	sub(t, conn, topicName, "ch")

	err = nsq.Ready(1).Write(conn)
	assert.Equal(t, err, nil)

	topic := nsqd.GetTopic(topicName)
	msg := nsq.NewMessage(<-nsqd.idChan, []byte("test body"))
	channel := topic.GetChannel("ch")
	topic.PutMessage(msg)

	// receive the first message via the client, finish it, and send new RDY
	resp, _ := nsq.ReadResponse(conn)
	_, data, _ := nsq.UnpackResponse(resp)
	msg, err = nsq.DecodeMessage(data)
	assert.Equal(t, msg.Body, []byte("test body"))

	err = nsq.Finish(msg.Id).Write(conn)
	assert.Equal(t, err, nil)

	err = nsq.Ready(1).Write(conn)
	assert.Equal(t, err, nil)

	// sleep to allow the RDY state to take effect
	time.Sleep(50 * time.Millisecond)

	// pause the channel... the client shouldn't receive any more messages
	channel.Pause()

	// sleep to allow the paused state to take effect
	time.Sleep(50 * time.Millisecond)

	msg = nsq.NewMessage(<-nsqd.idChan, []byte("test body2"))
	topic.PutMessage(msg)

	// allow the client to possibly get a message, the test would hang indefinitely
	// if pausing was not working on the internal clientMsgChan read
	time.Sleep(50 * time.Millisecond)
	msg = <-channel.clientMsgChan
	assert.Equal(t, msg.Body, []byte("test body2"))

	// unpause the channel... the client should now be pushed a message
	channel.UnPause()

	msg = nsq.NewMessage(<-nsqd.idChan, []byte("test body3"))
	topic.PutMessage(msg)