Golang MCRequest.Receive方法代码示例

func doReceive(
	uprconn *uprConnection, host string, msgch chan msgT, killSwitch chan bool) {

	var hdr [mcd.HDR_LEN]byte
	var msg msgT
	var pkt mcd.MCRequest
	var err error

	mcconn := uprconn.conn.Hijack()

loop:
	for {
		if _, err = pkt.Receive(mcconn, hdr[:]); err != nil {
			msg = msgT{uprconn: uprconn, err: err}
		} else {
			msg = msgT{uprconn: uprconn, pkt: pkt}
		}
		select {
		case msgch <- msg:
		case <-killSwitch:
			break loop
		}
	}
	return
}

// Internal goroutine that reads from the socket and writes events to
// the channel
func (mc *Client) runFeed(ch chan TapEvent, feed *TapFeed) {
	defer close(ch)
	var headerBuf [gomemcached.HDR_LEN]byte
loop:
	for {
		// Read the next request from the server.
		//
		//  (Can't call mc.Receive() because it reads a
		//  _response_ not a request.)
		var pkt gomemcached.MCRequest
		n, err := pkt.Receive(mc.conn, headerBuf[:])
		if TapRecvHook != nil {
			TapRecvHook(&pkt, n, err)
		}

		if err != nil {
			if err != io.EOF {
				feed.Error = err
			}
			break loop
		}

		//log.Printf("** TapFeed received %#v : %q", pkt, pkt.Body)

		if pkt.Opcode == gomemcached.TAP_CONNECT {
			// This is not an event from the server; it's
			// an error response to my connect request.
			feed.Error = fmt.Errorf("tap connection failed: %s", pkt.Body)
			break loop
		}

		event := makeTapEvent(pkt)
		if event != nil {
			if event.Opcode == tapEndStream {
				break loop
			}

			select {
			case ch <- *event:
			case <-feed.closer:
				break loop
			}
		}

		if len(pkt.Extras) >= 4 {
			reqFlags := binary.BigEndian.Uint16(pkt.Extras[2:])
			if reqFlags&gomemcached.TAP_ACK != 0 {
				if _, err := mc.sendAck(&pkt); err != nil {
					feed.Error = err
					break loop
				}
			}
		}
	}
	if err := mc.Close(); err != nil {
		log.Printf("Error closing memcached client:  %v", err)
	}
}

//.........这里部分代码省略.........
	recvEndCh := make(chan struct{})

	cleanup := func(progress int, err error) int {
		if err != nil {
			d.receiver.OnError(err)
		}
		go func() {
			<-recvEndCh
			close(sendCh)
		}()
		return progress
	}

	currVBuckets := make(map[uint16]*VBucketState)
	currVBucketsMutex := sync.Mutex{} // Protects currVBuckets.

	go func() { // Sender goroutine.
		defer close(sendEndCh)

		atomic.AddUint64(&d.stats.TotWorkerTransmitStart, 1)
		for msg := range sendCh {
			atomic.AddUint64(&d.stats.TotWorkerTransmit, 1)
			err := client.Transmit(msg)
			if err != nil {
				atomic.AddUint64(&d.stats.TotWorkerTransmitErr, 1)
				d.receiver.OnError(fmt.Errorf("client.Transmit, err: %v", err))
				return
			}
			atomic.AddUint64(&d.stats.TotWorkerTransmitOk, 1)
		}
		atomic.AddUint64(&d.stats.TotWorkerTransmitDone, 1)
	}()

	go func() { // Receiver goroutine.
		defer close(recvEndCh)

		atomic.AddUint64(&d.stats.TotWorkerReceiveStart, 1)

		var hdr [gomemcached.HDR_LEN]byte
		var pkt gomemcached.MCRequest
		var res gomemcached.MCResponse

		// Track received bytes in case we need to buffer-ack.
		recvBytesTotal := uint32(0)

		conn := client.Hijack()

		for {
			// TODO: memory allocation here.
			atomic.AddUint64(&d.stats.TotWorkerReceive, 1)
			_, err := pkt.Receive(conn, hdr[:])
			if err != nil {
				atomic.AddUint64(&d.stats.TotWorkerReceiveErr, 1)
				d.receiver.OnError(fmt.Errorf("pkt.Receive, err: %v", err))
				return
			}
			atomic.AddUint64(&d.stats.TotWorkerReceiveOk, 1)

			if pkt.Opcode == gomemcached.UPR_MUTATION ||
				pkt.Opcode == gomemcached.UPR_DELETION ||
				pkt.Opcode == gomemcached.UPR_EXPIRATION {
				atomic.AddUint64(&d.stats.TotUPRDataChange, 1)

				vbucketID := pkt.VBucket

				currVBucketsMutex.Lock()

func (feed *UprFeed) runFeed(ch chan *UprEvent) {
	defer close(ch)
	var headerBuf [gomemcached.HDR_LEN]byte
	var pkt gomemcached.MCRequest
	var event *UprEvent

	mc := feed.conn.Hijack()
	uprStats := &feed.stats

loop:
	for {
		sendAck := false
		bytes, err := pkt.Receive(mc, headerBuf[:])
		if err != nil {
			ul.LogError("", "", "Error in receive %s", err.Error())
			feed.Error = err
			// send all the stream close messages to the client
			feed.doStreamClose(ch)
			break loop
		} else {
			event = nil
			res := &gomemcached.MCResponse{
				Opcode: pkt.Opcode,
				Cas:    pkt.Cas,
				Opaque: pkt.Opaque,
				Status: gomemcached.Status(pkt.VBucket),
				Extras: pkt.Extras,
				Key:    pkt.Key,
				Body:   pkt.Body,
			}

			vb := vbOpaque(pkt.Opaque)
			uprStats.TotalBytes = uint64(bytes)

			feed.mu.RLock()
			stream := feed.vbstreams[vb]
			feed.mu.RUnlock()

			switch pkt.Opcode {
			case gomemcached.UPR_STREAMREQ:
				if stream == nil {
					ul.LogError("", "", "Stream not found for vb %d: %#v", vb, pkt)
					break loop
				}
				status, rb, flog, err := handleStreamRequest(res)
				if status == gomemcached.ROLLBACK {
					event = makeUprEvent(pkt, stream)
					// rollback stream
					msg := "UPR_STREAMREQ with rollback %d for vb %d Failed: %v"
					ul.LogError("", "", msg, rb, vb, err)
					// delete the stream from the vbmap for the feed
					feed.mu.Lock()
					delete(feed.vbstreams, vb)
					feed.mu.Unlock()

				} else if status == gomemcached.SUCCESS {
					event = makeUprEvent(pkt, stream)
					event.Seqno = stream.StartSeq
					event.FailoverLog = flog
					stream.connected = true
					ul.LogInfo("", "", "UPR_STREAMREQ for vb %d successful", vb)

				} else if err != nil {
					msg := "UPR_STREAMREQ for vbucket %d erro %s"
					ul.LogError("", "", msg, vb, err.Error())
					event = &UprEvent{
						Opcode:  gomemcached.UPR_STREAMREQ,
						Status:  status,
						VBucket: vb,
						Error:   err,
					}
				}

			case gomemcached.UPR_MUTATION,
				gomemcached.UPR_DELETION,
				gomemcached.UPR_EXPIRATION:
				if stream == nil {
					ul.LogError("", "", "Stream not found for vb %d: %#v", vb, pkt)
					break loop
				}
				event = makeUprEvent(pkt, stream)
				uprStats.TotalMutation++
				sendAck = true

			case gomemcached.UPR_STREAMEND:
				if stream == nil {
					ul.LogError("", "", "Stream not found for vb %d: %#v", vb, pkt)
					break loop
				}
				//stream has ended
				event = makeUprEvent(pkt, stream)
				ul.LogInfo("", "", "Stream Ended for vb %d", vb)
				sendAck = true

				feed.mu.Lock()
				delete(feed.vbstreams, vb)
				feed.mu.Unlock()

			case gomemcached.UPR_SNAPSHOT:
				if stream == nil {
//.........这里部分代码省略.........