本文解决的问题是:本Peer节点如何接收其他节点的数据,接到数据如何处理?
之前两节的分析是命令来源是CLI client,如何连接到Devops服务器、如何发送给Consensus模块、如何发送给ChainCodeSupportClient等。
接下来分析本文要讨论的问题
1)在进行网络初始化的过程中执行以下内容,在创建节点Engine过程中该节点作为客户端的身份连接到其他Peer
- peerServer, err = peer.NewPeerWithEngine(secHelperFunc, helper.GetEngine)
- </pre><pre name="code" class="cpp" style="font-size: 15px;">func (p *Impl) chatWithPeer(address string) error {
- peerLogger.Debugf("Initiating Chat with peer address: %s", address)
- conn, err := NewPeerClientConnectionWithAddress(address)
- if err != nil {
- peerLogger.Errorf("Error creating connection to peer address %s: %s", address, err)
- return err
- }
- serverClient := pb.NewPeerClient(conn)
- ctx := context.Background()
- stream, err := serverClient.Chat(ctx)
- if err != nil {
- peerLogger.Errorf("Error establishing chat with peer address %s: %s", address, err)
- return err
- }
- peerLogger.Debugf("Established Chat with peer address: %s", address)
- err = p.handleChat(ctx, stream, true)
- stream.CloseSend()
- if err != nil {
- peerLogger.Errorf("Ending Chat with peer address %s due to error: %s", address, err)
- return err
- }
- return nil
- }
2.在handleChat执行过程中,建立消息循环,而这里的handler.HandleMessage。这个handler之前介绍过,是Engine的消息响应句柄,该消息响应处理来自于Consensus模块
- func (p *Impl) handleChat(ctx context.Context, stream ChatStream, initiatedStream bool) error {
- deadline, ok := ctx.Deadline()
- peerLogger.Debugf("Current context deadline = %s, ok = %v", deadline, ok)
- handler, err := p.handlerFactory(p, stream, initiatedStream, nil)
- if err != nil {
- return fmt.Errorf("Error creating handler during handleChat initiation: %s", err)
- }
- defer handler.Stop()
- for {
- in, err := stream.Recv()
- if err == io.EOF {
- peerLogger.Debug("Received EOF, ending Chat")
- return nil
- }
- if err != nil {
- e := fmt.Errorf("Error during Chat, stopping handler: %s", err)
- peerLogger.Error(e.Error())
- return e
- }
- err = handler.HandleMessage(in)
- if err != nil {
- peerLogger.Errorf("Error handling message: %s", err)
-
- }
- }
- }
3.HandleMessage函数consenterChan 这个channel比较重要,该写入操作会触发engine.consensusFan的消息循环- func (handler *ConsensusHandler) HandleMessage(msg *pb.Message) error {
- if msg.Type == pb.Message_CONSENSUS {
- senderPE, _ := handler.To()
- select {
- case handler.consenterChan <- &util.Message{
- Msg: msg,
- Sender: senderPE.ID,
- }:
- return nil
- default:
- err := fmt.Errorf("Message channel for %v full, rejecting", senderPE.ID)
- logger.Errorf("Failed to queue consensus message because: %v", err)
- return err
- }
- }
-
- if logger.IsEnabledFor(logging.DEBUG) {
- logger.Debugf("Did not handle message of type %s, passing on to next MessageHandler", msg.Type)
- }
- return handler.MessageHandler.HandleMessage(msg)
- }
4.看到RecvMsg这个函数是不是有点眼熟,这个操作和 hyperledger fabric 结构分析 最后一个流程是一样的。
- func GetEngine(coord peer.MessageHandlerCoordinator) (peer.Engine, error) {
- var err error
- engineOnce.Do(func() {
- engine = new(EngineImpl)
- engine.helper = NewHelper(coord)
- engine.consenter = controller.NewConsenter(engine.helper)
- engine.helper.setConsenter(engine.consenter)
- engine.peerEndpoint, err = coord.GetPeerEndpoint()
- engine.consensusFan = util.NewMessageFan()
-
- go func() {
- logger.Debug("Starting up message thread for consenter")
-
-
- for msg := range engine.consensusFan.GetOutChannel() {
- engine.consenter.RecvMsg(msg.Msg, msg.Sender)
- }
- }()
- })
- return engine, err
- }
5.再往下的流程与 hyperledger fabric 结构分析(三)中的一致。