refactor

weed/mq/topic/local_partition.go

@@ -1,6 +1,7 @@
 package topic
 
 import (
+	"context"
 	"fmt"
 	"github.com/seaweedfs/seaweedfs/weed/glog"
 	"github.com/seaweedfs/seaweedfs/weed/pb"
@@ -128,6 +129,55 @@ func (p *LocalPartition) WaitUntilNoPublishers() {
 	}
 }
 
+func (p *LocalPartition) MaybeConnectToFollowers(initMessage *mq_pb.PublishMessageRequest_InitMessage, grpcDialOption grpc.DialOption) (err error) {
+	if p.FollowerStream != nil {
+		return nil
+	}
+	if len(initMessage.FollowerBrokers) == 0 {
+		return nil
+	}
+
+	follower := initMessage.FollowerBrokers[0]
+	ctx := context.Background()
+	p.FollowerGrpcConnection, err = pb.GrpcDial(ctx, follower, true, grpcDialOption)
+	if err != nil {
+		return fmt.Errorf("fail to dial %s: %v", follower, err)
+	}
+	followerClient := mq_pb.NewSeaweedMessagingClient(p.FollowerGrpcConnection)
+	p.FollowerStream, err = followerClient.PublishFollowMe(ctx)
+	if err != nil {
+		return fmt.Errorf("fail to create publish client: %v", err)
+	}
+	if err = p.FollowerStream.Send(&mq_pb.PublishFollowMeRequest{
+		Message: &mq_pb.PublishFollowMeRequest_Init{
+			Init: &mq_pb.PublishFollowMeRequest_InitMessage{
+				Topic:      initMessage.Topic,
+				Partition:  initMessage.Partition,
+			},
+		},
+	}); err != nil {
+		return err
+	}
+
+	// start receiving ack from follower
+	go func() {
+		defer func() {
+			println("stop receiving ack from follower")
+		}()
+
+		for {
+			ack, err := p.FollowerStream.Recv()
+			if err != nil {
+				glog.Errorf("Error receiving follower ack: %v", err)
+				return
+			}
+			atomic.StoreInt64(&p.AckTsNs, ack.AckTsNs)
+			println("recv ack", ack.AckTsNs)
+		}
+	}()
+	return nil
+}
+
 func (p *LocalPartition) MaybeShutdownLocalPartition() (hasShutdown bool) {
 	if p.MaybeShutdownLocalPartition() {
 		if p.FollowerStream != nil {