ask follower to follow

weed/mq/broker/broker_grpc_pub_follow.go

@@ -0,0 +1,78 @@
+package broker
+
+import (
+	"context"
+	"fmt"
+	"github.com/seaweedfs/seaweedfs/weed/glog"
+	"github.com/seaweedfs/seaweedfs/weed/pb"
+	"github.com/seaweedfs/seaweedfs/weed/pb/mq_pb"
+	"io"
+	"math/rand"
+	"time"
+)
+
+func (b *MessageQueueBroker)  PublishFollowMe(c context.Context, request *mq_pb.PublishFollowMeRequest) (*mq_pb.PublishFollowMeResponse, error){
+	glog.V(0).Infof("PublishFollowMe %v", request)
+	go b.withBrokerClient(true, pb.ServerAddress(request.BrokerSelf), func(client mq_pb.SeaweedMessagingClient) error {
+		followerId := rand.Int31()
+		subscribeClient, err := client.FollowInMemoryMessages(context.Background(), &mq_pb.FollowInMemoryMessagesRequest{
+			Message: &mq_pb.FollowInMemoryMessagesRequest_Init{
+				Init: &mq_pb.FollowInMemoryMessagesRequest_InitMessage{
+					ConsumerGroup: string(b.option.BrokerAddress()),
+					ConsumerId:    fmt.Sprintf("followMe-%d", followerId),
+					FollowerId:    followerId,
+					Topic:         request.Topic,
+					PartitionOffset: &mq_pb.PartitionOffset{
+						Partition: request.Partition,
+						StartTsNs: 0,
+						StartType: mq_pb.PartitionOffsetStartType_EARLIEST_IN_MEMORY,
+					},
+				},
+			},
+		})
+		if err != nil {
+			glog.Errorf("FollowInMemoryMessages error: %v", err)
+			return err
+		}
+
+		b.doFollowInMemoryMessage(context.Background(), subscribeClient)
+
+		return nil
+	})
+	return &mq_pb.PublishFollowMeResponse{}, nil
+}
+
+func (b *MessageQueueBroker) doFollowInMemoryMessage(c context.Context, client mq_pb.SeaweedMessaging_FollowInMemoryMessagesClient) {
+	for {
+		resp, err := client.Recv()
+		if err != nil {
+			if err != io.EOF {
+				glog.V(0).Infof("doFollowInMemoryMessage error: %v", err)
+			}
+			return
+		}
+		if resp == nil {
+			glog.V(0).Infof("doFollowInMemoryMessage nil response")
+			return
+		}
+		if resp.Message != nil {
+			// process ctrl message or data message
+			switch m:= resp.Message.(type) {
+			case *mq_pb.FollowInMemoryMessagesResponse_Data:
+				// process data message
+				print("d")
+			case *mq_pb.FollowInMemoryMessagesResponse_Ctrl:
+				// process ctrl message
+				if m.Ctrl.FlushedSequence > 0 {
+					flushTime := time.Unix(0, m.Ctrl.FlushedSequence)
+					glog.V(0).Infof("doFollowInMemoryMessage flushTime: %v", flushTime)
+				}
+				if m.Ctrl.FollowerChangedToId != 0 {
+					// follower changed
+					glog.V(0).Infof("doFollowInMemoryMessage follower changed to %d", m.Ctrl.FollowerChangedToId)
+					return
+				}
+			}
+		}
+	}
+}