seaweedfs/weed/mq/broker/broker_grpc_sub_follow.go
2024-05-30 09:49:08 -07:00

102 lines
3.4 KiB
Go

package broker
import (
"fmt"
"github.com/seaweedfs/seaweedfs/weed/filer"
"github.com/seaweedfs/seaweedfs/weed/glog"
"github.com/seaweedfs/seaweedfs/weed/mq/topic"
"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
"github.com/seaweedfs/seaweedfs/weed/pb/mq_pb"
"github.com/seaweedfs/seaweedfs/weed/util"
"io"
"time"
)
func (b *MessageQueueBroker) SubscribeFollowMe(stream mq_pb.SeaweedMessaging_SubscribeFollowMeServer) (err error) {
var req *mq_pb.SubscribeFollowMeRequest
req, err = stream.Recv()
if err != nil {
return err
}
initMessage := req.GetInit()
if initMessage == nil {
return fmt.Errorf("missing init message")
}
// create an in-memory offset
var lastOffset int64
// follow each published messages
for {
// receive a message
req, err = stream.Recv()
if err != nil {
if err == io.EOF {
err = nil
break
}
glog.V(0).Infof("topic %v partition %v subscribe stream error: %v", initMessage.Topic, initMessage.Partition, err)
break
}
// Process the received message
if ackMessage := req.GetAck(); ackMessage != nil {
lastOffset = ackMessage.TsNs
// println("sub follower got offset", lastOffset)
} else if closeMessage := req.GetClose(); closeMessage != nil {
glog.V(0).Infof("topic %v partition %v subscribe stream closed: %v", initMessage.Topic, initMessage.Partition, closeMessage)
return nil
} else {
glog.Errorf("unknown message: %v", req)
}
}
t, p := topic.FromPbTopic(initMessage.Topic), topic.FromPbPartition(initMessage.Partition)
if lastOffset > 0 {
err = b.saveConsumerGroupOffset(t, p, initMessage.ConsumerGroup, lastOffset)
}
glog.V(0).Infof("shut down follower for %v offset %d", initMessage, lastOffset)
return err
}
func (b *MessageQueueBroker) readConsumerGroupOffset(initMessage *mq_pb.SubscribeMessageRequest_InitMessage) (offset int64, err error) {
t, p := topic.FromPbTopic(initMessage.Topic), topic.FromPbPartition(initMessage.PartitionOffset.Partition)
topicDir := fmt.Sprintf("%s/%s/%s", filer.TopicsDir, t.Namespace, t.Name)
partitionGeneration := time.Unix(0, p.UnixTimeNs).UTC().Format(topic.TIME_FORMAT)
partitionDir := fmt.Sprintf("%s/%s/%04d-%04d", topicDir, partitionGeneration, p.RangeStart, p.RangeStop)
offsetFileName := fmt.Sprintf("%s.offset", initMessage.ConsumerGroup)
err = b.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
data, err := filer.ReadInsideFiler(client, partitionDir, offsetFileName)
if err != nil {
return err
}
if len(data) != 8 {
return fmt.Errorf("no offset found")
}
offset = int64(util.BytesToUint64(data))
return nil
})
return offset, err
}
func (b *MessageQueueBroker) saveConsumerGroupOffset(t topic.Topic, p topic.Partition, consumerGroup string, offset int64) error {
topicDir := fmt.Sprintf("%s/%s/%s", filer.TopicsDir, t.Namespace, t.Name)
partitionGeneration := time.Unix(0, p.UnixTimeNs).UTC().Format(topic.TIME_FORMAT)
partitionDir := fmt.Sprintf("%s/%s/%04d-%04d", topicDir, partitionGeneration, p.RangeStart, p.RangeStop)
offsetFileName := fmt.Sprintf("%s.offset", consumerGroup)
offsetBytes := make([]byte, 8)
util.Uint64toBytes(offsetBytes, uint64(offset))
return b.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
glog.V(0).Infof("saving topic %s partition %v consumer group %s offset %d", t, p, consumerGroup, offset)
return filer.SaveInsideFiler(client, partitionDir, offsetFileName, offsetBytes)
})
}