Fix rocksmq SeekToLatest (#11029)

Signed-off-by: Congqi Xia <congqi.xia@zilliz.com>

internal/msgstream/mq_msgstream_test.go

@@ -1619,3 +1619,42 @@ func printMsgPack(msgPack *MsgPack) {
 	}
 	log.Println("================")
 }
+
+func TestStream_RmqTtMsgStream_AsConsumerWithPosition(t *testing.T) {
+
+	producerChannels := []string{"insert1"}
+	consumerChannels := []string{"insert1"}
+	consumerSubName := "subInsert"
+
+	rocksdbName := "/tmp/rocksmq_asconsumer_withpos"
+	etcdKV := initRmq(rocksdbName)
+	factory := ProtoUDFactory{}
+
+	rmqClient, _ := mqclient.NewRmqClient(client.ClientOptions{Server: rocksmq.Rmq})
+
+	otherInputStream, _ := NewMqMsgStream(context.Background(), 100, 100, rmqClient, factory.NewUnmarshalDispatcher())
+	otherInputStream.AsProducer([]string{"root_timetick"})
+	otherInputStream.Start()
+	otherInputStream.Produce(getTimeTickMsgPack(999))
+
+	inputStream, _ := NewMqMsgStream(context.Background(), 100, 100, rmqClient, factory.NewUnmarshalDispatcher())
+	inputStream.AsProducer(producerChannels)
+	inputStream.Start()
+
+	for i := 0; i < 100; i++ {
+		inputStream.Produce(getTimeTickMsgPack(int64(i)))
+	}
+
+	rmqClient2, _ := mqclient.NewRmqClient(client.ClientOptions{Server: rocksmq.Rmq})
+	outputStream, _ := NewMqMsgStream(context.Background(), 100, 100, rmqClient2, factory.NewUnmarshalDispatcher())
+	outputStream.AsConsumerWithPosition(consumerChannels, consumerSubName, mqclient.SubscriptionPositionLatest)
+	outputStream.Start()
+
+	inputStream.Produce(getTimeTickMsgPack(1000))
+	pack := outputStream.Consume()
+	assert.NotNil(t, pack)
+	assert.Equal(t, 1, len(pack.Msgs))
+	assert.EqualValues(t, 1000, pack.Msgs[0].BeginTs())
+
+	Close(rocksdbName, inputStream, outputStream, etcdKV)
+}

internal/util/rocksmq/server/rocksmq/rocksmq_impl.go

@@ -12,6 +12,7 @@
 package rocksmq
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 	"strconv"
@@ -722,14 +723,30 @@ func (rmq *rocksmq) SeekToLatest(topicName, groupName string) error {
 
 	fixChanName, _ := fixChannelName(topicName)
 	iter.Seek([]byte(fixChanName + "/"))
+	var last []byte
+	// iter.SeekToLast bypass prefix limitation
+	// use for range until find next prefix for now
 	if iter.Valid() {
-		iter.SeekToLast()
+		last = iter.Key().Data()
+		current := last
+		for bytes.HasPrefix(current, []byte(topicName)) {
+			iter.Next()
+			if iter.Valid() {
+				current = last
+				last = iter.Key().Data()
+			} else {
+				break
+			}
+		}
 	} else {
 		// In this case there are no messages, so shouldn't return error
 		return nil
 	}
-	msgKey := iter.Key()
+
-	msgID, err := strconv.ParseInt(string(msgKey.Data())[FixedChannelNameLen+1:], 10, 64)
+	if len(last) <= FixedChannelNameLen {
+		return nil
+	}
+	msgID, err := strconv.ParseInt(string(last)[FixedChannelNameLen+1:], 10, 64)
 	if err != nil {
 		return err
 	}