create topic and report topic

weed/mq/broker/broker_grpc_lookup.go

@@ -45,3 +45,38 @@ func (broker *MessageQueueBroker) CheckTopicPartitionsStatus(c context.Context,
 	ret := &mq_pb.CheckTopicPartitionsStatusResponse{}
 	return ret, nil
 }
+
+func (broker *MessageQueueBroker) ListTopics(ctx context.Context, request *mq_pb.ListTopicsRequest) (resp *mq_pb.ListTopicsResponse, err error) {
+	if broker.currentBalancer == "" {
+		return nil, status.Errorf(codes.Unavailable, "no balancer")
+	}
+	if !broker.lockAsBalancer.IsLocked() {
+		proxyErr := broker.withBrokerClient(false, broker.currentBalancer, func(client mq_pb.SeaweedMessagingClient) error {
+			resp, err = client.ListTopics(ctx, request)
+			return nil
+		})
+		if proxyErr != nil {
+			return nil, proxyErr
+		}
+		return resp, err
+	}
+
+	ret := &mq_pb.ListTopicsResponse{}
+	knownTopics := make(map[*mq_pb.Topic]struct{})
+	for brokerStatsItem := range broker.Balancer.Brokers.IterBuffered() {
+		_, brokerStats := brokerStatsItem.Key, brokerStatsItem.Val
+		for topicPartitionStatsItem := range brokerStats.Stats.IterBuffered() {
+			topicPartitionStat := topicPartitionStatsItem.Val
+			topic := &mq_pb.Topic{
+				Namespace: topicPartitionStat.TopicPartition.Namespace,
+				Name:      topicPartitionStat.TopicPartition.Topic,
+			}
+			if _, found := knownTopics[topic]; found {
+				continue
+			}
+			ret.Topics = append(ret.Topics, topic)
+		}
+	}
+
+	return ret, nil
+}