release local topic partition if no publisher and subscribers

weed/mq/broker/broker_grpc_pub.go

@@ -48,8 +48,10 @@ func (b *MessageQueueBroker) PublishMessage(stream mq_pb.SeaweedMessaging_Publis
 	// TODO check whether current broker should be the leader for the topic partition
 	ackInterval := 1
 	initMessage := req.GetInit()
+	var t topic.Topic
+	var p topic.Partition
 	if initMessage != nil {
-		t, p := topic.FromPbTopic(initMessage.Topic), topic.FromPbPartition(initMessage.Partition)
+		t, p = topic.FromPbTopic(initMessage.Topic), topic.FromPbPartition(initMessage.Partition)
 		localTopicPartition = b.localTopicManager.GetTopicPartition(t, p)
 		if localTopicPartition == nil {
 			response.Error = fmt.Sprintf("topic %v partition %v not setup", initMessage.Topic, initMessage.Partition)
@@ -75,6 +77,9 @@ func (b *MessageQueueBroker) PublishMessage(stream mq_pb.SeaweedMessaging_Publis
 		atomic.StoreInt32(&isStopping, 1)
 		close(respChan)
 		localTopicPartition.Publishers.RemovePublisher(clientName)
+		if localTopicPartition.MaybeShutdownLocalPartition() {
+			b.localTopicManager.RemoveTopicPartition(t, p)
+		}
 	}()
 	go func() {
 		ticker := time.NewTicker(1 * time.Second)

weed/mq/broker/broker_grpc_sub.go

@@ -58,6 +58,9 @@ func (b *MessageQueueBroker) SubscribeMessage(req *mq_pb.SubscribeMessageRequest
 		isConnected = false
 		localTopicPartition.Subscribers.RemoveSubscriber(clientName)
 		glog.V(0).Infof("Subscriber %s on %v %v disconnected, sent %d", clientName, t, partition, counter)
+		if localTopicPartition.MaybeShutdownLocalPartition() {
+			b.localTopicManager.RemoveTopicPartition(t, partition)
+		}
 	}()
 
 	var startPosition log_buffer.MessagePosition

weed/mq/topic/local_partition.go

@@ -109,3 +109,11 @@ func (p *LocalPartition) WaitUntilNoPublishers() {
 		time.Sleep(113 * time.Millisecond)
 	}
 }
+
+func (p *LocalPartition) MaybeShutdownLocalPartition() (hasShutdown bool) {
+	if p.Publishers.IsEmpty() && p.Subscribers.IsEmpty() {
+		p.logBuffer.ShutdownLogBuffer()
+		hasShutdown = true
+	}
+	return
+}

weed/mq/topic/local_partition_subscribers.go

@@ -47,3 +47,10 @@ func (p *LocalPartitionSubscribers) SignalShutdown() {
 		Subscriber.SignalShutdown()
 	}
 }
+
+func (p *LocalPartitionSubscribers) IsEmpty() bool {
+	p.SubscribersLock.RLock()
+	defer p.SubscribersLock.RUnlock()
+
+	return len(p.Subscribers) == 0
+}