add size()

weed/mq/topic/local_partition_publishers.go

@@ -50,3 +50,10 @@ func (p *LocalPartitionPublishers) IsEmpty() bool {
 
 	return len(p.publishers) == 0
 }
+
+func (p *LocalPartitionPublishers) Size() int {
+	p.publishersLock.RLock()
+	defer p.publishersLock.RUnlock()
+
+	return len(p.publishers)
+}

weed/mq/topic/local_partition_subscribers.go

@@ -54,3 +54,10 @@ func (p *LocalPartitionSubscribers) IsEmpty() bool {
 
 	return len(p.Subscribers) == 0
 }
+
+func (p *LocalPartitionSubscribers) Size() int {
+	p.SubscribersLock.RLock()
+	defer p.SubscribersLock.RUnlock()
+
+	return len(p.Subscribers)
+}