read from disk if not in memory

weed/mq/broker/broker_grpc_sub.go

@@ -52,14 +52,15 @@ func (b *MessageQueueBroker) SubscribeMessage(req *mq_pb.SubscribeMessageRequest
 	glog.V(0).Infof("Subscriber %s connected on %v %v", clientName, t, partition)
 	isConnected := true
 	sleepIntervalCount := 0
+
+	var counter int64
 	defer func() {
 		isConnected = false
 		localTopicPartition.Subscribers.RemoveSubscriber(clientName)
-		glog.V(0).Infof("Subscriber %s on %v %v disconnected", clientName, t, partition)
+		glog.V(0).Infof("Subscriber %s on %v %v disconnected, sent %d", clientName, t, partition, counter)
 	}()
 
 	var startPosition log_buffer.MessagePosition
-	var inMemoryOnly bool
 	if req.GetInit()!=nil && req.GetInit().GetPartitionOffset() != nil {
 		offset := req.GetInit().GetPartitionOffset()
 		if offset.StartTsNs != 0 {
@@ -69,19 +70,10 @@ func (b *MessageQueueBroker) SubscribeMessage(req *mq_pb.SubscribeMessageRequest
 			startPosition = log_buffer.NewMessagePosition(1, -2)
 		} else if offset.StartType == mq_pb.PartitionOffsetStartType_LATEST {
 			startPosition = log_buffer.NewMessagePosition(time.Now().UnixNano(), -2)
-		} else if offset.StartType == mq_pb.PartitionOffsetStartType_EARLIEST_IN_MEMORY {
-			inMemoryOnly = true
-			for !localTopicPartition.HasData() {
-				time.Sleep(337 * time.Millisecond)
-			}
-			memPosition := localTopicPartition.GetEarliestInMemoryMessagePosition()
-			if startPosition.Before(memPosition.Time) {
-				startPosition = memPosition
-			}
 		}
 	}
 
-	localTopicPartition.Subscribe(clientName, startPosition, inMemoryOnly, func() bool {
+	return localTopicPartition.Subscribe(clientName, startPosition, func() bool {
 		if !isConnected {
 			return false
 		}
@@ -121,8 +113,8 @@ func (b *MessageQueueBroker) SubscribeMessage(req *mq_pb.SubscribeMessageRequest
 			glog.Errorf("Error sending setup response: %v", err)
 			return err
 		}
+
+		counter++
 		return nil
 	})
-
-	return nil
 }