x/sync: Remove duplicated call to TrackBandwidth (#2694)

x/sync/network_client.go

@@ -274,23 +274,24 @@ func (c *networkClient) request(
 
 	var (
 		response  []byte
+		responded bool
 		startTime = time.Now()
 	)
-
 	select {
 	case <-ctx.Done():
 		c.peers.TrackBandwidth(nodeID, 0)
 		return nil, ctx.Err()
-	case response = <-handler.responseChan:
-		elapsedSeconds := time.Since(startTime).Seconds()
-		bandwidth := float64(len(response))/elapsedSeconds + epsilon
-		c.peers.TrackBandwidth(nodeID, bandwidth)
+	case response, responded = <-handler.responseChan:
 	}
-	if handler.failed {
+	if !responded {
 		c.peers.TrackBandwidth(nodeID, 0)
 		return nil, errRequestFailed
 	}
 
+	elapsedSeconds := time.Since(startTime).Seconds()
+	bandwidth := float64(len(response))/elapsedSeconds + epsilon
+	c.peers.TrackBandwidth(nodeID, bandwidth)
+
 	c.log.Debug("received response from peer",
 		zap.Stringer("nodeID", nodeID),
 		zap.Uint32("requestID", requestID),

x/sync/response_handler.go

@@ -20,23 +20,22 @@ func newResponseHandler() *responseHandler {
 
 // Implements [ResponseHandler].
 // Used to wait for a response after making a synchronous request.
-// responseChan may contain response bytes if the original request has not failed.
+// responseChan contains response bytes if the request succeeded.
 // responseChan is closed in either fail or success scenario.
 type responseHandler struct {
 	// If [OnResponse] is called, the response bytes are sent on this channel.
+	// If [OnFailure] is called, the channel is closed without sending bytes.
 	responseChan chan []byte
-	// Set to true in [OnFailure].
-	failed bool
 }
 
-// OnResponse passes the response bytes to the responseChan and closes the channel
+// OnResponse passes the response bytes to the responseChan and closes the
+// channel.
 func (h *responseHandler) OnResponse(response []byte) {
 	h.responseChan <- response
 	close(h.responseChan)
 }
 
-// OnFailure sets the failed flag to true and closes the channel
+// OnFailure closes the channel.
 func (h *responseHandler) OnFailure() {
-	h.failed = true
 	close(h.responseChan)
 }