review comments

orca/call_metrics.go

@@ -50,8 +50,8 @@ type CallMetricsRecorder interface {
 
 type callMetricsRecorderCtxKey struct{}
 
-// CallMetricsRecorderFromContext returns the RPC specific custom metrics
-// recorder [CallMetricsRecorder] embedded in the provided RPC context.
+// CallMetricsRecorderFromContext returns the RPC-specific custom metrics
+// recorder embedded in the provided RPC context.
 //
 // Returns nil if no custom metrics recorder is found in the provided context,
 // which will be the case when custom metrics reporting is not enabled.
@@ -99,11 +99,11 @@ func (rw *recorderWrapper) setTrailerMetadata(ctx context.Context) {
 
 	b, err := proto.Marshal(sm.toLoadReportProto())
 	if err != nil {
-		logger.Warningf("failed to marshal load report: %v", err)
+		logger.Warningf("Failed to marshal load report: %v", err)
 		return
 	}
 	if err := grpc.SetTrailer(ctx, metadata.Pairs(internal.TrailerMetadataKey, string(b))); err != nil {
-		logger.Warningf("failed to set trailer metadata: %v", err)
+		logger.Warningf("Failed to set trailer metadata: %v", err)
 	}
 }
 

orca/server_metrics.go

@@ -152,7 +152,7 @@ func newServerMetricsRecorder() *serverMetricsRecorder {
 func (s *serverMetricsRecorder) ServerMetrics() *ServerMetrics {
 	s.mu.Lock()
 	defer s.mu.Unlock()
-	ret := &ServerMetrics{
+	return &ServerMetrics{
 		CPUUtilization: s.state.CPUUtilization,
 		MemUtilization: s.state.MemUtilization,
 		QPS:            s.state.QPS,
@@ -161,7 +161,6 @@ func (s *serverMetricsRecorder) ServerMetrics() *ServerMetrics {
 		RequestCost:    copyMap(s.state.RequestCost),
 		NamedMetrics:   copyMap(s.state.NamedMetrics),
 	}
-	return ret
 }
 
 func copyMap(m map[string]float64) map[string]float64 {

orca/service.go

@@ -110,8 +110,10 @@ func NewService(opts ServiceOptions) (*Service, error) {
 }
 
 // Register creates a new ORCA service implementation configured using the
-// provided options and registers the same on the provided service registrar.
+// provided options and registers the same on the provided grpc Server.
 func Register(s *grpc.Server, opts ServiceOptions) error {
+	// TODO(https://github.com/cncf/xds/issues/41): replace *grpc.Server with
+	// grpc.ServiceRegistrar when possible.
 	service, err := NewService(opts)
 	if err != nil {
 		return err