Remove NoStats (#603)

stats.Record is a low-cost call if there are no views the
user has subscribed to.

plugin/ocgrpc/client.go

@@ -24,10 +24,6 @@ import (
 // ClientHandler implements a gRPC stats.Handler for recording OpenCensus stats and
 // traces. Use with gRPC clients only.
 type ClientHandler struct {
-	// NoStats may be set to disable recording OpenCensus Stats around each
-	// gRPC method.
-	NoStats bool
-
 	// StartOptions allows configuring the StartOptions used to create new spans.
 	StartOptions trace.StartOptions
 }
@@ -45,16 +41,12 @@ func (c *ClientHandler) TagConn(ctx context.Context, cti *stats.ConnTagInfo) con
 // HandleRPC implements per-RPC tracing and stats instrumentation.
 func (c *ClientHandler) HandleRPC(ctx context.Context, rs stats.RPCStats) {
 	traceHandleRPC(ctx, rs)
-	if !c.NoStats {
-		c.statsHandleRPC(ctx, rs)
-	}
+	c.statsHandleRPC(ctx, rs)
 }
 
 // TagRPC implements per-RPC context management.
 func (c *ClientHandler) TagRPC(ctx context.Context, rti *stats.RPCTagInfo) context.Context {
 	ctx = c.traceTagRPC(ctx, rti)
-	if !c.NoStats {
-		ctx = c.statsTagRPC(ctx, rti)
-	}
+	ctx = c.statsTagRPC(ctx, rti)
 	return ctx
 }

plugin/ocgrpc/server.go

@@ -29,9 +29,6 @@ import (
 // present but the SpanContext isn't sampled, then a new trace may be started
 // (as determined by Sampler).
 type ServerHandler struct {
-	// NoStats may be set to true to disable recording OpenCensus stats for RPCs.
-	NoStats bool
-
 	// IsPublicEndpoint may be set to true to always start a new trace around
 	// each RPC. Any SpanContext in the RPC metadata will be added as a linked
 	// span instead of making it the parent of the span created around the
@@ -68,16 +65,12 @@ func (s *ServerHandler) TagConn(ctx context.Context, cti *stats.ConnTagInfo) con
 // HandleRPC implements per-RPC tracing and stats instrumentation.
 func (s *ServerHandler) HandleRPC(ctx context.Context, rs stats.RPCStats) {
 	traceHandleRPC(ctx, rs)
-	if !s.NoStats {
-		s.statsHandleRPC(ctx, rs)
-	}
+	s.statsHandleRPC(ctx, rs)
 }
 
 // TagRPC implements per-RPC context management.
 func (s *ServerHandler) TagRPC(ctx context.Context, rti *stats.RPCTagInfo) context.Context {
 	ctx = s.traceTagRPC(ctx, rti)
-	if !s.NoStats {
-		ctx = s.statsTagRPC(ctx, rti)
-	}
+	ctx = s.statsTagRPC(ctx, rti)
 	return ctx
 }

plugin/ocgrpc/trace_common_test.go

@@ -62,12 +62,12 @@ func newTracingOnlyTestClientAndServer() (client testpb.FooClient, server *grpc.
 	if err != nil {
 		return nil, nil, nil, fmt.Errorf("net.Listen: %v", err)
 	}
-	server = grpc.NewServer(grpc.StatsHandler(&ServerHandler{NoStats: true}))
+	server = grpc.NewServer(grpc.StatsHandler(&ServerHandler{}))
 	testpb.RegisterFooServer(server, &testServer{})
 	go server.Serve(listener)
 
 	// initialize client
-	clientConn, err := grpc.Dial(listener.Addr().String(), grpc.WithInsecure(), grpc.WithStatsHandler(&ClientHandler{NoStats: true}), grpc.WithBlock())
+	clientConn, err := grpc.Dial(listener.Addr().String(), grpc.WithInsecure(), grpc.WithStatsHandler(&ClientHandler{}), grpc.WithBlock())
 	if err != nil {
 		return nil, nil, nil, fmt.Errorf("grpc.Dial: %v", err)
 	}

plugin/ochttp/client.go

@@ -32,9 +32,6 @@ type Transport struct {
 	// the returned round tripper will be cancelable.
 	Base http.RoundTripper
 
-	// NoStats may be set to disable recording of stats.
-	NoStats bool
-
 	// Propagation defines how traces are propagated. If unspecified, a default
 	// (currently B3 format) will be used.
 	Propagation propagation.HTTPFormat
@@ -59,11 +56,7 @@ func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
 		format:       format,
 		startOptions: t.StartOptions,
 	}
-	if !t.NoStats {
-		rt = statsTransport{
-			base: rt,
-		}
-	}
+	rt = statsTransport{base: rt}
 	return rt.RoundTrip(req)
 }
 

plugin/ochttp/client_test.go

@@ -125,19 +125,11 @@ func TestClient(t *testing.T) {
 
 var noTrace = trace.StartOptions{Sampler: trace.NeverSample()}
 
-func BenchmarkTransportNoInstrumentation(b *testing.B) {
-	benchmarkClientServer(b, &ochttp.Transport{NoStats: true, StartOptions: noTrace})
-}
-
-func BenchmarkTransportTraceOnly(b *testing.B) {
-	benchmarkClientServer(b, &ochttp.Transport{NoStats: true})
-}
-
-func BenchmarkTransportStatsOnly(b *testing.B) {
+func BenchmarkTransportNoTrace(b *testing.B) {
 	benchmarkClientServer(b, &ochttp.Transport{StartOptions: noTrace})
 }
 
-func BenchmarkTransportAllInstrumentation(b *testing.B) {
+func BenchmarkTransport(b *testing.B) {
 	benchmarkClientServer(b, &ochttp.Transport{})
 }
 
@@ -169,19 +161,11 @@ func benchmarkClientServer(b *testing.B, transport *ochttp.Transport) {
 	}
 }
 
-func BenchmarkTransportParallel64NoInstrumentation(b *testing.B) {
-	benchmarkClientServerParallel(b, 64, &ochttp.Transport{StartOptions: noTrace, NoStats: true})
-}
-
-func BenchmarkTransportParallel64TraceOnly(b *testing.B) {
-	benchmarkClientServerParallel(b, 64, &ochttp.Transport{NoStats: true})
-}
-
-func BenchmarkTransportParallel64StatsOnly(b *testing.B) {
+func BenchmarkTransportParallel64NoTrace(b *testing.B) {
 	benchmarkClientServerParallel(b, 64, &ochttp.Transport{StartOptions: noTrace})
 }
 
-func BenchmarkTransportParallel64AllInstrumentation(b *testing.B) {
+func BenchmarkTransportParallel64(b *testing.B) {
 	benchmarkClientServerParallel(b, 64, &ochttp.Transport{})
 }
 

plugin/ochttp/server.go

@@ -38,9 +38,6 @@ import (
 //
 // Incoming propagation mechanism is determined by the given HTTP propagators.
 type Handler struct {
-	// NoStats may be set to disable recording of stats.
-	NoStats bool
-
 	// Propagation defines how traces are propagated. If unspecified,
 	// B3 propagation will be used.
 	Propagation propagation.HTTPFormat
@@ -60,14 +57,11 @@ type Handler struct {
 }
 
 func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	var end func()
-	r, end = h.startTrace(w, r)
-	defer end()
-	if !h.NoStats {
-		var end func()
-		w, end = h.startStats(w, r)
-		defer end()
-	}
+	var traceEnd, statsEnd func()
+	r, traceEnd = h.startTrace(w, r)
+	defer traceEnd()
+	w, statsEnd = h.startStats(w, r)
+	defer statsEnd()
 
 	handler := h.Handler
 	if handler == nil {

plugin/ochttp/trace_test.go

@@ -93,7 +93,6 @@ func TestTransport_RoundTrip(t *testing.T) {
 			transport := &testTransport{ch: make(chan *http.Request, 1)}
 
 			rt := &Transport{
-				NoStats:     true,
 				Propagation: &testPropagator{},
 				Base:        transport,
 			}
@@ -185,26 +184,26 @@ func TestEndToEnd(t *testing.T) {
 		{
 			name:            "internal default propagation",
 			handler:         &Handler{},
-			transport:       &Transport{NoStats: true},
+			transport:       &Transport{},
 			wantSameTraceID: true,
 		},
 		{
 			name:            "external default propagation",
 			handler:         &Handler{IsPublicEndpoint: true},
-			transport:       &Transport{NoStats: true},
+			transport:       &Transport{},
 			wantSameTraceID: false,
 			wantLinks:       true,
 		},
 		{
 			name:            "internal TraceContext propagation",
 			handler:         &Handler{Propagation: &tracecontext.HTTPFormat{}},
-			transport:       &Transport{NoStats: true, Propagation: &tracecontext.HTTPFormat{}},
+			transport:       &Transport{Propagation: &tracecontext.HTTPFormat{}},
 			wantSameTraceID: true,
 		},
 		{
 			name:            "misconfigured propagation",
 			handler:         &Handler{IsPublicEndpoint: true, Propagation: &tracecontext.HTTPFormat{}},
-			transport:       &Transport{NoStats: true, Propagation: &b3.HTTPFormat{}},
+			transport:       &Transport{Propagation: &b3.HTTPFormat{}},
 			wantSameTraceID: false,
 			wantLinks:       false,
 		},