Unexport NoopXXX trace types

api/global/internal/trace.go

@@ -36,6 +36,7 @@ import (
 	"sync"
 
 	"go.opentelemetry.io/otel/api/trace"
+	"go.opentelemetry.io/otel/internal/trace/noop"
 )
 
 // tracerProvider is a placeholder for a configured SDK Provider.
@@ -120,5 +121,5 @@ func (t *tracer) Start(ctx context.Context, name string, opts ...trace.SpanOptio
 	if t.delegate != nil {
 		return t.delegate.Start(ctx, name, opts...)
 	}
-	return trace.NoopTracer{}.Start(ctx, name, opts...)
+	return noop.Tracer.Start(ctx, name, opts...)
 }

api/global/trace_test.go

@@ -19,24 +19,25 @@ import (
 
 	"go.opentelemetry.io/otel/api/global"
 	"go.opentelemetry.io/otel/api/trace"
+	"go.opentelemetry.io/otel/internal/trace/noop"
 )
 
 type testTracerProvider struct{}
 
 var _ trace.Provider = &testTracerProvider{}
 
 func (*testTracerProvider) Tracer(_ string, _ ...trace.TracerOption) trace.Tracer {
-	return &trace.NoopTracer{}
+	return noop.Tracer
 }
 
 func TestMultipleGlobalTracerProvider(t *testing.T) {
 	p1 := testTracerProvider{}
-	p2 := trace.NoopProvider{}
+	p2 := trace.NoopProvider()
 	global.SetTracerProvider(&p1)
-	global.SetTracerProvider(&p2)
+	global.SetTracerProvider(p2)
 
 	got := global.TracerProvider()
-	want := &p2
+	want := p2
 	if got != want {
 		t.Fatalf("Provider: got %p, want %p\n", got, want)
 	}

api/trace/context.go

@@ -36,7 +36,7 @@ func SpanFromContext(ctx context.Context) Span {
 	if span, has := ctx.Value(currentSpanKey).(Span); has {
 		return span
 	}
-	return NoopSpan{}
+	return noopSpan{}
 }
 
 // ContextWithRemoteSpanContext creates a new context with a remote

api/trace/context_test.go

@@ -21,14 +21,14 @@ import (
 
 	"go.opentelemetry.io/otel/api/trace"
 	"go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/internal/trace/noop"
 	"go.opentelemetry.io/otel/label"
 )
 
 func TestSetCurrentSpanOverridesPreviouslySetSpan(t *testing.T) {
-	originalSpan := trace.NoopSpan{}
-	expectedSpan := mockSpan{}
-
 	ctx := context.Background()
+	originalSpan := noop.Span
+	expectedSpan := mockSpan{}
 
 	ctx = trace.ContextWithSpan(ctx, originalSpan)
 	ctx = trace.ContextWithSpan(ctx, expectedSpan)
@@ -47,7 +47,7 @@ func TestCurrentSpan(t *testing.T) {
 		{
 			name: "CurrentSpan() returns a NoopSpan{} from an empty context",
 			ctx:  context.Background(),
-			want: trace.NoopSpan{},
+			want: noop.Span,
 		},
 		{
 			name: "CurrentSpan() returns current span if set",
@@ -110,7 +110,7 @@ func (mockSpan) RecordError(ctx context.Context, err error, opts ...trace.ErrorO
 
 // Tracer returns noop implementation of Tracer.
 func (mockSpan) Tracer() trace.Tracer {
-	return trace.NoopTracer{}
+	return noop.Tracer
 }
 
 // Event does nothing.

api/trace/noop_span.go

@@ -22,58 +22,58 @@ import (
 	"go.opentelemetry.io/otel/label"
 )
 
-type NoopSpan struct {
+type noopSpan struct {
 }
 
-var _ Span = (*NoopSpan)(nil)
+var _ Span = noopSpan{}
 
 // SpanContext returns an invalid span context.
-func (NoopSpan) SpanContext() SpanContext {
+func (noopSpan) SpanContext() SpanContext {
 	return EmptySpanContext()
 }
 
 // IsRecording always returns false for NoopSpan.
-func (NoopSpan) IsRecording() bool {
+func (noopSpan) IsRecording() bool {
 	return false
 }
 
 // SetStatus does nothing.
-func (NoopSpan) SetStatus(status codes.Code, msg string) {
+func (noopSpan) SetStatus(status codes.Code, msg string) {
 }
 
 // SetError does nothing.
-func (NoopSpan) SetError(v bool) {
+func (noopSpan) SetError(v bool) {
 }
 
 // SetAttributes does nothing.
-func (NoopSpan) SetAttributes(attributes ...label.KeyValue) {
+func (noopSpan) SetAttributes(attributes ...label.KeyValue) {
 }
 
 // SetAttribute does nothing.
-func (NoopSpan) SetAttribute(k string, v interface{}) {
+func (noopSpan) SetAttribute(k string, v interface{}) {
 }
 
 // End does nothing.
-func (NoopSpan) End(options ...SpanOption) {
+func (noopSpan) End(options ...SpanOption) {
 }
 
 // RecordError does nothing.
-func (NoopSpan) RecordError(ctx context.Context, err error, opts ...ErrorOption) {
+func (noopSpan) RecordError(ctx context.Context, err error, opts ...ErrorOption) {
 }
 
 // Tracer returns noop implementation of Tracer.
-func (NoopSpan) Tracer() Tracer {
-	return NoopTracer{}
+func (noopSpan) Tracer() Tracer {
+	return noopTracer{}
 }
 
 // AddEvent does nothing.
-func (NoopSpan) AddEvent(ctx context.Context, name string, attrs ...label.KeyValue) {
+func (noopSpan) AddEvent(ctx context.Context, name string, attrs ...label.KeyValue) {
 }
 
 // AddEventWithTimestamp does nothing.
-func (NoopSpan) AddEventWithTimestamp(ctx context.Context, timestamp time.Time, name string, attrs ...label.KeyValue) {
+func (noopSpan) AddEventWithTimestamp(ctx context.Context, timestamp time.Time, name string, attrs ...label.KeyValue) {
 }
 
 // SetName does nothing.
-func (NoopSpan) SetName(name string) {
+func (noopSpan) SetName(name string) {
 }

api/trace/noop_trace.go

@@ -18,12 +18,12 @@ import (
 	"context"
 )
 
-type NoopTracer struct{}
+type noopTracer struct{}
 
-var _ Tracer = NoopTracer{}
+var _ Tracer = noopTracer{}
 
 // Start starts a noop span.
-func (NoopTracer) Start(ctx context.Context, name string, opts ...SpanOption) (context.Context, Span) {
-	span := NoopSpan{}
+func (noopTracer) Start(ctx context.Context, name string, opts ...SpanOption) (context.Context, Span) {
+	span := noopSpan{}
 	return ContextWithSpan(ctx, span), span
 }

api/trace/noop_trace_provider.go

@@ -14,11 +14,18 @@
 
 package trace
 
-type NoopProvider struct{}
+type noopProvider struct{}
 
-var _ Provider = NoopProvider{}
+var _ Provider = noopProvider{}
 
 // Tracer returns noop implementation of Tracer.
-func (p NoopProvider) Tracer(_ string, _ ...TracerOption) Tracer {
-	return NoopTracer{}
+func (p noopProvider) Tracer(_ string, _ ...TracerOption) Tracer {
+	return noopTracer{}
+}
+
+// NoopProvider returns a noop implementation of Provider.
+// The Tracer and Spans created from the noop provider will
+// also be noop.
+func NoopProvider() Provider {
+	return noopProvider{}
 }

bridge/opentracing/bridge.go

@@ -30,6 +30,7 @@ import (
 	otelpropagation "go.opentelemetry.io/otel/api/propagation"
 	oteltrace "go.opentelemetry.io/otel/api/trace"
 	"go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/internal/trace/noop"
 	otelparent "go.opentelemetry.io/otel/internal/trace/parent"
 	"go.opentelemetry.io/otel/label"
 
@@ -300,7 +301,7 @@ var _ ot.TracerContextWithSpanExtension = &BridgeTracer{}
 func NewBridgeTracer() *BridgeTracer {
 	return &BridgeTracer{
 		setTracer: bridgeSetTracer{
-			otelTracer: oteltrace.NoopTracer{},
+			otelTracer: noop.Tracer,
 		},
 		warningHandler: func(msg string) {},
 		propagators:    nil,
@@ -579,8 +580,7 @@ func otSpanReferenceTypeToString(refType ot.SpanReferenceType) string {
 // fakeSpan is just a holder of span context, nothing more. It's for
 // propagators, so they can get the span context from Go context.
 type fakeSpan struct {
-	oteltrace.NoopSpan
-
+	oteltrace.Span
 	sc oteltrace.SpanContext
 }
 
@@ -609,7 +609,8 @@ func (t *BridgeTracer) Inject(sm ot.SpanContext, format interface{}, carrier int
 	}
 	header := http.Header(hhcarrier)
 	fs := fakeSpan{
-		sc: bridgeSC.otelSpanContext,
+		Span: noop.Span,
+		sc:   bridgeSC.otelSpanContext,
 	}
 	ctx := oteltrace.ContextWithSpan(context.Background(), fs)
 	ctx = otelcorrelation.ContextWithMap(ctx, bridgeSC.baggageItems)

exporters/trace/jaeger/jaeger.go

@@ -156,7 +156,7 @@ func NewExportPipeline(endpointOption EndpointOption, opts ...Option) (apitrace.
 		opt(&o)
 	}
 	if o.Disabled {
-		return &apitrace.NoopProvider{}, func() {}, nil
+		return apitrace.NoopProvider(), func() {}, nil
 	}
 
 	exporter, err := NewRawExporter(endpointOption, opts...)

exporters/trace/jaeger/jaeger_test.go

@@ -69,7 +69,7 @@ func TestInstallNewPipeline(t *testing.T) {
 			options: []Option{
 				WithDisabled(true),
 			},
-			expectedProvider: &apitrace.NoopProvider{},
+			expectedProvider: apitrace.NoopProvider(),
 		},
 	}
 
@@ -108,7 +108,7 @@ func TestNewExportPipeline(t *testing.T) {
 			options: []Option{
 				WithDisabled(true),
 			},
-			expectedProviderType: &apitrace.NoopProvider{},
+			expectedProviderType: apitrace.NoopProvider(),
 		},
 		{
 			name:     "always on",
@@ -173,7 +173,7 @@ func TestNewExportPipelineWithDisabledFromEnv(t *testing.T) {
 	)
 	defer fn()
 	assert.NoError(t, err)
-	assert.IsType(t, &apitrace.NoopProvider{}, tp)
+	assert.IsType(t, apitrace.NoopProvider(), tp)
 }
 
 func TestNewRawExporter(t *testing.T) {

internal/trace/noop/noop.go

@@ -0,0 +1,35 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package noop provides noop tracing implementations for tracer and span.
+package noop
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/api/trace"
+)
+
+var (
+	// Tracer is a noop tracer that starts noop spans.
+	Tracer trace.Tracer
+
+	// Span is a noop Span.
+	Span trace.Span
+)
+
+func init() {
+	Tracer = trace.NoopProvider().Tracer("")
+	_, Span = Tracer.Start(context.Background(), "")
+}

propagators/b3_integration_test.go

@@ -23,6 +23,7 @@ import (
 
 	"go.opentelemetry.io/otel/api/propagation"
 	"go.opentelemetry.io/otel/api/trace"
+	"go.opentelemetry.io/otel/internal/trace/noop"
 	"go.opentelemetry.io/otel/propagators"
 )
 
@@ -64,7 +65,7 @@ func TestExtractB3(t *testing.T) {
 }
 
 type testSpan struct {
-	trace.NoopSpan
+	trace.Span
 	sc trace.SpanContext
 }
 
@@ -94,7 +95,10 @@ func TestInjectB3(t *testing.T) {
 				req, _ := http.NewRequest("GET", "http://example.com", nil)
 				ctx := trace.ContextWithSpan(
 					context.Background(),
-					testSpan{sc: tt.sc},
+					testSpan{
+						Span: noop.Span,
+						sc:   tt.sc,
+					},
 				)
 				propagator.Inject(ctx, req.Header)