1// Copyright The OpenTelemetry Authors
  2// SPDX-License-Identifier: Apache-2.0
  3
  4package trace // import "go.opentelemetry.io/otel/trace"
  5
  6import (
  7	"context"
  8
  9	"go.opentelemetry.io/otel/attribute"
 10	"go.opentelemetry.io/otel/codes"
 11	"go.opentelemetry.io/otel/trace/embedded"
 12)
 13
 14// NewNoopTracerProvider returns an implementation of TracerProvider that
 15// performs no operations. The Tracer and Spans created from the returned
 16// TracerProvider also perform no operations.
 17//
 18// Deprecated: Use [go.opentelemetry.io/otel/trace/noop.NewTracerProvider]
 19// instead.
 20func NewNoopTracerProvider() TracerProvider {
 21	return noopTracerProvider{}
 22}
 23
 24type noopTracerProvider struct{ embedded.TracerProvider }
 25
 26var _ TracerProvider = noopTracerProvider{}
 27
 28// Tracer returns noop implementation of Tracer.
 29func (p noopTracerProvider) Tracer(string, ...TracerOption) Tracer {
 30	return noopTracer{}
 31}
 32
 33// noopTracer is an implementation of Tracer that performs no operations.
 34type noopTracer struct{ embedded.Tracer }
 35
 36var _ Tracer = noopTracer{}
 37
 38// Start carries forward a non-recording Span, if one is present in the context, otherwise it
 39// creates a no-op Span.
 40func (t noopTracer) Start(ctx context.Context, name string, _ ...SpanStartOption) (context.Context, Span) {
 41	span := SpanFromContext(ctx)
 42	if _, ok := span.(nonRecordingSpan); !ok {
 43		// span is likely already a noopSpan, but let's be sure
 44		span = noopSpanInstance
 45	}
 46	return ContextWithSpan(ctx, span), span
 47}
 48
 49// noopSpan is an implementation of Span that performs no operations.
 50type noopSpan struct{ embedded.Span }
 51
 52var noopSpanInstance Span = noopSpan{}
 53
 54// SpanContext returns an empty span context.
 55func (noopSpan) SpanContext() SpanContext { return SpanContext{} }
 56
 57// IsRecording always returns false.
 58func (noopSpan) IsRecording() bool { return false }
 59
 60// SetStatus does nothing.
 61func (noopSpan) SetStatus(codes.Code, string) {}
 62
 63// SetError does nothing.
 64func (noopSpan) SetError(bool) {}
 65
 66// SetAttributes does nothing.
 67func (noopSpan) SetAttributes(...attribute.KeyValue) {}
 68
 69// End does nothing.
 70func (noopSpan) End(...SpanEndOption) {}
 71
 72// RecordError does nothing.
 73func (noopSpan) RecordError(error, ...EventOption) {}
 74
 75// AddEvent does nothing.
 76func (noopSpan) AddEvent(string, ...EventOption) {}
 77
 78// AddLink does nothing.
 79func (noopSpan) AddLink(Link) {}
 80
 81// SetName does nothing.
 82func (noopSpan) SetName(string) {}
 83
 84// TracerProvider returns a no-op TracerProvider.
 85func (s noopSpan) TracerProvider() TracerProvider {
 86	return s.tracerProvider(autoInstEnabled)
 87}
 88
 89// autoInstEnabled defines if the auto-instrumentation SDK is enabled.
 90//
 91// The auto-instrumentation is expected to overwrite this value to true when it
 92// attaches to the process.
 93var autoInstEnabled = new(bool)
 94
 95// tracerProvider return a noopTracerProvider if autoEnabled is false,
 96// otherwise it will return a TracerProvider from the sdk package used in
 97// auto-instrumentation.
 98func (noopSpan) tracerProvider(autoEnabled *bool) TracerProvider {
 99	if *autoEnabled {
100		return newAutoTracerProvider()
101	}
102	return noopTracerProvider{}
103}