49 lines
1.0 KiB
Go
49 lines
1.0 KiB
Go
// Package tracer provides an interface for distributed tracing
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package tracer
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import (
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"context"
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)
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type tracerKey struct{}
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// FromContext returns a tracer from context
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func FromContext(ctx context.Context) Tracer {
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if ctx == nil {
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return DefaultTracer
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}
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if tracer, ok := ctx.Value(tracerKey{}).(Tracer); ok {
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return tracer
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}
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return DefaultTracer
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}
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// NewContext saves the tracer in the context
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func NewContext(ctx context.Context, tracer Tracer) context.Context {
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if ctx == nil {
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ctx = context.Background()
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}
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return context.WithValue(ctx, tracerKey{}, tracer)
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}
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type spanKey struct{}
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// SpanFromContext returns a span from context
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func SpanFromContext(ctx context.Context) Span {
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if ctx == nil {
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return &noopSpan{}
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}
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if span, ok := ctx.Value(spanKey{}).(Span); ok {
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return span
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}
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return &noopSpan{}
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}
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// NewSpanContext saves the span in the context
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func NewSpanContext(ctx context.Context, span Span) context.Context {
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if ctx == nil {
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ctx = context.Background()
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}
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return context.WithValue(ctx, spanKey{}, span)
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}
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