mirror of https://github.com/docker/cli.git
59 lines
1.8 KiB
Go
59 lines
1.8 KiB
Go
// Copyright The OpenTelemetry Authors
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// SPDX-License-Identifier: Apache-2.0
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package otelhttp // import "go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
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import (
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"context"
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"sync"
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"go.opentelemetry.io/otel/attribute"
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)
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// Labeler is used to allow instrumented HTTP handlers to add custom attributes to
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// the metrics recorded by the net/http instrumentation.
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type Labeler struct {
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mu sync.Mutex
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attributes []attribute.KeyValue
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}
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// Add attributes to a Labeler.
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func (l *Labeler) Add(ls ...attribute.KeyValue) {
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l.mu.Lock()
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defer l.mu.Unlock()
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l.attributes = append(l.attributes, ls...)
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}
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// Get returns a copy of the attributes added to the Labeler.
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func (l *Labeler) Get() []attribute.KeyValue {
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l.mu.Lock()
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defer l.mu.Unlock()
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ret := make([]attribute.KeyValue, len(l.attributes))
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copy(ret, l.attributes)
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return ret
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}
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type labelerContextKeyType int
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const lablelerContextKey labelerContextKeyType = 0
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// ContextWithLabeler returns a new context with the provided Labeler instance.
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// Attributes added to the specified labeler will be injected into metrics
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// emitted by the instrumentation. Only one labeller can be injected into the
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// context. Injecting it multiple times will override the previous calls.
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func ContextWithLabeler(parent context.Context, l *Labeler) context.Context {
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return context.WithValue(parent, lablelerContextKey, l)
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}
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// LabelerFromContext retrieves a Labeler instance from the provided context if
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// one is available. If no Labeler was found in the provided context a new, empty
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// Labeler is returned and the second return value is false. In this case it is
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// safe to use the Labeler but any attributes added to it will not be used.
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func LabelerFromContext(ctx context.Context) (*Labeler, bool) {
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l, ok := ctx.Value(lablelerContextKey).(*Labeler)
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if !ok {
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l = &Labeler{}
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}
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return l, ok
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}
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