65 lines
2 KiB
Go
65 lines
2 KiB
Go
// Copyright The OpenTelemetry Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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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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func injectLabeler(ctx context.Context, l *Labeler) context.Context {
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return context.WithValue(ctx, 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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