53 lines
1.3 KiB
Go
53 lines
1.3 KiB
Go
package lightstep
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import (
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"errors"
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"github.com/opentracing/opentracing-go"
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)
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// PropagatorStack provides a Propagator interface that supports
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// multiple propagators per format.
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type PropagatorStack struct {
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propagators []Propagator
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}
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// PushPropagator adds a Propagator to a list of configured propagators
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func (stack *PropagatorStack) PushPropagator(p Propagator) {
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stack.propagators = append(stack.propagators, p)
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}
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// Inject iterates through configured propagators and calls
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// their Inject functions
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func (stack PropagatorStack) Inject(
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spanContext opentracing.SpanContext,
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opaqueCarrier interface{},
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) error {
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if len(stack.propagators) == 0 {
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return errors.New("No valid propagator configured")
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}
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for _, propagator := range stack.propagators {
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propagator.Inject(spanContext, opaqueCarrier)
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}
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return nil
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}
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// Extract iterates through configured propagators and
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// returns the first successfully extracted context
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func (stack PropagatorStack) Extract(
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opaqueCarrier interface{},
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) (opentracing.SpanContext, error) {
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if len(stack.propagators) == 0 {
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return nil, errors.New("No valid propagator configured")
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}
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for _, propagator := range stack.propagators {
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context, err := propagator.Extract(opaqueCarrier)
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if err == nil {
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return context, nil
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}
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}
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return nil, errors.New("No valid propagator configured")
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}
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