traefik/vendor/github.com/openzipkin-contrib/zipkin-go-opentracing/propagation.go
2019-04-05 11:58:06 +02:00

68 lines
1.8 KiB
Go

package zipkintracer
import (
opentracing "github.com/opentracing/opentracing-go"
"github.com/openzipkin-contrib/zipkin-go-opentracing/flag"
"github.com/openzipkin-contrib/zipkin-go-opentracing/types"
)
type accessorPropagator struct {
tracer *tracerImpl
}
// DelegatingCarrier is a flexible carrier interface which can be implemented
// by types which have a means of storing the trace metadata and already know
// how to serialize themselves (for example, protocol buffers).
type DelegatingCarrier interface {
SetState(traceID types.TraceID, spanID uint64, parentSpanID *uint64, sampled bool, flags flag.Flags)
State() (traceID types.TraceID, spanID uint64, parentSpanID *uint64, sampled bool, flags flag.Flags)
SetBaggageItem(key, value string)
GetBaggage(func(key, value string))
}
func (p *accessorPropagator) Inject(
spanContext opentracing.SpanContext,
carrier interface{},
) error {
dc, ok := carrier.(DelegatingCarrier)
if !ok || dc == nil {
return opentracing.ErrInvalidCarrier
}
sc, ok := spanContext.(SpanContext)
if !ok {
return opentracing.ErrInvalidSpanContext
}
dc.SetState(sc.TraceID, sc.SpanID, sc.ParentSpanID, sc.Sampled, sc.Flags)
for k, v := range sc.Baggage {
dc.SetBaggageItem(k, v)
}
return nil
}
func (p *accessorPropagator) Extract(
carrier interface{},
) (opentracing.SpanContext, error) {
dc, ok := carrier.(DelegatingCarrier)
if !ok || dc == nil {
return nil, opentracing.ErrInvalidCarrier
}
traceID, spanID, parentSpanID, sampled, flags := dc.State()
sc := SpanContext{
TraceID: traceID,
SpanID: spanID,
Sampled: sampled,
Baggage: nil,
ParentSpanID: parentSpanID,
Flags: flags,
}
dc.GetBaggage(func(k, v string) {
if sc.Baggage == nil {
sc.Baggage = map[string]string{}
}
sc.Baggage[k] = v
})
return sc, nil
}