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86 lines
1.6 KiB
Go
86 lines
1.6 KiB
Go
package trace
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import (
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"net/http"
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"google.golang.org/grpc/metadata"
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)
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const (
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HttpFormat = iota
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GrpcFormat
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)
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var (
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emptyHttpPropagator httpPropagator
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emptyGrpcPropagator grpcPropagator
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)
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type (
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Propagator interface {
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Extract(carrier interface{}) (Carrier, error)
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Inject(carrier interface{}) (Carrier, error)
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}
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httpPropagator struct{}
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grpcPropagator struct{}
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)
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func (h httpPropagator) Extract(carrier interface{}) (Carrier, error) {
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if c, ok := carrier.(http.Header); ok {
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return httpCarrier(c), nil
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}
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return nil, ErrInvalidCarrier
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}
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func (h httpPropagator) Inject(carrier interface{}) (Carrier, error) {
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if c, ok := carrier.(http.Header); ok {
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return httpCarrier(c), nil
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}
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return nil, ErrInvalidCarrier
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}
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func (g grpcPropagator) Extract(carrier interface{}) (Carrier, error) {
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if c, ok := carrier.(metadata.MD); ok {
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return grpcCarrier(c), nil
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}
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return nil, ErrInvalidCarrier
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}
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func (g grpcPropagator) Inject(carrier interface{}) (Carrier, error) {
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if c, ok := carrier.(metadata.MD); ok {
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return grpcCarrier(c), nil
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}
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return nil, ErrInvalidCarrier
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}
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func Extract(format, carrier interface{}) (Carrier, error) {
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switch v := format.(type) {
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case int:
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if v == HttpFormat {
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return emptyHttpPropagator.Extract(carrier)
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} else if v == GrpcFormat {
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return emptyGrpcPropagator.Extract(carrier)
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}
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}
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return nil, ErrInvalidCarrier
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}
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func Inject(format, carrier interface{}) (Carrier, error) {
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switch v := format.(type) {
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case int:
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if v == HttpFormat {
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return emptyHttpPropagator.Inject(carrier)
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} else if v == GrpcFormat {
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return emptyGrpcPropagator.Inject(carrier)
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}
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}
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return nil, ErrInvalidCarrier
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}
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