You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
91 lines
1.9 KiB
Go
91 lines
1.9 KiB
Go
package trace
|
|
|
|
import (
|
|
"net/http"
|
|
|
|
"google.golang.org/grpc/metadata"
|
|
)
|
|
|
|
const (
|
|
// HttpFormat means http carrier format.
|
|
HttpFormat = iota
|
|
// GrpcFormat means grpc carrier format.
|
|
GrpcFormat
|
|
)
|
|
|
|
var (
|
|
emptyHttpPropagator httpPropagator
|
|
emptyGrpcPropagator grpcPropagator
|
|
)
|
|
|
|
type (
|
|
// Propagator interface wraps the Extract and Inject methods.
|
|
Propagator interface {
|
|
Extract(carrier interface{}) (Carrier, error)
|
|
Inject(carrier interface{}) (Carrier, error)
|
|
}
|
|
|
|
httpPropagator struct{}
|
|
grpcPropagator struct{}
|
|
)
|
|
|
|
func (h httpPropagator) Extract(carrier interface{}) (Carrier, error) {
|
|
if c, ok := carrier.(http.Header); ok {
|
|
return httpCarrier(c), nil
|
|
}
|
|
|
|
return nil, ErrInvalidCarrier
|
|
}
|
|
|
|
func (h httpPropagator) Inject(carrier interface{}) (Carrier, error) {
|
|
if c, ok := carrier.(http.Header); ok {
|
|
return httpCarrier(c), nil
|
|
}
|
|
|
|
return nil, ErrInvalidCarrier
|
|
}
|
|
|
|
func (g grpcPropagator) Extract(carrier interface{}) (Carrier, error) {
|
|
if c, ok := carrier.(metadata.MD); ok {
|
|
return grpcCarrier(c), nil
|
|
}
|
|
|
|
return nil, ErrInvalidCarrier
|
|
}
|
|
|
|
func (g grpcPropagator) Inject(carrier interface{}) (Carrier, error) {
|
|
if c, ok := carrier.(metadata.MD); ok {
|
|
return grpcCarrier(c), nil
|
|
}
|
|
|
|
return nil, ErrInvalidCarrier
|
|
}
|
|
|
|
// Extract extracts tracing information from carrier with given format.
|
|
func Extract(format, carrier interface{}) (Carrier, error) {
|
|
switch v := format.(type) {
|
|
case int:
|
|
if v == HttpFormat {
|
|
return emptyHttpPropagator.Extract(carrier)
|
|
} else if v == GrpcFormat {
|
|
return emptyGrpcPropagator.Extract(carrier)
|
|
}
|
|
}
|
|
|
|
return nil, ErrInvalidCarrier
|
|
}
|
|
|
|
// Inject injects tracing information into carrier with given format.
|
|
func Inject(format, carrier interface{}) (Carrier, error) {
|
|
switch v := format.(type) {
|
|
case int:
|
|
if v == HttpFormat {
|
|
return emptyHttpPropagator.Inject(carrier)
|
|
} else if v == GrpcFormat {
|
|
return emptyGrpcPropagator.Inject(carrier)
|
|
}
|
|
}
|
|
|
|
return nil, ErrInvalidCarrier
|
|
}
|