traefik/pkg/middlewares/tracing/status_code.go

package tracing

import (
	"bufio"
	"net"
	"net/http"
)

type statusCodeRecoder interface {
	http.ResponseWriter
	Status() int
}

// newStatusCodeRecoder returns an initialized statusCodeRecoder.
func newStatusCodeRecoder(rw http.ResponseWriter, status int) statusCodeRecoder {
	recorder := &statusCodeWithoutCloseNotify{rw, status}
	if _, ok := rw.(http.CloseNotifier); ok {
		return &statusCodeWithCloseNotify{recorder}
	}
	return recorder
}

type statusCodeWithoutCloseNotify struct {
	http.ResponseWriter
	status int
}

// WriteHeader captures the status code for later retrieval.
func (s *statusCodeWithoutCloseNotify) WriteHeader(status int) {
	s.status = status
	s.ResponseWriter.WriteHeader(status)
}

// Status get response status.
func (s *statusCodeWithoutCloseNotify) Status() int {
	return s.status
}

// Hijack hijacks the connection.
func (s *statusCodeWithoutCloseNotify) Hijack() (net.Conn, *bufio.ReadWriter, error) {
	return s.ResponseWriter.(http.Hijacker).Hijack()
}

// Flush sends any buffered data to the client.
func (s *statusCodeWithoutCloseNotify) Flush() {
	if flusher, ok := s.ResponseWriter.(http.Flusher); ok {
		flusher.Flush()
	}
}

type statusCodeWithCloseNotify struct {
	*statusCodeWithoutCloseNotify
}

func (s *statusCodeWithCloseNotify) CloseNotify() <-chan bool {
	return s.ResponseWriter.(http.CloseNotifier).CloseNotify()
}