http.ResponseWriter embed

responsewriterwatcher.go

type ResponseWriterWatcher struct {
	rw     http.ResponseWriter
	Status int
	Size   int
}

func WatchResponseWriter(rw http.ResponseWriter) *ResponseWriterWatcher {
	return &ResponseWriterWatcher{
		rw: rw,
	}
}

func (l *ResponseWriterWatcher) Header() http.Header {
	return l.rw.Header()
}

func (l *ResponseWriterWatcher) Write(b []byte) (int, error) {
	if l.Status == 0 {
		// The status will be StatusOK if WriteHeader has not been called yet
		l.Status = http.StatusOK
	}
	size, err := l.rw.Write(b)
	l.Size += size
	return size, err
}

func (l *ResponseWriterWatcher) WriteHeader(s int) {
	l.rw.WriteHeader(s)
	l.Status = s
}

func (l *ResponseWriterWatcher) StatusSet() bool {
	return (l.Status != 0 && l.Status != 200)
}