Remove CloseNotifier

The CloseNotifier is in conflict with the Hijacker interface (they
cannot be used at the same time). The context will not be cancelled when
the close channel from CloseNotifier is called. This is because the behavior
is not well understood. We can introduce it later if it poses a real problem.

refs #291

pkg/server/router/common.go

@@ -43,7 +43,6 @@ func (r *commonRouter) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 		preprocessors []Processor
 		payload       *Payload
 		timedOut      bool
-		closed        bool
 	)
 
 	version := strings.TrimPrefix(skyversion.Version(), "v")
@@ -77,11 +76,6 @@ func (r *commonRouter) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 			httpStatus = defaultStatusCode(resp.Err)
 		}
 
-		if closed {
-			// There is no point writing to a closed connection.
-			return
-		}
-
 		writer.WriteHeader(httpStatus)
 		if err := writeEntity(writer, resp); err != nil {
 			panic(err)
@@ -118,9 +112,6 @@ func (r *commonRouter) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	select {
 	case <-payload.Context.Done():
 		// request conext cancelled or response generated
-	case <-getCloseChan(w):
-		// connection closed
-		closed = true
 	case <-getTimeoutChan(r.ResponseTimeout):
 		// timeout exceeded
 		timedOut = true
@@ -160,13 +151,6 @@ func writeEntity(w http.ResponseWriter, i interface{}) error {
 	return json.NewEncoder(w).Encode(i)
 }
 
-func getCloseChan(w http.ResponseWriter) <-chan bool {
-	if closeNotifier, ok := w.(http.CloseNotifier); ok {
-		return closeNotifier.CloseNotify()
-	}
-	return make(chan bool)
-}
-
 func getTimeoutChan(timeout time.Duration) <-chan time.Time {
 	if timeout.Seconds() > 0 {
 		return time.After(timeout)

pkg/server/router/logging.go

@@ -68,13 +68,6 @@ func (l *responseLogger) Hijack() (c net.Conn, w *bufio.ReadWriter, e error) {
 	return hijacker.Hijack()
 }
 
-func (l *responseLogger) CloseNotify() <-chan bool {
-	if notifier, ok := l.w.(http.CloseNotifier); ok {
-		return notifier.CloseNotify()
-	}
-	return make(chan bool)
-}
-
 type LoggingMiddleware struct {
 	Skips       []string
 	MimeConcern []string