+func (hn hijackNotifier) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+ close(hn.hijacked)
+ return hn.hijacker.Hijack()
+}
+
+// HandlerWithDeadline cancels the request context if the request
+// takes longer than the specified timeout without having its
+// connection hijacked.
+func HandlerWithDeadline(timeout time.Duration, next http.Handler) http.Handler {
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ ctx, cancel := context.WithCancel(r.Context())
+ defer cancel()
+ nodeadline := make(chan bool)
+ go func() {
+ select {
+ case <-nodeadline:
+ case <-ctx.Done():
+ case <-time.After(timeout):
+ cancel()
+ }
+ }()
+ if hj, ok := w.(hijacker); ok {
+ w = hijackNotifier{hj, nodeadline}
+ }
+ next.ServeHTTP(w, r.WithContext(ctx))
+ })
+}