// Execute trigger content negottion and the actual execution of one of the
// action's handlers.
func (base *Base) Execute(action interface{}) {
contentType := render.Negotiate(base.Ctx, base.R)
switch contentType {
case render.MimeHal, render.MimeJSON:
action, ok := action.(JSON)
if !ok {
goto NotAcceptable
}
action.JSON()
if base.Err != nil {
problem.Render(base.Ctx, base.W, base.Err)
return
}
case render.MimeEventStream:
action, ok := action.(SSE)
if !ok {
goto NotAcceptable
}
stream, ok := sse.NewStream(base.Ctx, base.W, base.R)
if !ok {
return
}
for {
action.SSE(stream)
if stream.IsDone() {
return
}
select {
case <-base.Ctx.Done():
return
case <-sse.Pumped():
//no-op, continue onto the next iteration
}
}
default:
goto NotAcceptable
}
return
NotAcceptable:
problem.Render(base.Ctx, base.W, problem.NotAcceptable)
return
}
// ServeHTTPC is a method for web.Handler
func (action RateLimitExceededAction) ServeHTTP(w http.ResponseWriter, r *http.Request) {
ap := &action.Action
c := web.C{
Env: map[interface{}]interface{}{
"app": action.App,
},
}
ap.Prepare(c, w, r)
ap.App = action.App
problem.Render(action.Ctx, action.W, problem.RateLimitExceeded)
}
// RecoverMiddleware helps the server recover from panics. It ensures that
// no request can fully bring down the horizon server, and it also logs the
// panics to the logging subsystem.
func RecoverMiddleware(c *web.C, h http.Handler) http.Handler {
fn := func(w http.ResponseWriter, r *http.Request) {
ctx := gctx.FromC(*c)
defer func() {
if err := recover(); err != nil {
stack := make([]byte, 4096) // 4k of stack should be sufficient to see the source
n := runtime.Stack(stack, false)
log.
WithField(ctx, "stacktrace", string(stack[:n])).
Errorf("panic: %+v", err)
//TODO: include stack trace if in debug mode
problem.Render(gctx.FromC(*c), w, problem.ServerError)
}
}()
h.ServeHTTP(w, r)
}
return http.HandlerFunc(fn)
}
// JSON is a method for actions.JSON
func (action *NotImplementedAction) JSON() {
problem.Render(action.Ctx, action.W, problem.NotImplemented)
}
// JSON is a method for actions.JSON
func (action *NotFoundAction) JSON() {
problem.Render(action.Ctx, action.W, problem.NotFound)
}