Function handleMessagesWait

modules/smtp/api.go:112–154

handleMessagesWait long-polls for a matching SMTP message. It holds the connection until a match arrives or the timeout expires. Returns 200 with the first matching event, or 408 on timeout.

(store event.Store, mod *Module)

// It holds the connection until a match arrives or the timeout expires.
// Returns 200 with the first matching event, or 408 on timeout.
func handleMessagesWait(store event.Store, mod *Module) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		f := parseFilter(r)

		// Parse timeout (default 30 s, max 60 s).
		timeout := 30 * time.Second
		if t := r.URL.Query().Get("timeout"); t != "" {
			if d, err := time.ParseDuration(t); err == nil && d > 0 {
				if d > 60*time.Second {
					d = 60 * time.Second
				}
				timeout = d
			}
		}

		// Subscribe BEFORE checking existing events to avoid the race where a
		// matching event arrives between the check and the wait.
		ch, unsub := mod.subscribe(f)
		defer unsub()

		// Check for an already-stored matching event.
		events, err := store.FindAll(r.Context(), event.FindOptions{Type: "smtp", Project: f.Project})
		if err != nil {
			smtpError(w, err.Error(), http.StatusInternalServerError)
			return
		}
		if matched := applyFilter(events, f); len(matched) > 0 {
			smtpJSON(w, matched[0])
			return
		}

		// Wait for a new matching event.
		ctx, cancel := context.WithTimeout(r.Context(), timeout)
		defer cancel()

		select {
		case ev := <-ch:
			smtpJSON(w, ev)
		case <-ctx.Done():
			smtpError(w, "timeout waiting for message", http.StatusRequestTimeout)
		}
	}
}

// handleDeleteMessages purges SMTP messages, optionally filtered by project.
func handleDeleteMessages(store event.Store) http.HandlerFunc {