1package notification
 2
 3// Sink is a function that accepts notification requests.
 4// This allows agents to publish notifications without knowing about the UI.
 5type Sink func(Notification)
 6
 7// NewChannelSink creates a Sink that sends notifications to a channel. The
 8// channel should have a buffer of 1.
 9//
10// Any pending notification is discarded before sending the new one. This
11// ensures the consumer always sees the most recent notification rather
12// than a potential barrage when only one is needed.
13func NewChannelSink(ch chan Notification) Sink {
14	return func(n Notification) {
15		// Drain any existing notification.
16		select {
17		case <-ch:
18		default:
19		}
20		// Send the new notification. The channel should be empty, but it uses a
21		// non-blocking send for safety in case of a race with the consumer.
22		select {
23		case ch <- n:
24		default:
25		}
26	}
27}