O_O

internal/broadcaster.go

@@ -0,0 +1,42 @@
+package internal
+
+import "sync"
+
+type broadcaster struct {
+	clients map[chan bool]bool
+	mu      sync.RWMutex
+}
+
+func newBroadcaster() *broadcaster {
+	return &broadcaster{
+		clients: make(map[chan bool]bool),
+	}
+}
+
+func (b *broadcaster) subscribe() chan bool {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	ch := make(chan bool, 10)
+	b.clients[ch] = true
+	return ch
+}
+
+func (b *broadcaster) unsubscribe(ch chan bool) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	delete(b.clients, ch)
+	close(ch)
+}
+
+func (b *broadcaster) broadcast() {
+	b.mu.RLock()
+	defer b.mu.RUnlock()
+	for ch := range b.clients {
+		select {
+		case ch <- true:
+		default:
+		}
+	}
+}
+
+var updates = newBroadcaster()