Initial Bus implementation

bus.go

@@ -0,0 +1,50 @@
+package main
+
+import "sync"
+
+type Bus struct {
+	mu    sync.Mutex
+	chans map[string][]chan Object
+}
+
+func NewBus() *Bus {
+	return &Bus{
+		chans: map[string][]chan Object{},
+	}
+}
+
+func (b *Bus) Announce(obj Object) {
+	key := ObjectKey(obj)
+
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	chans := b.chans[key]
+	newChans := []chan Object{}
+
+	for _, ch := range chans {
+		select {
+		case ch <- obj:
+			newChans = append(newChans, ch)
+		default:
+			close(ch)
+		}
+	}
+
+	if len(chans) != len(newChans) {
+		b.chans[key] = newChans
+	}
+}
+
+func (b *Bus) Subscribe(obj Object) chan Object {
+	key := ObjectKey(obj)
+
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	ch := make(chan Object, 100)
+
+	b.chans[key] = append(b.chans[key], ch)
+
+	return ch
+}