event cache and fireable interace

events/event_cache.go

@@ -0,0 +1,39 @@
+package events
+
+const (
+	eventsBufferSize = 1000
+)
+
+// An EventCache buffers events for a Fireable
+// All events are cached. Filtering happens on Flush
+type EventCache struct {
+	evsw   Fireable
+	events []eventInfo
+}
+
+// Create a new EventCache with an EventSwitch as backend
+func NewEventCache(evsw Fireable) *EventCache {
+	return &EventCache{
+		evsw:   evsw,
+		events: make([]eventInfo, eventsBufferSize),
+	}
+}
+
+// a cached event
+type eventInfo struct {
+	event string
+	msg   interface{}
+}
+
+// Cache an event to be fired upon finality.
+func (evc *EventCache) FireEvent(event string, msg interface{}) {
+	// append to list
+	evc.events = append(evc.events, eventInfo{event, msg})
+}
+
+// Fire events by running evsw.FireEvent on all cached events. Blocks.
+func (evc *EventCache) Flush() {
+	for _, ei := range evc.events {
+		evc.evsw.FireEvent(ei.event, ei.msg)
+	}
+}