bump(github.com/goraft/raft): 6bf34b9

Move from coreos/raft to goraft/raft and update to latest.

third_party/github.com/goraft/raft/event_dispatcher.go

@@ -0,0 +1,68 @@
+package raft
+
+import (
+	"reflect"
+	"sync"
+)
+
+// eventDispatcher is responsible for managing listeners for named events
+// and dispatching event notifications to those listeners.
+type eventDispatcher struct {
+	sync.RWMutex
+	source    interface{}
+	listeners map[string]eventListeners
+}
+
+// EventListener is a function that can receive event notifications.
+type EventListener func(Event)
+
+// EventListeners represents a collection of individual listeners.
+type eventListeners []EventListener
+
+// newEventDispatcher creates a new eventDispatcher instance.
+func newEventDispatcher(source interface{}) *eventDispatcher {
+	return &eventDispatcher{
+		source:    source,
+		listeners: make(map[string]eventListeners),
+	}
+}
+
+// AddEventListener adds a listener function for a given event type.
+func (d *eventDispatcher) AddEventListener(typ string, listener EventListener) {
+	d.Lock()
+	defer d.Unlock()
+	d.listeners[typ] = append(d.listeners[typ], listener)
+}
+
+// RemoveEventListener removes a listener function for a given event type.
+func (d *eventDispatcher) RemoveEventListener(typ string, listener EventListener) {
+	d.Lock()
+	defer d.Unlock()
+
+	// Grab a reference to the function pointer once.
+	ptr := reflect.ValueOf(listener).Pointer()
+
+	// Find listener by pointer and remove it.
+	listeners := d.listeners[typ]
+	for i, l := range listeners {
+		if reflect.ValueOf(l).Pointer() == ptr {
+			d.listeners[typ] = append(listeners[:i], listeners[i+1:]...)
+		}
+	}
+}
+
+// DispatchEvent dispatches an event.
+func (d *eventDispatcher) DispatchEvent(e Event) {
+	d.RLock()
+	defer d.RUnlock()
+
+	// Automatically set the event source.
+	if e, ok := e.(*event); ok {
+		e.source = d.source
+	}
+
+	// Dispatch the event to all listeners.
+	for _, l := range d.listeners[e.Type()] {
+		l(e)
+	}
+}