eventemitter stub

eventemitter.go

@@ -0,0 +1,71 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"sync"
+)
+
+type EventEmitter struct {
+	emitters map[string][]EventHandler
+	mutex    *sync.RWMutex
+}
+
+type EventHandler func(json.RawMessage)
+
+func NewEventEmitter() *EventEmitter {
+	return &EventEmitter{
+		emitters: make(map[string][]EventHandler),
+		mutex:    &sync.RWMutex{},
+	}
+}
+
+func (ee EventEmitter) getList(name string) []EventHandler {
+	list := ee.emitters[name]
+	if list == nil {
+		list = make([]EventHandler, 0)
+	}
+	return list
+}
+
+func (ee EventEmitter) setList(name string, list []EventHandler) {
+	ee.emitters[name] = list
+}
+
+func (ee EventEmitter) AddListener(name string, handler EventHandler) {
+	ee.mutex.Lock()
+	defer ee.mutex.Unlock()
+
+	list := ee.getList(name)
+	list = append(list, handler)
+	ee.setList(name, list)
+}
+
+func (ee EventEmitter) Emit(name string, msg json.RawMessage) {
+	ee.mutex.RLock()
+	defer ee.mutex.RUnlock()
+
+	list := ee.getList(name)
+	for _, handler := range list {
+		handler(msg)
+	}
+}
+
+func (ee EventEmitter) RemoveListener(name string, remove_handler EventHandler) {
+	ee.mutex.Lock()
+	defer ee.mutex.Unlock()
+
+	list := ee.getList(name)
+	newlist := make([]EventHandler, 0)
+
+	remove_handler_p := fmt.Sprintf("%v", remove_handler)
+
+	for _, handler := range list {
+		handler_p := fmt.Sprintf("%v", handler)
+		if remove_handler_p != handler_p {
+			newlist = append(newlist, handler)
+		}
+	}
+
+	ee.setList(name, newlist)
+}

eventemitter_test.go

@@ -0,0 +1,27 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"testing"
+)
+
+func TestEventEmitter(t *testing.T) {
+	ee := NewEventEmitter()
+	count := 0
+	handler := func(msg json.RawMessage) {
+		fmt.Println(msg)
+		count++
+	}
+
+	if count != 0 {
+		t.Fatal("Count not 0")
+	}
+	ee.AddListener("my-event", handler)
+	ee.Emit("my-event", []byte{1, 2, 3})
+	ee.RemoveListener("my-event", handler)
+
+	if count != 1 {
+		t.Fatal("Count not 0")
+	}
+}