observer

Author: coolpest

Decorator/decoator_test.go

@@ -15,7 +15,6 @@ func TestPi(t *testing.T) {
 }
 
 func TestWrapLogger(t *testing.T) {
-
 	f:= WrapLogger(Pi,log.New(os.Stdout,"test ",1))
 	f(100000)
 }

Observer/observer.go

@@ -0,0 +1,63 @@
+package Observer
+
+import (
+	"fmt"
+	"sync"
+	"time"
+)
+
+type Event struct {
+	Data int
+}
+
+type Observer interface {
+	NotifyCallback(event Event)
+}
+
+type Subject interface {
+	AddListener(observer Observer)
+	RemoveListener(observer Observer)
+	Notify(event Event)
+}
+
+type eventObserver struct {
+	ID   int
+	Time time.Time
+}
+
+type eventSubject struct {
+	Observers sync.Map
+}
+
+func (e eventObserver) NotifyCallback(event Event) {
+	fmt.Printf("Recieved:%d after %v\n", event.Data, time.Since(e.Time))
+}
+
+func (e *eventSubject) AddListener(obs Observer) {
+	e.Observers.Store(obs, struct{}{})
+}
+
+func (e *eventSubject) RemoveListener(obs Observer) {
+	e.Observers.Delete(obs)
+}
+
+func (e *eventSubject) Notify(event Event) {
+	e.Observers.Range(func(key, value interface{}) bool {
+		if key == nil {
+			return false
+		}
+		key.(Observer).NotifyCallback(event)
+		return true
+	})
+}
+
+func Fib(n int) chan int{
+	out := make(chan int)
+	go func() {
+		defer close(out)
+		for i,j:=0,1; i<n;i,j=i+j,i{
+			out <-i
+		}
+	}()
+	return out
+}

Observer/observer_test.go

@@ -0,0 +1,26 @@
+package Observer
+
+import (
+	"sync"
+	"testing"
+	"time"
+)
+
+func TestFib(t *testing.T) {
+	//for x:=range Fib(20){
+	//	fmt.Println(x)
+	//}
+
+	n := eventSubject{Observers:sync.Map{}}
+
+	obs1:= eventObserver{ID:1,Time:time.Now()}
+	obs2:= eventObserver{ID:2,Time:time.Now()}
+
+	n.AddListener(obs1)
+	n.AddListener(obs2)
+
+	for x:=range Fib(10){
+		n.Notify(Event{Data:x})
+	}
+}
+