Golang观察者模式实现事件通知解析

type Observer interface {

    Update(data interface{})

}

type Subject interface {

    Register(obs Observer)

    Unregister(obs Observer)

    Notify(data interface{})

}

type EventCenter struct {

    observers []Observer

    mutex     sync.RWMutex

}

func (ec *EventCenter) Register(obs Observer) {

    ec.mutex.Lock()

    defer ec.mutex.Unlock()

    ec.observers = append(ec.observers, obs)

}

func (ec *EventCenter) Unregister(obs Observer) {

    ec.mutex.Lock()

    defer ec.mutex.Unlock()

    for i, o := range ec.observers {

        if o == obs {

            ec.observers = append(ec.observers[:i], ec.observers[i+1:]...)

            break

        }

    }

}

func (ec *EventCenter) Notify(data interface{}) {

    ec.mutex.RLock()

    defer ec.mutex.RUnlock()

    for _, obs := range ec.observers {

        go obs.Update(data)

    }

}

type EmailService struct{}

func (e *EmailService) Update(data interface{}) {

    fmt.Printf("发送邮件: %v\n", data)

}

type LogService struct{}

func (l *LogService) Update(data interface{}) {

    fmt.Printf("记录日志: %v\n", data)

}

eventCenter := &EventCenter{observers: make([]Observer, 0)}

emailSvc := &EmailService{}

logSvc := &LogService{}

eventCenter.Register(emailSvc)

eventCenter.Register(logSvc)

eventCenter.Notify("用户已注册")