这是基于消息总线的发布-订阅模式吗？

Question

根据此 answer、

A Message Bus is a messaging infrastructure to allow different systems to communicate through a shared set of interfaces(message bus).

下面是由 main() 启动的 createHub() 函数和 Run() 方法，用于创建消息中心以与多个订阅者通信：

type PubHub struct {
    subscribers map[*subscriptionmediator.HandlerSubscription]struct{}
    Register    chan *subscriptionmediator.HandlerSubscription
    Unregister  chan *subscriptionmediator.HandlerSubscription
    Broadcast   chan *events.Env
}


func createHub() *PubHub {

    return &PubHub{
        subscribers: map[*subscriptionmediator.HandlerSubscription]struct{}{},
        Register:    make(chan *subscriptionmediator.HandlerSubscription),
        Unregister:  make(chan *subscriptionmediator.HandlerSubscription),
        Broadcast:   make(chan *events.Envelope),
    }
}

func (h *PubHub) Run() {

    for {
        select {
        case subscriber := <-h.Register:
            h.subscribers[subscriber] = struct{}{}

        case subscriber := <-h.Unregister:
            if _, ok := h.subscribers[subscriber]; ok {
                delete(h.subscribers, subscriber)
            }
        case message := <-h.Broadcast:
            for subscriber := range h.subscribers {
                subscriber.DataChannel <- message
            }
        }
    }
}

每个订阅者注册的地方，如下图：

    subscription := &subscriptionmediator.HandlerSubscription{
        conn,
        make(chan *events.Envelope),
    }
    hub.Register <- subscription

DataChannel用于发布者&多个订阅者之间的通信

type HandlerSubscription struct {
    ConnInstance *websocket.Conn
    DataChannel  chan *events.Envelope
}

1) 上面的代码是否可以视为遵循基于消息总线的发布-订阅模式？

2) 如何避免一个订阅者阻止所有订阅者在频道上发送信号？ subscriber.DataChannel <- message

Answer 1

Can the above code be considered following message bus based pub-sub pattern?

是的。

这是基于消息总线的发布-订阅模式吗？

Is this a message bus based pub-sub pattern?

design-patterns

go

publish-subscribe