Пример #1
0
// Unsubscribe broadcasts that the current Node is no longer interested in a Topic, preventing it from receiving future event notifications for that Topic.
func (p *Peter) Unsubscribe(t Topic) error {
	key, err := wendy.NodeIDFromBytes([]byte(string(t)))
	if err != nil {
		return err
	}
	msg := p.cluster.NewMessage(MSG_UNSUBSCRIBE, key, []byte{})
	err = p.cluster.Send(msg)
	return err
}
Пример #2
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// Broadcast sends an event notification for a Topic that will be sent to every Node subscribed to that Topic.
func (p *Peter) Broadcast(t Topic, body []byte) error {
	key, err := wendy.NodeIDFromBytes([]byte(string(t)))
	if err != nil {
		return err
	}
	msg := p.cluster.NewMessage(MSG_EVENT, key, body)
	err = p.cluster.Send(msg)
	return err
}
Пример #3
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// OnNodeJoin fulfills the wendy.Application interface, and will be called whenever a Node leaves the Cluster. Peter will detect which topics would use that Node as a parent in the subscription tree, and re-subscribe to those topics to repair the subscription tree.
func (p *Peter) OnNodeJoin(node wendy.Node) {
	topics := p.parents.topics()
	for _, topic := range topics {
		key, err := wendy.NodeIDFromBytes([]byte(string(topic)))
		if err != nil {
			p.err(err.Error())
		}
		target, err := p.cluster.Route(key)
		if err != nil {
			p.err(err.Error())
		}
		if node.ID.Equals(target.ID) {
			err = p.Unsubscribe(topic)
			if err != nil {
				p.err(err.Error())
			}
			err = p.Subscribe(topic)
			if err != nil {
				p.err(err.Error())
			}
		}
	}
}