Beispiel #1
0
func (this *Mirror) makeMirror(c1, c2 *zk.ZkCluster) {
	pub, err := this.makePub(c2)
	swallow(err)

	topics, topicsChanges, err := c1.WatchTopics()
	swallow(err)

	log.Printf("topics: %+v", topics)
	if len(topics) == 0 {
		log.Println("empty topics")
		return
	}

	group := fmt.Sprintf("%s.%s._mirror_", c1.Name(), c2.Name())
	sub, err := this.makeSub(c1, group, topics)
	swallow(err)

	pumpStopper := make(chan struct{})
	go this.pump(sub, pub, pumpStopper)

LOOP:
	for {
		select {
		case <-topicsChanges:
			log.Println("topics changed, stopping pump...")
			pumpStopper <- struct{}{} // stop pump
			<-pumpStopper             // await pump cleanup

			// refresh c1 topics
			topics, err = c1.Topics()
			if err != nil {
				// TODO how to handle this err?
				log.Println(err)
			}

			log.Printf("topics: %+v", topics)

			sub, err = this.makeSub(c1, group, topics)
			if err != nil {
				// TODO how to handle this err?
				log.Println(err)
			}

			go this.pump(sub, pub, pumpStopper)

		case <-this.quit:
			log.Println("awaiting pump cleanup...")
			<-pumpStopper
			log.Printf("total transferred: %s %smsgs",
				gofmt.ByteSize(this.transferBytes),
				gofmt.Comma(this.transferN))
			break LOOP
		}
	}

	pub.Close()
}