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()
}