Golang Conn.Get方法代碼示例

// Find possible addresses for cluster named name.
func lookup(b *doozer.Conn, name string) (as []string) {
	rev, err := b.Rev()
	if err != nil {
		panic(err)
	}

	path := "/ctl/ns/" + name
	names, err := b.Getdir(path, rev, 0, -1)
	if err == doozer.ErrNoEnt {
		return nil
	} else if err, ok := err.(*doozer.Error); ok && err.Err == doozer.ErrNoEnt {
		return nil
	} else if err != nil {
		panic(err)
	}

	path += "/"
	for _, name := range names {
		body, _, err := b.Get(path+name, &rev)
		if err != nil {
			panic(err)
		}
		as = append(as, string(body))
	}
	return as
}

// watch updates the peer list of servers based on changes to the
// doozer configuration or signals from the OS.
func watch(d *doozer.Conn) {
	peerFile := "/peers"
	var peers []string
	var rev int64

	// Run the initial get.
	data, rev, err := d.Get(peerFile, nil)
	if err != nil {
		log.Println("initial peer list get:", err)
		log.Println("using empty set to start")
		peers = []string{}
	} else {
		peers = strings.Split(string(data), " ")
	}

	// Add myself to the list.
	peers = append(peers, "http://"+addr)
	rev, err = d.Set(peerFile, rev,
		[]byte(strings.Join(peers, " ")))
	if err != nil {
		log.Println("unable to add myself to the peer list (no longer watching).")
		return
	}
	pool.Set(peers...)
	log.Println("added myself to the peer list.")

	// Setup signal handling to deal with ^C and others.
	sigs := make(chan os.Signal, 1)
	signal.Notify(sigs, os.Interrupt, os.Kill)

	// Get the channel that's listening for changes.
	updates := wait(d, peerFile, &rev)

	for {
		select {
		case <-sigs:
			// Remove ourselves from the peer list and exit.
			for i, peer := range peers {
				if peer == "http://"+addr {
					peers = append(peers[:i], peers[i+1:]...)
					d.Set(peerFile, rev, []byte(strings.Join(peers, " ")))
					log.Println("removed myself from peer list before exiting.")
				}
			}
			os.Exit(1)

		case update, ok := <-updates:
			// If the channel was closed, we should stop selecting on it.
			if !ok {
				updates = nil
				continue
			}

			// Otherwise, update the peer list.
			peers = update
			log.Println("got new peer list:", strings.Join(peers, " "))
			pool.Set(peers...)
		}
	}
}