Golang zk.Conn类代码示例

func getActions(wr *wrangler.Wrangler, zconn zk.Conn, actionPath string) ([]*actionnode.ActionNode, error) {
	actions, _, err := zconn.Children(actionPath)
	if err != nil {
		return nil, fmt.Errorf("getActions failed: %v %v", actionPath, err)
	}
	sort.Strings(actions)
	wg := sync.WaitGroup{}
	mu := sync.Mutex{}
	nodes := make([]*actionnode.ActionNode, 0, len(actions))
	for _, action := range actions {
		wg.Add(1)
		go func(action string) {
			defer wg.Done()
			actionNodePath := path.Join(actionPath, action)
			data, _, err := zconn.Get(actionNodePath)
			if err != nil && !zookeeper.IsError(err, zookeeper.ZNONODE) {
				wr.Logger().Warningf("getActions: %v %v", actionNodePath, err)
				return
			}
			actionNode, err := actionnode.ActionNodeFromJson(data, actionNodePath)
			if err != nil {
				wr.Logger().Warningf("getActions: %v %v", actionNodePath, err)
				return
			}
			mu.Lock()
			nodes = append(nodes, actionNode)
			mu.Unlock()
		}(action)
	}
	wg.Wait()

	return nodes, nil
}

// return a few values that need to be refreshed
func (zkc *ZkCache) refreshSomeValues(zconn zk.Conn, maxToRefresh int) {
	// build a list of a few values we want to refresh
	refreshThreshold := time.Now().Add(-10 * time.Minute)

	// range will randomize the traversal order, so we will not always try
	// the same entries in the same order
	dataEntries := make([]*zkCacheEntry, 0, maxToRefresh)
	childrenEntries := make([]*zkCacheEntry, 0, maxToRefresh)
	zkc.mutex.Lock()
	for _, entry := range zkc.Cache {
		shouldBeDataRefreshed, shouldBeChildrenRefreshed := entry.checkForRefresh(refreshThreshold)
		if shouldBeDataRefreshed {
			dataEntries = append(dataEntries, entry)
		}
		if shouldBeChildrenRefreshed {
			childrenEntries = append(childrenEntries, entry)
		}

		// check if we have enough work to do
		if len(dataEntries) == maxToRefresh || len(childrenEntries) == maxToRefresh {
			break
		}
	}
	zkc.mutex.Unlock()

	// now refresh the values
	for _, entry := range dataEntries {
		data, stat, watch, err := zconn.GetW(entry.node.Path)
		if err == nil {
			zkStat := &zk.ZkStat{}
			zkStat.FromZookeeperStat(stat)
			entry.updateData(data, zkStat, watch)
		} else if zookeeper.IsError(err, zookeeper.ZCLOSING) {
			// connection is closing, no point in asking for more
			relog.Warning("failed to refresh cache: %v (and stopping refresh)", err.Error())
			return
		} else {
			// individual failure
			relog.Warning("failed to refresh cache: %v", err.Error())
		}
	}

	for _, entry := range childrenEntries {
		children, stat, watch, err := zconn.ChildrenW(entry.node.Path)
		if err == nil {
			zkStat := &zk.ZkStat{}
			zkStat.FromZookeeperStat(stat)
			entry.updateChildren(children, zkStat, watch)
		} else if zookeeper.IsError(err, zookeeper.ZCLOSING) {
			// connection is closing, no point in asking for more
			relog.Warning("failed to refresh cache: %v (and stopping refresh)", err.Error())
			return
		} else {
			// individual failure
			relog.Warning("failed to refresh cache: %v", err.Error())
		}
	}
}

func ReadAddrs(zconn zk.Conn, zkPath string) (*ZknsAddrs, error) {
	data, stat, err := zconn.Get(zkPath)
	if err != nil {
		return nil, err
	}
	addrs := new(ZknsAddrs)
	err = json.Unmarshal([]byte(data), addrs)
	if err != nil {
		return nil, err
	}
	addrs.version = stat.Version()
	return addrs, nil
}

// ReadAddrs returns a ZknsAddrs record from the given path in Zookeeper.
func ReadAddrs(zconn zk.Conn, zkPath string) (*ZknsAddrs, error) {
	data, stat, err := zconn.Get(zkPath)
	if err != nil {
		return nil, err
	}
	// There are nodes that will have no data - for instance a subdomain node.
	if len(data) == 0 {
		return nil, nil
	}
	addrs := new(ZknsAddrs)
	err = json.Unmarshal([]byte(data), addrs)
	if err != nil {
		return nil, err
	}
	addrs.version = stat.Version()
	return addrs, nil
}

func (wr *Wrangler) exportVtnsToZkns(ctx context.Context, zconn zk.Conn, vtnsAddrPath, zknsAddrPath string) ([]string, error) {
	zknsPaths := make([]string, 0, 32)
	parts := strings.Split(vtnsAddrPath, "/")
	if len(parts) != 8 && len(parts) != 9 {
		return nil, fmt.Errorf("Invalid leaf zk path: %v", vtnsAddrPath)
	}
	cell := parts[2]
	keyspace := parts[5]
	shard := parts[6]
	tabletType := topo.TabletType(parts[7])
	if tabletType == "action" || tabletType == "actionlog" {
		return nil, nil
	}
	addrs, _, err := wr.ts.GetEndPoints(ctx, cell, keyspace, shard, tabletType)
	if err != nil {
		return nil, err
	}

	// Write the individual endpoints and compute the SRV entries.
	vtoccAddrs := LegacyZknsAddrs{make([]string, 0, 8)}
	defaultAddrs := LegacyZknsAddrs{make([]string, 0, 8)}
	for i, entry := range addrs.Entries {
		zknsAddrPath := fmt.Sprintf("%v/%v", zknsAddrPath, i)
		zknsPaths = append(zknsPaths, zknsAddrPath)
		zknsAddr := zkns.ZknsAddr{
			Host:    entry.Host,
			PortMap: entry.PortMap,
		}
		err := writeAddr(zconn, zknsAddrPath, &zknsAddr)
		if err != nil {
			return nil, err
		}
		defaultAddrs.Endpoints = append(defaultAddrs.Endpoints, zknsAddrPath)
		vtoccAddrs.Endpoints = append(vtoccAddrs.Endpoints, zknsAddrPath+":vt")
	}

	// Prune any zkns entries that are no longer referenced by the
	// shard graph.
	deleteIdx := len(addrs.Entries)
	for {
		zknsStaleAddrPath := fmt.Sprintf("%v/%v", zknsAddrPath, deleteIdx)
		// A "delete" is a write of sorts - just communicate up that nothing
		// needs to be done to this node.
		zknsPaths = append(zknsPaths, zknsStaleAddrPath)
		err := zconn.Delete(zknsStaleAddrPath, -1)
		if zookeeper.IsError(err, zookeeper.ZNONODE) {
			break
		}
		if err != nil {
			return nil, err
		}
		deleteIdx++
	}

	// Write the VDNS entries for both vtocc and mysql
	vtoccVdnsPath := fmt.Sprintf("%v/vt.vdns", zknsAddrPath)
	zknsPaths = append(zknsPaths, vtoccVdnsPath)
	if err = writeAddrs(zconn, vtoccVdnsPath, &vtoccAddrs); err != nil {
		return nil, err
	}

	defaultVdnsPath := fmt.Sprintf("%v.vdns", zknsAddrPath)
	zknsPaths = append(zknsPaths, defaultVdnsPath)
	if err = writeAddrs(zconn, defaultVdnsPath, &defaultAddrs); err != nil {
		return nil, err
	}
	return zknsPaths, nil
}