zkDesign

注册一个监视器，根据returnCode(rc)注册监视器，getWatches，由其实现者实现

返回对响应事件(event)的监视器集合

Code[Enum]

Code(int)+ intValue():int+ static getCode(int):Code

WatchedEvent[Class]

- keeperState:KeeperState- eventType:EventType- path:String

ClientWatchManager[Interface]

KeeperState[Enum]

+ Disconnected (0)+ SyncConnected (3)+ AuthFailed (4)+ ConnectedReadOnly (5)+ SaslAuthenticated(6)+ Expired (-112)

- KeeperState(int)

StaticHostProvider

- serverAddresses:List- lastIndex:int-currentIndex:int

+StaticHostProvider(List )+ size():Int+ next():InetSocketAddress+ onConnected():void

ClientCnxn

- SET_WATCHES_MAX_LENGTH- disableAutoWatchReset

ReplyHeader

- xid:int- zxid:int- err:int

...

HostProvider

+ size():int+ next(long):InetSocketAddress+ onConnected():void

用于管理客户端的Socket I/O

获取可供连接的zookeeper服务

Status[Enum]

+ isAlive():boolean+ isConnected():boolean

ChildWatchRegistration

+ override getWatches(int):void

Packet

requestHeader :RequestHeaderreplyHeader:ReplyHeaderrequest:Recordresponse:Recordbb:ByteBufferclientPath:StringserverPath:Stringfinished:booleancb:AsyncCallbackctx:ObjectwatchRegistration:WatchRegistration

+ operation1(params):returnType- operation2(params)- operation3()

Watcher[Interface]

+ process(WatchedEvent)

当 type为None时，返回并清空所维护的监视器(Watch);NodeCreated时，返回并移除dataWatches existWatches该路径下的监视器(Watch);NodeChildrenChanged时，返回并移除childWatches该路径下的监视器(Watch);NodeDeleted时，返回并移除dataWatches，childWatches该路径下的监视器(Watch)，只删除existWatches，不返回；

DataWatchRegistration

Event[Interface]

RequestHeader

- xid:int- type:int

ExistsWatchRegistration

+ override getWatches(int):void+ override shouldAddWatch(int):boolean

WatchRegistration[Class]

- watcher:Watcher- clientPath:String

EventType[Enum]

+ None (-1)+ NodeCreated (1)+ NodeDeleted (2)+ NodeDataChanged (3)+ NodeChildrenChanged (4)

- EventType(int)

Zookeeper

- watchManager:ZKWatchManager- cnxn:ClientCnxn

ZKWatchManager[Class]