zookeeper curator PathChildrenCache 记录

https://blog.csdn.net/hosaos/article/details/88658676对NodeCache,PathChildrenCache,TreeCache做了比较详尽的分析，但有一点没有说的很直接：对于PathChildrenCache，不同的startMode：

**
     * Method of priming cache on {@link PathChildrenCache#start(StartMode)}
     */
    public enum StartMode
    {
        
        NORMAL,

        
        BUILD_INITIAL_CACHE,

        
        POST_INITIALIZED_EVENT
    }

NORMAL，所有已经存在的childnode ，都会触发eventBUILD_INITIAL_CACHE，block模式初始化cache，只有新的child node变化才会触发实际POST_INITIALIZED_EVENT，在NORMAL的基础上触发INITIALIZED事件，但这个时间的child node的事件并不能保证时间顺序

另外PathChildrenCache本质还是TreeCache，可以从触发事件stack看到如下信息

Daemon Thread [main-EventThread] (Suspended (breakpoint at line 834 in TreeCache))	
	TreeCache.publishEvent(TreeCacheEvent) line: 834	
	TreeCache.publishEvent(TreeCacheEvent$Type, ChildData) line: 827	
	TreeCache.access$700(TreeCache, TreeCacheEvent$Type, ChildData) line: 71	
	TreeCache$TreeNode.processResult(Curatorframework, CuratorEvent) line: 452	
	CuratorframeworkImpl.sendToBackgroundCallback(OperationAndData, CuratorEvent) line: 749	
	CuratorframeworkImpl.processBackgroundOperation(OperationAndData, CuratorEvent) line: 522	
	GetDataBuilderImpl$3.processResult(int, String, Object, byte[], Stat) line: 256	
	ClientCnxn$EventThread.processEvent(Object) line: 561	
	ClientCnxn$EventThread.run() line: 498