Java Code Examples for org.apache.zookeeper.data.Stat#getNumChildren()

private void        processNode(String path, NodeEntry parent) throws Exception
{
    Stat        stat = exhibitor.getLocalConnection().checkExists().forPath(path);
    if ( stat == null )
    {
        return; // probably got deleted
    }

    NodeEntry       entry = new NodeEntry(parent, stat.getNumChildren(), stat.getCtime());
    details.put(path, entry);

    entry.addToDeepCount(stat.getNumChildren());
    if ( stat.getNumChildren() <= maxChildren )
    {
        List<String> children = exhibitor.getLocalConnection().getChildren().forPath(path);
        for ( String child : children )
        {
            String  thisPath = ZKPaths.makePath(path, child);
            processNode(thisPath, entry);
        }
    }
}
 

private void doWork()
{
  for ( String path : paths )
  {
    try
    {
      List<String> children = client.getChildren().forPath(path);
      for ( String name : children )
      {
        String thisPath = ZKPaths.makePath(path, name);
        Stat stat = client.checkExists().forPath(thisPath);
        if ( (stat != null) && (stat.getNumChildren() == 0) )
        {
          reaper.addPath(thisPath, mode);
        }
      }
    }
    catch ( Exception e )
    {
      log.error("Could not get children for path: " + path, e);
    }
  }
}
 

private void doWork()
{
  for ( String path : paths )
  {
    try
    {
      List<String> children = client.getChildren().forPath(path);
      for ( String name : children )
      {
        String thisPath = ZKPaths.makePath(path, name);
        Stat stat = client.checkExists().forPath(thisPath);
        if ( (stat != null) && (stat.getNumChildren() == 0) )
        {
          reaper.addPath(thisPath, mode);
        }
      }
    }
    catch ( Exception e )
    {
      log.error("Could not get children for path: " + path, e);
    }
  }
}
 

@Override
public int getNumChildren(final String key) {
    try {
        Stat stat = client.checkExists().forPath(key);
        if (null != stat) {
            return stat.getNumChildren();
        }
    } catch (final Exception ex) {
        RegExceptionHandler.handleException(ex);
    }
    return 0;
}
 

protected int getNumChildren(String path) {
  try {
    Stat s = curator.checkExists().forPath(path);
    if (s != null) {
      return s.getNumChildren();
    }
  } catch (NoNodeException nne) {} catch (Throwable t) {
    throw new RuntimeException(t);
  }

  return 0;
}
 

private boolean refreshRecursively(Node<T> oldRoot, Node<T> newRoot, String path) {
  boolean dataChanged = false;
  Stat newStat = _zkClient.getStat(path);
  Stat oldStat = (oldRoot != null) ? oldRoot.stat : null;
  newRoot.name = path;
  if (newStat != null) {
    if (oldStat == null) {
      newRoot.stat = newStat;
      newRoot.data = _zkClient.<T> readData(path, true);
      dataChanged = true;
    } else if (newStat.equals(oldStat)) {
      newRoot.stat = oldStat;
      newRoot.data = oldRoot.data;
    } else {
      dataChanged = true;
      newRoot.stat = newStat;
      newRoot.data = _zkClient.<T> readData(path, true);
    }
    if (newStat.getNumChildren() > 0) {
      List<String> children = _zkClient.getChildren(path);
      for (String child : children) {
        String newPath = path + "/" + child;
        Node<T> oldChild =
            (oldRoot != null && oldRoot.children != null) ? oldRoot.children.get(child) : null;
        if (newRoot.children == null) {
          newRoot.children = new ConcurrentHashMap<>();
        }
        if (!newRoot.children.contains(child)) {
          newRoot.children.put(child, new Node<T>());
        }
        Node<T> newChild = newRoot.children.get(child);
        boolean childChanged = refreshRecursively(oldChild, newChild, newPath);
        dataChanged = dataChanged || childChanged;
      }
    }
  } else {
    logger.info(path + " does not exist");
  }
  return dataChanged;
}
 

@Override
public boolean isOwner(ScheduleTask scheduleTask) throws Exception {
  Stat tempStat = null;
  //查看集群中是否注册当前任务，如果没有就自动注册
  String zkPath = this.pathTask + "/" + scheduleTask.getName();
  if (this.zkManager.isAutoRegisterTask()) {
    tempStat = this.getZooKeeper().exists(zkPath, false);
    if (tempStat == null) {
      this.getZooKeeper().create(zkPath, null, this.zkManager.getAcl(), CreateMode.PERSISTENT);
      tempStat = this.getZooKeeper().exists(zkPath, false);
      if (LOG.isDebugEnabled()) {
        LOG.debug(scheduleTask.getUuid() + ":自动向集群注册任务[" + scheduleTask.getName() + "]");
      }
    }
  }

  //@wjw_note: 当task下的子节点为空时,进行等待,防止错过执行!
  if (tempStat.getNumChildren() == 0) {
    int sleepCount = 0;
    Thread.sleep(1000);
    tempStat = this.zkManager.getZooKeeper().exists(zkPath, false);
    while (tempStat.getNumChildren() == 0 && sleepCount < 100) {
      sleepCount++;
      Thread.sleep(1000);
      tempStat = this.zkManager.getZooKeeper().exists(zkPath, false);
    }
  }

  //判断是否分配给当前节点
  zkPath = zkPath + "/" + scheduleTask.getUuid();
  if (this.getZooKeeper().exists(zkPath, false) != null) {
    //@wjw_note: 写一些数据
    this.refreshScheduleTask(scheduleTask);

    return true;
  }
  return false;
}
 

@Override
public int getNumChildren(final String key) {
    try {
        Stat stat = client.checkExists().forPath(key);
        if (null != stat) {
            return stat.getNumChildren();
        }
        //CHECKSTYLE:OFF
    } catch (final Exception ex) {
        //CHECKSTYLE:ON
        RegExceptionHandler.handleException(ex);
    }
    return 0;
}
 

public int countChildren(String path) {
    try {
        Stat stat = new Stat();
        this.readData(path, stat);
        return stat.getNumChildren();
        //return getChildren(path).size();
    } catch (ZkNoNodeException e) {
        return -1;
    }
}
 

@Override
public int getNumChildren(final String key) {
    try {
        Stat stat = client.getZookeeperClient().getZooKeeper().exists(getNameSpace() + key, false);
        if (null != stat) {
            return stat.getNumChildren();
        }
        //CHECKSTYLE:OFF
    } catch (final Exception ex) {
        //CHECKSTYLE:ON
        throw new EagleFrameException(ex);
    }
    return 0;
}
 

@Override
public int getNumChildren(final String key) {
    try {
        Stat stat = client.checkExists().forPath(key);
        if (null != stat) {
            return stat.getNumChildren();
        }
        //CHECKSTYLE:OFF
    } catch (final Exception ex) {
        //CHECKSTYLE:ON
        RegExceptionHandler.handleException(ex);
    }
    return 0;
}
 

private void register(String stringType, String value) {

		
		try {
			
			//can not switch the order of sysStat and appStat.because of the zk sequential consistency
			Stat sysStat = client.checkExists().creatingParentContainersIfNeeded().forPath(getSystemTypePath(stringType));
			Stat appStringStat = client.checkExists().forPath(getAppBaseItemPath(stringType, value));
			if(appStringStat != null) {
				return;
			}
			
			if(sysStat == null) {
				createNodeIfNotExists(getSystemTypePath(stringType));
			}
			createNodeIfNotExists(getAppTypePath(stringType));
			
			int numChildren = 0;
			if(sysStat != null) {
				numChildren = sysStat.getNumChildren();
			}
			client.inTransaction()
			.create().forPath(getSystemBaseItemPath(stringType, numChildren + 1),value.getBytes()).and()
			.create().forPath(getAppBaseItemPath(stringType, value),ByteBuffer.allocate(4).putInt(numChildren + 1).array()).and()
			.commit();
			
		} catch (Exception e) {
			LOG.warn("register string in zk failed", e);
		}
	
	}
 

private int getNumChildren(CuratorFramework client, final String key) {
	log.info("获取生产者节点个数 path={}", key);
	Stat stat = null;
	try {
		stat = client.checkExists().forPath(key);
	} catch (final Exception ex) {
		log.error("获取目录 key={}的子节点个数出现异常={}", key, ex.getMessage(), ex);
	}
	return stat == null ? 0 : stat.getNumChildren();
}
 

private int getNumChildrenCount(CuratorFramework client, final String key) {
	log.info("获取消费者节点个数 path={}", key);
	Stat stat = null;
	try {
		stat = client.checkExists().forPath(key);
	} catch (final Exception ex) {
		log.error("获取目录 key={}的子节点个数出现异常={}", key, ex.getMessage(), ex);
	}
	return stat == null ? 0 : stat.getNumChildren();

}
 

/**
 * Gets num children.
 *
 * @param key the key
 *
 * @return the num children
 */
@Override
public int getNumChildren(final String key) {
	Stat stat = null;
	try {
		stat = client.checkExists().forPath(key);
	} catch (final Exception ex) {
		RegExceptionHandler.handleException(ex);
	}
	return stat == null ? 0 : stat.getNumChildren();
}
 

private void addPathToReaperIfEmpty(String path) throws Exception
{
    Stat stat = client.checkExists().forPath(path);
    if ( (stat != null) && (stat.getNumChildren() == 0) )
    {
        log.info("Adding " + path);
        reaper.addPath(path, mode);
    }
}
 

private void doWork()
{
    if ( shouldDoWork() )
    {
        if ( (pathIterator == null) || !pathIterator.hasNext() )
        {
            pathIterator = paths.iterator();
        }
        while ( pathIterator.hasNext() )
        {
            String path = pathIterator.next();
            try
            {
                int maxChildren = this.maxChildren.get();
                if ( maxChildren > 0 )
                {
                    Stat stat = client.checkExists().forPath(path);
                    if ( (stat != null) && (stat.getNumChildren() > maxChildren) )
                    {
                        warnMaxChildren(path, stat);
                        continue;
                    }
                }

                List<String> children = client.getChildren().forPath(path);
                log.info(String.format("Found %d children for %s", children.size(), path));
                for ( String name : children )
                {
                    String childPath = ZKPaths.makePath(path, name);
                    addPathToReaperIfEmpty(childPath);
                    for ( String subNode : lockSchema )
                    {
                        addPathToReaperIfEmpty(ZKPaths.makePath(childPath, subNode));
                    }

                }
            }
            catch ( Exception e )
            {
                ThreadUtils.checkInterrupted(e);
                log.error("Could not get children for path: " + path, e);
            }
        }
    }
}
 

/**
 * Inserts data into queue.  If there are no other queue consumers, the offered element
 * will be immediately visible when this method returns.
 */
@Override
public void offer(byte[] data) throws KeeperException, InterruptedException {
  Timer.Context time = stats.time(dir + "_offer");
  try {
    while (true) {
      try {
        if (maxQueueSize > 0) {
          if (offerPermits.get() <= 0 || offerPermits.getAndDecrement() <= 0) {
            // If a max queue size is set, check it before creating a new queue item.
            Stat stat = zookeeper.exists(dir, null, true);
            if (stat == null) {
              // jump to the code below, which tries to create dir if it doesn't exist
              throw new KeeperException.NoNodeException();
            }
            int remainingCapacity = maxQueueSize - stat.getNumChildren();
            if (remainingCapacity <= 0) {
              throw new IllegalStateException("queue is full");
            }

            // Allow this client to push up to 1% of the remaining queue capacity without rechecking.
            offerPermits.set(remainingCapacity / 100);
          }
        }

        // Explicitly set isDirty here so that synchronous same-thread calls behave as expected.
        // This will get set again when the watcher actually fires, but that's ok.
        zookeeper.create(dir + "/" + PREFIX, data, CreateMode.PERSISTENT_SEQUENTIAL, true);
        isDirty = true;
        return;
      } catch (KeeperException.NoNodeException e) {
        try {
          zookeeper.create(dir, new byte[0], CreateMode.PERSISTENT, true);
        } catch (KeeperException.NodeExistsException ne) {
          // someone created it
        }
      }
    }
  } finally {
    time.stop();
  }
}
 

public int size() throws KeeperException, InterruptedException {
  Stat stat = new Stat();
  zookeeper.getData(dir, null, stat, true);
  return stat.getNumChildren();
}