package org.apache.helix.store.zk;
   
   /*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  
  import org.apache.zookeeper.data.Stat;
  
  public class ZNode
  {
    // used for a newly created item, because zkclient.create() doesn't return stat
    // or used for places where we don't care about stat
    public static final Stat ZERO_STAT = new Stat();
    
    final String _zkPath;
    private Stat _stat;
    Object _data;
    Set<String> _childSet;
  
    public ZNode(String zkPath, Object data, Stat stat)
    {
      _zkPath = zkPath;
      _childSet = Collections.<String>emptySet(); // new HashSet<String>();
      _data = data;
      _stat = stat;
    }
  
    public void removeChild(String child)
    {
      if (_childSet != Collections.<String>emptySet())
      {
        _childSet.remove(child);
      }
    }
    
    public void addChild(String child)
    {
      if (_childSet == Collections.<String>emptySet())
      {
        _childSet = new HashSet<String>();
      }
      
      _childSet.add(child);
    }
    
    public void addChildren(List<String> children)
    {
      if (children != null && !children.isEmpty())
      {
        if (_childSet == Collections.<String>emptySet())
        {
          _childSet = new HashSet<String>();
        }
  
        _childSet.addAll(children);
      }
    }
  
    public boolean hasChild(String child)
    {
      return _childSet.contains(child);
    }
  
    public Set<String> getChildSet()
    {
      return _childSet;
    }
    
    public void setData(Object data)
    {
  //    System.out.println("setData: " + _zkPath + ", data: " + data);
      _data= data;    
    }
    
    public Object getData()
    {
      return _data;
    }
    
   public void setStat(Stat stat)
   {
     _stat = stat;
   }
   
   public Stat getStat()
   {
     return _stat;
   }
   
   public void setChildSet(List<String> childNames)
   {
     if (childNames != null && !childNames.isEmpty())
     {
       if (_childSet == Collections.<String>emptySet())
       {
         _childSet = new HashSet<String>();
       }
 
       _childSet.clear();
       _childSet.addAll(childNames);
     }
   }
   
   @Override
   public String toString()
   {
     return _zkPath + ", " + _data + ", " + _childSet + ", " + _stat;
   }
 }