package org.apache.helix.manager.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.concurrent.atomic.AtomicBoolean;
  
  import org.apache.log4j.Logger;
  import org.apache.zookeeper.AsyncCallback.DataCallback;
  import org.apache.zookeeper.AsyncCallback.StatCallback;
  import org.apache.zookeeper.AsyncCallback.StringCallback;
  import org.apache.zookeeper.AsyncCallback.VoidCallback;
  import org.apache.zookeeper.KeeperException.Code;
  import org.apache.zookeeper.data.Stat;
  
  public class ZkAsyncCallbacks
  {
    private static Logger LOG = Logger.getLogger(ZkAsyncCallbacks.class);
  
    static class GetDataCallbackHandler extends DefaultCallback implements DataCallback
    {
      byte[] _data;
      Stat   _stat;
  
      @Override
      public void handle()
      {
        // TODO Auto-generated method stub
      }
  
      @Override
      public void processResult(int rc, String path, Object ctx, byte[] data, Stat stat)
      {
        if (rc == 0)
        {
          _data = data;
          _stat = stat;
        }
        callback(rc, path, ctx);
      }
    }
  
    static class SetDataCallbackHandler extends DefaultCallback implements StatCallback
    {
      Stat _stat;
  
      @Override
      public void handle()
      {
        // TODO Auto-generated method stub
      }
  
      @Override
      public void processResult(int rc, String path, Object ctx, Stat stat)
      {
        if (rc == 0)
        {
          _stat = stat;
        }
        callback(rc, path, ctx);
      }
      
      public Stat getStat()
      {
        return _stat;
      }
    }
    
    static class ExistsCallbackHandler extends DefaultCallback implements StatCallback
    {
      Stat _stat;
  
      @Override
      public void handle()
      {
        // TODO Auto-generated method stub
      }
  
      @Override
      public void processResult(int rc, String path, Object ctx, Stat stat)
      {
        if (rc == 0)
        {
         _stat = stat;
       }
       callback(rc, path, ctx);
     }
 
   }
 
   static class CreateCallbackHandler extends DefaultCallback implements StringCallback
   {
     @Override
     public void processResult(int rc, String path, Object ctx, String name)
     {
       callback(rc, path, ctx);
     }
 
     @Override
     public void handle()
     {
       // TODO Auto-generated method stub
     }
   }
 
   static class DeleteCallbackHandler extends DefaultCallback implements VoidCallback
   {
     @Override
     public void processResult(int rc, String path, Object ctx)
     {
       callback(rc, path, ctx);
     }
 
     @Override
     public void handle()
     {
       // TODO Auto-generated method stub
     }
 
   }
 
   /**
    * Default callback for zookeeper async api
    */
   static abstract class DefaultCallback
   {
     AtomicBoolean _lock = new AtomicBoolean(false);
     int           _rc   = -1;
 
     public void callback(int rc, String path, Object ctx)
     {
       if (rc != 0)
       {
         LOG.warn(this + ", rc:" + Code.get(rc) + ", path: " + path);
       }
       _rc = rc;
       handle();
       
       synchronized (_lock)
       {
         _lock.set(true);
         _lock.notify();
       }
     }
 
     public boolean waitForSuccess()
     {
       try
       {
         synchronized (_lock)
         {
           while (!_lock.get())
           {
             _lock.wait();
           }
         }
       }
       catch (InterruptedException e)
       {
         // TODO Auto-generated catch block
         e.printStackTrace();
       }
       return true;
     }
 
     public int getRc()
     {
       return _rc;
     }
 
     abstract public void handle();
   }
 
 }