package org.apache.commons.jcs.auxiliary.lateral.socket.tcp;
   
   /*
    * 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.io.IOException;
  import java.io.ObjectInputStream;
  import java.io.ObjectOutputStream;
  import java.net.InetSocketAddress;
  import java.net.Socket;
  
  import org.apache.commons.jcs.auxiliary.lateral.LateralElementDescriptor;
  import org.apache.commons.jcs.auxiliary.lateral.socket.tcp.behavior.ITCPLateralCacheAttributes;
  import org.apache.commons.jcs.io.ObjectInputStreamClassLoaderAware;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  /**
   * This class is based on the log4j SocketAppender class. I'm using a different repair structure, so
   * it is significantly different.
   */
  public class LateralTCPSender
  {
      /** The logger */
      private static final Log log = LogFactory.getLog( LateralTCPSender.class );
  
      /** Config */
      private int socketOpenTimeOut;
      private int socketSoTimeOut;
  
      /** The stream from the server connection. */
      private ObjectOutputStream oos;
  
      /** The socket connection with the server. */
      private Socket socket;
  
      /** how many messages sent */
      private int sendCnt = 0;
  
      /** Use to synchronize multiple threads that may be trying to get. */
      private final Object getLock = new int[0];
  
      /**
       * Constructor for the LateralTCPSender object.
       * <p>
       * @param lca
       * @throws IOException
       */
      public LateralTCPSender( ITCPLateralCacheAttributes lca )
          throws IOException
      {
          this.socketOpenTimeOut = lca.getOpenTimeOut();
          this.socketSoTimeOut = lca.getSocketTimeOut();
  
          String p1 = lca.getTcpServer();
          if ( p1 == null )
          {
              throw new IOException( "Invalid server (null)" );
          }
  
          String h2 = p1.substring( 0, p1.indexOf( ":" ) );
          int po = Integer.parseInt( p1.substring( p1.indexOf( ":" ) + 1 ) );
          if ( log.isDebugEnabled() )
          {
              log.debug( "h2 = " + h2 );
              log.debug( "po = " + po );
          }
  
          if ( h2.length() == 0 )
          {
              throw new IOException( "Cannot connect to invalid address [" + h2 + ":" + po + "]" );
          }
  
          init( h2, po );
      }
  
      /**
       * Creates a connection to a TCP server.
       * <p>
       * @param host
       * @param port
       * @throws IOException
       */
     protected void init( String host, int port )
         throws IOException
     {
         try
         {
             if ( log.isInfoEnabled() )
             {
                 log.info( "Attempting connection to [" + host + "]" );
             }
 
             // have time out socket open do this for us
             try
             {
                 socket = new Socket();
                 socket.connect( new InetSocketAddress( host, port ), this.socketOpenTimeOut );
             }
             catch ( IOException ioe )
             {
                 if (socket != null)
                 {
                     socket.close();
                 }
 
                 throw new IOException( "Cannot connect to " + host + ":" + port, ioe );
             }
 
             socket.setSoTimeout( socketSoTimeOut );
             synchronized ( this )
             {
                 oos = new ObjectOutputStream( socket.getOutputStream() );
             }
         }
         catch ( java.net.ConnectException e )
         {
             log.debug( "Remote host [" + host + "] refused connection." );
             throw e;
         }
         catch ( IOException e )
         {
             log.debug( "Could not connect to [" + host + "]. Exception is " + e );
             throw e;
         }
     }
 
     /**
      * Sends commands to the lateral cache listener.
      * <p>
      * @param led
      * @throws IOException
      */
     public <K, V> void send( LateralElementDescriptor<K, V> led )
         throws IOException
     {
         sendCnt++;
         if ( log.isInfoEnabled() && sendCnt % 100 == 0 )
         {
             log.info( "Send Count (port " + socket.getPort() + ") = " + sendCnt );
         }
 
         if ( log.isDebugEnabled() )
         {
             log.debug( "sending LateralElementDescriptor" );
         }
 
         if ( led == null )
         {
             return;
         }
 
         if ( oos == null )
         {
             throw new IOException( "No remote connection is available for LateralTCPSender." );
         }
 
         synchronized ( this.getLock )
         {
             oos.writeUnshared( led );
             oos.flush();
         }
     }
 
     /**
      * Sends commands to the lateral cache listener and gets a response. I'm afraid that we could
      * get into a pretty bad blocking situation here. This needs work. I just wanted to get some
      * form of get working. However, get is not recommended for performance reasons. If you have 10
      * laterals, then you have to make 10 failed gets to find out none of the caches have the item.
      * <p>
      * @param led
      * @return ICacheElement
      * @throws IOException
      */
     public <K, V> Object sendAndReceive( LateralElementDescriptor<K, V> led )
         throws IOException
     {
         if ( led == null )
         {
             return null;
         }
 
         if ( oos == null )
         {
             throw new IOException( "No remote connection is available for LateralTCPSender." );
         }
 
         Object response = null;
 
         // Synchronized to insure that the get requests to server from this
         // sender and the responses are processed in order, else you could
         // return the wrong item from the cache.
         // This is a big block of code. May need to re-think this strategy.
         // This may not be necessary.
         // Normal puts, etc to laterals do not have to be synchronized.
         synchronized ( this.getLock )
         {
             try
             {
                 // clean up input stream, nothing should be there yet.
                 if ( socket.getInputStream().available() > 0 )
                 {
                     socket.getInputStream().read( new byte[socket.getInputStream().available()] );
                 }
             }
             catch ( IOException ioe )
             {
                 log.error( "Problem cleaning socket before send " + socket, ioe );
                 throw ioe;
             }
 
             // write object to listener
             oos.writeUnshared( led );
             oos.flush();
             ObjectInputStream ois = null;
 
             try
             {
                 socket.setSoTimeout( socketSoTimeOut );
                 ois = new ObjectInputStreamClassLoaderAware( socket.getInputStream(), null );
                 response = ois.readObject();
             }
             catch ( IOException ioe )
             {
                 String message = "Could not open ObjectInputStream to " + socket +
                     " SoTimeout [" + socket.getSoTimeout() +
                     "] Connected [" + socket.isConnected() + "]";
                 log.error( message, ioe );
                 throw ioe;
             }
             catch ( Exception e )
             {
                 log.error( e );
             }
             finally
             {
                 if (ois != null)
                 {
                     ois.close();
                 }
             }
         }
 
         return response;
     }
 
     /**
      * Closes connection used by all LateralTCPSenders for this lateral connection. Dispose request
      * should come into the facade and be sent to all lateral cache services. The lateral cache
      * service will then call this method.
      * <p>
      * @throws IOException
      */
     public void dispose()
         throws IOException
     {
         if ( log.isInfoEnabled() )
         {
             log.info( "Dispose called" );
         }
         // WILL CLOSE CONNECTION USED BY ALL
         oos.close();
         socket.close();
     }
 }