ResourceDownloaderRetryImpl.java

/*
 * Created on 25-Apr-2004
 * Created by Paul Gardner
 * Copyright (C) 2004, 2005, 2006 Aelitis, All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 * 
 * AELITIS, SAS au capital de 46,603.30 euros
 * 8 Allee Lenotre, La Grille Royale, 78600 Le Mesnil le Roi, France.
 *
 */

package org.gudy.azureus2.pluginsimpl.local.utils.resourcedownloader;

/**
 * @author parg
 *
 */

import java.io.*;

import org.gudy.azureus2.core3.util.*;
import org.gudy.azureus2.plugins.utils.resourcedownloader.*;

public class 
ResourceDownloaderRetryImpl 	
	extends 	ResourceDownloaderBaseImpl
	implements	ResourceDownloaderListener
{
	protected ResourceDownloaderBaseImpl		delegate;
	protected int								retry_count;
	
	protected boolean					cancelled;
	protected ResourceDownloader		current_downloader;
	protected int						done_count;
	protected Object					result;
	protected AESemaphore				done_sem	= new AESemaphore("RDRretry");
		
	protected long						size	= -2;
	
	public
	ResourceDownloaderRetryImpl(
		ResourceDownloaderBaseImpl	_parent,
		ResourceDownloader		_delegate,
		int						_retry_count )
	{
		super( _parent );
		
		delegate		= (ResourceDownloaderBaseImpl)_delegate;
		
		delegate.setParent( this );

		retry_count		= _retry_count;
	}
	
	public String
	getName()
	{
		return( delegate.getName() + ", retry=" + retry_count );
	}
	
	public long
	getSize()
	
		throws ResourceDownloaderException
	{	
		if ( size != -2 ){
			
			return( size );
		}
		
		try{
			for (int i=0;i<retry_count;i++){
				
				try{
					ResourceDownloaderBaseImpl c =  delegate.getClone( this );
					
					addReportListener( c );
					
					size = c.getSize();
				
					setProperties( c );
					
					return( size );
					
				}catch( ResourceDownloaderException e ){
					
					if ( i == retry_count - 1 ){
						
						throw( e );
					}
				}
			}
		}finally{
			
			if ( size == -2 ){
				
				size = -1;
			}
			
			setSize( size );
		}

		return( size );
	}
	
	protected void
	setSize(
		long	l )
	{
		size	= l;
		
		if ( size >= 0 ){
			
			delegate.setSize( size );
		}
	}
	
	protected void
	setProperty(
		String	name,
		Object	value )
	{
		setPropertySupport( name, value );
		
		delegate.setProperty( name, value );
	}
	
	public ResourceDownloaderBaseImpl
	getClone(
		ResourceDownloaderBaseImpl parent )
	{
		ResourceDownloaderRetryImpl c =  new ResourceDownloaderRetryImpl( parent, delegate.getClone( this ), retry_count );
		
		c.setSize(size);
		
		c.setProperties( this );

		return( c );
	}
	
	public InputStream
	download()
	
		throws ResourceDownloaderException
	{
		asyncDownload();
		
		done_sem.reserve();
		
		if ( result instanceof InputStream ){
			
			return((InputStream)result);
		}
		
		throw((ResourceDownloaderException)result);
	}
	
	public void
	asyncDownload()
	{
		try{
			this_mon.enter();
			
			if ( done_count == retry_count || cancelled ){
				
				done_sem.release();
				
				informFailed((ResourceDownloaderException)result);
				
			}else{
			
				done_count++;
				
				if ( done_count > 1 ){
					
					informActivity( getLogIndent() + "  attempt " + done_count + " of " + retry_count );
				}
				
				current_downloader = delegate.getClone( this );
				
				current_downloader.addListener( this );
				
				current_downloader.asyncDownload();
			}
		}finally{
			
			this_mon.exit();
		}
	}
	
	public void
	cancel()
	{
		setCancelled();
		
		try{
			this_mon.enter();
		
			result	= new ResourceDownloaderException( "Download cancelled");
			
			cancelled	= true;
			
			informFailed((ResourceDownloaderException)result );
			
			done_sem.release();
			
			if ( current_downloader != null ){
				
				current_downloader.cancel();
			}
		}finally{
			
			this_mon.exit();
		}
	}	
	
	public boolean
	completed(
		ResourceDownloader	downloader,
		InputStream			data )
	{
		if ( informComplete( data )){
			
			result	= data;
			
			done_sem.release();
			
			return( true );
		}
		
		return( false );
	}
	
	public void
	failed(
		ResourceDownloader			downloader,
		ResourceDownloaderException e )
	{
		result		= e;
		
		asyncDownload();
	}
}