ddbaseimpl.java

这是一个基于java编写的torrent的P2P源码

/*
 * Created on 18-Feb-2005
 * 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.ddb;

import java.net.InetSocketAddress;
import java.util.*;


import org.gudy.azureus2.core3.util.AEMonitor;
import org.gudy.azureus2.core3.util.Debug;
import org.gudy.azureus2.core3.util.HashWrapper;
import org.gudy.azureus2.core3.util.SHA1Simple;
import org.gudy.azureus2.core3.util.SystemTime;
import org.gudy.azureus2.plugins.PluginInterface;
import org.gudy.azureus2.plugins.ddb.*;


import com.aelitis.azureus.core.AzureusCore;
import com.aelitis.azureus.plugins.dht.DHTPlugin;
import com.aelitis.azureus.plugins.dht.DHTPluginContact;
import com.aelitis.azureus.plugins.dht.DHTPluginKeyStats;
import com.aelitis.azureus.plugins.dht.DHTPluginOperationListener;
import com.aelitis.azureus.plugins.dht.DHTPluginProgressListener;
import com.aelitis.azureus.plugins.dht.DHTPluginTransferHandler;
import com.aelitis.azureus.plugins.dht.DHTPluginValue;

/**
 * @author parg
 *
 */

public class 
DDBaseImpl 
	implements DistributedDatabase
{
	private static DDBaseImpl	singleton;
	
	protected static AEMonitor		class_mon	= new AEMonitor( "DDBaseImpl:class");

	protected static Map			transfer_map = new HashMap();
	
	private static DDBaseTTTorrent	torrent_transfer;
	
	public static DistributedDatabase
	getSingleton(
		AzureusCore	azureus_core )
	{
		try{
			class_mon.enter();
	
			if ( singleton == null ){
				
				singleton = new DDBaseImpl( azureus_core );
			}
		}finally{
			
			class_mon.exit();
		}
		
		return( singleton );
	}
	
	
	private AzureusCore		azureus_core;
	private DHTPlugin		dht_use_accessor;
		
	protected
	DDBaseImpl(
		final AzureusCore	_azureus_core )
	{
		azureus_core	= _azureus_core;
		
		torrent_transfer =  new DDBaseTTTorrent( _azureus_core, this );
		
		grabDHT();
	}
	
	protected DHTPlugin
	grabDHT()
	{
		if ( dht_use_accessor != null ){
			
			return( dht_use_accessor );
		}
		
		try{
			class_mon.enter();
			
			if( dht_use_accessor == null ){
						
			PluginInterface dht_pi = 
					azureus_core.getPluginManager().getPluginInterfaceByClass(
								DHTPlugin.class );
						
				if ( dht_pi != null ){
					
					dht_use_accessor = (DHTPlugin)dht_pi.getPlugin();
					
					if ( dht_use_accessor.isEnabled()){
						
						try{
							addTransferHandler(	torrent_transfer, torrent_transfer );
		
						}catch( Throwable e ){
							
							Debug.printStackTrace(e);
						}
					}
				}
			}
		}finally{
			
			class_mon.exit();
		}
		
		return( dht_use_accessor );
	}
	
	public boolean
	isAvailable()
	{
		DHTPlugin	dht = grabDHT();
		
		if ( dht == null ){
			
			return( false );
		}
		
		return( dht.isEnabled());
	}
	
	public boolean
	isExtendedUseAllowed()
	{
		DHTPlugin	dht = grabDHT();
		
		if ( dht == null ){
			
			return( false );
		}
		
		return( dht.isExtendedUseAllowed());	
	}
	
	protected void
	throwIfNotAvailable()
	
		throws DistributedDatabaseException
	{
		if ( !isAvailable()){
			
			throw( new DistributedDatabaseException( "DHT not available" ));
		}
	}
	
	protected DHTPlugin
	getDHT()
	
		throws DistributedDatabaseException
	{
		throwIfNotAvailable();
		
		return( grabDHT());
	}
	
	protected void
	log(
		String	str )
	{
		DHTPlugin	dht = grabDHT();
		
		if ( dht != null ){
			
			dht.log( str );
		}
	}
	
	public DistributedDatabaseKey
	createKey(
		Object			key )
	
		throws DistributedDatabaseException
	{
		throwIfNotAvailable();
		
		return( new DDBaseKeyImpl( key ));
	}
	
	public DistributedDatabaseKey
	createKey(
		Object			key,
		String			description )
	
		throws DistributedDatabaseException
	{
		throwIfNotAvailable();
		
		return( new DDBaseKeyImpl( key, description ));
	}
	
	public DistributedDatabaseValue
	createValue(
		Object			value )
	
		throws DistributedDatabaseException
	{
		throwIfNotAvailable();
		
		return( new DDBaseValueImpl( new DDBaseContactImpl( this, getDHT().getLocalAddress()), value, SystemTime.getCurrentTime(), -1));
	}
	
	public DistributedDatabaseContact
	importContact(
		InetSocketAddress				address )
	
		throws DistributedDatabaseException
	{
		throwIfNotAvailable();
	
		DHTPluginContact	contact = getDHT().importContact( address );
		
		if ( contact == null ){
			
			throw( new DistributedDatabaseException( "import of '" + address + "' failed" ));
		}
		
		return( new DDBaseContactImpl( this, contact));
	}
	
	public void
	write(
		DistributedDatabaseListener		listener,
		DistributedDatabaseKey			key,
		DistributedDatabaseValue		value )
	
		throws DistributedDatabaseException
	{
		write( listener, key, new DistributedDatabaseValue[]{ value } );
	}
	
	public void
	write(
		final DistributedDatabaseListener	listener,
		final DistributedDatabaseKey		key,
		final DistributedDatabaseValue		values[] )
	
		throws DistributedDatabaseException
	{
		throwIfNotAvailable();
		
		for (int i=0;i<values.length;i++){
			
			if (((DDBaseValueImpl)values[i]).getBytes().length > DDBaseValueImpl.MAX_VALUE_SIZE ){
				
				throw( new DistributedDatabaseException("Value size limited to " + DDBaseValueImpl.MAX_VALUE_SIZE + " bytes" ));		
			}
		}
		
		if ( values.length == 0 ){
			
			delete( listener, key );
			
		}else if ( values.length == 1 ){
			
			getDHT().put(	
					((DDBaseKeyImpl)key).getBytes(),
					key.getDescription(),
					((DDBaseValueImpl)values[0]).getBytes(),
					DHTPlugin.FLAG_SINGLE_VALUE,
					new listenerMapper( listener, DistributedDatabaseEvent.ET_VALUE_WRITTEN, key, 0, false, false ));
		}else{
			
				
			// TODO: optimise re-publishing to avoid republishing everything each time
			/*
			DHTPluginValue	old_value = dht.getLocalValue( ((DDBaseKeyImpl)key).getBytes());
			
			List	old_values = new ArrayList();
			
			if ( old_value != null ){
				
				if (( old_value.getFlags() & DHTPlugin.FLAG_MULTI_VALUE ) == 0 ){
			
					old_values.add( old_value.getValue());
					
				}else{
					
					byte[]	encoded = old_value.getValue();
					
					
				}
			}
			*/
		
			byte[]	current_key = ((DDBaseKeyImpl)key).getBytes();
			
				// format is: <continuation> <len><len><data>
			
			byte[]	payload			= new byte[DHTPlugin.MAX_VALUE_SIZE];
			int		payload_length	= 1;
					
			int	pos = 0;
			
			while( pos < values.length ){
				
				DDBaseValueImpl	value = (DDBaseValueImpl)values[pos];
				
				byte[]	bytes = value.getBytes();
			
				int		len = bytes.length;
				
				if ( payload_length + len < payload.length - 2 ){
					
					payload[payload_length++] = (byte)(( len & 0x0000ff00 ) >> 8);
					payload[payload_length++] = (byte) ( len & 0x000000ff );
					
					System.arraycopy( bytes, 0, payload, payload_length, len );
					
					payload_length	+= len;
					
					pos++;
					
				}else{
					
					payload[0]	= 1;
					
					final byte[]	copy = new byte[payload_length];
					
					System.arraycopy( payload, 0, copy, 0, copy.length );
					
					final byte[]					f_current_key	= current_key;
					
					getDHT().put(	
							f_current_key,
							key.getDescription(),
							copy,
							DHTPlugin.FLAG_MULTI_VALUE,
							new listenerMapper( listener, DistributedDatabaseEvent.ET_VALUE_WRITTEN, key, 0, false, false ));
					
					payload_length	= 1;
					
					current_key = new SHA1Simple().calculateHash( current_key );
				}
			}
			
			if ( payload_length > 1 ){
				
				payload[0]	= 0;
				
				final byte[]	copy = new byte[payload_length];
				
				System.arraycopy( payload, 0, copy, 0, copy.length );
				
				final byte[]					f_current_key	= current_key;
				
				getDHT().put(	
						f_current_key,
						key.getDescription(),
						copy,
						DHTPlugin.FLAG_MULTI_VALUE,
						new listenerMapper( listener, DistributedDatabaseEvent.ET_VALUE_WRITTEN, key, 0, false, false ));
			}
		}
	}
		
	public void
	read(
		DistributedDatabaseListener		listener,
		DistributedDatabaseKey			key,
		long							timeout )
	
		throws DistributedDatabaseException
	{
		read( listener, key, timeout, OP_NONE );
	}
	
	public void
	read(
		final DistributedDatabaseListener		listener,
		final DistributedDatabaseKey			key,
		final long								timeout,
		int										options )
	
		throws DistributedDatabaseException
	{
		throwIfNotAvailable();
		
		boolean	exhaustive  	= (options&OP_EXHAUSTIVE_READ)!=0;
		boolean	high_priority  	= (options&OP_PRIORITY_HIGH)!=0;
		
			// TODO: max values?
		
		getDHT().get(	
			((DDBaseKeyImpl)key).getBytes(), 
			key.getDescription(),
			(byte)0, 
			256, 
			timeout, 
			exhaustive,
			high_priority,
			new listenerMapper( listener, DistributedDatabaseEvent.ET_VALUE_READ, key, timeout, exhaustive, high_priority ));
	}
	
	public void
	readKeyStats(
		DistributedDatabaseListener		listener,
		DistributedDatabaseKey			key,
		long							timeout )
	
		throws DistributedDatabaseException
	{
		throwIfNotAvailable();
				
		getDHT().get(	
			((DDBaseKeyImpl)key).getBytes(), 
			key.getDescription(),
			DHTPlugin.FLAG_STATS,
			256, 
			timeout, 
			false,
			false,
			new listenerMapper( listener, DistributedDatabaseEvent.ET_KEY_STATS_READ, key, timeout, false, false ));
		
	}