/*
* Created on Feb 19, 2005
* Created by Alon Rohter
* Copyright (C) 2004-2005 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 com.aelitis.azureus.core.peermanager.messaging.azureus;
import java.util.HashMap;
import java.util.Map;
import org.gudy.azureus2.core3.util.DirectByteBuffer;
import org.gudy.azureus2.core3.util.DirectByteBufferPool;
import org.gudy.azureus2.core3.util.RandomUtils;
import com.aelitis.azureus.core.networkmanager.RawMessage;
import com.aelitis.azureus.core.networkmanager.impl.RawMessageImpl;
import com.aelitis.azureus.core.peermanager.messaging.Message;
import com.aelitis.azureus.core.peermanager.messaging.MessageException;
import com.aelitis.azureus.core.peermanager.messaging.MessageManager;
import com.aelitis.azureus.core.peermanager.messaging.bittorrent.*;
/**
* Factory for handling AZ message creation.
* NOTE: wire format: [total message length] + [id length] + [id bytes] + [version byte] + [payload bytes]
*/
public class AZMessageFactory {
public static final byte MESSAGE_VERSION_INITIAL = BTMessageFactory.MESSAGE_VERSION_INITIAL;
public static final byte MESSAGE_VERSION_SUPPORTS_PADDING = BTMessageFactory.MESSAGE_VERSION_SUPPORTS_PADDING;
public static final int AZ_HANDSHAKE_PAD_MAX = 64;
public static final int SMALL_PAD_MAX = 8;
public static final int BIG_PAD_MAX = 20;
private static final byte bss = DirectByteBuffer.SS_MSG;
private static final Map<String,LegacyData> legacy_data = new HashMap<String,LegacyData>();
static {
legacy_data.put( BTMessage.ID_BT_CHOKE, new LegacyData( RawMessage.PRIORITY_HIGH, true, new Message[]{new BTUnchoke((byte)0)})); // with support for fast extension we don't cancel outstanding piece data, new BTPiece(-1, -1, null,(byte)0 )} ) );
legacy_data.put( BTMessage.ID_BT_UNCHOKE, new LegacyData( RawMessage.PRIORITY_NORMAL, true, new Message[]{new BTChoke((byte)0)} ) );
legacy_data.put( BTMessage.ID_BT_INTERESTED, new LegacyData( RawMessage.PRIORITY_HIGH, true, new Message[]{new BTUninterested((byte)0)} ) );
legacy_data.put( BTMessage.ID_BT_UNINTERESTED, new LegacyData( RawMessage.PRIORITY_NORMAL, false, new Message[]{new BTInterested((byte)0)} ) );
legacy_data.put( BTMessage.ID_BT_HAVE, new LegacyData( RawMessage.PRIORITY_LOW, false, null ) );
legacy_data.put( BTMessage.ID_BT_BITFIELD, new LegacyData( RawMessage.PRIORITY_HIGH, true, null ) );
legacy_data.put( BTMessage.ID_BT_HAVE_ALL, new LegacyData( RawMessage.PRIORITY_HIGH, true, null ) );
legacy_data.put( BTMessage.ID_BT_HAVE_NONE, new LegacyData( RawMessage.PRIORITY_HIGH, true, null ) );
legacy_data.put( BTMessage.ID_BT_REQUEST, new LegacyData( RawMessage.PRIORITY_NORMAL, true, null ) );
legacy_data.put( BTMessage.ID_BT_REJECT_REQUEST, new LegacyData( RawMessage.PRIORITY_NORMAL, true, null ) );
legacy_data.put( BTMessage.ID_BT_PIECE, new LegacyData( RawMessage.PRIORITY_LOW, false, null ) );
legacy_data.put( BTMessage.ID_BT_CANCEL, new LegacyData( RawMessage.PRIORITY_HIGH, true, null ) );
legacy_data.put( BTMessage.ID_BT_HANDSHAKE, new LegacyData( RawMessage.PRIORITY_HIGH, true, null ) );
legacy_data.put( BTMessage.ID_BT_KEEP_ALIVE, new LegacyData( RawMessage.PRIORITY_LOW, false, null ) );
legacy_data.put( BTMessage.ID_BT_DHT_PORT, new LegacyData( RawMessage.PRIORITY_LOW, false, null ) );
legacy_data.put( BTMessage.ID_BT_SUGGEST_PIECE, new LegacyData( RawMessage.PRIORITY_NORMAL, true, null ) );
legacy_data.put( BTMessage.ID_BT_ALLOWED_FAST, new LegacyData( RawMessage.PRIORITY_LOW, false, null ) );
}
/**
* Initialize the factory, i.e. register the messages with the message manager.
*/
public static void init() {
try {
MessageManager.getSingleton().registerMessageType( new AZHandshake( new byte[20], null, null, "", "", 0, 0, 0, null, 0, new String[0], new byte[0], 0, MESSAGE_VERSION_SUPPORTS_PADDING,false ) );
MessageManager.getSingleton().registerMessageType( new AZPeerExchange( new byte[20], null, null, MESSAGE_VERSION_SUPPORTS_PADDING ));
MessageManager.getSingleton().registerMessageType( new AZRequestHint( -1, -1, -1, -1, MESSAGE_VERSION_SUPPORTS_PADDING ));
MessageManager.getSingleton().registerMessageType( new AZHave( new int[0], MESSAGE_VERSION_SUPPORTS_PADDING ));
MessageManager.getSingleton().registerMessageType( new AZBadPiece( -1, MESSAGE_VERSION_SUPPORTS_PADDING ));
MessageManager.getSingleton().registerMessageType( new AZStatRequest( null, MESSAGE_VERSION_SUPPORTS_PADDING ));
MessageManager.getSingleton().registerMessageType( new AZStatReply( null, MESSAGE_VERSION_SUPPORTS_PADDING ));
MessageManager.getSingleton().registerMessageType( new AZMetaData( null, null, MESSAGE_VERSION_SUPPORTS_PADDING ));
/*
MessageManager.getSingleton().registerMessageType( new AZSessionSyn( new byte[20], -1, null) );
MessageManager.getSingleton().registerMessageType( new AZSessionAck( new byte[20], -1, null) );
MessageManager.getSingleton().registerMessageType( new AZSessionEnd( new byte[20], "" ) );
MessageManager.getSingleton().registerMessageType( new AZSessionBitfield( -1, null ) );
MessageManager.getSingleton().registerMessageType( new AZSessionCancel( -1, -1, -1, -1 ) );
MessageManager.getSingleton().registerMessageType( new AZSessionHave( -1, new int[]{-1} ) );
MessageManager.getSingleton().registerMessageType( new AZSessionPiece( -1, -1, -1, null ) );
MessageManager.getSingleton().registerMessageType( new AZSessionRequest( -1, (byte)-1, -1, -1, -1 ) );
*/
}
catch( MessageException me ) { me.printStackTrace(); }
}
/**
* Register a generic map payload type with the factory.
* @param type_id to register
* @throws MessageException on registration error
*/
public static void registerGenericMapPayloadMessageType( String type_id ) throws MessageException {
MessageManager.getSingleton().registerMessageType( new AZGenericMapPayload( type_id, null, MESSAGE_VERSION_INITIAL ) );
}
/**
* Construct a new AZ message instance from the given message raw byte stream.
* @param stream_payload data
* @return decoded/deserialized AZ message
* @throws MessageException if message creation failed.
* NOTE: Does not auto-return to buffer pool the given direct buffer on thrown exception.
*/
public static Message createAZMessage( DirectByteBuffer stream_payload ) throws MessageException {
int id_length = stream_payload.getInt( bss );
if( id_length < 1 || id_length > 1024 || id_length > stream_payload.remaining( bss ) - 1 ) {
byte bt_id = stream_payload.get( (byte)0, 0 );
throw new MessageException( "invalid AZ id length given: " +id_length+ ", stream_payload.remaining(): " +stream_payload.remaining( bss )+ ", BT id?=" +bt_id );
}
byte[] id_bytes = new byte[ id_length ];
stream_payload.get( bss, id_bytes );
// if only the version came first we could save a lot of space by changing the id length + id....
// in the meantime we overload the version byte to have a version number and flags
// flags = top 4 bits, version = bottom 4 bits
byte version_and_flags = stream_payload.get( bss );
byte version = (byte)( version_and_flags & 0x0f );
if ( version >= MESSAGE_VERSION_SUPPORTS_PADDING ){
byte flags = (byte)(( version_and_flags >> 4 ) & 0x0f );
if ( ( flags & 0x01 ) != 0 ){
short padding_length = stream_payload.getShort( bss );
byte[] padding = new byte[padding_length];
stream_payload.get( bss, padding );
}
}
return MessageManager.getSingleton().createMessage( id_bytes, stream_payload, version );
}
/**
* Create the proper AZ raw message from the given base message.
* @param base_message to create from
* @return AZ raw message
*/
public static RawMessage createAZRawMessage( Message base_message, int padding_mode ) {
byte[] id_bytes = base_message.getIDBytes();
byte version = base_message.getVersion();
DirectByteBuffer[] payload = base_message.getData();
int payload_size = 0;
for( int i=0; i < payload.length; i++ ) {
payload_size += payload[i].remaining( bss );
}
//create and fill header buffer
DirectByteBuffer header;
if ( version >= MESSAGE_VERSION_SUPPORTS_PADDING ){
boolean enable_padding = padding_mode != AZMessageEncoder.PADDING_MODE_NONE;
short padding_length;
if ( enable_padding ){
if ( padding_mode == AZMessageEncoder.PADDING_MODE_MINIMAL ){
padding_length = (short)( RandomUtils.nextInt( SMALL_PAD_MAX ));
}else{
padding_length = (short)( RandomUtils.nextInt( payload_size>256?SMALL_PAD_MAX:BIG_PAD_MAX ));
}
if ( padding_length == 0 ){
enable_padding = false;
}
}else{
padding_length = 0;
}
byte flags = enable_padding?(byte)0x01:(byte)0x00;
int header_size = 4 + 4 + id_bytes.length + 1 + (enable_padding?(2+padding_length):0);
header = DirectByteBufferPool.getBuffer( DirectByteBuffer.AL_MSG_AZ_HEADER, header_size );
header.putInt( bss, header_size - 4 + payload_size );
header.putInt( bss, id_bytes.length );
header.put( bss, id_bytes );
byte version_and_flags = (byte)( ( flags << 4 ) | version );
header.put( bss, version_and_flags );
if ( enable_padding ){
byte[] padding = new byte[padding_length];
header.putShort( bss, padding_length );
header.put( bss, padding );
}
}else{
int header_size = 4 + 4 + id_bytes.length + 1;
header = DirectByteBufferPool.getBuffer( DirectByteBuffer.AL_MSG_AZ_HEADER, header_size );
header.putInt( bss, header_size - 4 + payload_size );
header.putInt( bss, id_bytes.length );
header.put( bss, id_bytes );
header.put( bss, version );
}
header.flip( bss );
DirectByteBuffer[] raw_buffs = new DirectByteBuffer[ payload.length + 1 ];
raw_buffs[0] = header;
for( int i=0; i < payload.length; i++ ) {
raw_buffs[i+1] = payload[i];
}
String message_id = base_message.getID();
LegacyData ld = (LegacyData)legacy_data.get( message_id ); //determine if a legacy BT message
if( ld != null ) { //legacy message, use pre-configured values
return new RawMessageImpl( base_message, raw_buffs, ld.priority, ld.is_no_delay, ld.to_remove );
}
// these should really be properties of the message...
int priority;
boolean no_delay = true;
if ( message_id == AZMessage.ID_AZ_HANDSHAKE ){
// handshake needs to go out first - if not high then bitfield can get in front of it...
priority = RawMessage.PRIORITY_HIGH;
}else if ( message_id == AZMessage.ID_AZ_HAVE ){
priority = RawMessage.PRIORITY_LOW;
no_delay = false;
}else{
//standard message, ensure that protocol messages have wire priority over data payload messages
priority = base_message.getType() == Message.TYPE_DATA_PAYLOAD ? RawMessage.PRIORITY_LOW : RawMessage.PRIORITY_NORMAL;
}
return new RawMessageImpl( base_message, raw_buffs, priority, no_delay, null );
}
protected static class LegacyData {
protected final int priority;
protected final boolean is_no_delay;
protected final Message[] to_remove;
protected LegacyData( int prio, boolean no_delay, Message[] remove ) {
this.priority = prio;
this.is_no_delay = no_delay;
this.to_remove = remove;
}
}
}