/*
* Created on Feb 8, 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.advanced;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import org.gudy.azureus2.core3.util.*;
import com.aelitis.azureus.core.networkmanager.Transport;
import com.aelitis.azureus.core.peermanager.messaging.*;
//based on http://82.182.115.6/extension.txt //TODO
public class ADVMessageDecoder implements MessageStreamDecoder {
private static final byte SS = DirectByteBuffer.SS_MSG;
private static final int MAX_MESSAGE_LENGTH = 262144; //256K arbitrary limit
private DirectByteBuffer payload_buffer = null;
private final ByteBuffer[] decode_array = new ByteBuffer[] { null, null };
private final ADVHeaderReader header_reader = new ADVHeaderReader();
private boolean reading_length_mode = true;
private int message_length;
private int pre_read_start_buffer;
private int pre_read_start_position;
private volatile boolean destroyed = false;
private volatile boolean is_paused = false;
private ArrayList messages_last_read = new ArrayList();
private int protocol_bytes_last_read = 0;
private int data_bytes_last_read = 0;
private int data_bytes_owed = 0;
private int percent_complete = -1;
public ADVMessageDecoder() {
/*nothing*/
}
public int performStreamDecode( Transport transport, int max_bytes ) throws IOException {
protocol_bytes_last_read = 0;
data_bytes_last_read = 0;
int bytes_remaining = max_bytes;
while( bytes_remaining > 0 ) {
if( destroyed ) {
Debug.out( "ADV decoder already destroyed: " +transport.getDescription() );
break;
}
if( is_paused ) {
Debug.out( "ADV decoder paused" );
break;
}
int bytes_possible = preReadProcess( bytes_remaining );
if( bytes_possible < 1 ) {
Debug.out( "ERROR ADV: bytes_possible < 1" );
break;
}
if( reading_length_mode ) {
transport.read( decode_array, 1, 1 ); //only read into length buffer
}
else {
transport.read( decode_array, 0, 2 ); //read payload buffer, and possibly next message length buffer
}
int bytes_read = postReadProcess();
bytes_remaining -= bytes_read;
if( bytes_read < bytes_possible ) {
break;
}
}
return max_bytes - bytes_remaining;
}
public int getPercentDoneOfCurrentMessage() {
return percent_complete;
}
public Message[] removeDecodedMessages() {
if( messages_last_read.isEmpty() ) return null;
Message[] msgs = (Message[])messages_last_read.toArray( new Message[messages_last_read.size()] );
messages_last_read.clear();
return msgs;
}
public int getProtocolBytesDecoded() { return protocol_bytes_last_read; }
public int getDataBytesDecoded() { return data_bytes_last_read; }
public ByteBuffer destroy() {
is_paused = true;
destroyed = true;
header_reader.destroy();
if( payload_buffer != null ) {
payload_buffer.returnToPool();
payload_buffer = null;
}
for( int i=0; i < messages_last_read.size(); i++ ) {
Message msg = (Message)messages_last_read.get( i );
msg.destroy();
}
messages_last_read.clear();
return null; //NOTE: we don't bother returning any already-read data
}
private int preReadProcess( int allowed ) {
if( allowed < 1 ) {
Debug.out( "allowed < 1" );
}
decode_array[ 0 ] = payload_buffer == null ? null : payload_buffer.getBuffer( SS ); //ensure the decode array has the latest payload pointer
decode_array[ 1 ] = header_reader.getReadBuffer(); //ensure it has the latest header buffer ref
int bytes_available = 0;
boolean shrink_remaining_buffers = false;
int start_buff = reading_length_mode ? 1 : 0;
boolean marked = false;
for( int i = start_buff; i < 2; i++ ) { //set buffer limits according to bytes allowed
ByteBuffer bb = decode_array[ i ];
if( bb == null ) {
Debug.out( "preReadProcess:: bb["+i+"] == null, decoder destroyed=" +destroyed );
}
if( shrink_remaining_buffers ) {
bb.limit( 0 ); //ensure no read into this next buffer is possible
}
else {
int remaining = bb.remaining();
if( remaining < 1 ) continue; //skip full buffer
if( !marked ) {
pre_read_start_buffer = i;
pre_read_start_position = bb.position();
marked = true;
}
if( remaining > allowed ) { //read only part of this buffer
bb.limit( bb.position() + allowed ); //limit current buffer
bytes_available += bb.remaining();
shrink_remaining_buffers = true; //shrink any tail buffers
}
else { //full buffer is allowed to be read
bytes_available += remaining;
allowed -= remaining; //count this buffer toward allowed and move on to the next
}
}
}
return bytes_available;
}
private int postReadProcess() throws IOException {
int bytes_read = 0;
if( !reading_length_mode && !destroyed ) { //reading payload data mode
//ensure-restore proper buffer limits
payload_buffer.limit( SS, message_length );
bytes_read += payload_buffer.position( SS ) - pre_read_start_position;
if( !payload_buffer.hasRemaining( SS ) && !is_paused ) { //full message received!
payload_buffer.position( SS, 0 ); //prepare for use
DirectByteBuffer ref_buff = payload_buffer;
payload_buffer = null;
try {
header_reader.getMessageID();
header_reader.getMessageSubID();
Message msg = null;//AZMessageFactory.createAZMessage( ref_buff ); //TODO
if( false ) throw new MessageException( "" ); //TODO remove
messages_last_read.add( msg );
//we only learn what type of message it is AFTER we are done decoding it, so we probably need to work off the count post-hoc
if( msg.getType() == Message.TYPE_DATA_PAYLOAD ) {
data_bytes_owed += message_length;
}
}
catch( MessageException me ) {
ref_buff.returnToPool();
throw new IOException( "ADV message decode failed: " + me.getMessage() );
}
reading_length_mode = true; //see if we've already read the next message's length
percent_complete = -1; //reset receive percentage
}
else { //only partial received so far
percent_complete = (payload_buffer.position( SS ) * 100) / message_length; //compute receive percentage
}
}
if( reading_length_mode && !destroyed ) {
bytes_read += (pre_read_start_buffer == 1) ? decode_array[1].position() - pre_read_start_position : decode_array[1].position();
if( header_reader.isHeaderReadComplete() ) { //done reading the length and message id header
reading_length_mode = false;
message_length = header_reader.getMessageLength();
if( message_length > MAX_MESSAGE_LENGTH ) {
throw new IOException( "Invalid message length given for ADV message decode: " + message_length );
}
payload_buffer = DirectByteBufferPool.getBuffer( DirectByteBuffer.AL_MSG_AZ_PAYLOAD, message_length );
}
}
if( bytes_read < data_bytes_owed ) {
data_bytes_last_read += bytes_read;
data_bytes_owed -= bytes_read;
}
else { //bytes_read >= data_bytes_owed
data_bytes_last_read += data_bytes_owed;
data_bytes_owed = 0;
protocol_bytes_last_read += bytes_read - data_bytes_owed;
}
return bytes_read;
}
public void pauseDecoding() {
is_paused = true;
}
public void resumeDecoding() {
is_paused = false;
}
}
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