waazdoh.cp2p.messaging.MessageDecoder.java Source code

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Here is the source code for waazdoh.cp2p.messaging.MessageDecoder.java

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/*******************************************************************************
 * Copyright (c) 2013 Juuso Vilmunen.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Public License v3.0
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/gpl.html
 * 
 * Contributors:
 *     Juuso Vilmunen - initial API and implementation
 ******************************************************************************/
package waazdoh.cp2p.messaging;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ByteToMessageDecoder;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.util.LinkedList;
import java.util.List;

import org.xml.sax.SAXException;

import waazdoh.common.WLogger;

public final class MessageDecoder extends ByteToMessageDecoder {
    private WLogger log = WLogger.getLogger(this);
    private ByteArrayOutputStream baos;

    @Override
    protected void decode(ChannelHandlerContext arg0, ByteBuf cb, List<Object> msgs) throws Exception {
        if (cb.readableBytes() < 8)
            return;
        cb.markReaderIndex();
        int length = cb.readInt();

        if (cb.readableBytes() < length) {
            log.info("missing readablebytes " + cb.readableBytes() + " vs " + length);
            cb.resetReaderIndex();
            return;
        }

        byte[] bs = new byte[length];
        cb.readBytes(bs);

        DataInputStream dis = new DataInputStream(new ByteArrayInputStream(bs));
        msgs.add(parse(dis));
    }

    private List<MMessage> parse(DataInputStream dis) throws IOException {
        //
        List<MMessage> ret = new LinkedList<MMessage>();
        int messagecount = dis.readInt();
        log.debug("messagecount : " + messagecount);
        for (int i = 0; i < messagecount; i++) {
            MMessage m = readMessage(dis);
            ret.add(m);
        }
        return ret;
    }

    private MMessage readMessage(DataInputStream dis) throws IOException {
        int messagelength = dis.readInt();
        log.debug("decoder reading " + messagelength);
        byte messagebytes[] = new byte[messagelength];
        dis.read(messagebytes, 0, messagelength);
        MMessage m;
        try {
            m = new MMessage(messagebytes);
            log.info("decoded " + m);
            return m;
        } catch (SAXException e) {
            log.error(e);
            return null;
        }
    }
}