package org.moparscape.msc.gs.connection.codec;
import org.apache.mina.common.ByteBuffer;
import org.apache.mina.common.IoSession;
import org.apache.mina.filter.codec.CumulativeProtocolDecoder;
import org.apache.mina.filter.codec.ProtocolDecoderOutput;
import org.moparscape.msc.gs.connection.RSCPacket;
import org.moparscape.msc.gs.util.Logger;
/**
* A decoder for the RSC protocol. Parses the incoming data from an IoSession
* and outputs it as a <code>RSCPacket</code> object.
*/
public class RSCProtocolDecoder extends CumulativeProtocolDecoder {
/**
* Releases the buffer used by the given session.
*
* @param session
* The session for which to release the buffer
* @throws Exception
* if failed to dispose all resources
*/
public void dispose(IoSession session) throws Exception {
super.dispose(session);
}
/**
* Parses the data in the provided byte buffer and writes it to
* <code>out</code> as a <code>RSCPacket</code>.
*
* @param session
* The IoSession the data was read from
* @param in
* The buffer
* @param out
* The decoder output stream to which to write the
* <code>RSCPacket</code>
* @return Whether enough data was available to create a packet
*/
protected synchronized boolean doDecode(IoSession session, ByteBuffer in,
ProtocolDecoderOutput out) {
try {
if (in.remaining() >= 2) {
byte[] buf = new byte[] { in.get(), in.get() };
int length = ((short) ((buf[0] & 0xff) << 8) | (short) (buf[1] & 0xff));
// Logger.log("len="+length);
if (length <= in.remaining()) {
if (length - 1 < 0) {
Logger.println("Negative array length! id="
+ in.getUnsigned() + ",len=" + length);
session.close();
return true;
}
byte[] payload = new byte[length - 1];
int id = in.get() & 0xff;
in.get(payload);
RSCPacket p = new RSCPacket(session, id, payload);
out.write(p);
return true;
} else {
in.rewind();
return false;
}
}
} catch (Exception e) {
e.printStackTrace();
}
return false;
}
}