package org.openamq.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.openamq.framing.AMQDataBlockDecoder;
import org.openamq.framing.ProtocolInitiation;
/**
* There is one instance of this class per session. Any changes or configuration done
* at run time to the encoders or decoders only affects decoding/encoding of the
* protocol session data to which is it bound.
*
*/
public class AMQDecoder extends CumulativeProtocolDecoder
{
private AMQDataBlockDecoder _dataBlockDecoder = new AMQDataBlockDecoder();
private ProtocolInitiation.Decoder _piDecoder = new ProtocolInitiation.Decoder();
private boolean _expectProtocolInitiation;
public AMQDecoder(boolean expectProtocolInitiation)
{
_expectProtocolInitiation = expectProtocolInitiation;
}
protected boolean doDecode(IoSession session, ByteBuffer in, ProtocolDecoderOutput out) throws Exception
{
if (_expectProtocolInitiation)
{
return doDecodePI(session, in, out);
}
else
{
return doDecodeDataBlock(session, in, out);
}
}
protected boolean doDecodeDataBlock(IoSession session, ByteBuffer in, ProtocolDecoderOutput out) throws Exception
{
int pos = in.position();
boolean enoughData = _dataBlockDecoder.decodable(session, in);
in.position(pos);
if (!enoughData)
{
// returning false means it will leave the contents in the buffer and
// call us again when more data has been read
return false;
}
else
{
_dataBlockDecoder.decode(session, in, out);
return true;
}
}
private boolean doDecodePI(IoSession session, ByteBuffer in, ProtocolDecoderOutput out) throws Exception
{
boolean enoughData = _piDecoder.decodable(session, in);
if (!enoughData)
{
// returning false means it will leave the contents in the buffer and
// call us again when more data has been read
return false;
}
else
{
_piDecoder.decode(session, in, out);
return true;
}
}
public void setExpectProtocolInitiation(boolean expectProtocolInitiation)
{
_expectProtocolInitiation = expectProtocolInitiation;
}
}