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/*
*
* Copyright (c) 2006 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.apache.qpid.framing;
import org.apache.log4j.Logger;
import org.apache.mina.common.ByteBuffer;
import org.apache.mina.common.IoSession;
import org.apache.mina.filter.codec.ProtocolDecoderOutput;
import java.util.HashMap;
import java.util.Map;
public class AMQDataBlockDecoder
{
Logger _logger = Logger.getLogger(AMQDataBlockDecoder.class);
private final Map _supportedBodies = new HashMap();
public AMQDataBlockDecoder()
{
_supportedBodies.put(new Byte(AMQMethodBody.TYPE), AMQMethodBodyFactory.getInstance());
_supportedBodies.put(new Byte(ContentHeaderBody.TYPE), ContentHeaderBodyFactory.getInstance());
_supportedBodies.put(new Byte(ContentBody.TYPE), ContentBodyFactory.getInstance());
_supportedBodies.put(new Byte(HeartbeatBody.TYPE), new HeartbeatBodyFactory());
}
public boolean decodable(IoSession session, ByteBuffer in) throws AMQFrameDecodingException
{
// type, channel, body size and end byte
if (in.remaining() < (1 + 2 + 4 + 1))
{
return false;
}
final byte type = in.get();
final int channel = in.getUnsignedShort();
final long bodySize = in.getUnsignedInt();
// bodySize can be zero
if (type <= 0 || channel < 0 || bodySize < 0)
{
throw new AMQFrameDecodingException("Undecodable frame: type = " + type + " channel = " + channel +
" bodySize = " + bodySize);
}
if (in.remaining() < (bodySize + 1))
{
return false;
}
return true;
}
private boolean isSupportedFrameType(byte frameType)
{
final boolean result = _supportedBodies.containsKey(new Byte(frameType));
if (!result)
{
_logger.warn("AMQDataBlockDecoder does not handle frame type " + frameType);
}
return result;
}
protected Object createAndPopulateFrame(ByteBuffer in)
throws AMQFrameDecodingException
{
final byte type = in.get();
if (!isSupportedFrameType(type))
{
throw new AMQFrameDecodingException("Unsupported frame type: " + type);
}
final int channel = in.getUnsignedShort();
final long bodySize = in.getUnsignedInt();
BodyFactory bodyFactory = (BodyFactory) _supportedBodies.get(new Byte(type));
if (bodyFactory == null)
{
throw new AMQFrameDecodingException("Unsupported body type: " + type);
}
AMQFrame frame = new AMQFrame();
frame.populateFromBuffer(in, channel, bodySize, bodyFactory);
byte marker = in.get();
if ((marker & 0xFF) != 0xCE)
{
throw new AMQFrameDecodingException("End of frame marker not found. Read " + marker + " size=" + bodySize + " type=" + type);
}
return frame;
}
public void decode(IoSession session, ByteBuffer in, ProtocolDecoderOutput out)
throws Exception
{
out.write(createAndPopulateFrame(in));
}
}
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