/**
* Copyright (c) 2011 Yahoo! Inc. All rights reserved.
*
* 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. See accompanying LICENSE file.
*/
package com.yahoo.omid.tso.serialization;
import java.io.EOFException;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.handler.codec.frame.FrameDecoder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.yahoo.omid.replication.Zipper;
import com.yahoo.omid.tso.TSOMessage;
import com.yahoo.omid.tso.messages.AbortRequest;
import com.yahoo.omid.tso.messages.CommitQueryRequest;
import com.yahoo.omid.tso.messages.CommitQueryResponse;
import com.yahoo.omid.tso.messages.CommitRequest;
import com.yahoo.omid.tso.messages.CommitResponse;
import com.yahoo.omid.tso.messages.CommittedTransactionReport;
import com.yahoo.omid.tso.messages.FullAbortRequest;
import com.yahoo.omid.tso.messages.LargestDeletedTimestampReport;
import com.yahoo.omid.tso.messages.TimestampRequest;
import com.yahoo.omid.tso.messages.TimestampResponse;
public class TSODecoder extends FrameDecoder {
private static final Logger LOG = LoggerFactory.getLogger(TSODecoder.class);
private Zipper zipper;
public TSODecoder(Zipper zipper) {
this.zipper = zipper;
}
protected Object decode(ChannelHandlerContext ctx, Channel channel, ChannelBuffer buf) throws Exception {
// Mark the current buffer position before any reading
// because the whole frame might not be in the buffer yet.
// We will reset the buffer position to the marked position if
// there's not enough bytes in the buffer.
buf.markReaderIndex();
TSOMessage msg;
try {
if (zipper != null) {
msg = zipper.decodeMessage(buf);
LOG.debug("Zipper returned " + msg);
if (msg != null) {
return msg;
}
buf.resetReaderIndex();
}
byte type = buf.readByte();
if (LOG.isTraceEnabled()) {
LOG.trace("Decoding message : " + type);
}
switch (type) {
case TSOMessage.TimestampRequest:
msg = new TimestampRequest();
break;
case TSOMessage.TimestampResponse:
msg = new TimestampResponse();
break;
case TSOMessage.CommitRequest:
msg = new CommitRequest();
break;
case TSOMessage.CommitResponse:
msg = new CommitResponse();
break;
case TSOMessage.CommitQueryRequest:
msg = new CommitQueryRequest();
break;
case TSOMessage.CommitQueryResponse:
msg = new CommitQueryResponse();
break;
case TSOMessage.CommittedTransactionReport:
msg = new CommittedTransactionReport();
break;
case TSOMessage.LargestDeletedTimestampReport:
msg = new LargestDeletedTimestampReport();
break;
case TSOMessage.AbortRequest:
msg = new AbortRequest();
break;
case TSOMessage.FullAbortReport:
msg = new FullAbortRequest();
break;
default:
throw new Exception("Wrong type " + type + " (" + Integer.toHexString(type) +") " + buf.toString().length());
}
msg.readObject(buf);
} catch (IndexOutOfBoundsException e) {
// Not enough byte in the buffer, reset to the start for the next try
buf.resetReaderIndex();
return null;
} catch (EOFException e) {
// Not enough byte in the buffer, reset to the start for the next try
buf.resetReaderIndex();
return null;
}
return msg;
}
}