/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.cassandra.db;
import java.io.DataInputStream;
import java.io.IOException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.io.util.DataOutputBuffer;
import org.apache.cassandra.io.util.FastByteArrayInputStream;
import org.apache.cassandra.net.IVerbHandler;
import org.apache.cassandra.net.Message;
import org.apache.cassandra.net.MessagingService;
import org.apache.cassandra.service.StorageService;
import org.apache.cassandra.utils.ByteBufferUtil;
import org.apache.cassandra.utils.FBUtilities;
public class ReadVerbHandler implements IVerbHandler
{
private static Logger logger_ = LoggerFactory.getLogger( ReadVerbHandler.class );
// re-use output buffers between requests
private static ThreadLocal<DataOutputBuffer> threadLocalOut = new ThreadLocal<DataOutputBuffer>()
{
@Override
protected DataOutputBuffer initialValue()
{
return new DataOutputBuffer();
}
};
public void doVerb(Message message, String id)
{
if (StorageService.instance.isBootstrapMode())
{
throw new RuntimeException("Cannot service reads while bootstrapping!");
}
try
{
FastByteArrayInputStream in = new FastByteArrayInputStream(message.getMessageBody());
ReadCommand command = ReadCommand.serializer().deserialize(new DataInputStream(in), message.getVersion());
Table table = Table.open(command.table);
Row row = command.getRow(table);
DataOutputBuffer out = threadLocalOut.get();
out.reset();
ReadResponse.serializer().serialize(getResponse(command, row), out, message.getVersion());
byte[] bytes = new byte[out.getLength()];
System.arraycopy(out.getData(), 0, bytes, 0, bytes.length);
Message response = message.getReply(FBUtilities.getBroadcastAddress(), bytes, message.getVersion());
if (logger_.isDebugEnabled())
logger_.debug(String.format("Read key %s; sending response to %s@%s",
ByteBufferUtil.bytesToHex(command.key), id, message.getFrom()));
MessagingService.instance().sendReply(response, id, message.getFrom());
}
catch (IOException ex)
{
throw new RuntimeException(ex);
}
}
public static ReadResponse getResponse(ReadCommand command, Row row)
{
if (command.isDigestQuery())
{
if (logger_.isDebugEnabled())
logger_.debug("digest is " + ByteBufferUtil.bytesToHex(ColumnFamily.digest(row.cf)));
return new ReadResponse(ColumnFamily.digest(row.cf));
}
else
{
return new ReadResponse(row);
}
}
}