/*
* Copyright (c) 2009-2010 "Neo Technology,"
* Network Engine for Objects in Lund AB [http://neotechnology.com]
*
* This file is part of Neo4j.
*
* Neo4j is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.neo4j.onlinebackup.net;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.channels.FileChannel;
import java.util.Random;
import org.neo4j.kernel.impl.transaction.xaframework.XaDataSource;
import org.neo4j.onlinebackup.ha.AbstractSlave;
public class HandleMasterConnection extends ConnectionJob
{
private static final Random r = new Random( System.currentTimeMillis() );
private static enum Status implements JobStatus
{
GET_LOG,
GET_MESSAGE,
SETUP_NOT_OK,
SEND_NOT_OK,
SETUP_OK,
SEND_OK,
SETUP_REQUEST,
SEND_REQUEST,
}
private final XaDataSource xaDs;
private int retries = 0;
private File tempFile;
private FileChannel logToWrite = null;
private long logLength = -1;
private long logVersionWriting = -1;
private long masterVersion = -1;
public HandleMasterConnection( Connection connection, AbstractSlave slave,
long masterVersion, XaDataSource xaDs )
{
super( connection, slave );
this.xaDs = xaDs;
this.masterVersion = masterVersion;
if ( xaDs.getCurrentLogVersion() < (masterVersion - 1) )
{
setStatus( Status.SETUP_REQUEST );
}
else
{
setStatus( Status.GET_MESSAGE );
}
}
private boolean getMessage()
{
if ( !acquireReadBuffer() )
{
return false;
}
try
{
// HEADER(1) + VERSION(8) + LOG_LENGTH(8)
buffer.limit( 17 );
int read = connection.read();
if ( read == 17 )
{
buffer.flip();
byte request = buffer.get();
if ( request != HeaderConstants.OFFER_LOG )
{
log( "Unkown request: " + request );
close();
return true;
}
long version = buffer.getLong();
if ( version < xaDs.getCurrentLogVersion() )
{
log( "Got wrong version [" + version + "]" );
setStatus( Status.SETUP_NOT_OK );
return true;
}
if ( version > masterVersion )
{
masterVersion = version;
}
logLength = buffer.getLong();
log( "Got offer: " + version + "," + logLength );
if ( !xaDs.hasLogicalLog( version ) )
{
try
{
logVersionWriting = version;
do
{
tempFile = new File( xaDs.getName() +
"-logical-transfer.v" +
Long.toString( version ) + "_" +
r.nextLong() );
} while ( tempFile.exists() );
logToWrite = new RandomAccessFile( tempFile,
"rw").getChannel();
logToWrite.truncate( 0 );
}
catch ( IOException e )
{
close();
throw new SocketException(
"Unable to setup logical log[" + version +
"] for writing", e );
}
setStatus( Status.SETUP_OK );
}
else
{
log( "We already have log version[" + version + "]" );
setStatus( Status.SETUP_NOT_OK );
}
retries = 0;
return true;
}
else
{
if ( read > 0 )
{
connection.pushBackAllReadData();
}
return false;
}
}
finally
{
releaseReadBuffer();
}
}
private boolean setupRequest()
{
long version = xaDs.getCurrentLogVersion();
while ( version < masterVersion )
{
if ( xaDs.hasLogicalLog( version ) )
{
version++;
}
else
{
break;
}
}
if ( version == masterVersion )
{
setStatus( Status.GET_MESSAGE );
return true;
}
if ( retries > 20 )
{
close();
}
if ( !acquireWriteBuffer() )
{
retries++;
return false;
}
buffer.put( HeaderConstants.REQUEST_LOG );
buffer.putLong( version );
buffer.flip();
log( "Setup request: " + version );
setStatus( Status.SEND_REQUEST );
retries = 0;
return true;
}
private boolean sendRequest()
{
if ( retries > 20 )
{
close();
}
log( "Send request" );
connection.write();
if ( !buffer.hasRemaining() )
{
buffer.clear();
releaseWriteBuffer();
setStatus( Status.GET_MESSAGE );
return true;
}
retries++;
return false;
}
private boolean setupNotOk()
{
if ( retries > 20 )
{
close();
}
if ( !acquireWriteBuffer() )
{
retries++;
return false;
}
buffer.put( HeaderConstants.NOT_OK );
buffer.flip();
log( "Setup not ok" );
setStatus( Status.SEND_NOT_OK );
retries = 0;
return true;
}
private boolean sendNotOk()
{
if ( retries > 20 )
{
close();
}
log( "Send not ok" );
connection.write();
if ( !buffer.hasRemaining() )
{
buffer.clear();
releaseWriteBuffer();
setStatus( Status.GET_MESSAGE );
return true;
}
retries++;
return false;
}
private boolean setupOk()
{
if ( retries > 20 )
{
close();
}
if ( !acquireWriteBuffer() )
{
retries++;
return false;
}
buffer.put( HeaderConstants.OK );
buffer.flip();
log( "Setup ok" );
setStatus( Status.SEND_OK );
retries = 0;
return true;
}
private boolean sendOk()
{
if ( retries > 20 )
{
close();
}
log( "Send ok" );
connection.write();
if ( !buffer.hasRemaining() )
{
buffer.clear();
releaseWriteBuffer();
setStatus( Status.GET_LOG );
return true;
}
retries++;
return false;
}
private boolean getLog()
{
if ( !acquireReadBuffer() )
{
return false;
}
log( "Get log" );
try
{
int read = connection.read();
if ( read > 0 )
{
buffer.flip();
if ( logToWrite.position() + read <= logLength )
{
logToWrite.write( buffer );
}
else
{
int readLimit = buffer.limit();
int logLimit = (int) (logLength - logToWrite.position());
buffer.limit( logLimit );
logToWrite.write( buffer );
buffer.limit( readLimit );
byte[] pushData = new byte[readLimit - logLimit];
buffer.get( pushData );
connection.pushBackReadData( pushData );
}
if ( logToWrite.position() >= logLength )
{
log( "Log transfer complete" );
if ( xaDs.getCurrentLogVersion() < (masterVersion - 1) )
{
setStatus( Status.SETUP_REQUEST );
}
else
{
setStatus( Status.GET_MESSAGE );
}
logToWrite.close();
String newName = xaDs.getFileName( logVersionWriting );
File newLog = new File( newName );
if ( newLog.exists() )
{
log( "Error new log file[" + newName +
"] already exist" );
close();
}
if ( !tempFile.renameTo( new File( newName ) ) )
{
log( "Unable to move log to " + newName );
close();
}
logVersionWriting = -1;
tempFile = null;
logToWrite = null;
// slave.tryApplyNewLog();
}
return true;
}
else
{
return false;
}
}
catch ( IOException e )
{
close();
log( "Error getting log.", e );
return true;
}
finally
{
releaseReadBuffer();
}
}
@Override
public boolean performJob()
{
switch ( (Status) getStatus() )
{
case GET_LOG: return getLog();
case GET_MESSAGE: return getMessage();
case SETUP_REQUEST: return setupRequest();
case SEND_REQUEST: return sendRequest();
case SETUP_OK: return setupOk();
case SEND_OK: return sendOk();
case SETUP_NOT_OK: return setupNotOk();
case SEND_NOT_OK: return sendNotOk();
default:
throw new IllegalStateException( "Unkown status: " +
getStatus() );
}
}
@Override
void connectionClosed()
{
System.out.println( "Connection closed " + connection );
}
}