/**
* Copyright (c) 2002-2011 "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.kernel.impl.index;
import javax.transaction.Synchronization;
import javax.transaction.SystemException;
import javax.transaction.Transaction;
import javax.transaction.TransactionManager;
import javax.transaction.xa.XAResource;
import org.neo4j.graphdb.NotInTransactionException;
import org.neo4j.kernel.impl.transaction.xaframework.XaConnection;
import org.neo4j.kernel.impl.util.ArrayMap;
public abstract class IndexConnectionBroker<T extends XaConnection>
{
private final ArrayMap<Transaction, T> txConnectionMap =
new ArrayMap<Transaction, T>( 5, true, true );
private final TransactionManager transactionManager;
protected IndexConnectionBroker( TransactionManager transactionManager )
{
this.transactionManager = transactionManager;
}
public T acquireResourceConnection()
{
T con = null;
Transaction tx = this.getCurrentTransaction();
if ( tx == null )
{
throw new NotInTransactionException();
}
con = txConnectionMap.get( tx );
if ( con == null )
{
try
{
con = (T) newConnection();
if ( !tx.enlistResource( con.getXaResource() ) )
{
throw new RuntimeException( "Unable to enlist '"
+ con.getXaResource() + "' in "
+ tx );
}
tx.registerSynchronization( new TxCommitHook( tx ) );
txConnectionMap.put( tx, con );
}
catch ( javax.transaction.RollbackException re )
{
String msg = "The transaction is marked for rollback only.";
throw new RuntimeException( msg, re );
}
catch ( javax.transaction.SystemException se )
{
String msg = "TM encountered an unexpected error condition.";
throw new RuntimeException( msg, se );
}
}
return con;
}
protected abstract T newConnection();
public T acquireReadOnlyResourceConnection()
{
Transaction tx = this.getCurrentTransaction();
return tx != null ? txConnectionMap.get( tx ) : null;
}
void releaseResourceConnectionsForTransaction( Transaction tx )
throws NotInTransactionException
{
T con = txConnectionMap.remove( tx );
if ( con != null )
{
con.destroy();
}
}
void delistResourcesForTransaction() throws NotInTransactionException
{
Transaction tx = this.getCurrentTransaction();
if ( tx == null )
{
throw new NotInTransactionException();
}
T con = txConnectionMap.get( tx );
if ( con != null )
{
try
{
tx.delistResource( con.getXaResource(), XAResource.TMSUCCESS );
}
catch ( IllegalStateException e )
{
throw new RuntimeException(
"Unable to delist lucene resource from tx", e );
}
catch ( SystemException e )
{
throw new RuntimeException(
"Unable to delist lucene resource from tx", e );
}
}
}
private Transaction getCurrentTransaction()
throws NotInTransactionException
{
try
{
return transactionManager.getTransaction();
}
catch ( SystemException se )
{
throw new NotInTransactionException(
"Error fetching transaction for current thread", se );
}
}
private class TxCommitHook implements Synchronization
{
private final Transaction tx;
TxCommitHook( Transaction tx )
{
this.tx = tx;
}
public void afterCompletion( int param )
{
releaseResourceConnectionsForTransaction( tx );
}
public void beforeCompletion()
{
delistResourcesForTransaction();
}
}
}