/*
* StreamCruncher: Copyright (c) 2006-2008, Ashwin Jayaprakash. All Rights Reserved.
* Contact: ashwin {dot} jayaprakash {at} gmail {dot} com
* Web: http://www.StreamCruncher.com
*
* This file is part of StreamCruncher.
*
* StreamCruncher is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* StreamCruncher 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with StreamCruncher. If not, see <http://www.gnu.org/licenses/>.
*/
package streamcruncher.innards.core.partition;
import streamcruncher.boot.Registry;
import streamcruncher.innards.core.QueryContext;
import streamcruncher.innards.db.DatabaseInterface;
import streamcruncher.util.PerpetualResultSet;
/*
* Author: Ashwin Jayaprakash Date: Feb 12, 2006 Time: 3:30:36 PM
*/
public abstract class StreamReaderPartitioner<P extends PartitionedTable> extends Partitioner<P> {
protected PartitionedTable partitionedTable;
protected DatabaseInterface dbInterface;
// -------------
/**
* @param queryName
* @param partitionedTable
* @throws Exception
*/
@Override
public void init(String queryName, P partitionedTable) throws Exception {
super.init(queryName, partitionedTable);
this.partitionedTable = partitionedTable;
dbInterface = Registry.getImplFor(DatabaseInterface.class);
PartitionOutputStore store = createStore();
initStorage(store);
}
protected abstract PartitionOutputStore createStore();
// -------------
@Override
protected int copyAndDescend(QueryContext context) throws Exception {
int copied = 0;
int rows = partitionedTable.forceFilter();
if (rows > 0) {
PerpetualResultSet resultSet = null;
try {
resultSet = partitionedTable.getPerpetualResultSet();
int maxRows = resultSet.getSize();
resultSet.startSession(maxRows);
copied = partitionDescender.descendAndAddRows(context, resultSet);
}
finally {
resultSet.closeSession();
}
}
return copied;
}
protected void postProcess(QueryContext context, int rowsCopied, int rowsOusted,
int rowsInserted) {
}
// -------------
@Override
public void discard() {
super.discard();
partitionedTable = null;
}
}