/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Sep 4, 2010
*/
package com.bigdata.bop.solutions;
import java.util.Comparator;
import java.util.Map;
import com.bigdata.bop.BOp;
import com.bigdata.bop.IValueExpression;
import com.bigdata.bop.PipelineOp;
/**
* Base class for operators which sort binding sets.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
abstract public class SortOp extends PipelineOp {
/**
*
*/
private static final long serialVersionUID = 1L;
public interface Annotations extends PipelineOp.Annotations {
/**
* An {@link ISortOrder}[] specifying an ordered list of
* {@link IValueExpression}s on which the sort will be imposed and the
* order (ascending or descending) for each {@link IValueExpression}.
*/
String SORT_ORDER = SortOp.class.getName() + ".sortOrder";
/**
* The {@link Comparator} used to compare individual as-bound / computed
* values within binding sets. This will be wrapped up with a comparator
* which knows how to compare the different values within the binding
* sets based on the declared {@link #SORT_ORDER}.
*/
String VALUE_COMPARATOR = SortOp.class.getName() + ".valueComparator";
}
/**
* @param op
*/
public SortOp(final SortOp op) {
super(op);
}
/**
* @param args
* @param annotations
*/
public SortOp(final BOp[] args, final Map<String, Object> annotations) {
super(args, annotations);
}
/**
* @see Annotations#SORT_ORDER
*/
public ISortOrder[] getSortOrder() {
return (ISortOrder[]) getRequiredProperty(Annotations.SORT_ORDER);
}
/**
* @see Annotations#VALUE_COMPARATOR
*/
public Comparator getValueComparator() {
return (Comparator) getRequiredProperty(Annotations.VALUE_COMPARATOR);
}
}