/**
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 Aug 18, 2010
*/
package com.bigdata.bop.controller;
import java.util.Map;
import com.bigdata.bop.BOp;
import com.bigdata.bop.IBindingSet;
import com.bigdata.bop.NV;
import com.bigdata.bop.PipelineOp;
/**
* STEPS(ops)
*
* <pre>
* STEPS([],{subqueries=[a,b,c]})
* </pre>
*
* Will run the subqueries <i>a</i>, <i>b</i>, and <i>c</i> in sequence. Each
* subquery will be initialized with a single empty {@link IBindingSet}. The
* output of those subqueries will be routed to the STEPS operator (their
* parent) unless the subqueries explicitly override this behavior using
* {@link PipelineOp.Annotations#SINK_REF}.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
* @version $Id$
*/
public class Steps extends AbstractSubqueryOp {
/**
*
*/
private static final long serialVersionUID = 1L;
/**
* Deep copy constructor.
*/
public Steps(Steps op) {
super(op);
}
/**
* Shallow copy constructor.
*
* @param args
* @param annotations
*/
public Steps(final BOp[] args,
final Map<String, Object> annotations) {
super(args, annotations);
if (getMaxParallelSubqueries() != 1) {
/*
* This version of the operator runs the subquery steps in a strict
* sequence. This is appropriate for things like the fast closure
* program, where some steps must execute in the given order while
* others may execute concurrently. Use UNION if you want to have
* concurrent evaluation of the subqueries.
*/
throw new IllegalArgumentException(Annotations.MAX_PARALLEL_SUBQUERIES + "="
+ getMaxParallelSubqueries());
}
}
public Steps(final BOp[] args, NV... annotations) {
this(args, NV.asMap(annotations));
}
}