/**
* Copyright (c) 2013, Institute of Information Systems (Sven Groppe and contributors of LUPOSDATE), University of Luebeck
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
* following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice, this list of conditions and the following
* disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other materials provided with the distribution.
* - Neither the name of the University of Luebeck nor the names of its contributors may be used to endorse or promote
* products derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package lupos.optimizations.logical.rules.rdfs;
import java.util.Collection;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.Map;
import lupos.engine.operators.BasicOperator;
import lupos.engine.operators.SimpleOperatorGraphVisitor;
import lupos.engine.operators.rdfs.index.RDFSPutIntoIndices;
import lupos.engine.operators.singleinput.Result;
import lupos.engine.operators.tripleoperator.TriplePattern;
import lupos.misc.Tuple;
import lupos.optimizations.logical.rules.Rule;
import lupos.optimizations.logical.rules.RuleEngine;
public class RuleDeleteNotConnectedToResultOperator extends Rule {
@Override
protected void init() {
final BasicOperator bo = new TriplePattern();
subGraphMap = new HashMap<BasicOperator, String>();
subGraphMap.put(bo, "bo");
startNode = bo;
}
public Rule[] getRulesToApply(final RuleEngine ruleEngine) {
return new Rule[] {};
}
@Override
protected boolean checkPrecondition(final Map<String, BasicOperator> mso) {
final BasicOperator bo = mso.get("bo");
final FindResultOperatorVisitor frov = new FindResultOperatorVisitor();
final Object o = bo.visit(frov);
return !frov.found();
}
@Override
public Tuple<Collection<BasicOperator>, Collection<BasicOperator>> transformOperatorGraph(
final Map<String, BasicOperator> mso,
final BasicOperator rootOperator) {
final Collection<BasicOperator> deleted = new LinkedList<BasicOperator>();
final Collection<BasicOperator> added = new LinkedList<BasicOperator>();
final BasicOperator bo = mso.get("bo");
for (final BasicOperator pred : bo.getPrecedingOperators()) {
pred.removeSucceedingOperator(bo);
}
bo.visit(new SimpleOperatorGraphVisitor() {
public Object visit(final BasicOperator basicOperator) {
deleted.add(basicOperator);
return null;
}
});
if (deleted.size() > 0 || added.size() > 0)
return new Tuple<Collection<BasicOperator>, Collection<BasicOperator>>(
added, deleted);
else
return null;
}
private class FindResultOperatorVisitor implements
SimpleOperatorGraphVisitor {
private boolean found = false;
public Object visit(final BasicOperator basicOperator) {
if (basicOperator instanceof Result
|| basicOperator instanceof RDFSPutIntoIndices)
found = true;
return null;
}
public boolean found() {
return found;
}
}
}