/**
* 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.engine.operators.rdfs.index;
import java.util.Collection;
import java.util.HashSet;
import java.util.LinkedList;
import lupos.datastructures.items.Item;
import lupos.datastructures.items.Variable;
import lupos.engine.operators.OperatorIDTuple;
import lupos.engine.operators.index.BasicIndexScan;
import lupos.engine.operators.index.Dataset;
import lupos.engine.operators.multiinput.join.Join;
import lupos.engine.operators.tripleoperator.TriplePattern;
import lupos.engine.operators.tripleoperator.patternmatcher.PatternMatcher;
public class RDFSRoot extends
lupos.engine.operators.index.Root {
@Override
public BasicIndexScan newIndexScan(final OperatorIDTuple succeedingOperator,
final Collection<TriplePattern> triplePattern, final Item data) {
return new ToStreamIndexScan(succeedingOperator, triplePattern, this);
}
@Override
public lupos.engine.operators.index.Root newInstance(Dataset dataset) {
this.dataset = dataset;
return new RDFSRoot();
}
public void addToPatternMatcher(final PatternMatcher pm) {
for (final OperatorIDTuple oit : succeedingOperators) {
final ToStreamIndexScan tsi = (ToStreamIndexScan) oit.getOperator();
if (tsi.getTriplePattern().size() == 1)
for (final TriplePattern tp : tsi.getTriplePattern()) {
pm.add(tp);
tp.setPrecedingOperator(pm);
}
else {
final Join j = new Join();
j.setSucceedingOperator(tsi.getSucceedingOperators().get(0));
int i = 0;
final HashSet<Variable> unionVariables = new HashSet<Variable>();
final HashSet<Variable> intersectionVariables = new HashSet<Variable>();
intersectionVariables.addAll(tsi.getTriplePattern().iterator()
.next().getUnionVariables());
for (final TriplePattern tp : tsi.getTriplePattern()) {
final LinkedList<OperatorIDTuple> succeedingOperatorsTP = new LinkedList<OperatorIDTuple>();
succeedingOperatorsTP.add(new OperatorIDTuple(j, i));
tp.addSucceedingOperators(succeedingOperatorsTP);
j.addPrecedingOperator(tp);
pm.add(tp);
tp.addPrecedingOperator(pm);
unionVariables.addAll(tp.getUnionVariables());
intersectionVariables.retainAll(tp.getUnionVariables());
i++;
}
j.setUnionVariables(unionVariables);
j.setIntersectionVariables(intersectionVariables);
}
}
}
}