/**
* 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.LinkedList;
import java.util.List;
import lupos.datastructures.items.Item;
import lupos.datastructures.items.literal.Literal;
import lupos.engine.operators.BasicOperator;
import lupos.engine.operators.OperatorIDTuple;
import lupos.engine.operators.messages.BoundVariablesMessage;
import lupos.engine.operators.singleinput.generate.Generate;
import lupos.engine.operators.tripleoperator.TriplePattern;
public class PreOptimization {
/**
*
*/
private static final long serialVersionUID = 1L;
public PreOptimization() {
}
public LinkedList<Generate> calculateGenerates(
final BasicOperator rootOperator) {
final LinkedList<Generate> generates = new LinkedList<Generate>();
return generates;
}
public void connectGenPat(final BasicOperator rootOperator) {
final List<OperatorIDTuple> pats = rootOperator
.getSucceedingOperators();
final LinkedList<Generate> generates = RDFSRuleEngine0.generates;
for (int i = 0; i < generates.size(); i++) {
System.out.println("Connects Generate number " + i);
final Generate generate = generates.get(i);
final LinkedList<OperatorIDTuple> possiblePats = new LinkedList<OperatorIDTuple>();
TriplePattern pat;
for (int a = 0; a < pats.size(); a++) {
pat = (TriplePattern) pats.get(a).getOperator();
if (matchPossible(generate.getValueOrVariable(), pat.getItems())) {
possiblePats.add(new OperatorIDTuple(pat, 0));
pat.addPrecedingOperator(generate);
}
}
if (possiblePats.size() > 0) {
try {
Thread.sleep(50);
} catch (final InterruptedException e) {
System.err.println(e);
e.printStackTrace();
}
System.out.println(generate.toString() + "----"
+ possiblePats.toString());
generate.setSucceedingOperators(possiblePats);
for (int p = 0; p < possiblePats.size(); p++) {
pat = (TriplePattern) possiblePats.get(p).getOperator();
pat.addPrecedingOperator(generate);
}
} else {
generate
.setSucceedingOperators(new LinkedList<OperatorIDTuple>());
}
}
rootOperator.deleteParents();
rootOperator.setParents();
rootOperator.detectCycles();
rootOperator.sendMessage(new BoundVariablesMessage());
}
/**
* @param generateItems
* Generate pattern
* @param patItems
* TriplePattern
* @return Whether match between parameter objects are possible
*/
private static boolean matchPossible(final Item[] generateItems,
final Item[] patItems) { // If there is one Generate literal, which
// is not equal to corresponding
// TriplePattern literal, then no match is possible
Literal patLit;
Literal generateLit;
for (int b = 0; b < 3; b++) {
if ((!generateItems[b].isVariable()) && (!patItems[b].isVariable())) {
generateLit = (Literal) generateItems[b];
patLit = (Literal) patItems[b];
if (!generateLit.equals(patLit)) {
return false;
}
}
}
return true;
}
}