/**
* 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.datastructures.items.Variable;
import lupos.datastructures.items.literal.Literal;
import lupos.engine.operators.BasicOperator;
import lupos.engine.operators.OperatorIDTuple;
import lupos.engine.operators.singleinput.ReplaceLit;
import lupos.engine.operators.singleinput.ReplaceVar;
import lupos.misc.Tuple;
import lupos.optimizations.logical.rules.Rule;
public class RuleReplaceVarUnderReplaceLit extends Rule {
public RuleReplaceVarUnderReplaceLit() {
super();
}
@Override
protected void init() {
final ReplaceLit repLit = new ReplaceLit();
final ReplaceVar repVar = new ReplaceVar();
repLit.setSucceedingOperator(new OperatorIDTuple(repVar, 0));
repVar.setPrecedingOperator(repLit);
subGraphMap = new HashMap<BasicOperator, String>();
subGraphMap.put(repLit, "repLit");
subGraphMap.put(repVar, "repVar");
startNode = repVar;
}
@Override
protected boolean checkPrecondition(final Map<String, BasicOperator> mso) {
return true;
}
@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 ReplaceLit repLit = (ReplaceLit) mso.get("repLit");
final ReplaceVar repVar = (ReplaceVar) mso.get("repVar");
final ReplaceVar repVar_new = new ReplaceVar();
repVar_new.setSubstitutionsVariableLeft(repVar
.getSubstitutionsVariableLeft());
repVar_new.setSubstitutionsVariableRight(repVar
.getSubstitutionsVariableRight());
repVar_new.setIntersectionVariables(repVar.getIntersectionVariables());
repVar_new.setUnionVariables(repVar.getUnionVariables());
final ReplaceLit repLit_new = new ReplaceLit();
repLit_new.setSubstitutionsLiteralLeft(repLit
.getSubstitutionsLiteralLeft());
repLit_new.setSubstitutionsLiteralRight(repLit
.getSubstitutionsLiteralRight());
repLit_new.setIntersectionVariables(repLit.getIntersectionVariables());
repLit_new.setUnionVariables(repLit.getUnionVariables());
final LinkedList<Variable> repVarLeft = repVar
.getSubstitutionsVariableLeft();
final LinkedList<Variable> repVarRight = repVar
.getSubstitutionsVariableRight();
final LinkedList<Variable> repLitLeft = repLit
.getSubstitutionsLiteralLeft();
final LinkedList<Literal> repLitRight = repLit
.getSubstitutionsLiteralRight();
Variable var;
int index = -1;
for (int i = 0; i < repVarRight.size(); i++) {
var = repVarRight.get(i);
index = repLitLeft.indexOf(var);
// (x,<a>),(y,x) => (x,<a>),(y,<a>)
if (index > -1) {
final Variable var2 = repVarLeft.get(i);
repVar_new.removeSubstitution(var2, var);
repLit_new.addSubstitution(var2, repLitRight.get(index));
}
}
final LinkedList<BasicOperator> pres = (LinkedList<BasicOperator>) repLit
.getPrecedingOperators();
final LinkedList<OperatorIDTuple> succs = (LinkedList<OperatorIDTuple>) repVar
.getSucceedingOperators();
BasicOperator pre;
for (int i = 0; i < pres.size(); i++) {
pre = pres.get(i);
pre.addSucceedingOperator(new OperatorIDTuple(repVar_new, 0));
pre.removeSucceedingOperator(repLit);
}
repVar_new.setPrecedingOperators(pres);
repVar_new.setSucceedingOperator(new OperatorIDTuple(repLit_new, 0));
repLit_new.setPrecedingOperator(repVar_new);
repLit_new.setSucceedingOperators(succs);
BasicOperator succ;
for (int i = 0; i < succs.size(); i++) {
succ = succs.get(i).getOperator();
succ.addPrecedingOperator(repLit_new);
succ.removePrecedingOperator(repVar);
}
rootOperator.deleteParents();
rootOperator.setParents();
rootOperator.detectCycles();
// should have been done manually: rootOperator.sendMessage(new
// BoundVariablesMessage());
added.add(repVar_new);
added.add(repLit_new);
deleted.add(repVar);
deleted.add(repLit);
if (deleted.size() > 0 || added.size() > 0)
return new Tuple<Collection<BasicOperator>, Collection<BasicOperator>>(
added, deleted);
else
return null;
}
}