/**
* 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.externalontology;
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.OperatorIDTuple;
import lupos.engine.operators.multiinput.join.Join;
import lupos.engine.operators.tripleoperator.TriggerOneTime;
import lupos.misc.Tuple;
import lupos.optimizations.logical.rules.Rule;
public class RuleDeleteTriggerOneTimeJoin extends Rule {
@Override
protected void init() {
final TriggerOneTime trigger = new TriggerOneTime();
final Join join = new Join();
trigger.setSucceedingOperator(new OperatorIDTuple(join, -1));
join.setPrecedingOperator(trigger);
subGraphMap = new HashMap<BasicOperator, String>();
subGraphMap.put(trigger, "trigger");
subGraphMap.put(join, "join");
startNode = join;
}
@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 TriggerOneTime trigger = (TriggerOneTime) mso.get("trigger");
final Join join = (Join) mso.get("join");
join.removePrecedingOperator(trigger);
if (join.getPrecedingOperators().size() <= 1) {
// remove join
for (final OperatorIDTuple oit : join.getSucceedingOperators()) {
oit.getOperator().removePrecedingOperator(join);
}
for (final BasicOperator bo : join.getPrecedingOperators()) {
bo.removeSucceedingOperator(join);
bo.addSucceedingOperators(join.getSucceedingOperators());
for (final OperatorIDTuple oit : join.getSucceedingOperators()) {
oit.getOperator().addPrecedingOperator(bo);
}
}
deleted.add(join);
}
// remove join from trigger operator
trigger.removeSucceedingOperator(join);
if (trigger.getSucceedingOperators().size() == 0) {
// remove trigger operator
for (final BasicOperator bo : trigger.getPrecedingOperators()) {
bo.removeSucceedingOperator(trigger);
}
deleted.add(trigger);
}
if (deleted.size() > 0 || added.size() > 0)
return new Tuple<Collection<BasicOperator>, Collection<BasicOperator>>(
added, deleted);
else
return null;
}
}