/**
* 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.singleinput.federated;
import java.util.HashSet;
import lupos.datastructures.items.Variable;
import lupos.engine.operators.messages.BoundVariablesMessage;
import lupos.engine.operators.messages.Message;
import lupos.sparql1_1.Node;
public abstract class FederatedQueryWithoutSucceedingJoin extends FederatedQuery {
public FederatedQueryWithoutSucceedingJoin(Node federatedQuery) {
super(federatedQuery);
}
@Override
public Message preProcessMessage(final BoundVariablesMessage msg) {
this.intersectionVariables = new HashSet<Variable>();
this.unionVariables = new HashSet<Variable>();
// fetch-as-needed and join-at-endpoint compute a join with the previous result, i.e. the previous bound variables are also bound afterwards:
this.unionVariables.addAll(msg.getVariables());
checkVariables(this.federatedQuery, this.unionVariables);
this.intersectionVariables.addAll(this.unionVariables);
final BoundVariablesMessage result = new BoundVariablesMessage(msg);
result.getVariables().addAll(this.unionVariables);
return result;
}
}