/**
* 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;
import java.util.Collection;
import java.util.LinkedList;
import lupos.datastructures.bindings.Bindings;
import lupos.datastructures.items.Item;
import lupos.datastructures.items.literal.AnonymousLiteral;
import lupos.datastructures.items.literal.LazyLiteral;
import lupos.datastructures.items.literal.LiteralFactory;
import lupos.datastructures.queryresult.GraphResult;
import lupos.datastructures.queryresult.QueryResult;
import lupos.engine.operators.tripleoperator.TriplePattern;
public class Construct extends SingleInputOperator {
private static final long serialVersionUID = 1L;
protected Collection<TriplePattern> ctp;
protected int id=0; // used for reification of blank nodes...
protected boolean containsBlankNodes = false;
public void setTemplates(final Collection<TriplePattern> ctp) {
this.ctp = ctp;
for(TriplePattern tp: ctp){
for(Item item: tp){
if(item instanceof AnonymousLiteral){
containsBlankNodes=true;
} else if(item instanceof LazyLiteral){
if(((LazyLiteral)item).getLiteral() instanceof LazyLiteral){
containsBlankNodes=true;
}
}
}
}
}
public Collection<TriplePattern> getTemplates() {
return ctp;
}
@Override
public QueryResult process(final QueryResult qr, final int operandID) {
if(this.containsBlankNodes){
// do reification of blank nodes!
final GraphResult gr = new GraphResult();
for(Bindings b: qr){
Collection<TriplePattern> ctp_new = new LinkedList<TriplePattern>();
for(TriplePattern tp: ctp){
TriplePattern tp_new=new TriplePattern(reificate(tp.getItems()[0]), reificate(tp.getItems()[1]), reificate(tp.getItems()[2]));
ctp_new.add(tp_new);
}
gr.setTemplate(ctp_new);
gr.add(b);
id++;
}
qr.release();
return gr;
} else {
final GraphResult gr = new GraphResult(ctp);
gr.add(qr);
qr.release();
return gr;
}
}
private Item reificate(Item item) {
if(item instanceof LazyLiteral)
item=((LazyLiteral)item).getLiteral();
if(item instanceof AnonymousLiteral){
return LiteralFactory.createAnonymousLiteral(((AnonymousLiteral)item).toString()+"_reificated_"+id);
} else return item;
}
@Override
public String toString() {
return super.toString() + ctp;
}
@Override
public String toString(lupos.rdf.Prefix prefixInstance) {
StringBuffer result = new StringBuffer("Construct: ");
for(TriplePattern tp : this.ctp) {
result.append(tp.toString(prefixInstance)).append("\n");
}
return result.toString();
}
}