/**
* 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.Iterator;
import lupos.datastructures.bindings.Bindings;
import lupos.datastructures.queryresult.ParallelIteratorMultipleQueryResults;
import lupos.datastructures.queryresult.QueryResult;
import lupos.datastructures.queryresult.QueryResultDebug;
import lupos.engine.operators.Operator;
import lupos.engine.operators.OperatorIDTuple;
import lupos.engine.operators.messages.ComputeIntermediateResultMessage;
import lupos.engine.operators.messages.EndOfEvaluationMessage;
import lupos.engine.operators.messages.Message;
import lupos.engine.operators.singleinput.sort.comparator.ComparatorAST;
import lupos.engine.operators.singleinput.sort.comparator.ComparatorBindings;
import lupos.misc.debug.DebugStep;
public class Group extends SingleInputOperator {
/**
*
*/
private static final long serialVersionUID = -3636219378615890918L;
private final ComparatorBindings comp;
/**
* Constructor sets the node, the parent and the comparator
*
* @param node
*/
public Group(final lupos.sparql1_1.Node node) {
this.comp = new ComparatorAST(node);
}
public Group(final ComparatorBindings comp) {
this.comp = comp;
}
protected ParallelIteratorMultipleQueryResults queryResults = new ParallelIteratorMultipleQueryResults();
/**
* saving the QueryResult
*
* @param QueryResult
* @param int
* @return QueryResult
*/
@Override
public synchronized QueryResult process(final QueryResult queryResult, final int operandID) {
this.queryResults.addQueryResult(queryResult);
return null;
}
/**
* Bindings are compared and split in separate QueryResults
*
*/
private void computeResult(){
if (!this.queryResults.isEmpty()) {
QueryResult newQueryResult = QueryResult.createInstance();
final Iterator<Bindings> it = this.queryResults.getQueryResult().oneTimeIterator();
Bindings oldBinding = null;
boolean firstRun = true;
while (it.hasNext()) {
final Bindings b = it.next();
if (!firstRun) {
final int compareValue = this.comp.compare(oldBinding, b);
if (compareValue == 0) {
newQueryResult.add(b);
} else {
// Send queryResult
for (final OperatorIDTuple opId: this.succeedingOperators) {
opId.processAll(newQueryResult);
}
newQueryResult = QueryResult.createInstance();
newQueryResult.add(b);
}
} else {
firstRun = false;
newQueryResult.add(b);
}
oldBinding = b;
}
// Send queryResult
for (final OperatorIDTuple opId: this.succeedingOperators) {
opId.processAll(newQueryResult);
}
this.queryResults.clear();
}
}
/**
* Bindings are compared and split in separate QueryResults
*
* @param EndOfEvaluationMessage
* @return Message
*/
@Override
public Message preProcessMessage(final EndOfEvaluationMessage msg) {
this.computeResult();
return msg;
}
/**
* Bindings are compared and split in separate QueryResults
*
* @param ComputeIntermediateResultMessage
* @return Message
*/
@Override
public Message preProcessMessage(final ComputeIntermediateResultMessage msg) {
this.deleteAllAtSucceedingOperators();
this.computeResult();
this.queryResults.reset();
return msg;
}
private void computeResultDebug(final DebugStep debugstep){
if (!this.queryResults.isEmpty()) {
QueryResult newQueryResult = QueryResult.createInstance();
final Iterator<Bindings> it = this.queryResults.getQueryResult().oneTimeIterator();
Bindings oldBinding = null;
boolean firstRun = true;
while (it.hasNext()) {
final Bindings b = it.next();
if (!firstRun) {
final int compareValue = this.comp.compare(oldBinding, b);
if (compareValue == 0) {
newQueryResult.add(b);
} else {
// Send queryResult
for (final OperatorIDTuple opId: this.succeedingOperators) {
final QueryResultDebug qrDebug = new QueryResultDebug(newQueryResult, debugstep, this, opId.getOperator(), true);
((Operator) opId.getOperator()).processAllDebug(qrDebug, opId.getId(), debugstep);
}
newQueryResult = QueryResult.createInstance();
newQueryResult.add(b);
}
} else {
firstRun = false;
newQueryResult.add(b);
}
oldBinding = b;
}
// Send queryResult
for (final OperatorIDTuple opId: this.succeedingOperators) {
final QueryResultDebug qrDebug = new QueryResultDebug(newQueryResult, debugstep, this, opId.getOperator(), true);
((Operator) opId.getOperator()).processAllDebug(qrDebug, opId.getId(), debugstep);
}
this.queryResults.clear();
}
}
@Override
public Message preProcessMessageDebug(final ComputeIntermediateResultMessage msg, final DebugStep debugstep) {
this.computeResultDebug(debugstep);
return msg;
}
@Override
public Message preProcessMessageDebug(final EndOfEvaluationMessage msg, final DebugStep debugstep) {
this.computeResultDebug(debugstep);
return msg;
}
@Override
public QueryResult deleteQueryResult(final QueryResult queryResult, final int operandID) {
this.queryResults.removeAll(queryResult);
return null;
}
@Override
public void deleteQueryResult(final int operandID) {
this.queryResults.removeAll();
}
}