/**
* {@inheritDoc}
*
* <p>Creating a new query result with an empty binding to handle an empty BIND statement
*/
@Override
public QueryResult process(final Dataset dataset) {
final QueryResult queryResult = QueryResult.createInstance();
if (this.rdfGraph != null && this.rdfGraph.isVariable()) {
final Variable graphConstraint = (Variable) this.rdfGraph;
if (this.root.namedGraphs != null && this.root.namedGraphs.size() > 0) {
// Convert the named graphs' names into URILiterals
// to be applicable later on
for (final String name : this.root.namedGraphs) {
final Bindings graphConstraintBindings = this.bindingsFactory.createInstance();
try {
graphConstraintBindings.add(
graphConstraint, LiteralFactory.createURILiteralWithoutLazyLiteral(name));
} catch (final URISyntaxException e) {
System.err.println(e);
e.printStackTrace();
}
queryResult.add(graphConstraintBindings);
}
} else {
final Collection<Indices> dataSetIndices = dataset.getNamedGraphIndices();
if (dataSetIndices != null) {
for (final Indices indices : dataSetIndices) {
final Bindings graphConstraintBindings = this.bindingsFactory.createInstance();
graphConstraintBindings.add(graphConstraint, indices.getRdfName());
queryResult.add(graphConstraintBindings);
}
}
}
} else {
queryResult.add(this.bindingsFactory.createInstance());
}
return queryResult;
}
/** {@inheritDoc} */
@Override
public QueryResult deleteQueryResult(final QueryResult queryResult, final int operandID) {
final Iterator<Bindings> itb = queryResult.oneTimeIterator();
while (itb.hasNext()) {
this.bindings.remove(itb.next());
}
return null;
}
/** {@inheritDoc} */
@Override
public void consume(final Triple triple) {
if (this.firstTime) {
this.firstTime = false;
this.processAtSucceedingOperators(
QueryResult.createInstance(this.bindingsFactory.createInstance()));
}
}
/** {@inheritDoc} */
@Override
public QueryResult process(final QueryResult _bindings, final int operandID) {
final Iterator<Bindings> itb = _bindings.oneTimeIterator();
if (!itb.hasNext()) {
return null;
} else {
return QueryResult.createInstance(
new ImmutableIterator<Bindings>() {
Bindings next = null;
@Override
public boolean hasNext() {
if (this.next != null) {
return true;
}
if (itb.hasNext()) {
this.next = this.next();
if (this.next != null) {
return true;
}
}
return false;
}
@Override
public Bindings next() {
if (this.next != null) {
final Bindings znext = this.next;
this.next = null;
return znext;
}
while (itb.hasNext()) {
final Bindings b = itb.next();
if (!NonBlockingDistinct.this.bindings.contains(b)) {
NonBlockingDistinct.this.bindings.add(b);
return b;
}
}
return null;
}
});
}
}
/** {@inheritDoc} */
@Override
public QueryResult deleteQueryResult(final QueryResult queryResult, final int operandID) {
// problem: it does not count the number of occurrences of a binding
// i.e. { ?a=<a> }, { ?a=<a> } and delete { ?a=<a> } will result in
// {} instead of { ?a=<a> }!!!!!!
final Iterator<Bindings> itb = queryResult.oneTimeIterator();
while (itb.hasNext()) {
this.bindings.remove(itb.next());
}
return null;
}
@Override
public QueryResult process(final QueryResult bindings, final int operandID) {
if (operandID < this.operandResults.length) {
this.operandResults[operandID] = bindings;
} else
System.err.println(
"NAryMergeJoin is a "
+ this.operandResults.length
+ "-ary operator, but received the operand number "
+ operandID);
boolean go = true;
for (int i = 0; i < this.operandResults.length; i++) {
if (this.operandResults[i] == null) {
go = false;
break;
}
}
if (go) {
this.comp.setVariables(this.intersectionVariables);
if (this.minimum == null) return null;
@SuppressWarnings("unchecked")
final Iterator<Bindings>[] itb = new Iterator[this.operandResults.length];
for (int i = 0; i < this.operandResults.length; i++) {
itb[i] = this.operandResults[i].oneTimeIterator();
}
final ParallelIterator<Bindings> currentResult =
(this.intersectionVariables.size() == 0)
? MergeJoin.cartesianProductIterator(this.operandResults)
: MergeJoin.mergeJoinIterator(
itb, this.comp, this.intersectionVariables, this.minimum, this.maximum);
if (currentResult != null && currentResult.hasNext()) {
final QueryResult result =
QueryResult.createInstance(
new SIPParallelIterator<Bindings, Bindings>() {
int number = 0;
@Override
public void close() {
currentResult.close();
}
@Override
public boolean hasNext() {
if (!currentResult.hasNext()) {
NAryMergeJoinWithoutSorting.this.realCardinality = this.number;
close();
}
return currentResult.hasNext();
}
@Override
public Bindings next() {
final Bindings b = currentResult.next();
if (b != null) this.number++;
if (!currentResult.hasNext()) {
NAryMergeJoinWithoutSorting.this.realCardinality = this.number;
close();
}
return b;
}
public Bindings getNext(final Bindings k) {
@SuppressWarnings("unchecked")
final Bindings b =
((SIPParallelIterator<Bindings, Bindings>) currentResult).next(k);
if (b != null) this.number++;
if (!currentResult.hasNext()) {
NAryMergeJoinWithoutSorting.this.realCardinality = this.number;
close();
}
return b;
}
@Override
public void remove() {
currentResult.remove();
}
@Override
public void finalize() {
close();
}
@Override
public Bindings next(final Bindings k) {
if (currentResult instanceof SIPParallelIterator) return getNext(k);
else return next();
}
});
return result;
} else {
for (int i = 0; i < this.operandResults.length; i++) {
if (this.operandResults[i] != null) {
this.operandResults[i].release();
this.operandResults[i] = null;
}
}
return null;
}
} else {
return null;
}
}
/** {@inheritDoc} */
@Override
public QueryResult process(final QueryResult _bindings, final int operandID) {
if (_bindings.isEmpty()) {
return null;
}
final BoundedBuffer<Bindings> distinctElements = new BoundedBuffer<Bindings>();
final BoundedBuffer<Bindings> toBeChecked = new BoundedBuffer<Bindings>();
final BoundedBuffer<Tuple<Bindings, Boolean>> toBeAddedToSet =
new BoundedBuffer<Tuple<Bindings, Boolean>>();
final Feeder feeder = new Feeder(_bindings, toBeChecked);
final FastDecider fastDecider =
new FastDecider(distinctElements, toBeChecked, toBeAddedToSet, this.bindings);
final DetailedDecider detailedDecider =
new DetailedDecider(distinctElements, toBeAddedToSet, this.bindings);
feeder.start();
fastDecider.start();
detailedDecider.start();
return QueryResult.createInstance(
new ParallelIterator<Bindings>() {
@Override
public boolean hasNext() {
try {
return distinctElements.hasNext();
} catch (final InterruptedException e) {
System.err.println(e);
e.printStackTrace();
}
return false;
}
@Override
public Bindings next() {
if (this.hasNext()) {
try {
return distinctElements.get();
} catch (final InterruptedException e) {
System.err.println(e);
e.printStackTrace();
}
}
return null;
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
@Override
public void close() {
feeder.stopIt();
distinctElements.stopIt();
toBeChecked.stopIt();
toBeAddedToSet.stopIt();
}
@Override
public void finalize() {
this.close();
}
});
}
@SuppressWarnings("unchecked")
@Override
public QueryResult process(final QueryResult bindings, final int operandID) {
bindings.materialize();
this.comp.setVariables(this.intersectionVariables);
final QueryResult oldLeft = this.left;
final QueryResult oldRight = this.right;
if (operandID == 0) {
if (this.left == null) this.left = bindings;
else
this.left =
QueryResult.createInstance(
new MergeIterator<Bindings>(this.comp, this.left.iterator(), bindings.iterator()));
} else if (operandID == 1) {
if (this.right == null) this.right = bindings;
else
this.right =
QueryResult.createInstance(
new MergeIterator<Bindings>(this.comp, this.right.iterator(), bindings.iterator()));
} else
System.err.println(
"MergeJoin is a binary operator, but received the operand number " + operandID);
if (this.left != null && this.right != null) {
this.left.materialize();
this.right.materialize();
final Iterator<Bindings> leftIterator =
(operandID == 0 && oldLeft != null)
? new MinusIterator(bindings.iterator(), oldLeft.iterator())
: this.left.iterator();
final QueryResult rightLocal =
(operandID == 1 && oldRight != null)
? QueryResult.createInstance(
new MinusIterator(bindings.iterator(), oldRight.iterator()))
: this.right;
final ParallelIterator<Bindings> currentResult =
(this.intersectionVariables.size() == 0)
? MergeJoin.cartesianProductIterator(leftIterator, rightLocal)
: MergeJoin.mergeJoinIterator(
leftIterator, rightLocal.iterator(), this.comp, this.intersectionVariables);
if (currentResult != null && currentResult.hasNext()) {
final QueryResult result =
QueryResult.createInstance(
new ParallelIterator<Bindings>() {
int number = 0;
@Override
public void close() {
currentResult.close();
}
@Override
public boolean hasNext() {
if (!currentResult.hasNext()) {
MergeJoinWithoutSortingSeveralIterations.this.realCardinality = this.number;
close();
}
return currentResult.hasNext();
}
@Override
public Bindings next() {
final Bindings b = currentResult.next();
if (!currentResult.hasNext()) {
MergeJoinWithoutSortingSeveralIterations.this.realCardinality = this.number;
close();
}
if (b != null) this.number++;
return b;
}
@Override
public void remove() {
currentResult.remove();
}
@Override
public void finalize() {
close();
}
});
return result;
} else {
return null;
}
} else {
return null;
}
}