@Override
public QueryIterator execOneList(
Binding binding, Node listNode, Node predicate, Node length, ExecutionContext execCxt) {
Graph graph = execCxt.getActiveGraph();
if (Var.isVar(listNode))
throw new ARQInternalErrorException("listLength: Subject is a variable");
// Case : arg 1 (the list) is bound and arg 2 not bound => generate possibilities
// Case : arg 1 is bound and arg 2 is bound => test for membership.
if (Var.isVar(length)) return length(binding, graph, listNode, Var.alloc(length), execCxt);
else return verify(binding, graph, listNode, length, execCxt);
}
private QueryIterator resultsToQueryIterator(
Binding binding,
Node s,
Node score,
Node literal,
Collection<TextHit> results,
ExecutionContext execCxt) {
Var sVar = Var.isVar(s) ? Var.alloc(s) : null;
Var scoreVar = (score == null) ? null : Var.alloc(score);
Var literalVar = (literal == null) ? null : Var.alloc(literal);
Function<TextHit, Binding> converter =
(TextHit hit) -> {
if (score == null && literal == null)
return sVar != null
? BindingFactory.binding(binding, sVar, hit.getNode())
: BindingFactory.binding(binding);
BindingMap bmap = BindingFactory.create(binding);
if (sVar != null) bmap.add(sVar, hit.getNode());
if (scoreVar != null) bmap.add(scoreVar, NodeFactoryExtra.floatToNode(hit.getScore()));
if (literalVar != null) bmap.add(literalVar, hit.getLiteral());
return bmap;
};
Iterator<Binding> bIter = Iter.map(results.iterator(), converter);
QueryIterator qIter = new QueryIterPlainWrapper(bIter, execCxt);
return qIter;
}
/**
* Choose a graph from a DatasetGraph. If it's the union, provide a union graph (not always the
* best way to deal with union).
*
* @param dataset
* @param graphNode
* @return Graph
*/
protected static Graph chooseGraph(DatasetGraph dataset, Node graphNode) {
if (graphNode == null) return dataset.getDefaultGraph();
else if (Var.isVar(graphNode))
throw new NotImplemented("Choosing a graph OpExecutorStage.executeBlockFilter[Variable]");
else if (graphNode == Node.ANY)
throw new NotImplemented("OpExecutorMain.executeBlockFilter[Node.ANY]");
else if (Quad.isUnionGraph(graphNode)) {
// TODO Check this! Work needed here to consolidate union graph handling.
List<Node> graphs = Iter.toList(dataset.listGraphNodes());
return new GraphUnionRead(dataset, graphs);
} else return dataset.getGraph(graphNode);
}
@Override
public QueryIterator exec(
Binding binding,
PropFuncArg argSubject,
Node predicate,
PropFuncArg argObject,
ExecutionContext execCxt) {
if (textIndex == null) {
if (!warningIssued) {
Log.warn(getClass(), "No text index - no text search performed");
warningIssued = true;
}
// Not a text dataset - no-op
return IterLib.result(binding, execCxt);
}
DatasetGraph dsg = execCxt.getDataset();
argSubject = Substitute.substitute(argSubject, binding);
argObject = Substitute.substitute(argObject, binding);
Node s = null;
Node score = null;
Node literal = null;
if (argSubject.isList()) {
// Length checked in build()
s = argSubject.getArg(0);
score = argSubject.getArg(1);
if (!score.isVariable())
throw new QueryExecException("Hit score is not a variable: " + argSubject);
if (argSubject.getArgListSize() > 2) {
literal = argSubject.getArg(2);
if (!literal.isVariable())
throw new QueryExecException("Hit literal is not a variable: " + argSubject);
}
} else {
s = argSubject.getArg();
}
if (s.isLiteral())
// Does not match
return IterLib.noResults(execCxt);
StrMatch match = objectToStruct(argObject, true);
if (match == null) {
// can't match
return IterLib.noResults(execCxt);
}
// ----
QueryIterator qIter =
(Var.isVar(s))
? variableSubject(binding, s, score, literal, match, execCxt)
: concreteSubject(binding, s, score, literal, match, execCxt);
if (match.getLimit() >= 0) qIter = new QueryIterSlice(qIter, 0, match.getLimit(), execCxt);
return qIter;
}