/** Get exactly one triple, or null for none or more than one. */
public static Triple triple1(DatasetGraph dsg, Node s, Node p, Node o) {
Iterator<Quad> iter = dsg.find(Node.ANY, s, p, o);
if (!iter.hasNext()) return null;
Quad q = iter.next();
if (iter.hasNext()) return null;
return q.asTriple();
}
@Override
protected boolean accepts(Object key, QuadWritable tuple) {
Quad q = tuple.get();
if (!q.isConcrete()) return false;
// Ground if all nodes are URI/Literal
return (q.getGraph().isURI() || q.getGraph().isLiteral())
&& (q.getSubject().isURI() || q.getSubject().isLiteral())
&& (q.getPredicate().isURI() || q.getPredicate().isLiteral())
&& (q.getObject().isURI() || q.getObject().isLiteral());
}
/**
* 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);
}
private ListMultimap<String, TextHit> query(
Node property, String queryString, int limit, ExecutionContext execCxt) {
// use the graph information in the text index if possible
if (textIndex.getDocDef().getGraphField() != null
&& execCxt.getActiveGraph() instanceof GraphView) {
GraphView activeGraph = (GraphView) execCxt.getActiveGraph();
if (!Quad.isUnionGraph(activeGraph.getGraphName())) {
String uri =
activeGraph.getGraphName() != null
? TextQueryFuncs.graphNodeToString(activeGraph.getGraphName())
: Quad.defaultGraphNodeGenerated.getURI();
String escaped = QueryParserBase.escape(uri);
String qs2 = textIndex.getDocDef().getGraphField() + ":" + escaped;
queryString = "(" + queryString + ") AND " + qs2;
}
}
// for language-based search extension
if (textIndex.getDocDef().getLangField() != null) {
String field = textIndex.getDocDef().getLangField();
if (langArg != null) {
String qs2 = !"none".equals(langArg) ? field + ":" + langArg : "-" + field + ":*";
queryString = "(" + queryString + ") AND " + qs2;
}
}
Explain.explain(execCxt.getContext(), "Text query: " + queryString);
if (log.isDebugEnabled()) log.debug("Text query: {} ({})", queryString, limit);
String cacheKey = limit + " " + property + " " + queryString;
Cache<String, ListMultimap<String, TextHit>> queryCache =
(Cache<String, ListMultimap<String, TextHit>>) execCxt.getContext().get(cacheSymbol);
if (queryCache == null) {
/* doesn't yet exist, need to create it */
queryCache = CacheFactory.createCache(CACHE_SIZE);
execCxt.getContext().put(cacheSymbol, queryCache);
}
final String queryStr = queryString; // final needed for the lambda function
ListMultimap<String, TextHit> results =
queryCache.getOrFill(
cacheKey,
() -> {
List<TextHit> resultList = textIndex.query(property, queryStr, limit);
ListMultimap<String, TextHit> resultMultimap = LinkedListMultimap.create();
for (TextHit result : resultList) {
resultMultimap.put(result.getNode().getURI(), result);
}
return resultMultimap;
});
return results;
}
@Override
public QuadBlock rewrite(SDBRequest request, QuadBlock quadBlock) {
// Does not consider if the property slot is a variable.
if (!quadBlock.contains(null, null, rdfType, null)) return quadBlock;
quadBlock = new QuadBlock(quadBlock);
int i = 0;
// Better/clearer : do as copy over from one block to another.
while ((i = quadBlock.findFirst(i, null, null, rdfType, null)) != -1) {
// { :s rdf:type :C } => { :s rdf:type ?V . ?V rdfs:subClassOf :C }
Quad rdfTypeQuad = quadBlock.get(i);
Var var = request.genVar();
Quad q1 = new Quad(rdfTypeQuad.getGraph(), rdfTypeQuad.getSubject(), rdfType, var);
Quad q2 =
new Quad(rdfTypeQuad.getGraph(), var, RDFS.subClassOf.asNode(), rdfTypeQuad.getObject());
quadBlock.set(i, q1); // replace rdf:type statement
quadBlock.add(i + 1, q2); // add subClassOf statement
i = i + 2; // Skip the two statements.
}
return quadBlock;
}