@Override
protected double getCardinality(StatementPattern sp) {
logger.info("get cardinality");
try {
Value subj = getConstantValue(sp.getSubjectVar());
if (!(subj instanceof Resource)) {
// can happen when a previous optimizer has inlined a
// comparison operator.
// this can cause, for example, the subject variable to be
// equated to a literal value.
// See SES-970
subj = null;
}
Value pred = getConstantValue(sp.getPredicateVar());
if (!(pred instanceof URI)) {
// can happen when a previous optimizer has inlined a
// comparison operator. See SES-970
pred = null;
}
Value obj = getConstantValue(sp.getObjectVar());
Value context = getConstantValue(sp.getContextVar());
if (!(context instanceof Resource)) {
// can happen when a previous optimizer has inlined a
// comparison operator. See SES-970
context = null;
}
// System.out.println("begin to do kvStore.cardinalitty");
return kvStore.cardinality((Resource) subj, (URI) pred, obj, (Resource) context);
} catch (Exception e) {
logger.error(
"Failed to estimate statement pattern cardinality, falling back to generic implementation",
e);
return super.getCardinality(sp);
}
}
public void meet(StatementPattern node) {
if (!Scope.DEFAULT_CONTEXTS.equals(node.getScope())) {
basicPattern = false;
} else if (node.getContextVar() != null) {
basicPattern = false;
} else {
super.meet(node);
}
}
@Override
public void meet(StatementPattern node) throws RepositoryException {
Resource subj = (Resource) node.getSubjectVar().getValue();
IRI pred = (IRI) node.getPredicateVar().getValue();
Value obj = node.getObjectVar().getValue();
Resource[] ctx = getContexts(node.getContextVar());
for (RepositoryConnection member : members) {
if (member.hasStatement(subj, pred, obj, true, ctx)) {
return;
}
}
node.replaceWith(new EmptySet());
}
@Override
protected void meetSP(StatementPattern node) throws Exception {
StatementPattern sp = node.clone();
final Var predVar = sp.getPredicateVar();
URI pred = (URI) predVar.getValue();
String predNamespace = pred.getNamespace();
final Var objVar = sp.getObjectVar();
final Var cntxtVar = sp.getContextVar();
if (objVar != null
&& !RDF.NAMESPACE.equals(predNamespace)
&& !SESAME.NAMESPACE.equals(predNamespace)
&& !RDFS.NAMESPACE.equals(predNamespace)
&& !EXPANDED.equals(cntxtVar)) {
URI transPropUri = (URI) predVar.getValue();
if (inferenceEngine.isTransitiveProperty(transPropUri)) {
node.replaceWith(
new TransitivePropertySP(
sp.getSubjectVar(), sp.getPredicateVar(), sp.getObjectVar(), sp.getContextVar()));
}
}
}
