private static Filter genericFunctionFilter(Function function, Context context) {
if (function.valueType() != DataTypes.BOOLEAN) {
raiseUnsupported(function);
}
// avoid field-cache
// reason1: analyzed columns or columns with index off wouldn't work
// substr(n, 1, 1) in the case of n => analyzed would throw an error because n would be an
// array
// reason2: would have to load each value into the field cache
function = (Function) DocReferenceConverter.convertIf(function);
final CollectInputSymbolVisitor.Context ctx =
context.inputSymbolVisitor.extractImplementations(function);
assert ctx.topLevelInputs().size() == 1;
@SuppressWarnings("unchecked")
final Input<Boolean> condition = (Input<Boolean>) ctx.topLevelInputs().get(0);
@SuppressWarnings("unchecked")
final List<LuceneCollectorExpression> expressions = ctx.docLevelExpressions();
final CollectorContext collectorContext =
new CollectorContext(
context.mapperService,
context.fieldDataService,
new CollectorFieldsVisitor(expressions.size()));
for (LuceneCollectorExpression expression : expressions) {
expression.startCollect(collectorContext);
}
return new Filter() {
@Override
public DocIdSet getDocIdSet(AtomicReaderContext context, Bits acceptDocs)
throws IOException {
for (LuceneCollectorExpression expression : expressions) {
expression.setNextReader(context.reader().getContext());
}
return BitsFilteredDocIdSet.wrap(
new FunctionDocSet(
context.reader(),
collectorContext.visitor(),
condition,
expressions,
context.reader().maxDoc(),
acceptDocs),
acceptDocs);
}
};
}
@Override
protected boolean matchDoc(int doc) {
if (fieldsVisitorEnabled) {
fieldsVisitor.reset();
try {
reader.document(doc, fieldsVisitor);
} catch (IOException e) {
throw Throwables.propagate(e);
}
}
for (LuceneCollectorExpression expression : expressions) {
expression.setNextDocId(doc);
}
Boolean value = condition.value();
if (value == null) {
return false;
}
return value;
}