@Override
public Scorer filteredScorer(LeafReaderContext context, Weight weight, DocIdSet docIdSet)
throws IOException {
// CHANGE: If threshold is 0, always pass down the accept docs, don't pay the price of calling
// nextDoc even...
final Bits filterAcceptDocs = docIdSet.bits();
if (threshold == 0) {
if (filterAcceptDocs != null) {
return weight.scorer(context, filterAcceptDocs);
} else {
return FilteredQuery.LEAP_FROG_QUERY_FIRST_STRATEGY.filteredScorer(
context, weight, docIdSet);
}
}
// CHANGE: handle "default" value
if (threshold == -1) {
// default value, don't iterate on only apply filter after query if its not a "fast"
// docIdSet
// TODO: is there a way we could avoid creating an iterator here?
if (filterAcceptDocs != null && DocIdSets.isBroken(docIdSet.iterator())) {
return FilteredQuery.QUERY_FIRST_FILTER_STRATEGY.filteredScorer(
context, weight, docIdSet);
}
}
return super.filteredScorer(context, weight, docIdSet);
}
@Override
public DocIdSetIterator iterator() throws IOException {
// we try and be smart here, if we can iterate through docsets quickly, prefer to iterate
// over them as much as possible, before actually going to "bits" based ones to check
List<DocIdSet> iterators = new ArrayList<DocIdSet>(sets.length);
List<Bits> bits = new ArrayList<Bits>(sets.length);
for (DocIdSet set : sets) {
if (DocIdSets.isFastIterator(set)) {
iterators.add(set);
} else {
Bits bit = set.bits();
if (bit != null) {
bits.add(bit);
} else {
iterators.add(set);
}
}
}
if (bits.isEmpty()) {
return new IteratorBasedIterator(iterators.toArray(new DocIdSet[iterators.size()]));
}
if (iterators.isEmpty()) {
return new BitsDocIdSetIterator(new AndBits(bits.toArray(new Bits[bits.size()])));
}
// combination of both..., first iterating over the "fast" ones, and then checking on the more
// expensive ones
return new BitsDocIdSetIterator.FilteredIterator(
new IteratorBasedIterator(iterators.toArray(new DocIdSet[iterators.size()])),
new AndBits(bits.toArray(new Bits[bits.size()])));
}
