/**
* Returns the TopGroups for the specified BlockJoinQuery. The groupValue of each GroupDocs will
* be the parent docID for that group. The number of documents within each group is calculated as
* minimum of <code>maxDocsPerGroup</code> and number of matched child documents for that group.
* Returns null if no groups matched.
*
* @param query Search query
* @param withinGroupSort Sort criteria within groups
* @param offset Parent docs offset
* @param maxDocsPerGroup Upper bound of documents per group number
* @param withinGroupOffset Offset within each group of child docs
* @param fillSortFields Specifies whether to add sort fields or not
* @return TopGroups for specified query
* @throws IOException if there is a low-level I/O error
*/
public TopGroups<Integer> getTopGroups(
ToParentBlockJoinQuery query,
Sort withinGroupSort,
int offset,
int maxDocsPerGroup,
int withinGroupOffset,
boolean fillSortFields)
throws IOException {
final Integer _slot = joinQueryID.get(query);
if (_slot == null && totalHitCount == 0) {
return null;
}
if (sortedGroups == null) {
if (offset >= queue.size()) {
return null;
}
sortQueue();
} else if (offset > sortedGroups.length) {
return null;
}
return accumulateGroups(
_slot == null ? -1 : _slot.intValue(),
offset,
maxDocsPerGroup,
withinGroupOffset,
withinGroupSort,
fillSortFields);
}
private void sortQueue() {
sortedGroups = new OneGroup[queue.size()];
for (int downTo = queue.size() - 1; downTo >= 0; downTo--) {
sortedGroups[downTo] = queue.pop();
}
}