/**
* Accumulates groups for the BlockJoinQuery specified by its slot.
*
* @param slot Search query's slot
* @param offset Parent docs offset
* @param maxDocsPerGroup Upper bound of documents per group number
* @param withinGroupOffset Offset within each group of child docs
* @param withinGroupSort Sort criteria within groups
* @param fillSortFields Specifies whether to add sort fields or not
* @return TopGroups for the query specified by slot
* @throws IOException if there is a low-level I/O error
*/
@SuppressWarnings({"unchecked", "rawtypes"})
private TopGroups<Integer> accumulateGroups(
int slot,
int offset,
int maxDocsPerGroup,
int withinGroupOffset,
Sort withinGroupSort,
boolean fillSortFields)
throws IOException {
final GroupDocs<Integer>[] groups = new GroupDocs[sortedGroups.length - offset];
final FakeScorer fakeScorer = new FakeScorer();
int totalGroupedHitCount = 0;
// System.out.println("slot=" + slot);
for (int groupIDX = offset; groupIDX < sortedGroups.length; groupIDX++) {
final OneGroup og = sortedGroups[groupIDX];
final int numChildDocs;
if (slot == -1 || slot >= og.counts.length) {
numChildDocs = 0;
} else {
numChildDocs = og.counts[slot];
}
// Number of documents in group should be bounded to prevent redundant memory allocation
final int numDocsInGroup = Math.max(1, Math.min(numChildDocs, maxDocsPerGroup));
// System.out.println("parent doc=" + og.doc + " numChildDocs=" + numChildDocs + " maxDocsPG="
// + maxDocsPerGroup);
// At this point we hold all docs w/ in each group,
// unsorted; we now sort them:
final TopDocsCollector<?> collector;
if (withinGroupSort == null) {
// System.out.println("sort by score");
// Sort by score
if (!trackScores) {
throw new IllegalArgumentException(
"cannot sort by relevance within group: trackScores=false");
}
collector = TopScoreDocCollector.create(numDocsInGroup, true);
} else {
// Sort by fields
collector =
TopFieldCollector.create(
withinGroupSort, numDocsInGroup, fillSortFields, trackScores, trackMaxScore, true);
}
collector.setScorer(fakeScorer);
collector.setNextReader(og.readerContext);
for (int docIDX = 0; docIDX < numChildDocs; docIDX++) {
// System.out.println("docIDX=" + docIDX + " vs " + og.docs[slot].length);
final int doc = og.docs[slot][docIDX];
fakeScorer.doc = doc;
if (trackScores) {
fakeScorer.score = og.scores[slot][docIDX];
}
collector.collect(doc);
}
totalGroupedHitCount += numChildDocs;
final Object[] groupSortValues;
if (fillSortFields) {
groupSortValues = new Object[comparators.length];
for (int sortFieldIDX = 0; sortFieldIDX < comparators.length; sortFieldIDX++) {
groupSortValues[sortFieldIDX] = comparators[sortFieldIDX].value(og.slot);
}
} else {
groupSortValues = null;
}
final TopDocs topDocs = collector.topDocs(withinGroupOffset, numDocsInGroup);
groups[groupIDX - offset] =
new GroupDocs<>(
og.score,
topDocs.getMaxScore(),
numChildDocs,
topDocs.scoreDocs,
og.doc,
groupSortValues);
}
return new TopGroups<>(
new TopGroups<>(
sort.getSort(),
withinGroupSort == null ? null : withinGroupSort.getSort(),
0,
totalGroupedHitCount,
groups,
maxScore),
totalHitCount);
}