private void UpdateNextGroup(int topN, ShardIter <T> shard)
{
while (shard.Iter.MoveNext())
{
ISearchGroup <T> group = shard.Next();
MergedGroup <T> mergedGroup = groupsSeen.ContainsKey(group.GroupValue) ? groupsSeen[group.GroupValue] : null;
bool isNew = mergedGroup == null;
//System.out.println(" next group=" + (group.groupValue == null ? "null" : ((BytesRef) group.groupValue).utf8ToString()) + " sort=" + Arrays.toString(group.sortValues));
if (isNew)
{
// Start a new group:
//System.out.println(" new");
mergedGroup = new MergedGroup <T>(group.GroupValue);
mergedGroup.MinShardIndex = shard.ShardIndex;
Debug.Assert(group.SortValues != null);
mergedGroup.TopValues = group.SortValues;
groupsSeen[group.GroupValue] = mergedGroup;
mergedGroup.IsInQueue = true;
queue.Add(mergedGroup);
}
else if (mergedGroup.IsProcessed)
{
// This shard produced a group that we already
// processed; move on to next group...
continue;
}
else
{
//System.out.println(" old");
bool competes = false;
for (int compIDX = 0; compIDX < groupComp.Comparers.Length; compIDX++)
{
int cmp = groupComp.Reversed[compIDX] * groupComp.Comparers[compIDX].CompareValues(group.SortValues[compIDX],
mergedGroup.TopValues[compIDX]);
if (cmp < 0)
{
// Definitely competes
competes = true;
break;
}
else if (cmp > 0)
{
// Definitely does not compete
break;
}
else if (compIDX == groupComp.Comparers.Length - 1)
{
if (shard.ShardIndex < mergedGroup.MinShardIndex)
{
competes = true;
}
}
}
//System.out.println(" competes=" + competes);
if (competes)
{
// Group's sort changed -- remove & re-insert
if (mergedGroup.IsInQueue)
{
queue.Remove(mergedGroup);
}
mergedGroup.TopValues = group.SortValues;
mergedGroup.MinShardIndex = shard.ShardIndex;
queue.Add(mergedGroup);
mergedGroup.IsInQueue = true;
}
}
mergedGroup.Shards.Add(shard);
break;
}
// Prune un-competitive groups:
while (queue.Count > topN)
{
MergedGroup <T> group = queue.Last();
queue.Remove(group);
//System.out.println("PRUNE: " + group);
group.IsInQueue = false;
}
}