public TopGroups(TopGroups <TGroupValueType> oldTopGroups, int?totalGroupCount)
{
GroupSort = oldTopGroups.GroupSort;
WithinGroupSort = oldTopGroups.WithinGroupSort;
TotalHitCount = oldTopGroups.TotalHitCount;
TotalGroupedHitCount = oldTopGroups.TotalGroupedHitCount;
Groups = oldTopGroups.Groups;
MaxScore = oldTopGroups.MaxScore;
TotalGroupCount = totalGroupCount;
}
/// <summary>
/// Merges an array of TopGroups, for example obtained from the second-pass
/// collector across multiple shards. Each TopGroups must have been sorted by the
/// same groupSort and docSort, and the top groups passed to all second-pass
/// collectors must be the same.
///
/// <b>NOTE</b>: We can't always compute an exact totalGroupCount.
/// Documents belonging to a group may occur on more than
/// one shard and thus the merged totalGroupCount can be
/// higher than the actual totalGroupCount. In this case the
/// totalGroupCount represents a upper bound. If the documents
/// of one group do only reside in one shard then the
/// totalGroupCount is exact.
///
/// <b>NOTE</b>: the topDocs in each GroupDocs is actually
/// an instance of TopDocsAndShards
/// </summary>
public static TopGroups <T> Merge <T>(TopGroups <T>[] shardGroups, Sort groupSort, Sort docSort, int docOffset, int docTopN, ScoreMergeMode scoreMergeMode)
{
//System.out.println("TopGroups.merge");
if (shardGroups.Length == 0)
{
return(null);
}
int totalHitCount = 0;
int totalGroupedHitCount = 0;
// Optionally merge the totalGroupCount.
int?totalGroupCount = null;
int numGroups = shardGroups[0].Groups.Length;
foreach (var shard in shardGroups)
{
if (numGroups != shard.Groups.Length)
{
throw new ArgumentException("number of groups differs across shards; you must pass same top groups to all shards' second-pass collector");
}
totalHitCount += shard.TotalHitCount;
totalGroupedHitCount += shard.TotalGroupedHitCount;
if (shard.TotalGroupCount != null)
{
if (totalGroupCount == null)
{
totalGroupCount = 0;
}
totalGroupCount += shard.TotalGroupCount;
}
}
var mergedGroupDocs = new GroupDocs <T> [numGroups];
TopDocs[] shardTopDocs = new TopDocs[shardGroups.Length];
float totalMaxScore = float.MinValue;
for (int groupIDX = 0; groupIDX < numGroups; groupIDX++)
{
T groupValue = shardGroups[0].Groups[groupIDX].GroupValue;
//System.out.println(" merge groupValue=" + groupValue + " sortValues=" + Arrays.toString(shardGroups[0].groups[groupIDX].groupSortValues));
float maxScore = float.MinValue;
int totalHits = 0;
double scoreSum = 0.0;
for (int shardIdx = 0; shardIdx < shardGroups.Length; shardIdx++)
{
//System.out.println(" shard=" + shardIDX);
TopGroups <T> shard = shardGroups[shardIdx];
var shardGroupDocs = shard.Groups[groupIDX];
if (groupValue == null)
{
if (shardGroupDocs.GroupValue != null)
{
throw new ArgumentException("group values differ across shards; you must pass same top groups to all shards' second-pass collector");
}
}
else if (!groupValue.Equals(shardGroupDocs.GroupValue))
{
throw new ArgumentException("group values differ across shards; you must pass same top groups to all shards' second-pass collector");
}
/*
* for(ScoreDoc sd : shardGroupDocs.scoreDocs) {
* System.out.println(" doc=" + sd.doc);
* }
*/
shardTopDocs[shardIdx] = new TopDocs(shardGroupDocs.TotalHits, shardGroupDocs.ScoreDocs, shardGroupDocs.MaxScore);
maxScore = Math.Max(maxScore, shardGroupDocs.MaxScore);
totalHits += shardGroupDocs.TotalHits;
scoreSum += shardGroupDocs.Score;
}
TopDocs mergedTopDocs = TopDocs.Merge(docSort, docOffset + docTopN, shardTopDocs);
// Slice;
ScoreDoc[] mergedScoreDocs;
if (docOffset == 0)
{
mergedScoreDocs = mergedTopDocs.ScoreDocs;
}
else if (docOffset >= mergedTopDocs.ScoreDocs.Length)
{
mergedScoreDocs = new ScoreDoc[0];
}
else
{
mergedScoreDocs = new ScoreDoc[mergedTopDocs.ScoreDocs.Length - docOffset];
Array.Copy(mergedTopDocs.ScoreDocs, docOffset, mergedScoreDocs, 0, mergedTopDocs.ScoreDocs.Length - docOffset);
}
float groupScore;
switch (scoreMergeMode)
{
case ScoreMergeMode.None:
groupScore = float.NaN;
break;
case ScoreMergeMode.Avg:
if (totalHits > 0)
{
groupScore = (float)(scoreSum / totalHits);
}
else
{
groupScore = float.NaN;
}
break;
case ScoreMergeMode.Total:
groupScore = (float)scoreSum;
break;
default:
throw new ArgumentException("can't handle ScoreMergeMode " + scoreMergeMode);
}
//System.out.println("SHARDS=" + Arrays.toString(mergedTopDocs.shardIndex));
mergedGroupDocs[groupIDX] = new GroupDocs <T>(groupScore, maxScore, totalHits, mergedScoreDocs, groupValue, shardGroups[0].Groups[groupIDX].GroupSortValues);
totalMaxScore = Math.Max(totalMaxScore, maxScore);
}
if (totalGroupCount != null)
{
var result = new TopGroups <T>(groupSort.GetSort(), docSort == null ? null : docSort.GetSort(), totalHitCount, totalGroupedHitCount, mergedGroupDocs, totalMaxScore);
return(new TopGroups <T>(result, totalGroupCount));
}
return(new TopGroups <T>(groupSort.GetSort(), docSort == null ? null : docSort.GetSort(), totalHitCount, totalGroupedHitCount, mergedGroupDocs, totalMaxScore));
}
