Package org.apache.lucene.search.grouping

Class TopGroups<T>

java.lang.Object

org.apache.lucene.search.grouping.TopGroups<T>

public class TopGroups<T>
extends Object

Represents result returned by a grouping search.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	TopGroups.ScoreMergeMode	How the GroupDocs score (if any) should be merged.

Field Summary

Fields

Modifier and Type	Field	Description
GroupDocs<T>[]	groups	Group results in groupSort order
SortField[]	groupSort	How groups are sorted against each other
float	maxScore	Highest score across all hits, or Float.NaN if scores were not computed.
Integer	totalGroupCount	The total number of unique groups.
int	totalGroupedHitCount	Number of documents grouped into the topN groups
int	totalHitCount	Number of documents matching the search
SortField[]	withinGroupSort	How docs are sorted within each group

Constructor Summary

Constructors

Constructor	Description
TopGroups(TopGroups<T> oldTopGroups, Integer totalGroupCount)
TopGroups(SortField[] groupSort, SortField[] withinGroupSort, int totalHitCount, int totalGroupedHitCount, GroupDocs<T>[] groups, float maxScore)

Method Summary

Modifier and Type	Method	Description
static <T> TopGroups<T>	merge(TopGroups<T>[] shardGroups, Sort groupSort, Sort docSort, int docOffset, int docTopN, TopGroups.ScoreMergeMode scoreMergeMode)	Merges an array of TopGroups, for example obtained from the second-pass collector across multiple shards.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

totalHitCount

public final int totalHitCount

Number of documents matching the search

totalGroupedHitCount

public final int totalGroupedHitCount

Number of documents grouped into the topN groups

totalGroupCount

public final Integer totalGroupCount

The total number of unique groups. If null this value is not computed.

groups

public final GroupDocs<T>[] groups

Group results in groupSort order

groupSort

public final SortField[] groupSort

How groups are sorted against each other

withinGroupSort

public final SortField[] withinGroupSort

How docs are sorted within each group

maxScore

public final float maxScore

Highest score across all hits, or Float.NaN if scores were not computed.

Constructor Detail

TopGroups

public TopGroups(SortField[] groupSort,
                 SortField[] withinGroupSort,
                 int totalHitCount,
                 int totalGroupedHitCount,
                 GroupDocs<T>[] groups,
                 float maxScore)

TopGroups

public TopGroups(TopGroups<T> oldTopGroups,
                 Integer totalGroupCount)

Method Detail

merge

public static <T> TopGroups<T> merge(TopGroups<T>[] shardGroups,
                                     Sort groupSort,
                                     Sort docSort,
                                     int docOffset,
                                     int docTopN,
                                     TopGroups.ScoreMergeMode scoreMergeMode)

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.

NOTE: 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.

NOTE: the topDocs in each GroupDocs is actually an instance of TopDocsAndShards