Module org.apache.lucene.core

Package org.apache.lucene.search

Class TopScoreDocCollector

java.lang.Object

org.apache.lucene.search.TopDocsCollector<ScoreDoc>

org.apache.lucene.search.TopScoreDocCollector

All Implemented Interfaces:

Collector

public class TopScoreDocCollector
extends TopDocsCollector<ScoreDoc>

A Collector implementation that collects the top-scoring hits, returning them as a TopDocs. This is used by IndexSearcher to implement TopDocs-based search. Hits are sorted by score descending and then (when the scores are tied) docID ascending. When you create an instance of this collector you should know in advance whether documents are going to be collected in doc Id order or not.

NOTE: The values Float.NaN and Float.NEGATIVE_INFINITY are not valid scores. This collector will not properly collect hits with such scores.

Field Summary

Fields

Modifier and Type	Field	Description
private final ScoreDoc	after
(package private) final MaxScoreAccumulator	minScoreAcc
(package private) final int	totalHitsThreshold

Fields inherited from class org.apache.lucene.search.TopDocsCollector

EMPTY_TOPDOCS, pq, totalHits, totalHitsRelation

Constructor Summary

Constructors

Constructor	Description
TopScoreDocCollector(int numHits, ScoreDoc after, int totalHitsThreshold, MaxScoreAccumulator minScoreAcc)

Method Summary

Modifier and Type	Method	Description
LeafCollector	getLeafCollector(LeafReaderContext context)	Create a new collector to collect the given context.
protected TopDocs	newTopDocs(ScoreDoc[] results, int start)	Returns a TopDocs instance containing the given results.
ScoreMode	scoreMode()	Indicates what features are required from the scorer.
protected int	topDocsSize()	The number of valid PQ entries

Methods inherited from class org.apache.lucene.search.TopDocsCollector

getTotalHits, populateResults, topDocs, topDocs, topDocs

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.lucene.search.Collector

setWeight

Field Details

after

private final ScoreDoc after

totalHitsThreshold

final int totalHitsThreshold

minScoreAcc

final MaxScoreAccumulator minScoreAcc

Constructor Details

TopScoreDocCollector

TopScoreDocCollector(int numHits,
 ScoreDoc after,
 int totalHitsThreshold,
 MaxScoreAccumulator minScoreAcc)

Method Details

topDocsSize

protected int topDocsSize()

Description copied from class: TopDocsCollector

The number of valid PQ entries

Overrides:

topDocsSize in class TopDocsCollector<ScoreDoc>

newTopDocs

protected TopDocs newTopDocs(ScoreDoc[] results,
 int start)

Description copied from class: TopDocsCollector

Returns a TopDocs instance containing the given results. If results is null it means there are no results to return, either because there were 0 calls to collect() or because the arguments to topDocs were invalid.

Overrides:

newTopDocs in class TopDocsCollector<ScoreDoc>

scoreMode

public ScoreMode scoreMode()

Description copied from interface: Collector

Indicates what features are required from the scorer.

getLeafCollector

public LeafCollector getLeafCollector(LeafReaderContext context)
                               throws IOException

Description copied from interface: Collector

Create a new collector to collect the given context.

Parameters:

context - next atomic reader context

Throws:

IOException