Module org.apache.lucene.facet

Package org.apache.lucene.facet

Class FacetsCollector

java.lang.Object

org.apache.lucene.search.SimpleCollector

org.apache.lucene.facet.FacetsCollector

All Implemented Interfaces:

Collector, LeafCollector

Direct Known Subclasses:

FacetsCollectorManager.ReducedFacetsCollector, RandomSamplingFacetsCollector

public class FacetsCollector
extends SimpleCollector

Collects hits for subsequent faceting. Once you've run a search and collect hits into this, instantiate one of the Facets subclasses to do the facet counting. Use the search utility methods to perform an "ordinary" search but also collect into a Collector.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final record	FacetsCollector.MatchingDocs	Holds the documents that were matched in the LeafReaderContext.

Field Summary

Fields

Modifier and Type	Field	Description
private LeafReaderContext	context
private DocIdSetBuilder	docsBuilder
private final boolean	keepScores
private final List<FacetsCollector.MatchingDocs>	matchingDocs
private Scorable	scorer
private float[]	scores
private int	totalHits

Constructor Summary

Constructors

Constructor	Description
FacetsCollector()	Default constructor
FacetsCollector(boolean keepScores)	Create this; if keepScores is true then a float[] is allocated to hold score of all hits.

Method Summary

Modifier and Type	Method	Description
void	collect(int doc)	Called once for every document matching a query, with the unbased document number.
protected void	doSetNextReader(LeafReaderContext context)	This method is called before collecting context.
void	finish()	Hook that gets called once the leaf that is associated with this collector has finished collecting successfully, including when a CollectionTerminatedException is thrown.
final boolean	getKeepScores()	True if scores were saved.
List<FacetsCollector.MatchingDocs>	getMatchingDocs()	Returns the documents matched by the query, one FacetsCollector.MatchingDocs per visited segment.
ScoreMode	scoreMode()	Indicates what features are required from the scorer.
final void	setScorer(Scorable scorer)	Called before successive calls to LeafCollector.collect(int).

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

getLeafCollector

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

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

collect, competitiveIterator

Field Details

context

private LeafReaderContext context

scorer

private Scorable scorer

totalHits

private int totalHits

scores

private float[] scores

keepScores

private final boolean keepScores

matchingDocs

private final List<FacetsCollector.MatchingDocs> matchingDocs

docsBuilder

private DocIdSetBuilder docsBuilder

Constructor Details

FacetsCollector

public FacetsCollector()

Default constructor

FacetsCollector

public FacetsCollector(boolean keepScores)

Create this; if keepScores is true then a float[] is allocated to hold score of all hits.

Method Details

getKeepScores

public final boolean getKeepScores()

True if scores were saved.

getMatchingDocs

public List<FacetsCollector.MatchingDocs> getMatchingDocs()

Returns the documents matched by the query, one FacetsCollector.MatchingDocs per visited segment.

collect

public void collect(int doc)
             throws IOException

Description copied from interface: LeafCollector

Called once for every document matching a query, with the unbased document number.

Note: The collection of the current segment can be terminated by throwing a CollectionTerminatedException. In this case, the last docs of the current LeafReaderContext will be skipped and IndexSearcher will swallow the exception and continue collection with the next leaf.

Note: This is called in an inner search loop. For good search performance, implementations of this method should not call StoredFields.document(int) on every hit. Doing so can slow searches by an order of magnitude or more.

Specified by:

collect in interface LeafCollector

Specified by:

collect in class SimpleCollector

Throws:

IOException

scoreMode

public ScoreMode scoreMode()

Description copied from interface: Collector

Indicates what features are required from the scorer.

setScorer

public final void setScorer(Scorable scorer)
                     throws IOException

Description copied from interface: LeafCollector

Called before successive calls to LeafCollector.collect(int). Implementations that need the score of the current document (passed-in to LeafCollector.collect(int)), should save the passed-in Scorer and call scorer.score() when needed.

Specified by:

setScorer in interface LeafCollector

Overrides:

setScorer in class SimpleCollector

Throws:

IOException

doSetNextReader

protected void doSetNextReader(LeafReaderContext context)
                        throws IOException

Description copied from class: SimpleCollector

This method is called before collecting context.

Overrides:

doSetNextReader in class SimpleCollector

Throws:

IOException

finish

public void finish()
            throws IOException

Description copied from interface: LeafCollector

Hook that gets called once the leaf that is associated with this collector has finished collecting successfully, including when a CollectionTerminatedException is thrown. This is typically useful to compile data that has been collected on this leaf, e.g. to convert facet counts on leaf ordinals to facet counts on global ordinals. The default implementation does nothing.

Note: It can be assumed that this method will only be called once per LeafCollector instance.

Throws:

IOException