org.apache.lucene.search

Class FilterWeight

java.lang.Object

org.apache.lucene.search.Weight

org.apache.lucene.search.FilterWeight

All Implemented Interfaces:

SegmentCacheable

public abstract class FilterWeight
extends Weight

A FilterWeight contains another Weight and implements all abstract methods by calling the contained weight's method. Note that FilterWeight does not override the non-abstract Weight.bulkScorer(LeafReaderContext) method and subclasses of FilterWeight must provide their bulkScorer implementation if required.

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.search.Weight

Weight.DefaultBulkScorer, Weight.StartDISIWrapper

Field Summary

Fields

Modifier and Type	Field and Description
protected Weight	in

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

parentQuery

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	FilterWeight(Query query, Weight weight) Alternative constructor.
protected	FilterWeight(Weight weight) Default constructor.

Method Summary

Modifier and Type	Method and Description
Explanation	explain(LeafReaderContext context, int doc) An explanation of the score computation for the named document.
void	extractTerms(Set<Term> terms) Expert: adds all terms occurring in this query to the terms set.
boolean	isCacheable(LeafReaderContext ctx)
Matches	matches(LeafReaderContext context, int doc) Returns Matches for a specific document, or null if the document does not match the parent query A query match that contains no position information (for example, a Point or DocValues query) will return MatchesUtils.MATCH_WITH_NO_TERMS
Scorer	scorer(LeafReaderContext context) Returns a Scorer which can iterate in order over all matching documents and assign them a score.

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

bulkScorer, getQuery, scorerSupplier

Methods inherited from class java.lang.Object

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

Field Detail

in

protected final Weight in

Constructor Detail

FilterWeight

protected FilterWeight(Weight weight)

Default constructor.

FilterWeight

protected FilterWeight(Query query,
                       Weight weight)

Alternative constructor. Use this variant only if the weight was not obtained via the Query.createWeight(IndexSearcher, ScoreMode, float) method of the query object.

Method Detail

isCacheable

public boolean isCacheable(LeafReaderContext ctx)

Returns:

true if the object can be cached against a given leaf

extractTerms

public void extractTerms(Set<Term> terms)

Description copied from class: Weight

Expert: adds all terms occurring in this query to the terms set. If the Weight was created with needsScores == true then this method will only extract terms which are used for scoring, otherwise it will extract all terms which are used for matching.

Specified by:

extractTerms in class Weight

explain

public Explanation explain(LeafReaderContext context,
                           int doc)
                    throws IOException

Description copied from class: Weight

An explanation of the score computation for the named document.

Specified by:

explain in class Weight

Parameters:

context - the readers context to create the Explanation for.

doc - the document's id relative to the given context's reader

Returns:

an Explanation for the score

Throws:

IOException - if an IOException occurs

scorer

public Scorer scorer(LeafReaderContext context)
              throws IOException

Description copied from class: Weight

Returns a Scorer which can iterate in order over all matching documents and assign them a score.

NOTE: null can be returned if no documents will be scored by this query.

NOTE: The returned Scorer does not have LeafReader.getLiveDocs() applied, they need to be checked on top.

Specified by:

scorer in class Weight

Parameters:

context - the LeafReaderContext for which to return the Scorer.

Returns:

a Scorer which scores documents in/out-of order.

Throws:

IOException - if there is a low-level I/O error

matches

public Matches matches(LeafReaderContext context,
                       int doc)
                throws IOException

Description copied from class: Weight

Returns Matches for a specific document, or null if the document does not match the parent query A query match that contains no position information (for example, a Point or DocValues query) will return MatchesUtils.MATCH_WITH_NO_TERMS

Overrides:

matches in class Weight

Parameters:

context - the reader's context to create the Matches for

doc - the document's id relative to the given context's reader

Throws:

IOException