Package org.apache.lucene.search

Class BM25FQuery.BM25FWeight

java.lang.Object

org.apache.lucene.search.Weight

org.apache.lucene.search.BM25FQuery.BM25FWeight

All Implemented Interfaces:

SegmentCacheable

Enclosing class:

BM25FQuery

class BM25FQuery.BM25FWeight
extends Weight

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	Description
private final IndexSearcher	searcher
private final Similarity.SimScorer	simWeight
private final TermStates[]	termStates

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

parentQuery

Constructor Summary

Constructors

Constructor	Description
BM25FWeight(Query query, IndexSearcher searcher, ScoreMode scoreMode, float boost)

Method Summary

Modifier and Type	Method	Description
Explanation	explain(LeafReaderContext context, int doc)	An explanation of the score computation for the named document.
void	extractTerms(Set<Term> termSet)	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
private CollectionStatistics	mergeCollectionStatistics(IndexSearcher searcher)
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 Details

searcher

private final IndexSearcher searcher

termStates

private final TermStates[] termStates

simWeight

private final Similarity.SimScorer simWeight

Constructor Details

BM25FWeight

BM25FWeight(Query query,
 IndexSearcher searcher,
 ScoreMode scoreMode,
 float boost)
     throws IOException

Throws:

IOException

Method Details

mergeCollectionStatistics

private CollectionStatistics mergeCollectionStatistics(IndexSearcher searcher)
                                                throws IOException

Throws:

IOException

extractTerms

public void extractTerms(Set<Term> termSet)

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

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

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

isCacheable

public boolean isCacheable(LeafReaderContext ctx)

Returns:

true if the object can be cached against a given leaf