org.apache.lucene.search

Class BooleanWeight

java.lang.Object

org.apache.lucene.search.Weight

org.apache.lucene.search.BooleanWeight

final class BooleanWeight
extends Weight

Expert: the Weight for BooleanQuery, used to normalize, score and explain these queries.

Nested Class Summary

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

Weight.DefaultBulkScorer

Field Summary

Fields

Modifier and Type	Field and Description
(package private) float[]	coords
(package private) boolean	disableCoord
(package private) int	maxCoord
(package private) boolean	needsScores
(package private) BooleanQuery	query
(package private) Similarity	similarity The Similarity implementation.
(package private) java.util.ArrayList<Weight>	weights

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

parentQuery

Constructor Summary

Constructors

Constructor and Description
BooleanWeight(BooleanQuery query, IndexSearcher searcher, boolean needsScores, boolean disableCoord)

Method Summary

Modifier and Type	Method and Description
(package private) BulkScorer	booleanScorer(LeafReaderContext context) Try to build a boolean scorer for this weight.
BulkScorer	bulkScorer(LeafReaderContext context) Optional method, to return a BulkScorer to score the query and send hits to a Collector.
float	coord(int overlap, int maxOverlap)
(package private) static BulkScorer	disableScoring(BulkScorer scorer)
private Scorer	excl(Scorer main, java.util.List<Scorer> prohibited)
Explanation	explain(LeafReaderContext context, int doc) An explanation of the score computation for the named document.
void	extractTerms(java.util.Set<Term> terms) Expert: adds all terms occurring in this query to the terms set.
float	getValueForNormalization() The value for normalization of contained query clauses (e.g.
void	normalize(float norm, float boost) Assigns the query normalization factor and boost to this.
private Scorer	opt(java.util.List<Scorer> optional, int minShouldMatch, boolean disableCoord)
(package private) BulkScorer	optionalBulkScorer(LeafReaderContext context)
private Scorer	req(java.util.List<Scorer> required, java.util.List<Scorer> requiredScoring, boolean disableCoord) Create a new scorer for the given required clauses.
private BulkScorer	requiredBulkScorer(LeafReaderContext context)
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

getQuery

Methods inherited from class java.lang.Object

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

Field Detail

similarity

final Similarity similarity

The Similarity implementation.

query

final BooleanQuery query

weights

final java.util.ArrayList<Weight> weights

maxCoord

final int maxCoord

disableCoord

final boolean disableCoord

needsScores

final boolean needsScores

coords

final float[] coords

Constructor Detail

BooleanWeight

BooleanWeight(BooleanQuery query,
              IndexSearcher searcher,
              boolean needsScores,
              boolean disableCoord)
       throws java.io.IOException

Throws:

java.io.IOException

Method Detail

extractTerms

public void extractTerms(java.util.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

getValueForNormalization

public float getValueForNormalization()
                               throws java.io.IOException

Description copied from class: Weight

The value for normalization of contained query clauses (e.g. sum of squared weights).

Specified by:

getValueForNormalization in class Weight

Throws:

java.io.IOException

coord

public float coord(int overlap,
                   int maxOverlap)

normalize

public void normalize(float norm,
                      float boost)

Description copied from class: Weight

Assigns the query normalization factor and boost to this.

Specified by:

normalize in class Weight

explain

public Explanation explain(LeafReaderContext context,
                           int doc)
                    throws java.io.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:

java.io.IOException - if an IOException occurs

disableScoring

static BulkScorer disableScoring(BulkScorer scorer)

optionalBulkScorer

BulkScorer optionalBulkScorer(LeafReaderContext context)
                       throws java.io.IOException

Throws:

java.io.IOException

requiredBulkScorer

private BulkScorer requiredBulkScorer(LeafReaderContext context)
                               throws java.io.IOException

Throws:

java.io.IOException

booleanScorer

BulkScorer booleanScorer(LeafReaderContext context)
                  throws java.io.IOException

Try to build a boolean scorer for this weight. Returns null if BooleanScorer cannot be used.

Throws:

java.io.IOException

bulkScorer

public BulkScorer bulkScorer(LeafReaderContext context)
                      throws java.io.IOException

Description copied from class: Weight

Optional method, to return a BulkScorer to score the query and send hits to a Collector. Only queries that have a different top-level approach need to override this; the default implementation pulls a normal Scorer and iterates and collects the resulting hits which are not marked as deleted.

Overrides:

bulkScorer in class Weight

Parameters:

context - the LeafReaderContext for which to return the Scorer.

Returns:

a BulkScorer which scores documents and passes them to a collector.

Throws:

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

scorer

public Scorer scorer(LeafReaderContext context)
              throws java.io.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:

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

req

private Scorer req(java.util.List<Scorer> required,
                   java.util.List<Scorer> requiredScoring,
                   boolean disableCoord)

Create a new scorer for the given required clauses. Note that requiredScoring is a subset of required containing required clauses that should participate in scoring.

excl

private Scorer excl(Scorer main,
                    java.util.List<Scorer> prohibited)
             throws java.io.IOException

Throws:

java.io.IOException

opt

private Scorer opt(java.util.List<Scorer> optional,
                   int minShouldMatch,
                   boolean disableCoord)
            throws java.io.IOException

Throws:

java.io.IOException