Module org.apache.lucene.core

Package org.apache.lucene.search

Class DisjunctionMaxScorer

java.lang.Object

org.apache.lucene.search.Scorable

org.apache.lucene.search.Scorer

org.apache.lucene.search.DisjunctionScorer

org.apache.lucene.search.DisjunctionMaxScorer

final class DisjunctionMaxScorer
extends DisjunctionScorer

The Scorer for DisjunctionMaxQuery. The union of all documents generated by the subquery scorers is generated in document number order. The score for each document is the maximum of the scores computed by the subquery scorers that generate that document, plus tieBreakerMultiplier times the sum of the scores for the other subqueries that generate the document.

Nested Class Summary

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

Scorable.ChildScorable

Field Summary

Fields

Modifier and Type	Field	Description
private final DisjunctionScoreBlockBoundaryPropagator	disjunctionBlockPropagator
private final List<Scorer>	subScorers
private final float	tieBreakerMultiplier

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

weight

Constructor Summary

Constructors

Constructor	Description
DisjunctionMaxScorer(Weight weight, float tieBreakerMultiplier, List<Scorer> subScorers, ScoreMode scoreMode)	Creates a new instance of DisjunctionMaxScorer

Method Summary

Modifier and Type	Method	Description
int	advanceShallow(int target)	Advance to the block of documents that contains target in order to get scoring information about this block.
float	getMaxScore(int upTo)	Return the maximum score that documents between the last target that this iterator was shallow-advanced to included and upTo included.
protected float	score(DisiWrapper topList)	Compute the score for the given linked list of scorers.
void	setMinCompetitiveScore(float minScore)	Optional method: Tell the scorer that its iterator may safely ignore all documents whose score is less than the given minScore.

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

docID, getChildren, getSubMatches, iterator, score, twoPhaseIterator

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

getWeight

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

smoothingScore

Methods inherited from class java.lang.Object

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

Field Details

subScorers

private final List<Scorer> subScorers

tieBreakerMultiplier

private final float tieBreakerMultiplier

disjunctionBlockPropagator

private final DisjunctionScoreBlockBoundaryPropagator disjunctionBlockPropagator

Constructor Details

DisjunctionMaxScorer

DisjunctionMaxScorer(Weight weight,
 float tieBreakerMultiplier,
 List<Scorer> subScorers,
 ScoreMode scoreMode)
              throws IOException

Creates a new instance of DisjunctionMaxScorer

Parameters:

weight - The Weight to be used.

tieBreakerMultiplier - Multiplier applied to non-maximum-scoring subqueries for a document as they are summed into the result.

subScorers - The sub scorers this Scorer should iterate on

Throws:

IOException

Method Details

score

protected float score(DisiWrapper topList)
               throws IOException

Description copied from class: DisjunctionScorer

Compute the score for the given linked list of scorers.

Specified by:

score in class DisjunctionScorer

Throws:

IOException

advanceShallow

public int advanceShallow(int target)
                   throws IOException

Description copied from class: Scorer

Advance to the block of documents that contains target in order to get scoring information about this block. This method is implicitly called by DocIdSetIterator.advance(int) and DocIdSetIterator.nextDoc() on the returned doc ID. Calling this method doesn't modify the current DocIdSetIterator.docID(). It returns a number that is greater than or equal to all documents contained in the current block, but less than any doc IDS of the next block. target must be >= Scorable.docID() as well as all targets that have been passed to Scorer.advanceShallow(int) so far.

Overrides:

advanceShallow in class Scorer

Throws:

IOException

getMaxScore

public float getMaxScore(int upTo)
                  throws IOException

Description copied from class: Scorer

Return the maximum score that documents between the last target that this iterator was shallow-advanced to included and upTo included.

Specified by:

getMaxScore in class Scorer

Throws:

IOException

setMinCompetitiveScore

public void setMinCompetitiveScore(float minScore)
                            throws IOException

Description copied from class: Scorable

Optional method: Tell the scorer that its iterator may safely ignore all documents whose score is less than the given minScore. This is a no-op by default.

This method may only be called from collectors that use ScoreMode.TOP_SCORES, and successive calls may only set increasing values of minScore.

Overrides:

setMinCompetitiveScore in class Scorable

Throws:

IOException