Module org.apache.lucene.core

Package org.apache.lucene.search

Class MaxScoreCache

java.lang.Object

org.apache.lucene.search.MaxScoreCache

public final class MaxScoreCache
extends Object

Compute maximum scores based on Impacts and keep them in a cache in order not to run expensive similarity score computations multiple times on the same data.

Field Summary

Fields

Modifier and Type	Field	Description
private final float	globalMaxScore
private final ImpactsSource	impactsSource
private float[]	maxScoreCache
private int[]	maxScoreCacheUpTo
private final Similarity.SimScorer	scorer

Constructor Summary

Constructors

Constructor	Description
MaxScoreCache(ImpactsSource impactsSource, Similarity.SimScorer scorer)	Sole constructor.

Method Summary

Modifier and Type	Method	Description
int	advanceShallow(int target)	Implement the contract of Scorer.advanceShallow(int) based on the wrapped ImpactsSource.
private float	computeMaxScore(List<Impact> impacts)
private void	ensureCacheSize(int size)
private int	getLevel(int upTo)	Return the first level that includes all doc IDs up to upTo, or -1 if there is no such level.
float	getMaxScore(int upTo)	Return the maximum score up to upTo included.
private float	getMaxScoreForLevel(int level)	Return the maximum score for the given level.
(package private) float	getMaxScoreForLevelZero()
private int	getSkipLevel(Impacts impacts, float minScore)	Return the maximum level at which scores are all less than minScore, or -1 if none.
(package private) int	getSkipUpTo(float minScore)	Return the an inclusive upper bound of documents that all have a score that is less than minScore, or -1 if the current document may be competitive.

Methods inherited from class java.lang.Object

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

Field Details

impactsSource

private final ImpactsSource impactsSource

scorer

private final Similarity.SimScorer scorer

globalMaxScore

private final float globalMaxScore

maxScoreCache

private float[] maxScoreCache

maxScoreCacheUpTo

private int[] maxScoreCacheUpTo

Constructor Details

MaxScoreCache

public MaxScoreCache(ImpactsSource impactsSource,
 Similarity.SimScorer scorer)

Sole constructor.

Method Details

advanceShallow

public int advanceShallow(int target)
                   throws IOException

Implement the contract of Scorer.advanceShallow(int) based on the wrapped ImpactsSource.

Throws:

IOException

See Also:

• Scorer.advanceShallow(int)

ensureCacheSize

private void ensureCacheSize(int size)

computeMaxScore

private float computeMaxScore(List<Impact> impacts)

getMaxScore

public float getMaxScore(int upTo)
                  throws IOException

Return the maximum score up to upTo included.

Throws:

IOException

See Also:

• Scorer.getMaxScore(int)

getLevel

private int getLevel(int upTo)
              throws IOException

Return the first level that includes all doc IDs up to upTo, or -1 if there is no such level.

Throws:

IOException

getMaxScoreForLevelZero

float getMaxScoreForLevelZero()
                       throws IOException

Throws:

IOException

getMaxScoreForLevel

private float getMaxScoreForLevel(int level)
                           throws IOException

Return the maximum score for the given level.

Throws:

IOException

getSkipLevel

private int getSkipLevel(Impacts impacts,
 float minScore)
                  throws IOException

Return the maximum level at which scores are all less than minScore, or -1 if none.

Throws:

IOException

getSkipUpTo

int getSkipUpTo(float minScore)
         throws IOException

Return the an inclusive upper bound of documents that all have a score that is less than minScore, or -1 if the current document may be competitive.

Throws:

IOException