Module org.apache.lucene.core

Package org.apache.lucene.search

Class ScoringRewrite<B>

java.lang.Object

org.apache.lucene.search.MultiTermQuery.RewriteMethod

org.apache.lucene.search.TermCollectingRewrite<B>

org.apache.lucene.search.ScoringRewrite<B>

public abstract class ScoringRewrite<B>
extends TermCollectingRewrite<B>

Base rewrite method that translates each term into a query, and keeps the scores as computed by the query.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) final class	ScoringRewrite.ParallelArraysTermCollector
(package private) static final class	ScoringRewrite.TermFreqBoostByteStart	Special implementation of BytesStartArray that keeps parallel arrays for boost and docFreq

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

TermCollectingRewrite.TermCollector

Field Summary

Fields

Modifier and Type	Field	Description
static final MultiTermQuery.RewriteMethod	CONSTANT_SCORE_BOOLEAN_REWRITE	Like SCORING_BOOLEAN_REWRITE except scores are not computed.
static final ScoringRewrite<BooleanQuery.Builder>	SCORING_BOOLEAN_REWRITE	A rewrite method that first translates each term into BooleanClause.Occur.SHOULD clause in a BooleanQuery, and keeps the scores as computed by the query.

Constructor Summary

Constructors

Constructor	Description
ScoringRewrite()

Method Summary

Modifier and Type	Method	Description
protected abstract void	checkMaxClauseCount(int count)	This method is called after every new term to check if the number of max clauses (e.g.
final Query	rewrite(IndexReader reader, MultiTermQuery query)

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

addClause, addClause, build, collectTerms, getTopLevelBuilder

Methods inherited from class org.apache.lucene.search.MultiTermQuery.RewriteMethod

getTermsEnum

Methods inherited from class java.lang.Object

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

Field Details

SCORING_BOOLEAN_REWRITE

public static final ScoringRewrite<BooleanQuery.Builder> SCORING_BOOLEAN_REWRITE

A rewrite method that first translates each term into BooleanClause.Occur.SHOULD clause in a BooleanQuery, and keeps the scores as computed by the query. Note that typically such scores are meaningless to the user, and require non-trivial CPU to compute, so it's almost always better to use MultiTermQuery.CONSTANT_SCORE_BLENDED_REWRITE or MultiTermQuery.CONSTANT_SCORE_REWRITE instead.

NOTE: This rewrite method will hit IndexSearcher.TooManyClauses if the number of terms exceeds IndexSearcher.getMaxClauseCount().

CONSTANT_SCORE_BOOLEAN_REWRITE

public static final MultiTermQuery.RewriteMethod CONSTANT_SCORE_BOOLEAN_REWRITE

Like SCORING_BOOLEAN_REWRITE except scores are not computed. Instead, each matching document receives a constant score equal to the query's boost.

NOTE: This rewrite method will hit IndexSearcher.TooManyClauses if the number of terms exceeds IndexSearcher.getMaxClauseCount().

Constructor Details

ScoringRewrite

public ScoringRewrite()

Method Details

checkMaxClauseCount

protected abstract void checkMaxClauseCount(int count)
                                     throws IOException

This method is called after every new term to check if the number of max clauses (e.g. in BooleanQuery) is not exceeded. Throws the corresponding RuntimeException.

Throws:

IOException

rewrite

public final Query rewrite(IndexReader reader,
 MultiTermQuery query)
                    throws IOException

Specified by:

rewrite in class MultiTermQuery.RewriteMethod

Throws:

IOException