org.apache.lucene.search

Class RandomAccessWeight

java.lang.Object

org.apache.lucene.search.Weight

org.apache.lucene.search.ConstantScoreWeight

org.apache.lucene.search.RandomAccessWeight

public abstract class RandomAccessWeight
extends ConstantScoreWeight

Base class to build Weights that are based on random-access structures such as live docs or doc values. Such weights return a Scorer which consists of an approximation that matches everything, and a confirmation phase that first checks live docs and then the Bits returned by getMatchingDocs(LeafReaderContext).

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

Nested Class Summary

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

Weight.DefaultBulkScorer

Field Summary

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

parentQuery

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	RandomAccessWeight(Query query) Sole constructor.

Method Summary

Modifier and Type	Method and Description
protected abstract Bits	getMatchingDocs(LeafReaderContext context) Return a Bits instance representing documents that match this weight on the given 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.ConstantScoreWeight

boost, explain, extractTerms, getValueForNormalization, normalize, queryNorm, score

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

bulkScorer, getQuery

Methods inherited from class java.lang.Object

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

Constructor Detail

RandomAccessWeight

protected RandomAccessWeight(Query query)

Sole constructor.

Method Detail

getMatchingDocs

protected abstract Bits getMatchingDocs(LeafReaderContext context)
                                 throws IOException

Return a Bits instance representing documents that match this weight on the given context. A return value of null indicates that no documents matched. Note: it is not needed to care about live docs as they will be checked before the returned bits.

Throws:

IOException

scorer

public final 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