Module org.apache.lucene.core

Package org.apache.lucene.search

Class LRUQueryCache.CachingWrapperWeight

java.lang.Object

org.apache.lucene.search.Weight

org.apache.lucene.search.ConstantScoreWeight

org.apache.lucene.search.LRUQueryCache.CachingWrapperWeight

All Implemented Interfaces:

SegmentCacheable

Enclosing class:

LRUQueryCache

private class LRUQueryCache.CachingWrapperWeight
extends ConstantScoreWeight

Nested Class Summary

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

Weight.DefaultBulkScorer, Weight.DefaultScorerSupplier

Field Summary

Fields

Modifier and Type	Field	Description
private final Weight	in
private final QueryCachingPolicy	policy
private final AtomicBoolean	used

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

parentQuery

Constructor Summary

Constructors

Constructor	Description
CachingWrapperWeight(Weight in, QueryCachingPolicy policy)

Method Summary

Modifier and Type	Method	Description
private boolean	cacheEntryHasReasonableWorstCaseSize(int maxDoc)
int	count(LeafReaderContext context)	Counts the number of live documents that match a given Weight.parentQuery in a leaf.
boolean	isCacheable(LeafReaderContext ctx)
Matches	matches(LeafReaderContext context, int doc)	Returns Matches for a specific document, or null if the document does not match the parent query
ScorerSupplier	scorerSupplier(LeafReaderContext context)	Get a ScorerSupplier, which allows knowing the cost of the Scorer before building it.
private boolean	shouldCache(LeafReaderContext context)	Check whether this segment is eligible for caching, regardless of the query.

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

explain, score

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

bulkScorer, getQuery, scorer

Methods inherited from class java.lang.Object

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

Field Details

in

private final Weight in

policy

private final QueryCachingPolicy policy

used

private final AtomicBoolean used

Constructor Details

CachingWrapperWeight

CachingWrapperWeight(Weight in,
 QueryCachingPolicy policy)

Method Details

matches

public Matches matches(LeafReaderContext context,
 int doc)
                throws IOException

Description copied from class: Weight

Returns Matches for a specific document, or null if the document does not match the parent query

A query match that contains no position information (for example, a Point or DocValues query) will return MatchesUtils.MATCH_WITH_NO_TERMS

Overrides:

matches in class Weight

Parameters:

context - the reader's context to create the Matches for

doc - the document's id relative to the given context's reader

Throws:

IOException

cacheEntryHasReasonableWorstCaseSize

private boolean cacheEntryHasReasonableWorstCaseSize(int maxDoc)

shouldCache

private boolean shouldCache(LeafReaderContext context)
                     throws IOException

Check whether this segment is eligible for caching, regardless of the query.

Throws:

IOException

scorerSupplier

public ScorerSupplier scorerSupplier(LeafReaderContext context)
                              throws IOException

Description copied from class: Weight

Get a ScorerSupplier, which allows knowing the cost of the Scorer before building it. A scorer supplier for the same LeafReaderContext instance may be requested multiple times as part of a single search call.

Note: It must return null if the scorer is null.

Specified by:

scorerSupplier in class Weight

Parameters:

context - the leaf reader context

Returns:

a ScorerSupplier providing the scorer, or null if scorer is null

Throws:

IOException - if an IOException occurs

See Also:

• Scorer
• Weight.DefaultScorerSupplier

count

public int count(LeafReaderContext context)
          throws IOException

Description copied from class: Weight

Counts the number of live documents that match a given Weight.parentQuery in a leaf.

The default implementation returns -1 for every query. This indicates that the count could not be computed in sub-linear time.

Specific query classes should override it to provide other accurate sub-linear implementations (that actually return the count). Look at MatchAllDocsQuery.createWeight(IndexSearcher, ScoreMode, float) for an example

We use this property of the function to count hits in IndexSearcher.count(Query).

Overrides:

count in class Weight

Parameters:

context - the LeafReaderContext for which to return the count.

Returns:

integer count of the number of matches

Throws:

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

isCacheable

public boolean isCacheable(LeafReaderContext ctx)

Returns:

true if the object can be cached against a given leaf