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

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
BulkScorer	bulkScorer(LeafReaderContext context)	Optional method, to return a BulkScorer to score the query and send hits to a Collector.
private LRUQueryCache.CacheAndCount	cache(LeafReaderContext context)
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
Scorer	scorer(LeafReaderContext context)	Returns a Scorer which can iterate in order over all matching documents and assign them a score.
ScorerSupplier	scorerSupplier(LeafReaderContext context)	Optional method.
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

getQuery

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)

cache

private LRUQueryCache.CacheAndCount cache(LeafReaderContext context)
                                   throws IOException

Throws:

IOException

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

Optional method. Get a ScorerSupplier, which allows to know the cost of the Scorer before building it. The default implementation calls Weight.scorer(org.apache.lucene.index.LeafReaderContext) and builds a ScorerSupplier wrapper around it.

Overrides:

scorerSupplier in class Weight

Throws:

IOException

See Also:

• Weight.scorer(org.apache.lucene.index.LeafReaderContext)

scorer

public 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

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

bulkScorer

public BulkScorer bulkScorer(LeafReaderContext context)
                      throws IOException

Description copied from class: Weight

Optional method, to return a BulkScorer to score the query and send hits to a Collector. Only queries that have a different top-level approach need to override this; the default implementation pulls a normal Scorer and iterates and collects the resulting hits which are not marked as deleted.

Overrides:

bulkScorer in class Weight

Parameters:

context - the LeafReaderContext for which to return the Scorer.

Returns:

a BulkScorer which scores documents and passes them to a collector.

Throws:

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