Module org.apache.lucene.sandbox

Package org.apache.lucene.sandbox.search

Class QueryProfilerWeight

java.lang.Object

org.apache.lucene.search.Weight

org.apache.lucene.search.FilterWeight

org.apache.lucene.sandbox.search.QueryProfilerWeight

All Implemented Interfaces:

SegmentCacheable

class QueryProfilerWeight
extends FilterWeight

Weight wrapper that will compute how much time it takes to build the Scorer and then return a Scorer that is wrapped in order to compute timings as well.

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 QueryProfilerBreakdown	profile

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

in

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

parentQuery

Constructor Summary

Constructors

Constructor	Description
QueryProfilerWeight(Weight subQueryWeight, QueryProfilerBreakdown profile)

Method Summary

Modifier and Type	Method	Description
int	count(LeafReaderContext context)	Counts the number of live documents that match a given Weight.parentQuery in a leaf.
boolean	isCacheable(LeafReaderContext ctx)
ScorerSupplier	scorerSupplier(LeafReaderContext context)	Get a ScorerSupplier, which allows knowing the cost of the Scorer before building it.

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

explain, matches

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

profile

private final QueryProfilerBreakdown profile

Constructor Details

QueryProfilerWeight

public QueryProfilerWeight(Weight subQueryWeight,
 QueryProfilerBreakdown profile)

Method Details

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

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.

Overrides:

scorerSupplier in class FilterWeight

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

isCacheable

public boolean isCacheable(LeafReaderContext ctx)

Specified by:

isCacheable in interface SegmentCacheable

Overrides:

isCacheable in class FilterWeight

Returns:

true if the object can be cached against a given leaf