Module org.apache.lucene.suggest

Package org.apache.lucene.search.suggest.document

Class CompletionWeight

java.lang.Object

org.apache.lucene.search.Weight

org.apache.lucene.search.suggest.document.CompletionWeight

All Implemented Interfaces:

SegmentCacheable

Direct Known Subclasses:

ContextQuery.ContextCompletionWeight, FuzzyCompletionQuery.FuzzyCompletionWeight

public class CompletionWeight
extends Weight

Expert: the Weight for CompletionQuery, used to score and explain these queries.

Subclasses can override setNextMatch(IntsRef), boost() and context() to calculate the boost and extract the context of a matched path prefix.

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 Automaton	automaton
private final CompletionQuery	completionQuery

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

parentQuery

Constructor Summary

Constructors

Constructor	Description
CompletionWeight(CompletionQuery query, Automaton automaton)	Creates a weight for query with an automaton, using the reader for index stats

Method Summary

Modifier and Type	Method	Description
protected float	boost()	Returns the boost of the partial path set by setNextMatch(IntsRef)
protected CharSequence	context()	Returns the context of the partial path set by setNextMatch(IntsRef)
Explanation	explain(LeafReaderContext context, int doc)	An explanation of the score computation for the named document.
Automaton	getAutomaton()	Returns the automaton specified by the CompletionQuery
boolean	isCacheable(LeafReaderContext ctx)	This object can be cached
ScorerSupplier	scorerSupplier(LeafReaderContext context)	Get a ScorerSupplier, which allows knowing the cost of the Scorer before building it.
protected void	setNextMatch(IntsRef pathPrefix)	Set for every partial path in the index that matched the query automaton.

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

bulkScorer, count, getQuery, matches, scorer

Methods inherited from class java.lang.Object

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

Field Details

completionQuery

private final CompletionQuery completionQuery

automaton

private final Automaton automaton

Constructor Details

CompletionWeight

public CompletionWeight(CompletionQuery query,
 Automaton automaton)
                 throws IOException

Creates a weight for query with an automaton, using the reader for index stats

Throws:

IOException

Method Details

getAutomaton

public Automaton getAutomaton()

Returns the automaton specified by the CompletionQuery

Returns:

query automaton

setNextMatch

protected void setNextMatch(IntsRef pathPrefix)

Set for every partial path in the index that matched the query automaton.

Subclasses should override boost() and context() to return an appropriate value with respect to the current pathPrefix.

Parameters:

pathPrefix - the prefix of a matched path

boost

protected float boost()

Returns the boost of the partial path set by setNextMatch(IntsRef)

Returns:

suggestion query-time boost

context

protected CharSequence context()

Returns the context of the partial path set by setNextMatch(IntsRef)

Returns:

suggestion context

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

isCacheable

public boolean isCacheable(LeafReaderContext ctx)

This object can be cached

Returns:

true if the object can be cached against a given leaf

See Also:

• SegmentCacheable.isCacheable(LeafReaderContext)

explain

public Explanation explain(LeafReaderContext context,
 int doc)
                    throws IOException

Description copied from class: Weight

An explanation of the score computation for the named document.

Specified by:

explain in class Weight

Parameters:

context - the readers context to create the Explanation for.

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

Returns:

an Explanation for the score

Throws:

IOException - if an IOException occurs