org.apache.lucene.search.spans

Class SpanWeight

java.lang.Object

org.apache.lucene.search.Weight

org.apache.lucene.search.spans.SpanWeight

All Implemented Interfaces:

SegmentCacheable

Direct Known Subclasses:

org.apache.lucene.search.spans.SpanContainQuery.SpanContainWeight, SpanNearQuery.SpanNearWeight, SpanNotQuery.SpanNotWeight, SpanOrQuery.SpanOrWeight, SpanPositionCheckQuery.SpanPositionCheckWeight, SpanTermQuery.SpanTermWeight

public abstract class SpanWeight
extends Weight

Expert-only. Public for use by other weight implementations

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SpanWeight.Postings Enumeration defining what postings information should be retrieved from the index for a given Spans

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

Weight.DefaultBulkScorer, Weight.StartDISIWrapper

Field Summary

Fields

Modifier and Type	Field and Description
protected String	field
protected Similarity	similarity
protected Similarity.SimScorer	simScorer

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

parentQuery

Constructor Summary

Constructors

Constructor and Description
SpanWeight(SpanQuery query, IndexSearcher searcher, Map<Term,TermStates> termStates, float boost) Create a new SpanWeight

Method Summary

Modifier and Type	Method and Description
Explanation	explain(LeafReaderContext context, int doc) An explanation of the score computation for the named document.
abstract void	extractTermStates(Map<Term,TermStates> contexts) Collect all TermStates used by this Weight
LeafSimScorer	getSimScorer(LeafReaderContext context) Return a LeafSimScorer for this context
abstract Spans	getSpans(LeafReaderContext ctx, SpanWeight.Postings requiredPostings) Expert: Return a Spans object iterating over matches from this Weight
Matches	matches(LeafReaderContext context, int doc) 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
SpanScorer	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.Weight

bulkScorer, extractTerms, getQuery, scorerSupplier

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.lucene.search.SegmentCacheable

isCacheable

Field Detail

similarity

protected final Similarity similarity

simScorer

protected final Similarity.SimScorer simScorer

field

protected final String field

Constructor Detail

SpanWeight

public SpanWeight(SpanQuery query,
                  IndexSearcher searcher,
                  Map<Term,TermStates> termStates,
                  float boost)
           throws IOException

Create a new SpanWeight

Parameters:

query - the parent query

searcher - the IndexSearcher to query against

termStates - a map of terms to TermStates for use in building the similarity. May be null if scores are not required

Throws:

IOException - on error

Method Detail

extractTermStates

public abstract void extractTermStates(Map<Term,TermStates> contexts)

Collect all TermStates used by this Weight

Parameters:

contexts - a map to add the TermStates to

getSpans

public abstract Spans getSpans(LeafReaderContext ctx,
                               SpanWeight.Postings requiredPostings)
                        throws IOException

Expert: Return a Spans object iterating over matches from this Weight

Parameters:

ctx - a LeafReaderContext for this Spans

Returns:

a Spans

Throws:

IOException - on error

scorer

public SpanScorer 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

getSimScorer

public LeafSimScorer getSimScorer(LeafReaderContext context)
                           throws IOException

Return a LeafSimScorer for this context

Parameters:

context - the LeafReaderContext

Returns:

a SimWeight

Throws:

IOException - on error

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

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