org.apache.lucene.search

Class PhraseWildcardQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.search.PhraseWildcardQuery

public class PhraseWildcardQuery
extends Query

A generalized version of PhraseQuery, built with one or more MultiTermQuery that provides term expansions for multi-terms (one of the expanded terms must match).

Its main advantage is to control the total number of expansions across all MultiTermQuery and across all segments.

Use the PhraseWildcardQuery.Builder to build a PhraseWildcardQuery.

This query is similar to MultiPhraseQuery, but it handles, controls and optimizes the multi-term expansions.

This query is equivalent to building an ordered SpanNearQuery with a list of SpanTermQuery and SpanMultiTermQueryWrapper. But it optimizes the multi-term expansions and the segment accesses. It first resolves the single-terms to early stop if some does not match. Then it expands each multi-term sequentially, stopping immediately if one does not match. It detects the segments that do not match to skip them for the next expansions. This often avoid expanding the other multi-terms on some or even all segments. And finally it controls the total number of expansions.

Immutable.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	PhraseWildcardQuery.Builder Builds a PhraseWildcardQuery.
protected static class	PhraseWildcardQuery.MultiTerm Phrase term with expansions.
protected static class	PhraseWildcardQuery.PhraseTerm All PhraseWildcardQuery.PhraseTerm are light and immutable.
protected class	PhraseWildcardQuery.SegmentTermsSizeComparator Compares segments based of the number of terms they contain.
protected static class	PhraseWildcardQuery.SingleTerm Phrase term with no expansion.
static class	PhraseWildcardQuery.TermBytesTermState Holds a pair of term bytes - term state.
protected static class	PhraseWildcardQuery.TermData Holds the TermState for all the collected Term, for a specific phrase term, for all segments.
protected static class	PhraseWildcardQuery.TermsData Holds the TermState and TermStatistics for all the matched and collected Term, for all phrase terms, for all segments.
static class	PhraseWildcardQuery.TermStats Accumulates the doc freq and total term freq.
protected static class	PhraseWildcardQuery.TestCounters Test counters incremented when assertions are enabled.

Field Summary

Fields

Modifier and Type	Field and Description
protected String	field
protected int	maxMultiTermExpansions
protected static Query	NO_MATCH_QUERY
protected List<PhraseWildcardQuery.PhraseTerm>	phraseTerms
protected boolean	segmentOptimizationEnabled
protected int	slop

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	PhraseWildcardQuery(String field, List<PhraseWildcardQuery.PhraseTerm> phraseTerms, int slop, int maxMultiTermExpansions, boolean segmentOptimizationEnabled)

Method Summary

Modifier and Type	Method and Description
protected void	checkTermsHavePositions(Terms terms)
protected int	collectMultiTermData(PhraseWildcardQuery.MultiTerm multiTerm, IndexSearcher searcher, List<LeafReaderContext> segments, int remainingMultiTerms, int maxExpansionsForTerm, PhraseWildcardQuery.TermsData termsData) Collects the TermState and TermStatistics for a multi-term with expansion.
protected List<PhraseWildcardQuery.TermBytesTermState>	collectMultiTermDataForSegment(PhraseWildcardQuery.MultiTerm multiTerm, LeafReaderContext leafReaderContext, int remainingExpansions, MutableValueBool shouldStopSegmentIteration, Map<BytesRef,PhraseWildcardQuery.TermStats> termStatsMap) Collects the TermState list and TermStatistics for a multi-term on a specific index segment.
protected void	collectMultiTermStats(IndexSearcher searcher, Map<BytesRef,PhraseWildcardQuery.TermStats> termStatsMap, PhraseWildcardQuery.TermsData termsData, PhraseWildcardQuery.TermData termData) Collect the term stats across all segments.
protected int	collectSingleTermData(PhraseWildcardQuery.SingleTerm singleTerm, IndexSearcher searcher, List<LeafReaderContext> segments, PhraseWildcardQuery.TermsData termsData) Collects the TermState and TermStatistics for a single-term without expansion.
protected PhraseWildcardQuery.TermsData	createTermsData(int numSegments) Creates new PhraseWildcardQuery.TermsData.
protected TermsEnum	createTermsEnum(PhraseWildcardQuery.MultiTerm multiTerm, LeafReaderContext leafReaderContext) Creates the TermsEnum for the given PhraseWildcardQuery.MultiTerm and segment.
protected Map<BytesRef,PhraseWildcardQuery.TermStats>	createTermStatsMap(PhraseWildcardQuery.MultiTerm multiTerm) Creates a PhraseWildcardQuery.TermStats map for a PhraseWildcardQuery.MultiTerm.
Weight	createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost)
protected Weight	earlyStopWeight()
boolean	equals(Object o)
String	getField()
int	hashCode()
protected Weight	noMatchWeight()
Query	rewrite(IndexReader reader)
protected boolean	shouldOptimizeSegments()
String	toString(String omittedField)
void	visit(QueryVisitor visitor)

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

classHash, sameClassAs, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

NO_MATCH_QUERY

protected static final Query NO_MATCH_QUERY

field

protected final String field

phraseTerms

protected final List<PhraseWildcardQuery.PhraseTerm> phraseTerms

slop

protected final int slop

maxMultiTermExpansions

protected final int maxMultiTermExpansions

segmentOptimizationEnabled

protected final boolean segmentOptimizationEnabled

Constructor Detail

PhraseWildcardQuery

protected PhraseWildcardQuery(String field,
                              List<PhraseWildcardQuery.PhraseTerm> phraseTerms,
                              int slop,
                              int maxMultiTermExpansions,
                              boolean segmentOptimizationEnabled)

Method Detail

getField

public String getField()

rewrite

public Query rewrite(IndexReader reader)
              throws IOException

Overrides:

rewrite in class Query

Throws:

IOException

visit

public void visit(QueryVisitor visitor)

Overrides:

visit in class Query

createWeight

public Weight createWeight(IndexSearcher searcher,
                           ScoreMode scoreMode,
                           float boost)
                    throws IOException

Overrides:

createWeight in class Query

Throws:

IOException

createTermsData

protected PhraseWildcardQuery.TermsData createTermsData(int numSegments)

Creates new PhraseWildcardQuery.TermsData.

earlyStopWeight

protected Weight earlyStopWeight()

noMatchWeight

protected Weight noMatchWeight()

equals

public boolean equals(Object o)

Specified by:

equals in class Query

hashCode

public int hashCode()

Specified by:

hashCode in class Query

toString

public final String toString(String omittedField)

Specified by:

toString in class Query

collectSingleTermData

protected int collectSingleTermData(PhraseWildcardQuery.SingleTerm singleTerm,
                                    IndexSearcher searcher,
                                    List<LeafReaderContext> segments,
                                    PhraseWildcardQuery.TermsData termsData)
                             throws IOException

Collects the TermState and TermStatistics for a single-term without expansion.

Parameters:

termsData - receives the collected data.

Throws:

IOException

collectMultiTermData

protected int collectMultiTermData(PhraseWildcardQuery.MultiTerm multiTerm,
                                   IndexSearcher searcher,
                                   List<LeafReaderContext> segments,
                                   int remainingMultiTerms,
                                   int maxExpansionsForTerm,
                                   PhraseWildcardQuery.TermsData termsData)
                            throws IOException

Collects the TermState and TermStatistics for a multi-term with expansion.

Parameters:

remainingMultiTerms - the number of remaining multi-terms to process, including the current one, excluding the multi-terms already processed.

termsData - receives the collected data.

Throws:

IOException

shouldOptimizeSegments

protected boolean shouldOptimizeSegments()

createTermStatsMap

protected Map<BytesRef,PhraseWildcardQuery.TermStats> createTermStatsMap(PhraseWildcardQuery.MultiTerm multiTerm)

Creates a PhraseWildcardQuery.TermStats map for a PhraseWildcardQuery.MultiTerm.

collectMultiTermDataForSegment

protected List<PhraseWildcardQuery.TermBytesTermState> collectMultiTermDataForSegment(PhraseWildcardQuery.MultiTerm multiTerm,
                                                                                      LeafReaderContext leafReaderContext,
                                                                                      int remainingExpansions,
                                                                                      MutableValueBool shouldStopSegmentIteration,
                                                                                      Map<BytesRef,PhraseWildcardQuery.TermStats> termStatsMap)
                                                                               throws IOException

Collects the TermState list and TermStatistics for a multi-term on a specific index segment.

Parameters:

remainingExpansions - the number of remaining expansions allowed for the segment.

shouldStopSegmentIteration - to be set to true to stop the segment iteration calling this method repeatedly.

termStatsMap - receives the collected PhraseWildcardQuery.TermStats across all segments.

Throws:

IOException

createTermsEnum

protected TermsEnum createTermsEnum(PhraseWildcardQuery.MultiTerm multiTerm,
                                    LeafReaderContext leafReaderContext)
                             throws IOException

Creates the TermsEnum for the given PhraseWildcardQuery.MultiTerm and segment.

Returns:

null if there is no term for this query field in the segment.

Throws:

IOException

collectMultiTermStats

protected void collectMultiTermStats(IndexSearcher searcher,
                                     Map<BytesRef,PhraseWildcardQuery.TermStats> termStatsMap,
                                     PhraseWildcardQuery.TermsData termsData,
                                     PhraseWildcardQuery.TermData termData)
                              throws IOException

Collect the term stats across all segments.

Parameters:

termStatsMap - input map of already collected PhraseWildcardQuery.TermStats.

termsData - receives the TermStatistics computed for all PhraseWildcardQuery.TermStats.

termData - receives all the collected Term.

Throws:

IOException

checkTermsHavePositions

protected void checkTermsHavePositions(Terms terms)