Module org.apache.lucene.sandbox

Package org.apache.lucene.sandbox.search

Class PhraseWildcardQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.sandbox.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.

Nested Class Summary

Nested Classes

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

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	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.
(package private) PhraseWeight	createPhraseWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost, PhraseWildcardQuery.TermsData termsData)
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)	Expert: Constructs an appropriate Weight implementation for this query.
protected Weight	earlyStopWeight()
boolean	equals(Object o)	Override and implement query instance equivalence properly in a subclass.
String	getField()
int	hashCode()	Override and implement query hash code properly in a subclass.
protected Weight	noMatchWeight()
Query	rewrite(IndexSearcher indexSearcher)	Expert: called to re-write queries into primitive queries.
protected boolean	shouldOptimizeSegments()
final String	toString(String omittedField)	Prints a query to a string, with field assumed to be the default field and omitted.
void	visit(QueryVisitor visitor)	Recurse through the query tree, visiting any child queries.

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

classHash, rewrite, sameClassAs, toString

Methods inherited from class java.lang.Object

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

Field Details

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 Details

PhraseWildcardQuery

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

Method Details

getField

public String getField()

rewrite

public Query rewrite(IndexSearcher indexSearcher)
              throws IOException

Description copied from class: Query

Expert: called to re-write queries into primitive queries. For example, a PrefixQuery will be rewritten into a BooleanQuery that consists of TermQuerys.

Callers are expected to call rewrite multiple times if necessary, until the rewritten query is the same as the original query.

The rewrite process may be able to make use of IndexSearcher's executor and be executed in parallel if the executor is provided.

However, if any of the intermediary queries do not satisfy the new API, parallel rewrite is not possible for any subsequent sub-queries. To take advantage of this API, the entire query tree must override this method.

Overrides:

rewrite in class Query

Throws:

IOException

See Also:

• IndexSearcher.rewrite(Query)

visit

public void visit(QueryVisitor visitor)

Description copied from class: Query

Recurse through the query tree, visiting any child queries.

Specified by:

visit in class Query

Parameters:

visitor - a QueryVisitor to be called by each query in the tree

createWeight

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

Description copied from class: Query

Expert: Constructs an appropriate Weight implementation for this query.

Only implemented by primitive queries, which re-write to themselves.

Overrides:

createWeight in class Query

Parameters:

scoreMode - How the produced scorers will be consumed.

boost - The boost that is propagated by the parent queries.

Throws:

IOException

createTermsData

protected PhraseWildcardQuery.TermsData createTermsData(int numSegments)

Creates new PhraseWildcardQuery.TermsData.

earlyStopWeight

protected Weight earlyStopWeight()

noMatchWeight

protected Weight noMatchWeight()

createPhraseWeight

PhraseWeight createPhraseWeight(IndexSearcher searcher,
 ScoreMode scoreMode,
 float boost,
 PhraseWildcardQuery.TermsData termsData)
                         throws IOException

Throws:

IOException

equals

public boolean equals(Object o)

Description copied from class: Query

Override and implement query instance equivalence properly in a subclass. This is required so that QueryCache works properly.

Typically a query will be equal to another only if it's an instance of the same class and its document-filtering properties are identical to those of the other instance. Utility methods are provided for certain repetitive code.

Specified by:

equals in class Query

See Also:

• Query.sameClassAs(Object)
• Query.classHash()

hashCode

public int hashCode()

Description copied from class: Query

Override and implement query hash code properly in a subclass. This is required so that QueryCache works properly.

Specified by:

hashCode in class Query

See Also:

• Query.equals(Object)

toString

public final String toString(String omittedField)

Description copied from class: Query

Prints a query to a string, with field assumed to be the default field and omitted.

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)