Lucene::SloppyPhraseScorer Class Reference

#include <SloppyPhraseScorer.h>

Inheritance diagram for Lucene::SloppyPhraseScorer:

Public Member Functions
	SloppyPhraseScorer (WeightPtr weight, Collection< TermPositionsPtr > tps, Collection< int32_t > offsets, SimilarityPtr similarity, int32_t slop, ByteArray norms)
virtual	~SloppyPhraseScorer ()
virtual String	getClassName ()
boost::shared_ptr < SloppyPhraseScorer >	shared_from_this ()
virtual double	phraseFreq ()
	Score a candidate doc for all slop-valid position-combinations (matches) encountered while traversing/hopping the PhrasePositions. The score contribution of a match depends on the distance: More...
Public Member Functions inherited from Lucene::PhraseScorer
	PhraseScorer (WeightPtr weight, Collection< TermPositionsPtr > tps, Collection< int32_t > offsets, SimilarityPtr similarity, ByteArray norms)
virtual	~PhraseScorer ()
boost::shared_ptr< PhraseScorer >	shared_from_this ()
virtual int32_t	docID ()
	Returns the following: More...
virtual int32_t	nextDoc ()
	Advances to the next document in the set and returns the doc it is currently on, or NO_MORE_DOCS if there are no more docs in the set. More...
virtual double	score ()
	Returns the score of the current document matching the query. Initially invalid, until nextDoc() or advance(int32_t) is called the first time, or when called from within Collector#collect. More...
virtual int32_t	advance (int32_t target)
	Advances to the first beyond the current whose document number is greater than or equal to target. Returns the current document number or NO_MORE_DOCS if there are no more docs in the set. More...
double	currentFreq ()
	Phrase frequency in current doc as computed by phraseFreq(). More...
virtual String	toString ()
	Returns a string representation of the object. More...
Public Member Functions inherited from Lucene::Scorer
	Scorer (SimilarityPtr similarity)
	Constructs a Scorer. More...
virtual	~Scorer ()
boost::shared_ptr< Scorer >	shared_from_this ()
SimilarityPtr	getSimilarity ()
	Returns the Similarity implementation used by this scorer. More...
virtual void	score (CollectorPtr collector)
	Scores and collects all matching documents. More...
Public Member Functions inherited from Lucene::DocIdSetIterator
virtual	~DocIdSetIterator ()
boost::shared_ptr < DocIdSetIterator >	shared_from_this ()
Public Member Functions inherited from Lucene::LuceneObject
virtual	~LuceneObject ()
virtual void	initialize ()
	Called directly after instantiation to create objects that depend on this object being fully constructed. More...
virtual LuceneObjectPtr	clone (LuceneObjectPtr other=LuceneObjectPtr())
	Return clone of this object. More...
virtual int32_t	hashCode ()
	Return hash code for this object. More...
virtual bool	equals (LuceneObjectPtr other)
	Return whether two objects are equal. More...
virtual int32_t	compareTo (LuceneObjectPtr other)
	Compare two objects. More...
Public Member Functions inherited from Lucene::LuceneSync
virtual	~LuceneSync ()
virtual SynchronizePtr	getSync ()
	Return this object synchronize lock. More...
virtual LuceneSignalPtr	getSignal ()
	Return this object signal. More...
virtual void	lock (int32_t timeout=0)
	Lock this object using an optional timeout. More...
virtual void	unlock ()
	Unlock this object. More...
virtual bool	holdsLock ()
	Returns true if this object is currently locked by current thread. More...
virtual void	wait (int32_t timeout=0)
	Wait for signal using an optional timeout. More...
virtual void	notifyAll ()
	Notify all threads waiting for signal. More...

Static Public Member Functions
static String	_getClassName ()
Static Public Member Functions inherited from Lucene::PhraseScorer
static String	_getClassName ()
Static Public Member Functions inherited from Lucene::Scorer
static String	_getClassName ()
Static Public Member Functions inherited from Lucene::DocIdSetIterator
static String	_getClassName ()

Protected Member Functions
PhrasePositionsPtr	flip (PhrasePositionsPtr pp, PhrasePositionsPtr pp2)
	Flip pp2 and pp in the queue: pop until finding pp2, insert back all but pp2, insert pp back. Assumes: pp!=pp2, pp2 in pq, pp not in pq. Called only when there are repeating pps. More...
int32_t	initPhrasePositions ()
	Init PhrasePositions in place. There is a one time initialization for this scorer: More...
PhrasePositionsPtr	termPositionsDiffer (PhrasePositionsPtr pp)
	We disallow two pp's to have the same TermPosition, thereby verifying multiple occurrences in the query of the same word would go elsewhere in the matched doc. More...
Protected Member Functions inherited from Lucene::PhraseScorer
bool	doNext ()
	Next without initial increment. More...
void	init ()
void	sort ()
void	pqToList ()
void	firstToLast ()
Protected Member Functions inherited from Lucene::Scorer
virtual bool	score (CollectorPtr collector, int32_t max, int32_t firstDocID)
	Collects matching documents in a range. Hook for optimization. Note, firstDocID is added to ensure that nextDoc() was called before this method. More...

Protected Attributes
int32_t	slop
Collection< PhrasePositionsPtr >	repeats
Collection< PhrasePositionsPtr >	tmpPos
bool	checkedRepeats
Protected Attributes inherited from Lucene::PhraseScorer
WeightPtr	weight
ByteArray	norms
double	value
bool	firstTime
bool	more
PhraseQueuePtr	pq
PhrasePositionsPtr	first
PhrasePositionsPtr	last
double	freq
Protected Attributes inherited from Lucene::Scorer
SimilarityPtr	similarity

Additional Inherited Members
Static Public Attributes inherited from Lucene::DocIdSetIterator
static const int32_t	NO_MORE_DOCS
	When returned by nextDoc(), advance(int) and docID() it means there are no more docs in the iterator. More...

Constructor & Destructor Documentation

Lucene::SloppyPhraseScorer::SloppyPhraseScorer	(	WeightPtr	weight,
		Collection< TermPositionsPtr >	tps,
		Collection< int32_t >	offsets,
		SimilarityPtr	similarity,
		int32_t	slop,
		ByteArray	norms
	)

virtual Lucene::SloppyPhraseScorer::~SloppyPhraseScorer ( )

virtual

Member Function Documentation

static String Lucene::SloppyPhraseScorer::_getClassName ( )

inlinestatic

PhrasePositionsPtr Lucene::SloppyPhraseScorer::flip ( PhrasePositionsPtr  pp, PhrasePositionsPtr  pp2  )

protected

Flip pp2 and pp in the queue: pop until finding pp2, insert back all but pp2, insert pp back. Assumes: pp!=pp2, pp2 in pq, pp not in pq. Called only when there are repeating pps.

virtual String Lucene::SloppyPhraseScorer::getClassName ( )

inlinevirtual

Reimplemented from Lucene::PhraseScorer.

int32_t Lucene::SloppyPhraseScorer::initPhrasePositions ( )

protected

Init PhrasePositions in place. There is a one time initialization for this scorer:

• Put in repeats[] each pp that has another pp with same position in the doc.
• Also mark each such pp by pp.repeats = true. Later can consult with repeats[] in termPositionsDiffer(pp), making that check efficient. In particular, this allows to score queries with no repetitions with no overhead due to this computation.
• Example 1 - query with no repetitions: "ho my"~2
• Example 2 - query with repetitions: "ho my my"~2
• Example 3 - query with repetitions: "my ho my"~2 Init per doc with repeats in query, includes propagating some repeating pp's to avoid false phrase detection.

  Returns

  end (max position), or -1 if any term ran out (ie. done)

virtual double Lucene::SloppyPhraseScorer::phraseFreq ( )

virtual

Score a candidate doc for all slop-valid position-combinations (matches) encountered while traversing/hopping the PhrasePositions. The score contribution of a match depends on the distance:

• highest score for distance=0 (exact match).
• score gets lower as distance gets higher. Example: for query "a b"~2, a document "x a b a y" can be scored twice: once for "a b" (distance=0), and once for "b a" (distance=2). Possibly not all valid combinations are encountered, because for efficiency we always propagate the least PhrasePosition. This allows to base on PriorityQueue and move forward faster. As result, for example, document "a b c b a" would score differently for queries "a b c"~4 and "c b a"~4, although they really are equivalent. Similarly, for doc "a b c b a f g", query "c b"~2 would get same score as "g f"~2, although "c b"~2 could be matched twice. We may want to fix this in the future (currently not, for performance reasons).

Implements Lucene::PhraseScorer.

boost::shared_ptr< SloppyPhraseScorer > Lucene::SloppyPhraseScorer::shared_from_this ( )

inline

PhrasePositionsPtr Lucene::SloppyPhraseScorer::termPositionsDiffer ( PhrasePositionsPtr  pp)

protected

We disallow two pp's to have the same TermPosition, thereby verifying multiple occurrences in the query of the same word would go elsewhere in the matched doc.

Returns

null if differ (i.e. valid) otherwise return the higher offset PhrasePositions out of the first two PPs found to not differ.

Field Documentation

bool Lucene::SloppyPhraseScorer::checkedRepeats

protected

Collection<PhrasePositionsPtr> Lucene::SloppyPhraseScorer::repeats

protected

int32_t Lucene::SloppyPhraseScorer::slop

protected

Collection<PhrasePositionsPtr> Lucene::SloppyPhraseScorer::tmpPos

protected

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The documentation for this class was generated from the following file:

• SloppyPhraseScorer.h