org.apache.lucene.search

Class ReqOptSumScorer

java.lang.Object

org.apache.lucene.search.Scorer

org.apache.lucene.search.ReqOptSumScorer

class ReqOptSumScorer
extends Scorer

A Scorer for queries with a required part and an optional part. Delays skipTo() on the optional part until a score() is needed.

Nested Class Summary

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

Scorer.ChildScorer

Field Summary

Fields

Modifier and Type	Field and Description
protected DocIdSetIterator	optIterator
protected Scorer	optScorer
protected Scorer	reqScorer The scorers passed from the constructor.

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

weight

Constructor Summary

Constructors

Constructor and Description
ReqOptSumScorer(Scorer reqScorer, Scorer optScorer) Construct a ReqOptScorer.

Method Summary

Modifier and Type	Method and Description
int	docID() Returns the doc ID that is currently being scored.
int	freq() Returns the freq of this Scorer on the current document
java.util.Collection<Scorer.ChildScorer>	getChildren() Returns child sub-scorers positioned on the current document Note that this method should not be called on Scorers passed to LeafCollector.setScorer(Scorer), as these may be synthetic Scorers produced by BulkScorer which will throw an Exception.
DocIdSetIterator	iterator() Return a DocIdSetIterator over matching documents.
float	score() Returns the score of the current document matching the query.
TwoPhaseIterator	twoPhaseIterator() Optional method: Return a TwoPhaseIterator view of this Scorer.

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

getWeight

Methods inherited from class java.lang.Object

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

Field Detail

reqScorer

protected final Scorer reqScorer

The scorers passed from the constructor. These are set to null as soon as their next() or skipTo() returns false.

optScorer

protected final Scorer optScorer

optIterator

protected final DocIdSetIterator optIterator

Constructor Detail

ReqOptSumScorer

public ReqOptSumScorer(Scorer reqScorer,
                       Scorer optScorer)

Construct a ReqOptScorer.

Parameters:

reqScorer - The required scorer. This must match.

optScorer - The optional scorer. This is used for scoring only.

Method Detail

twoPhaseIterator

public TwoPhaseIterator twoPhaseIterator()

Description copied from class: Scorer

Optional method: Return a TwoPhaseIterator view of this Scorer. A return value of null indicates that two-phase iteration is not supported. Note that the returned TwoPhaseIterator's approximation must advance synchronously with the Scorer.iterator(): advancing the approximation must advance the iterator and vice-versa. Implementing this method is typically useful on Scorers that have a high per-document overhead in order to confirm matches. The default implementation returns null.

Overrides:

twoPhaseIterator in class Scorer

iterator

public DocIdSetIterator iterator()

Description copied from class: Scorer

Return a DocIdSetIterator over matching documents. The returned iterator will either be positioned on -1 if no documents have been scored yet, DocIdSetIterator.NO_MORE_DOCS if all documents have been scored already, or the last document id that has been scored otherwise. The returned iterator is a view: calling this method several times will return iterators that have the same state.

Specified by:

iterator in class Scorer

docID

public int docID()

Description copied from class: Scorer

Returns the doc ID that is currently being scored. This will return -1 if the Scorer.iterator() is not positioned or DocIdSetIterator.NO_MORE_DOCS if it has been entirely consumed.

Specified by:

docID in class Scorer

See Also:

DocIdSetIterator.docID()

score

public float score()
            throws java.io.IOException

Returns the score of the current document matching the query. Initially invalid, until the iterator() is advanced the first time.

Specified by:

score in class Scorer

Returns:

The score of the required scorer, eventually increased by the score of the optional scorer when it also matches the current document.

Throws:

java.io.IOException

freq

public int freq()
         throws java.io.IOException

Description copied from class: Scorer

Returns the freq of this Scorer on the current document

Specified by:

freq in class Scorer

Throws:

java.io.IOException

getChildren

public java.util.Collection<Scorer.ChildScorer> getChildren()

Description copied from class: Scorer

Returns child sub-scorers positioned on the current document Note that this method should not be called on Scorers passed to LeafCollector.setScorer(Scorer), as these may be synthetic Scorers produced by BulkScorer which will throw an Exception.

Overrides:

getChildren in class Scorer