Class Scorer
- Direct Known Subclasses:
ConstantScoreScorer,FilterScorer,IndriScorer,TermScorer
A Scorer exposes an iterator() over documents matching a query in
increasing order of doc id.
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Nested Class Summary
Nested classes/interfaces inherited from class org.apache.lucene.search.Scorable
Scorable.ChildScorable -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionintadvanceShallow(int target) Advance to the block of documents that containstargetin order to get scoring information about this block.abstract intdocID()Returns the doc ID that is currently being scored.abstract floatgetMaxScore(int upTo) Return the maximum score that documents between the lasttargetthat this iterator wasshallow-advancedto included andupToincluded.abstract DocIdSetIteratoriterator()Return aDocIdSetIteratorover matching documents.Optional method: Return aTwoPhaseIteratorview of thisScorer.Methods inherited from class org.apache.lucene.search.Scorable
getChildren, score, setMinCompetitiveScore, smoothingScore
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Constructor Details
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Scorer
public Scorer()
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Method Details
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docID
public abstract int docID()Returns the doc ID that is currently being scored. -
iterator
Return aDocIdSetIteratorover matching documents.The returned iterator will either be positioned on
-1if no documents have been scored yet,DocIdSetIterator.NO_MORE_DOCSif 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.
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twoPhaseIterator
Optional method: Return aTwoPhaseIteratorview of thisScorer. A return value ofnullindicates that two-phase iteration is not supported.Note that the returned
TwoPhaseIterator'sapproximationmust advance synchronously with theiterator(): 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
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advanceShallow
Advance to the block of documents that containstargetin order to get scoring information about this block. This method is implicitly called byDocIdSetIterator.advance(int)andDocIdSetIterator.nextDoc()on the returned doc ID. Calling this method doesn't modify the currentDocIdSetIterator.docID(). It returns a number that is greater than or equal to all documents contained in the current block, but less than any doc IDS of the next block.targetmust be >=docID()as well as all targets that have been passed toadvanceShallow(int)so far.- Throws:
IOException
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getMaxScore
Return the maximum score that documents between the lasttargetthat this iterator wasshallow-advancedto included andupToincluded.- Throws:
IOException
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