Package org.apache.lucene.search

Class ImpactsDISI

java.lang.Object

org.apache.lucene.search.DocIdSetIterator

org.apache.lucene.search.ImpactsDISI

public final class ImpactsDISI
extends DocIdSetIterator

DocIdSetIterator that skips non-competitive docs thanks to the indexed impacts. Call setMinCompetitiveScore(float) in order to give this iterator the ability to skip low-scoring documents.

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

Field Summary

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

NO_MORE_DOCS

Constructor Summary

Constructors

Constructor	Description
ImpactsDISI(DocIdSetIterator in, ImpactsSource impactsSource, Similarity.SimScorer scorer)	Sole constructor.

Method Summary

Modifier and Type	Method	Description
int	advance(int target)	Advances to the first beyond the current whose document number is greater than or equal to target, and returns the document number itself.
int	advanceShallow(int target)	Implement the contract of Scorer.advanceShallow(int) based on the wrapped ImpactsEnum.
long	cost()	Returns the estimated cost of this DocIdSetIterator.
int	docID()	Returns the following: -1 if DocIdSetIterator.nextDoc() or DocIdSetIterator.advance(int) were not called yet.
float	getMaxScore(int upTo)	Implement the contract of Scorer.getMaxScore(int) based on the wrapped ImpactsEnum and Scorer.
int	nextDoc()	Advances to the next document in the set and returns the doc it is currently on, or DocIdSetIterator.NO_MORE_DOCS if there are no more docs in the set. NOTE: after the iterator has exhausted you should not call this method, as it may result in unpredicted behavior.
void	setMinCompetitiveScore(float minCompetitiveScore)	Set the minimum competitive score.

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

all, empty, range, slowAdvance

Methods inherited from class java.lang.Object

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

Constructor Details

ImpactsDISI

public ImpactsDISI(DocIdSetIterator in,
 ImpactsSource impactsSource,
 Similarity.SimScorer scorer)

Sole constructor.

Parameters:

in - wrapped iterator

impactsSource - source of impacts

scorer - scorer

Method Details

setMinCompetitiveScore

public void setMinCompetitiveScore(float minCompetitiveScore)

Set the minimum competitive score.

See Also:

• Scorable.setMinCompetitiveScore(float)

advanceShallow

public int advanceShallow(int target)
                   throws IOException

Implement the contract of Scorer.advanceShallow(int) based on the wrapped ImpactsEnum.

Throws:

IOException

See Also:

• Scorer.advanceShallow(int)

getMaxScore

public float getMaxScore(int upTo)
                  throws IOException

Implement the contract of Scorer.getMaxScore(int) based on the wrapped ImpactsEnum and Scorer.

Throws:

IOException

See Also:

• Scorer.getMaxScore(int)

advance

public int advance(int target)
            throws IOException

Description copied from class: DocIdSetIterator

Advances to the first beyond the current whose document number is greater than or equal to target, and returns the document number itself. Exhausts the iterator and returns DocIdSetIterator.NO_MORE_DOCS if target is greater than the highest document number in the set.

The behavior of this method is undefined when called with target ≤ current , or after the iterator has exhausted. Both cases may result in unpredicted behavior.

When target > current it behaves as if written:

 int advance(int target) {
   int doc;
   while ((doc = nextDoc()) < target) {
   }
   return doc;
 }
 

Some implementations are considerably more efficient than that.

NOTE: this method may be called with DocIdSetIterator.NO_MORE_DOCS for efficiency by some Scorers. If your implementation cannot efficiently determine that it should exhaust, it is recommended that you check for that value in each call to this method.

Specified by:

advance in class DocIdSetIterator

Throws:

IOException

nextDoc

public int nextDoc()
            throws IOException

Description copied from class: DocIdSetIterator

Advances to the next document in the set and returns the doc it is currently on, or DocIdSetIterator.NO_MORE_DOCS if there are no more docs in the set.
NOTE: after the iterator has exhausted you should not call this method, as it may result in unpredicted behavior.

Specified by:

nextDoc in class DocIdSetIterator

Throws:

IOException

docID

public int docID()

Description copied from class: DocIdSetIterator

Returns the following:

• -1 if DocIdSetIterator.nextDoc() or DocIdSetIterator.advance(int) were not called yet.
• DocIdSetIterator.NO_MORE_DOCS if the iterator has exhausted.
• Otherwise it should return the doc ID it is currently on.

Specified by:

docID in class DocIdSetIterator

cost

public long cost()

Description copied from class: DocIdSetIterator

Returns the estimated cost of this DocIdSetIterator.

This is generally an upper bound of the number of documents this iterator might match, but may be a rough heuristic, hardcoded value, or otherwise completely inaccurate.

Specified by:

cost in class DocIdSetIterator