org.apache.lucene.queries.function

Class ValueSourceScorer

java.lang.Object

org.apache.lucene.search.DocIdSetIterator

org.apache.lucene.search.Scorer

org.apache.lucene.queries.function.ValueSourceScorer

public abstract class ValueSourceScorer
extends Scorer

Scorer which returns the result of FunctionValues.floatVal(int) as the score for a document, and which filters out documents that don't match matches(int). This Scorer has a TwoPhaseIterator. This is similar to FunctionQuery, but this one has no Weight normalization factors/multipliers and that one doesn't filter either.

Note: If the scores are needed, then the underlying value will probably be fetched/computed twice -- once to filter and next to return the score. If that's non-trivial then consider wrapping it in an implementation that will cache the current value.

See Also:

FunctionQuery

WARNING: This API is experimental and might change in incompatible ways in the next release.

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 FunctionValues	values

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

weight

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

NO_MORE_DOCS

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ValueSourceScorer(IndexReader reader, FunctionValues values)

Method Summary

Methods

Modifier and Type	Method and Description
int	advance(int target)
TwoPhaseIterator	asTwoPhaseIterator()
long	cost()
int	docID()
int	freq()
abstract boolean	matches(int doc) Override to decide if this document matches.
int	nextDoc()
float	score()

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

getChildren, getWeight

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

all, empty, slowAdvance

Methods inherited from class java.lang.Object

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

Field Detail

values

protected final FunctionValues values

Constructor Detail

ValueSourceScorer

protected ValueSourceScorer(IndexReader reader,
                 FunctionValues values)

Method Detail

matches

public abstract boolean matches(int doc)

Override to decide if this document matches. It's called by TwoPhaseIterator.matches().

asTwoPhaseIterator

public TwoPhaseIterator asTwoPhaseIterator()

Overrides:

asTwoPhaseIterator in class Scorer

docID

public int docID()

Specified by:

docID in class DocIdSetIterator

nextDoc

public int nextDoc()
            throws IOException

Specified by:

nextDoc in class DocIdSetIterator

Throws:

IOException

advance

public int advance(int target)
            throws IOException

Specified by:

advance in class DocIdSetIterator

Throws:

IOException

score

public float score()
            throws IOException

Specified by:

score in class Scorer

Throws:

IOException

freq

public int freq()
         throws IOException

Specified by:

freq in class Scorer

Throws:

IOException

cost

public long cost()

Specified by:

cost in class DocIdSetIterator