org.apache.lucene.search

Class ScorerSupplier

java.lang.Object

org.apache.lucene.search.ScorerSupplier

public abstract class ScorerSupplier
extends Object

A supplier of Scorer. This allows to get an estimate of the cost before building the Scorer.

Constructor Summary

Constructors

Constructor and Description
ScorerSupplier()

Method Summary

Modifier and Type	Method and Description
abstract long	cost() Get an estimate of the Scorer that would be returned by get(boolean).
abstract Scorer	get(boolean randomAccess) Get the Scorer.

Methods inherited from class java.lang.Object

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

Constructor Detail

ScorerSupplier

public ScorerSupplier()

Method Detail

get

public abstract Scorer get(boolean randomAccess)
                    throws IOException

Get the Scorer. This may not return null and must be called at most once.

Parameters:

randomAccess - A hint about the expected usage of the Scorer. If DocIdSetIterator.advance(int) or TwoPhaseIterator will be used to check whether given doc ids match, then pass true. Otherwise if the Scorer will be mostly used to lead the iteration using DocIdSetIterator.nextDoc(), then false should be passed. Under doubt, pass false which usually has a better worst-case.

Throws:

IOException

cost

public abstract long cost()

Get an estimate of the Scorer that would be returned by get(boolean). This may be a costly operation, so it should only be called if necessary.

See Also:

DocIdSetIterator.cost()