org.apache.lucene.codecs.bloom
Class BloomFilterFactory

java.lang.Object
  org.apache.lucene.codecs.bloom.BloomFilterFactory

Direct Known Subclasses:

DefaultBloomFilterFactory

public abstract class BloomFilterFactory
extends Object

Class used to create index-time FuzzySet appropriately configured for each field. Also called to right-size bitsets for serialization.

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

Constructor Summary

BloomFilterFactory()

Method Summary

FuzzySet	downsize(FieldInfo fieldInfo, FuzzySet initialSet) Called when downsizing bitsets for serialization
abstract FuzzySet	getSetForField(SegmentWriteState state, FieldInfo info)
abstract boolean	isSaturated(FuzzySet bloomFilter, FieldInfo fieldInfo) Used to determine if the given filter has reached saturation and should be retired i.e.

Methods inherited from class java.lang.Object

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

Constructor Detail

BloomFilterFactory

public BloomFilterFactory()

Method Detail

getSetForField

public abstract FuzzySet getSetForField(SegmentWriteState state,
                                        FieldInfo info)

Parameters:

state - The content to be indexed

info - the field requiring a BloomFilter

Returns:

An appropriately sized set or null if no BloomFiltering required

downsize

public FuzzySet downsize(FieldInfo fieldInfo,
                         FuzzySet initialSet)

Called when downsizing bitsets for serialization

Parameters:

fieldInfo - The field with sparse set bits

initialSet - The bits accumulated

Returns:

null or a hopefully more densely packed, smaller bitset

isSaturated

public abstract boolean isSaturated(FuzzySet bloomFilter,
                                    FieldInfo fieldInfo)

Used to determine if the given filter has reached saturation and should be retired i.e. not saved any more

Parameters:

bloomFilter - The bloomFilter being tested

fieldInfo - The field with which this filter is associated

Returns:

true if the set has reached saturation and should be retired