org.apache.lucene.util

Class RoaringDocIdSet

java.lang.Object

org.apache.lucene.search.DocIdSet

org.apache.lucene.util.RoaringDocIdSet

All Implemented Interfaces:

Accountable

public class RoaringDocIdSet
extends DocIdSet

DocIdSet implementation inspired from http://roaringbitmap.org/ The space is divided into blocks of 2^16 bits and each block is encoded independently. In each block, if less than 2^12 bits are set, then documents are simply stored in a short[]. If more than 2^16-2^12 bits are set, then the inverse of the set is encoded in a simple short[]. Otherwise a FixedBitSet is used.

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

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	RoaringDocIdSet.Builder A builder of RoaringDocIdSets.

Field Summary

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

EMPTY

Method Summary

Modifier and Type	Method and Description
int	cardinality() Return the exact number of documents that are contained in this set.
DocIdSetIterator	iterator() Provides a DocIdSetIterator to access the set.
long	ramBytesUsed() Return the memory usage of this object in bytes.
String	toString()

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

bits

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.lucene.util.Accountable

getChildResources

Method Detail

ramBytesUsed

public long ramBytesUsed()

Description copied from interface: Accountable

Return the memory usage of this object in bytes. Negative values are illegal.

iterator

public DocIdSetIterator iterator()
                          throws IOException

Description copied from class: DocIdSet

Provides a DocIdSetIterator to access the set. This implementation can return null if there are no docs that match.

Specified by:

iterator in class DocIdSet

Throws:

IOException

cardinality

public int cardinality()

Return the exact number of documents that are contained in this set.

toString

public String toString()

Overrides:

toString in class Object