Package org.apache.lucene.util

Class BitDocIdSet

java.lang.Object

org.apache.lucene.search.DocIdSet

org.apache.lucene.util.BitDocIdSet

All Implemented Interfaces:

Accountable

public class BitDocIdSet
extends DocIdSet

Implementation of the DocIdSet interface on top of a BitSet.

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.DocIdSet

EMPTY

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

NULL_ACCOUNTABLE

Constructor Summary

Constructors

Constructor	Description
BitDocIdSet(BitSet set)	Same as BitDocIdSet(BitSet, long) but uses the set's approximate cardinality as a cost.
BitDocIdSet(BitSet set, long cost)	Wrap the given BitSet as a DocIdSet.

Method Summary

Modifier and Type	Method	Description
BitSet	bits()	Optionally provides a Bits interface for random access to matching documents.
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

all

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

Constructor Detail

BitDocIdSet

public BitDocIdSet(BitSet set,
                   long cost)

Wrap the given BitSet as a DocIdSet. The provided BitSet must not be modified afterwards.

BitDocIdSet

public BitDocIdSet(BitSet set)

Same as BitDocIdSet(BitSet, long) but uses the set's approximate cardinality as a cost.

Method Detail

iterator

public DocIdSetIterator iterator()

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

bits

public BitSet bits()

Description copied from class: DocIdSet

Optionally provides a Bits interface for random access to matching documents.

Overrides:

bits in class DocIdSet

Returns:

null, if this DocIdSet does not support random access. In contrast to DocIdSet.iterator(), a return value of null does not imply that no documents match the filter! The default implementation does not provide random access, so you only need to implement this method if your DocIdSet can guarantee random access to every docid in O(1) time without external disk access (as Bits interface cannot throw IOException). This is generally true for bit sets like FixedBitSet, which return itself if they are used as DocIdSet.

ramBytesUsed

public long ramBytesUsed()

Description copied from interface: Accountable

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

toString

public String toString()

Overrides:

toString in class Object