org.wikidata.wdtk.storage.datastructures

Class RankedBitVectorImpl

java.lang.Object

org.wikidata.wdtk.storage.datastructures.RankedBitVectorImpl

All Implemented Interfaces:

Iterable<Boolean>, BitVector, RankedBitVector

public class RankedBitVectorImpl
extends Object
implements RankedBitVector, Iterable<Boolean>

Default implementation of RankedBitVector. This implementation uses auxiliary classes to have efficient performance for the methods of a ranked bit vector. Hence, countBits(boolean, long) uses an instance of CountBitsArray and findPosition(boolean, long) uses two instances of FindPositionArray.

Author:

Julian Mendez

See Also:

CountBitsArray, FindPositionArray

Field Summary

Fields inherited from interface org.wikidata.wdtk.storage.datastructures.RankedBitVector

NOT_FOUND

Constructor Summary

Constructors

Constructor and Description
RankedBitVectorImpl() Constructor of a ranked bit vector of size 0.
RankedBitVectorImpl(BitVector bitVector) Copy constructor of a ranked bit vector.
RankedBitVectorImpl(long initialSize) Constructor of a ranked bit vector of size initialSize.
RankedBitVectorImpl(long initialSize, int countBlockSize, int findPositionBlockSize) Constructor of a ranked bit vector of size initialSize and block size blockSize.

Method Summary

Modifier and Type	Method and Description
boolean	addBit(boolean bit) Appends a bit to this bit vector.
long	countBits(boolean bit, long position) This is the "rank" method of bit vectors.
boolean	equals(Object obj) Returns true if and only if the specified object is also a BitVector and both contain the same bits in the same order.
long	findPosition(boolean bit, long nOccurrence) This is the "select" method of bit vectors.
boolean	getBit(long position) This is the "access" method of bit vectors.
int	hashCode()
Iterator<Boolean>	iterator()
void	setBit(long position, boolean bit) Sets a bit at a particular position.
long	size()
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

RankedBitVectorImpl

public RankedBitVectorImpl()

Constructor of a ranked bit vector of size 0.

RankedBitVectorImpl

public RankedBitVectorImpl(BitVector bitVector)

Copy constructor of a ranked bit vector.

Parameters:

bitVector - bit vector

RankedBitVectorImpl

public RankedBitVectorImpl(long initialSize)

Constructor of a ranked bit vector of size initialSize. The bit vector contains false at all indexes.

Parameters:

initialSize - initial size of this ranked bit vector

RankedBitVectorImpl

public RankedBitVectorImpl(long initialSize,
                           int countBlockSize,
                           int findPositionBlockSize)

Constructor of a ranked bit vector of size initialSize and block size blockSize. The bit vector contains false at all indexes.

Parameters:

initialSize - initial size of this ranked bit vector

countBlockSize - block size to count number of occurrences of a value; this value must be a positive number

findPositionBlockSize - block size to find the position of the n-th occurrence of a value; this value must be greater than or equal to 64

Throws:

IllegalArgumentException - if any of the block sizes is too small

Method Detail

addBit

public boolean addBit(boolean bit)

Description copied from interface: BitVector

Appends a bit to this bit vector.

Specified by:

addBit in interface BitVector

Returns:

true if the element was successfully added

countBits

public long countBits(boolean bit,
                      long position)

Description copied from interface: RankedBitVector

This is the "rank" method of bit vectors. This method returns the number of occurrences of bit up to position.

Specified by:

countBits in interface RankedBitVector

Parameters:

bit - bit

position - position

Returns:

number of occurrences of bit at position

equals

public boolean equals(Object obj)

Description copied from interface: BitVector

Returns true if and only if the specified object is also a BitVector and both contain the same bits in the same order.

Specified by:

equals in interface BitVector

Overrides:

equals in class Object

Parameters:

obj - the object to be compared with this BitVector

Returns:

true if and only if the specified object is also a BitVector and both contain the same bits in the same order

findPosition

public long findPosition(boolean bit,
                         long nOccurrence)

Description copied from interface: RankedBitVector

This is the "select" method of bit vectors. This method returns the position of the n-th occurrence (nOccurrence) of bit or NOT_FOUND if there are not enough occurrences.

Specified by:

findPosition in interface RankedBitVector

Parameters:

bit - bit

nOccurrence - number of occurrences

Returns:

position of the n-th occurrence (nOccurrence) of bit or NOT_FOUND if there are not enough occurrences

getBit

public boolean getBit(long position)

Description copied from interface: BitVector

This is the "access" method of bit vectors.

Specified by:

getBit in interface BitVector

Returns:

value of a bit at position

hashCode

public int hashCode()

Overrides:

hashCode in class Object

iterator

public Iterator<Boolean> iterator()

Specified by:

iterator in interface Iterable<Boolean>

Specified by:

iterator in interface BitVector

Returns:

an iterator for this bit vector

setBit

public void setBit(long position,
                   boolean bit)

Description copied from interface: BitVector

Sets a bit at a particular position.

Specified by:

setBit in interface BitVector

Parameters:

position - position

bit - bit

size

public long size()

Specified by:

size in interface BitVector

Returns:

size of this bit vector

toString

public String toString()

Overrides:

toString in class Object