it.unimi.dsi.bits
Class AbstractBitVector

java.lang.Object
  java.util.AbstractCollection<Boolean>
      it.unimi.dsi.fastutil.booleans.AbstractBooleanCollection
          it.unimi.dsi.fastutil.booleans.AbstractBooleanBigList
              it.unimi.dsi.bits.AbstractBitVector

All Implemented Interfaces:

BitVector, BigList<Boolean>, BooleanBigList, BooleanCollection, BooleanIterable, BooleanStack, Size64, Stack<Boolean>, Comparable<BigList<? extends Boolean>>, Iterable<Boolean>, Collection<Boolean>, RandomAccess

Direct Known Subclasses:

AbstractBitVector.SubBitVector, BooleanListBitVector, LongArrayBitVector

public abstract class AbstractBitVector
extends AbstractBooleanBigList
implements BitVector

An abstract implementation of a BitVector.

This abstract implementation provides almost all methods: you have to provide just BooleanList.getBoolean(int) and List.size(). No attributes are defined.

Note that the integer-set view provided by asLongSet() is not cached: if you want to cache the result of the first call, you must do your own caching.

Warning: this class has several optimised methods that assume that getLong(long, long) is implemented efficiently when its arguments are multiples of Long.SIZE (see, e.g., the implementation of compareTo(BitVector) and longestCommonPrefixLength(BitVector)). If you want speed up the processing of your own BitVector implementations, just implement getLong(long, long) so that it is fast under the above conditions.

Nested Class Summary

static class	AbstractBitVector.LongBigListView A list-of-integers view of a bit vector.
static class	AbstractBitVector.LongSetView An integer sorted set view of a bit vector.
static class	AbstractBitVector.SubBitVector A subvector of a given bit vector, specified by an initial and a final bit.

Nested classes/interfaces inherited from class it.unimi.dsi.fastutil.booleans.AbstractBooleanBigList

AbstractBooleanBigList.BooleanSubList

Constructor Summary

AbstractBitVector()

Method Summary

boolean	add(boolean value)
void	add(int value) Adds a bit with specified value at the end of this bit vector.
void	add(int index, boolean value)
void	add(long index, boolean value) Adds a bit with specified value at the specified index (optional operation).
void	add(long index, int value) Adds a bit with specified integer value at the specified index (optional operation).
BitVector	and(BitVector v) Performs a logical and between this bit vector and another one, leaving the result in this vector.
BitVector	append(BitVector bv) Appends another bit vector to this bit vector.
BitVector	append(long value, int k) Appends the less significant bits of a long integer to this bit vector.
LongBigList	asLongBigList(int width) Returns a view of this bit vector as a list of nonnegative integers of specified width.
LongSortedSet	asLongSet() Returns a view of this bit vector as a sorted set of long integers.
long[]	bits() Returns the bits in this bit vector as an array of longs, not to be modified.
void	clear()
void	clear(int index)
void	clear(long index) Clears a bit in this bit vector (optional operation).
int	compareTo(BigList<? extends Boolean> list)
int	compareTo(BitVector v)
BitVector	copy() Returns a copy of this bit vector.
BitVector	copy(long from, long to) Returns a copy of a part of this bit vector.
long	count() Counts the number of bits set to true in this bit vector.
protected void	ensureIndex(long index)
protected void	ensureRestrictedIndex(long index)
boolean	equals(BitVector v, long start, long end) Checks for equality with a segment of another vector.
boolean	equals(Object o)
BitVector	fast() Returns an instance of LongArrayBitVector containing a copy of this bit vector.
void	fill(boolean value) Sets all bits this bit vector to the given boolean value (optional operation).
void	fill(int value) Sets all bits this bit vector to the given integer value (optional operation).
void	fill(long from, long to, boolean value) Fills a range of bits in this bit vector (optional operation).
void	fill(long from, long to, int value) Clears a range of bits in this bit vector (optional operation).
long	firstOne() Returns the position of the first bit set in this vector.
long	firstZero() Returns the position of the first bit unset in this vector.
void	flip() Flips all bits in this bit vector (optional operation).
void	flip(int index)
void	flip(long index) Flips a bit in this bit vector (optional operation).
void	flip(long from, long to) Flips a range of bits in this bit vector (optional operation).
boolean	getBoolean(int index)
int	getInt(long index) Returns the value of the specified bit as an integer.
long	getLong(long from, long to) Returns the specified bit range as a long.
int	hashCode() Returns a hash code for this bit vector.
boolean	isPrefix(BitVector v) Returns true if this vector is a prefix of the specified vector.
boolean	isProperPrefix(BitVector v) Returns true if this vector is a proper prefix of the specified vector.
long	lastOne() Returns the position of the last bit set in this vector.
long	lastZero() Returns the position of the last bit unset in this vector.
BitVector	length(long newLength) Sets the number of bits in this bit vector.
long	longestCommonPrefixLength(BitVector v) Returns the length of the greatest common prefix between this and the specified vector.
long	nextOne(long index) Returns the position of the first bit set after the given position.
long	nextZero(long index) Returns the position of the first bit unset after the given position.
BitVector	or(BitVector v) Performs a logical or between this bit vector and another one, leaving the result in this vector.
long	previousOne(long index) Returns the position of the first bit set before or at the given position.
long	previousZero(long index) Returns the position of the first bit unset before or at the given position.
boolean	removeBoolean(int index)
boolean	removeBoolean(long index) Removes a bit with specified index (optional operation).
BitVector	replace(BitVector bv) Replaces the content of this bit vector with another bit vector.
void	set(int index)
boolean	set(int index, boolean value)
void	set(long index) Sets a bit in this bit vector (optional operation).
boolean	set(long index, boolean value) Sets the value of the specified bit (optional operation).
void	set(long index, int value) Sets the value of the specified bit as an integer (optional operation).
int	size()
void	size(int newSize)
void	size(long newSize)
long	size64()
AbstractBitVector.SubBitVector	subList(int from, int to)
BitVector	subVector(long from) Returns a subvector view specified by initial index and running up to the end of this vector.
BitVector	subVector(long from, long to) Returns a subvector view specified by initial and final index.
String	toString() Returns a string representation of this vector.
BitVector	xor(BitVector v) Performs a logical xor between this bit vector and another one, leaving the result in this vector.

Methods inherited from class it.unimi.dsi.fastutil.booleans.AbstractBooleanBigList

add, addAll, addAll, addAll, addAll, addAll, addAll, addAll, addElements, addElements, contains, get, getElements, indexOf, indexOf, iterator, lastIndexOf, lastIndexOf, listIterator, listIterator, listIterator, peek, peekBoolean, pop, popBoolean, push, push, rem, remove, remove, removeElements, set, subList, top, topBoolean

Methods inherited from class it.unimi.dsi.fastutil.booleans.AbstractBooleanCollection

add, booleanIterator, contains, containsAll, containsAll, isEmpty, rem, remove, removeAll, removeAll, retainAll, retainAll, toArray, toArray, toArray, toBooleanArray, toBooleanArray

Methods inherited from class java.lang.Object

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

Methods inherited from interface it.unimi.dsi.bits.BitVector

getBoolean, length

Methods inherited from interface it.unimi.dsi.fastutil.booleans.BooleanBigList

addAll, addAll, addAll, addElements, addElements, getElements, indexOf, iterator, lastIndexOf, listIterator, listIterator, removeElements, subList

Methods inherited from interface it.unimi.dsi.fastutil.BigList

add, addAll, get, indexOf, lastIndexOf, remove, set

Methods inherited from interface it.unimi.dsi.fastutil.booleans.BooleanCollection

addAll, booleanIterator, contains, containsAll, rem, removeAll, retainAll, toArray, toArray, toBooleanArray, toBooleanArray

Methods inherited from interface java.util.Collection

add, addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray

Methods inherited from interface it.unimi.dsi.fastutil.Stack

isEmpty

Constructor Detail

AbstractBitVector

public AbstractBitVector()

Method Detail

ensureRestrictedIndex

protected void ensureRestrictedIndex(long index)

Overrides:

ensureRestrictedIndex in class AbstractBooleanBigList

ensureIndex

protected void ensureIndex(long index)

Overrides:

ensureIndex in class AbstractBooleanBigList

set

public void set(int index)

clear

public void clear(int index)

flip

public void flip(int index)

set

public void set(long index)

Description copied from interface: BitVector

Sets a bit in this bit vector (optional operation).

Specified by:

set in interface BitVector

Parameters:

index - the index of a bit.

clear

public void clear(long index)

Description copied from interface: BitVector

Clears a bit in this bit vector (optional operation).

Specified by:

clear in interface BitVector

Parameters:

index - the index of a bit.

flip

public void flip(long index)

Description copied from interface: BitVector

Flips a bit in this bit vector (optional operation).

Specified by:

flip in interface BitVector

Parameters:

index - the index of a bit.

fill

public void fill(boolean value)

Description copied from interface: BitVector

Sets all bits this bit vector to the given boolean value (optional operation).

Specified by:

fill in interface BitVector

fill

public void fill(int value)

Description copied from interface: BitVector

Sets all bits this bit vector to the given integer value (optional operation).

Specified by:

fill in interface BitVector

flip

public void flip()

Description copied from interface: BitVector

Flips all bits in this bit vector (optional operation).

Specified by:

flip in interface BitVector

fill

public void fill(long from,
                 long to,
                 boolean value)

Description copied from interface: BitVector

Fills a range of bits in this bit vector (optional operation).

Specified by:

fill in interface BitVector

Parameters:

from - the first index (inclusive).

to - the last index (not inclusive).

value - the value (true or false).

fill

public void fill(long from,
                 long to,
                 int value)

Description copied from interface: BitVector

Clears a range of bits in this bit vector (optional operation).

Specified by:

fill in interface BitVector

Parameters:

from - the first index (inclusive).

to - the last index (not inclusive).

value - the value (zero or nonzero).

flip

public void flip(long from,
                 long to)

Description copied from interface: BitVector

Flips a range of bits in this bit vector (optional operation).

Specified by:

flip in interface BitVector

Parameters:

from - the first index (inclusive).

to - the last index (not inclusive).

getInt

public int getInt(long index)

Description copied from interface: BitVector

Returns the value of the specified bit as an integer.

This method is a useful synonym for BitVector.getBoolean(long).

Specified by:

getInt in interface BitVector

Parameters:

index - the index of a bit.

Returns:

the value of the specified bit as an integer (0 or 1).

getLong

public long getLong(long from,
                    long to)

Description copied from interface: BitVector

Returns the specified bit range as a long.

Note that bit 0 of the returned long will be bit from of this bit vector.

Implementations are invited to provide high-speed implementations for the case in which from is a multiple of Long.SIZE and to is from + Long.SIZE (or less, in case the vector length is exceeded). This behaviour make it possible to implement high-speed hashing, copies, etc.

Specified by:

getLong in interface BitVector

Parameters:

from - the starting bit (inclusive).

to - the ending bit (exclusive).

Returns:

the long value contained in the specified bits.

getBoolean

public boolean getBoolean(int index)

Overrides:

getBoolean in class AbstractBooleanBigList

removeBoolean

public boolean removeBoolean(int index)

Overrides:

removeBoolean in class AbstractBooleanBigList

set

public boolean set(int index,
                   boolean value)

Overrides:

set in class AbstractBooleanBigList

add

public void add(int index,
                boolean value)

removeBoolean

public boolean removeBoolean(long index)

Description copied from interface: BitVector

Removes a bit with specified index (optional operation).

This method is semantically equivalent to BooleanList.removeBoolean(int), but it gives access to long indices.

Specified by:

removeBoolean in interface BitVector

Specified by:

removeBoolean in interface BooleanBigList

Overrides:

removeBoolean in class AbstractBooleanBigList

Parameters:

index - the index of a bit.

Returns:

the previous value of the bit.

set

public boolean set(long index,
                   boolean value)

Description copied from interface: BitVector

Sets the value of the specified bit (optional operation).

This method is semantically equivalent to BooleanList.set(int,boolean), but it gives access to long indices.

Specified by:

set in interface BitVector

Specified by:

set in interface BooleanBigList

Overrides:

set in class AbstractBooleanBigList

Parameters:

index - the index of a bit.

value - the new value.

add

public void add(long index,
                boolean value)

Description copied from interface: BitVector

Adds a bit with specified value at the specified index (optional operation).

This method is semantically equivalent to BooleanList.add(int,boolean), but it gives access to long indices.

Specified by:

add in interface BitVector

Specified by:

add in interface BooleanBigList

Overrides:

add in class AbstractBooleanBigList

Parameters:

index - the index of a bit.

value - the value that will be inserted at position index.

set

public void set(long index,
                int value)

Description copied from interface: BitVector

Sets the value of the specified bit as an integer (optional operation).

This method is a useful synonym for BitVector.set(long, boolean).

Specified by:

set in interface BitVector

Parameters:

index - the index of a bit.

value - the new value (any nonzero integer for setting the bit, zero for clearing the bit).

add

public void add(long index,
                int value)

Description copied from interface: BitVector

Adds a bit with specified integer value at the specified index (optional operation).

This method is a useful synonym for BitVector.add(long, boolean).

Specified by:

add in interface BitVector

Parameters:

index - the index of a bit.

value - the value that will be inserted at position index (any nonzero integer for a true bit, zero for a false bit).

add

public boolean add(boolean value)

Specified by:

add in interface BooleanCollection

Overrides:

add in class AbstractBooleanBigList

add

public void add(int value)

Description copied from interface: BitVector

Adds a bit with specified value at the end of this bit vector.

This method is a useful synonym for BooleanList.add(boolean).

Specified by:

add in interface BitVector

Parameters:

value - the new value (any nonzero integer for a true bit, zero for a false bit).

append

public BitVector append(long value,
                        int k)

Description copied from interface: BitVector

Appends the less significant bits of a long integer to this bit vector.

Specified by:

append in interface BitVector

Parameters:

value - a value to be appended

k - the number of less significant bits to be added to this bit vector.

Returns:

this bit vector.

append

public BitVector append(BitVector bv)

Description copied from interface: BitVector

Appends another bit vector to this bit vector.

Specified by:

append in interface BitVector

Parameters:

bv - a bit vector to be appended.

Returns:

this bit vector.

copy

public BitVector copy()

Description copied from interface: BitVector

Returns a copy of this bit vector.

Specified by:

copy in interface BitVector

Returns:

a copy of this bit vector.

copy

public BitVector copy(long from,
                      long to)

Description copied from interface: BitVector

Returns a copy of a part of this bit vector.

Specified by:

copy in interface BitVector

Parameters:

from - the starting bit, inclusive.

to - the ending bit, not inclusive.

Returns:

a copy of the part of this bit vector going from bit from (inclusive) to bit to (not inclusive)

fast

public BitVector fast()

Returns an instance of LongArrayBitVector containing a copy of this bit vector.

Specified by:

fast in interface BitVector

Returns:

an instance of LongArrayBitVector containing a copy of this bit vector.

count

public long count()

Description copied from interface: BitVector

Counts the number of bits set to true in this bit vector.

Specified by:

count in interface BitVector

Returns:

the number of bits set to true in this bit vector.

firstOne

public long firstOne()

Description copied from interface: BitVector

Returns the position of the first bit set in this vector.

Specified by:

firstOne in interface BitVector

Returns:

the first bit set, or -1 for a vector of zeroes.

lastOne

public long lastOne()

Description copied from interface: BitVector

Returns the position of the last bit set in this vector.

Specified by:

lastOne in interface BitVector

Returns:

the last bit set, or -1 for a vector of zeroes.

firstZero

public long firstZero()

Description copied from interface: BitVector

Returns the position of the first bit unset in this vector.

Specified by:

firstZero in interface BitVector

Returns:

the first bit unset, or -1 for a vector of ones.

lastZero

public long lastZero()

Description copied from interface: BitVector

Returns the position of the last bit unset in this vector.

Specified by:

lastZero in interface BitVector

Returns:

the last bit unset, or -1 for a vector of ones.

nextOne

public long nextOne(long index)

Description copied from interface: BitVector

Returns the position of the first bit set after the given position.

Specified by:

nextOne in interface BitVector

Returns:

the first bit set after position index (inclusive), or -1 if no such bit exists.

previousOne

public long previousOne(long index)

Description copied from interface: BitVector

Returns the position of the first bit set before or at the given position.

Specified by:

previousOne in interface BitVector

Returns:

the first bit set before or at the given position, or -1 if no such bit exists.

nextZero

public long nextZero(long index)

Description copied from interface: BitVector

Returns the position of the first bit unset after the given position.

Specified by:

nextZero in interface BitVector

Returns:

the first bit unset after position index (inclusive), or -1 if no such bit exists.

previousZero

public long previousZero(long index)

Description copied from interface: BitVector

Returns the position of the first bit unset before or at the given position.

Specified by:

previousZero in interface BitVector

Returns:

the first bit unset before or at the given position, or -1 if no such bit exists.

longestCommonPrefixLength

public long longestCommonPrefixLength(BitVector v)

Description copied from interface: BitVector

Returns the length of the greatest common prefix between this and the specified vector.

Specified by:

longestCommonPrefixLength in interface BitVector

Parameters:

v - a bit vector.

Returns:

the length of the greatest common prefix.

isPrefix

public boolean isPrefix(BitVector v)

Description copied from interface: BitVector

Returns true if this vector is a prefix of the specified vector.

Specified by:

isPrefix in interface BitVector

Parameters:

v - a bit vector.

Returns:

true if this vector is a prefix of v.

isProperPrefix

public boolean isProperPrefix(BitVector v)

Description copied from interface: BitVector

Returns true if this vector is a proper prefix of the specified vector.

Specified by:

isProperPrefix in interface BitVector

Parameters:

v - a bit vector.

Returns:

true if this vector is a proper prefix of v (i.e., it is a prefix but not equal).

and

public BitVector and(BitVector v)

Description copied from interface: BitVector

Performs a logical and between this bit vector and another one, leaving the result in this vector.

Specified by:

and in interface BitVector

Parameters:

v - a bit vector.

Returns:

this bit vector.

or

public BitVector or(BitVector v)

Description copied from interface: BitVector

Performs a logical or between this bit vector and another one, leaving the result in this vector.

Specified by:

or in interface BitVector

Parameters:

v - a bit vector.

Returns:

this bit vector.

xor

public BitVector xor(BitVector v)

Description copied from interface: BitVector

Performs a logical xor between this bit vector and another one, leaving the result in this vector.

Specified by:

xor in interface BitVector

Parameters:

v - a bit vector.

Returns:

this bit vector.

size

public int size()

Specified by:

size in interface Size64

Specified by:

size in interface Collection<Boolean>

Overrides:

size in class AbstractBooleanBigList

size

public void size(int newSize)

Overrides:

size in class AbstractBooleanBigList

size64

public long size64()

Specified by:

size64 in interface Size64

clear

public void clear()

Specified by:

clear in interface Collection<Boolean>

Overrides:

clear in class AbstractCollection<Boolean>

replace

public BitVector replace(BitVector bv)

Description copied from interface: BitVector

Replaces the content of this bit vector with another bit vector.

Specified by:

replace in interface BitVector

Parameters:

bv - a bit vector.

Returns:

this bit vector.

equals

public boolean equals(Object o)

Specified by:

equals in interface Collection<Boolean>

Overrides:

equals in class AbstractBooleanBigList

equals

public boolean equals(BitVector v,
                      long start,
                      long end)

Description copied from interface: BitVector

Checks for equality with a segment of another vector.

Specified by:

equals in interface BitVector

Parameters:

v - a bit vector.

start - the starting bit, inclusive.

end - the ending bit, not inclusive.

Returns:

true if this vector and v are equal in the range of positions [from..to).

hashCode

public int hashCode()

Description copied from interface: BitVector

Returns a hash code for this bit vector.

Hash codes for bit vectors are defined as follows:

 final long length = length();
 long fullLength = length - length % Long.SIZE;
 long h = 0x9e3779b97f4a7c13L ^ length; 
 for( long i = 0; i < fullLength; i += Long.SIZE ) h ^= ( h << 5 ) + getLong( i, i + Long.SIZE ) + ( h >>> 2 );
 if ( length != fullLength ) h ^= ( h << 5 ) + getLong( fullLength, length ) + ( h >>> 2 );
 (int)( ( h >>> 32 ) ^ h );
 

The last value is the hash code of the bit vector. This hashing is based on shift-add-xor hashing (M.V. Ramakrishna and Justin Zobel, “Performance in practice of string hashing functions”, Proc. of the Fifth International Conference on Database Systems for Advanced Applications, 1997, pages 215−223).

The returned value is not a high-quality hash such as Jenkins's, but it can be computed very quickly; in any case, 32 bits are too few for a high-quality hash to be used in large-scale applications.

Important: all bit vector implementations are required to return the value defined here. The simplest way to obtain this result is to subclass AbstractBitVector.

Specified by:

hashCode in interface BitVector

Specified by:

hashCode in interface Collection<Boolean>

Overrides:

hashCode in class AbstractBooleanBigList

Returns:

a hash code for this bit vector.

bits

public long[] bits()

Description copied from interface: BitVector

Returns the bits in this bit vector as an array of longs, not to be modified.

Specified by:

bits in interface BitVector

Returns:

an array of longs whose first BitVector.length() bits contain the bits of this bit vector. The array cannot be modified.

length

public BitVector length(long newLength)

Description copied from interface: BitVector

Sets the number of bits in this bit vector.

It is expected that this method will try to allocate exactly the necessary space.

If the number of bits in this vector is smaller than or equal to Integer.MAX_VALUE, this method is semantically equivalent to BooleanList.size(int). In any case, this method is semantically essentially equivalent to BigList.size(long).

Specified by:

length in interface BitVector

Returns:

this bit vector.

size

public void size(long newSize)

Specified by:

size in interface BigList<Boolean>

Overrides:

size in class AbstractBooleanBigList

asLongSet

public LongSortedSet asLongSet()

Description copied from interface: BitVector

Returns a view of this bit vector as a sorted set of long integers.

More formally, this bit vector is infinitely extended to the left with zeros (e.g., all bits beyond BitVector.length(long) are considered zeroes). The resulting infinite string is interpreted as the characteristic function of a set of integers.

Note that, in particular, the resulting string representation is exactly that of a BitSet.

Specified by:

asLongSet in interface BitVector

asLongBigList

public LongBigList asLongBigList(int width)

Description copied from interface: BitVector

Returns a view of this bit vector as a list of nonnegative integers of specified width.

More formally, getLong(p) will return the nonnegative integer defined by the bits starting at p * width (bit 0, inclusive) and ending at (p + 1) * width (bit width − 1, exclusive).

Specified by:

asLongBigList in interface BitVector

subList

public AbstractBitVector.SubBitVector subList(int from,
                                              int to)

subVector

public BitVector subVector(long from,
                           long to)

Description copied from interface: BitVector

Returns a subvector view specified by initial and final index.

The object returned by this method is a bit vector representing a view of this bit vector restricted to the given indices. Changes to the subvector will be reflected in the main vector.

Specified by:

subVector in interface BitVector

Parameters:

from - the first index (inclusive).

to - the last index (not inclusive).

subVector

public BitVector subVector(long from)

Description copied from interface: BitVector

Returns a subvector view specified by initial index and running up to the end of this vector.

Specified by:

subVector in interface BitVector

Parameters:

from - the first index (inclusive).

See Also:

BitVector.subVector(long, long)

compareTo

public int compareTo(BigList<? extends Boolean> list)

Specified by:

compareTo in interface Comparable<BigList<? extends Boolean>>

Overrides:

compareTo in class AbstractBooleanBigList

compareTo

public int compareTo(BitVector v)

toString

public String toString()

Returns a string representation of this vector.

Note that this string representation shows the bit of index 0 at the leftmost position.

Overrides:

toString in class AbstractBooleanBigList

Returns:

a string representation of this vector, with the bit of index 0 on the left.