io.druid.extendedset.intset

Class ConciseSet

java.lang.Object

io.druid.extendedset.intset.AbstractIntSet

io.druid.extendedset.intset.ConciseSet

All Implemented Interfaces:

IntSet, Serializable, Cloneable, Comparable<IntSet>

public class ConciseSet
extends AbstractIntSet
implements Serializable

This is CONCISE: COmpressed 'N' Composable Integer SEt.

This class is an instance of IntSet internally represented by compressed bitmaps though a RLE (Run-Length Encoding) compression algorithm. See http ://ricerca.mat.uniroma3.it/users/colanton/docs/concise.pdf for more details.

Notice that the iterator by iterator() is fail-fast, similar to most Collection-derived classes. If the set is structurally modified at any time after the iterator is created, the iterator will throw a ConcurrentModificationException. Thus, in the face of concurrent modification, the iterator fails quickly and cleanly, rather than risking arbitrary, non-deterministic behavior at an undetermined time in the future. The iterator throws a ConcurrentModificationException on a best-effort basis. Therefore, it would be wrong to write a program that depended on this exception for its correctness: the fail-fast behavior of iterators should be used only to detect bugs.

Version:

$Id$

Author:

Alessandro Colantonio

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface io.druid.extendedset.intset.IntSet

IntSet.IntIterator

Constructor Summary

Constructors

Constructor and Description
ConciseSet() Creates an empty integer set
ConciseSet(boolean simulateWAH) Creates an empty integer set
ConciseSet(int[] words, boolean simulateWAH)

Method Summary

Modifier and Type	Method and Description
boolean	add(int e) Adds the specified element to this set if it is not already present.
boolean	addAll(IntSet c) Adds all of the elements in the specified collection to this set if they're not already present.
double	bitmapCompressionRatio() Computes the compression factor of the equivalent bitmap representation (1 means not compressed, namely a memory footprint similar to BitSet, 2 means twice the size of BitSet, etc.)
void	clear() Removes all of the elements from this set.
void	clear(int from, int to) Removes from the set all the elements between first and last, both included.
ConciseSet	clone() See the clone() of Object
double	collectionCompressionRatio() Computes the compression factor of the equivalent integer collection (1 means not compressed, namely a memory footprint similar to ArrayList, 2 means twice the size of ArrayList, etc.)
int	compareTo(IntSet o)
void	complement() Complements the current set.
ConciseSet	complemented() Generates the complement set.
boolean	contains(int o) Returns true if this set contains the specified element.
boolean	containsAll(IntSet c) Returns true if this set contains all of the elements of the specified collection.
boolean	containsAny(IntSet c) Returns true if the specified IntSet instance contains any elements that are also contained within this IntSet instance
boolean	containsAtLeast(IntSet c, int minElements) Returns true if the specified IntSet instance contains at least minElements elements that are also contained within this IntSet instance
ConciseSet	convert(Collection<Integer> c) Converts a given collection into an instance of the current class.
ConciseSet	convert(int... a) Converts a given array into an instance of the current class.
String	debugInfo() Prints debug info about the given IntSet implementation
IntSet.IntIterator	descendingIterator()
ConciseSet	difference(IntSet other) Generates the difference set
ConciseSet	empty() Generates an empty set
boolean	equals(Object obj)
void	fill(int from, int to) Adds to the set all the elements between first and last, both included.
void	flip(int e) Adds the element if it not existing, or removes it if existing
int	get(int i) Gets the ith element of the set
int[]	getWords()
int	hashCode()
int	indexOf(int e) Provides position of element within the set.
ConciseSet	intersection(IntSet other) Generates the intersection set
int	intersectionSize(IntSet o) Computes the intersection set size.
boolean	isEmpty()
IntSet.IntIterator	iterator()
int	last() Returns the last (highest) element currently in this set.
boolean	remove(int o) Removes the specified element from this set if it is present.
boolean	removeAll(IntSet c) Removes from this set all of its elements that are contained in the specified collection.
boolean	retainAll(IntSet c) Retains only the elements in this set that are contained in the specified collection.
int	size()
ConciseSet	symmetricDifference(IntSet other) Generates the symmetric difference set
ByteBuffer	toByteBuffer()
ConciseSet	union(IntSet other) Generates the union set

Methods inherited from class io.druid.extendedset.intset.AbstractIntSet

complementSize, differenceSize, first, jaccardDistance, jaccardSimilarity, powerSet, powerSet, powerSetSize, powerSetSize, symmetricDifferenceSize, toArray, toArray, toString, unionSize, weightedJaccardDistance, weightedJaccardSimilarity

Methods inherited from class java.lang.Object

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

Constructor Detail

ConciseSet

public ConciseSet()

Creates an empty integer set

ConciseSet

public ConciseSet(boolean simulateWAH)

Creates an empty integer set

Parameters:

simulateWAH - true if the class must simulate the behavior of WAH

ConciseSet

public ConciseSet(int[] words,
                  boolean simulateWAH)

Method Detail

clone

public ConciseSet clone()

See the clone() of Object

Specified by:

clone in interface IntSet

Specified by:

clone in class AbstractIntSet

Returns:

cloned object

intersectionSize

public int intersectionSize(IntSet o)

Computes the intersection set size.

This is faster than calling IntSet.intersection(IntSet) and then IntSet.size()

Specified by:

intersectionSize in interface IntSet

Overrides:

intersectionSize in class AbstractIntSet

Parameters:

o - IntSet instance that represents the right operand

Returns:

the size

toByteBuffer

public ByteBuffer toByteBuffer()

getWords

public int[] getWords()

get

public int get(int i)

Gets the i^th element of the set

Specified by:

get in interface IntSet

Specified by:

get in class AbstractIntSet

Parameters:

i - position of the element in the sorted set

Returns:

the i^th element of the set

indexOf

public int indexOf(int e)

Provides position of element within the set.

It returns -1 if the element does not exist within the set.

Specified by:

indexOf in interface IntSet

Specified by:

indexOf in class AbstractIntSet

Parameters:

e - element of the set

Returns:

the element position

intersection

public ConciseSet intersection(IntSet other)

Generates the intersection set

Specified by:

intersection in interface IntSet

Overrides:

intersection in class AbstractIntSet

Parameters:

other - IntSet instance that represents the right operand

Returns:

the result of the operation

See Also:

IntSet.retainAll(IntSet)

union

public ConciseSet union(IntSet other)

Generates the union set

Specified by:

union in interface IntSet

Overrides:

union in class AbstractIntSet

Parameters:

other - IntSet instance that represents the right operand

Returns:

the result of the operation

See Also:

IntSet.addAll(IntSet)

difference

public ConciseSet difference(IntSet other)

Generates the difference set

Specified by:

difference in interface IntSet

Overrides:

difference in class AbstractIntSet

Parameters:

other - IntSet instance that represents the right operand

Returns:

the result of the operation

See Also:

IntSet.removeAll(IntSet)

symmetricDifference

public ConciseSet symmetricDifference(IntSet other)

Generates the symmetric difference set

Specified by:

symmetricDifference in interface IntSet

Overrides:

symmetricDifference in class AbstractIntSet

Parameters:

other - IntSet instance that represents the right operand

Returns:

the result of the operation

See Also:

IntSet.flip(int)

complemented

public ConciseSet complemented()

Generates the complement set. The returned set is represented by all the elements strictly less than IntSet.last() that do not exist in the current set.

Specified by:

complemented in interface IntSet

Overrides:

complemented in class AbstractIntSet

Returns:

the complement set

See Also:

IntSet.complement()

complement

public void complement()

Complements the current set. The modified set is represented by all the elements strictly less than IntSet.last() that do not exist in the current set.

Specified by:

complement in interface IntSet

Overrides:

complement in class AbstractIntSet

See Also:

IntSet.complemented()

iterator

public IntSet.IntIterator iterator()

Specified by:

iterator in interface IntSet

Specified by:

iterator in class AbstractIntSet

Returns:

a IntSet.IntIterator instance to iterate over the set

descendingIterator

public IntSet.IntIterator descendingIterator()

Specified by:

descendingIterator in interface IntSet

Specified by:

descendingIterator in class AbstractIntSet

Returns:

a IntSet.IntIterator instance to iterate over the set in descending order

clear

public void clear()

Removes all of the elements from this set. The set will be empty after this call returns.

Specified by:

clear in interface IntSet

Overrides:

clear in class AbstractIntSet

last

public int last()

Returns the last (highest) element currently in this set.

Specified by:

last in interface IntSet

Specified by:

last in class AbstractIntSet

Returns:

the last (highest) element currently in this set

convert

public ConciseSet convert(int... a)

Converts a given array into an instance of the current class.

Specified by:

convert in interface IntSet

Specified by:

convert in class AbstractIntSet

Parameters:

a - array to use to generate the new instance

Returns:

the converted collection

convert

public ConciseSet convert(Collection<Integer> c)

Converts a given collection into an instance of the current class.

Specified by:

convert in interface IntSet

Specified by:

convert in class AbstractIntSet

Parameters:

c - array to use to generate the new instance

Returns:

the converted collection

add

public boolean add(int e)

Adds the specified element to this set if it is not already present. It ensures that sets never contain duplicate elements.

Specified by:

add in interface IntSet

Specified by:

add in class AbstractIntSet

Parameters:

e - element to be added to this set

Returns:

true if this set did not already contain the specified element

remove

public boolean remove(int o)

Removes the specified element from this set if it is present.

Specified by:

remove in interface IntSet

Specified by:

remove in class AbstractIntSet

Parameters:

o - object to be removed from this set, if present

Returns:

true if this set contained the specified element

contains

public boolean contains(int o)

Returns true if this set contains the specified element.

Specified by:

contains in interface IntSet

Specified by:

contains in class AbstractIntSet

Parameters:

o - element whose presence in this set is to be tested

Returns:

true if this set contains the specified element

containsAll

public boolean containsAll(IntSet c)

Returns true if this set contains all of the elements of the specified collection.

Specified by:

containsAll in interface IntSet

Overrides:

containsAll in class AbstractIntSet

Parameters:

c - collection to be checked for containment in this set

Returns:

true if this set contains all of the elements of the specified collection

See Also:

IntSet.contains(int)

containsAny

public boolean containsAny(IntSet c)

Returns true if the specified IntSet instance contains any elements that are also contained within this IntSet instance

Specified by:

containsAny in interface IntSet

Overrides:

containsAny in class AbstractIntSet

Parameters:

c - IntSet to intersect with

Returns:

a boolean indicating whether this IntSet intersects the specified IntSet.

containsAtLeast

public boolean containsAtLeast(IntSet c,
                               int minElements)

Returns true if the specified IntSet instance contains at least minElements elements that are also contained within this IntSet instance

Specified by:

containsAtLeast in interface IntSet

Overrides:

containsAtLeast in class AbstractIntSet

Parameters:

c - IntSet instance to intersect with

minElements - minimum number of elements to be contained within this IntSet instance

Returns:

a boolean indicating whether this IntSet intersects the specified IntSet.

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface IntSet

Specified by:

isEmpty in class AbstractIntSet

Returns:

true if this set contains no elements

retainAll

public boolean retainAll(IntSet c)

Retains only the elements in this set that are contained in the specified collection. In other words, removes from this set all of its elements that are not contained in the specified collection.

Specified by:

retainAll in interface IntSet

Overrides:

retainAll in class AbstractIntSet

Parameters:

c - collection containing elements to be retained in this set

Returns:

true if this set changed as a result of the call

See Also:

IntSet.remove(int)

addAll

public boolean addAll(IntSet c)

Adds all of the elements in the specified collection to this set if they're not already present.

Specified by:

addAll in interface IntSet

Overrides:

addAll in class AbstractIntSet

Parameters:

c - collection containing elements to be added to this set

Returns:

true if this set changed as a result of the call

See Also:

IntSet.add(int)

removeAll

public boolean removeAll(IntSet c)

Removes from this set all of its elements that are contained in the specified collection.

Specified by:

removeAll in interface IntSet

Overrides:

removeAll in class AbstractIntSet

Parameters:

c - collection containing elements to be removed from this set

Returns:

true if this set changed as a result of the call

See Also:

IntSet.remove(int), IntSet.contains(int)

size

public int size()

Specified by:

size in interface IntSet

Specified by:

size in class AbstractIntSet

Returns:

the number of elements in this set (its cardinality)

empty

public ConciseSet empty()

Generates an empty set

Specified by:

empty in interface IntSet

Specified by:

empty in class AbstractIntSet

Returns:

the empty set

hashCode

public int hashCode()

Overrides:

hashCode in class AbstractIntSet

equals

public boolean equals(Object obj)

Overrides:

equals in class AbstractIntSet

compareTo

public int compareTo(IntSet o)

Specified by:

compareTo in interface Comparable<IntSet>

Overrides:

compareTo in class AbstractIntSet

clear

public void clear(int from,
                  int to)

Removes from the set all the elements between first and last, both included.

Specified by:

clear in interface IntSet

Overrides:

clear in class AbstractIntSet

Parameters:

from - first element

to - last element

fill

public void fill(int from,
                 int to)

Adds to the set all the elements between first and last, both included.

Specified by:

fill in interface IntSet

Overrides:

fill in class AbstractIntSet

Parameters:

from - first element

to - last element

flip

public void flip(int e)

Adds the element if it not existing, or removes it if existing

Specified by:

flip in interface IntSet

Overrides:

flip in class AbstractIntSet

Parameters:

e - element to flip

See Also:

IntSet.symmetricDifference(IntSet)

bitmapCompressionRatio

public double bitmapCompressionRatio()

Computes the compression factor of the equivalent bitmap representation (1 means not compressed, namely a memory footprint similar to BitSet, 2 means twice the size of BitSet, etc.)

Specified by:

bitmapCompressionRatio in interface IntSet

Specified by:

bitmapCompressionRatio in class AbstractIntSet

Returns:

the compression factor

collectionCompressionRatio

public double collectionCompressionRatio()

Computes the compression factor of the equivalent integer collection (1 means not compressed, namely a memory footprint similar to ArrayList, 2 means twice the size of ArrayList, etc.)

Specified by:

collectionCompressionRatio in interface IntSet

Specified by:

collectionCompressionRatio in class AbstractIntSet

Returns:

the compression factor

debugInfo

public String debugInfo()

Prints debug info about the given IntSet implementation

Specified by:

debugInfo in interface IntSet

Specified by:

debugInfo in class AbstractIntSet

Returns:

a string that describes the internal representation of the instance