org.plumelib.util

Class LimitedSizeIntSet

java.lang.Object

org.plumelib.util.LimitedSizeIntSet

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable

public class LimitedSizeIntSet
extends java.lang.Object
implements java.io.Serializable, java.lang.Cloneable

LimitedSizeIntSet stores up to some maximum number of unique values. If more than that many elements are added, then functionality is degraded: most operations return a conservative estimate (because the internal representation is nulled, in order to save space).

The advantage of this class over LimitedSizeSet<Integer> is that it does not autobox the int values, so it takes less memory.

See Also:

LimitedSizeSet, Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected int[]	values If null, then at least numValues distinct values have been seen.

Constructor Summary

Constructors

Constructor and Description
LimitedSizeIntSet(@Positive int maxValues) Create a new LimitedSizeIntSet that can hold maxValues values.

Method Summary

Modifier and Type	Method and Description
void	add(int elt) Add an element to this set.
void	addAll(LimitedSizeIntSet s) Add all elements of s to this set.
LimitedSizeIntSet	clone()
boolean	contains(int elt) Return true if this set contains the given element.
@Positive int	maxSize() An upper bound on how many distinct elements can be individually represented in the set.
static LimitedSizeIntSet	merge(@Positive int maxValues, java.util.List<LimitedSizeIntSet> slist) Merges a list of LimitedSizeIntSet objects into a single object that represents the values seen by the entire list.
boolean	repNulled() Returns true if more elements have been added than this set can contain (which is the integer that was passed to the constructor when creating this set).
int	size() A lower bound on the number of elements in the set.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

values

protected int[] values

If null, then at least numValues distinct values have been seen. The size is not separately stored, because that would take extra space.

Constructor Detail

LimitedSizeIntSet

public LimitedSizeIntSet(@Positive int maxValues)

Create a new LimitedSizeIntSet that can hold maxValues values.

Parameters:

maxValues - the maximum number of values this set will be able to hold; must be positive

Method Detail

add

public void add(int elt)

Add an element to this set.

Parameters:

elt - the element to add to this set

addAll

public void addAll(LimitedSizeIntSet s)

Add all elements of s to this set.

Parameters:

s - the elements to add to this set

contains

@Pure
public boolean contains(int elt)

Return true if this set contains the given element.

Parameters:

elt - the element whose membership to test

Returns:

true if this set contains elt

size

@Pure
public int size(@GuardSatisfied LimitedSizeIntSet this)

A lower bound on the number of elements in the set. Returns either the number of elements that have been inserted in the set, or maxSize(), whichever is less.

Returns:

a number that is a lower bound on the number of elements added to the set

maxSize

public @Positive int maxSize()

An upper bound on how many distinct elements can be individually represented in the set. Returns maxValues+1 (where maxValues is the argument to the constructor).

Returns:

maximum capacity of the set representation

repNulled

@EnsuresNonNullIf(result=false,
                  expression="values")
 @Pure
public boolean repNulled(@GuardSatisfied LimitedSizeIntSet this)

Returns true if more elements have been added than this set can contain (which is the integer that was passed to the constructor when creating this set).

Returns:

true if this set has been filled to capacity and its internal representation is nulled

clone

@SideEffectFree
public LimitedSizeIntSet clone(@GuardSatisfied LimitedSizeIntSet this)

Overrides:

clone in class java.lang.Object

merge

public static LimitedSizeIntSet merge(@Positive int maxValues,
                                      java.util.List<LimitedSizeIntSet> slist)

Merges a list of LimitedSizeIntSet objects into a single object that represents the values seen by the entire list. Returns the new object, whose maxValues is the given integer.

Parameters:

maxValues - the maximum size for the returned LimitedSizeIntSet

slist - a list of LimitedSizeIntSet, whose elements will be merged

Returns:

a LimitedSizeIntSet that merges the elements of slist

toString

@SideEffectFree
public java.lang.String toString(@GuardSatisfied LimitedSizeIntSet this)

Overrides:

toString in class java.lang.Object