org.plumelib.util

Class LimitedSizeSet<T>

java.lang.Object

org.plumelib.util.LimitedSizeSet<T>

Type Parameters:

T - the type of elements in the set

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable

public class LimitedSizeSet<T>
extends java.lang.Object
implements java.io.Serializable, java.lang.Cloneable

LimitedSizeSet 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).

If you nee LimitedSizeSet<Integer, use LimitedSizeIntSet instead.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected int	numValues The number of active elements (equivalently, the first unused index).
protected T[]	values If null, then at least numValues distinct values have been seen (and numValues equals the maxValues argument to the constructor).

Constructor Summary

Constructors

Constructor and Description
LimitedSizeSet(int maxValues) Create a new LimitedSizeSet that can hold maxValues values.

Method Summary

Modifier and Type	Method and Description
void	add(T elt) Add an element to this set.
void	addAll(LimitedSizeSet<? extends T> s) Add all elements of s to this set.
LimitedSizeSet<T>	clone()
boolean	contains(T elt) Return true if this set contains the given element.
int	maxSize() An upper bound on how many distinct elements can be individually represented in the set.
static <T> LimitedSizeSet<T>	merge(int maxValues, java.util.List<LimitedSizeSet<? extends T>> slist) Merges a list of LimitedSizeSet<T> 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 T[] values

If null, then at least numValues distinct values have been seen (and numValues equals the maxValues argument to the constructor).

numValues

protected int numValues

The number of active elements (equivalently, the first unused index).

Constructor Detail

LimitedSizeSet

public LimitedSizeSet(int maxValues)

Create a new LimitedSizeSet 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(T elt)

Add an element to this set.

Parameters:

elt - the element to add to this set

addAll

public void addAll(LimitedSizeSet<? extends T> s)

Add all elements of s to this set.

Parameters:

s - the elements to add to this set

contains

@Pure
public boolean contains(T 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 LimitedSizeSet<T> 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 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 LimitedSizeSet<T> 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 LimitedSizeSet<T> clone(@GuardSatisfied LimitedSizeSet<T> this)

Overrides:

clone in class java.lang.Object

merge

public static <T> LimitedSizeSet<T> merge(int maxValues,
                                          java.util.List<LimitedSizeSet<? extends T>> slist)

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

Type Parameters:

T - (super)type of elements of the sets

Parameters:

maxValues - the maximum size for the returned LimitedSizeSet

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

Returns:

a LimitedSizeSet that merges the elements of slist

toString

@SideEffectFree
public java.lang.String toString(@GuardSatisfied LimitedSizeSet<T> this)

Overrides:

toString in class java.lang.Object