org.openjdk.jmc.common.collection

Class SimpleArray<T>

java.lang.Object

org.openjdk.jmc.common.collection.SimpleArray<T>

Type Parameters:

T - type of elements in the array

All Implemented Interfaces:

java.lang.Iterable<T>

public class SimpleArray<T>
extends java.lang.Object
implements java.lang.Iterable<T>

An array that can be iterated over.

This class is useful in a few cases:

• You expect that there are a large, but unknown, number of elements that will be added. This class grows its internal storage array more aggressively to avoid multiple array copying. The back side to this is that it may waste more memory.
• You want to reuse a preallocated array.

If you don't have any of those needs, then you might as well use a standard ArrayList instead.

Field Summary

Fields

Modifier and Type	Field and Description
private T[]	elements
private int	size

Constructor Summary

Constructors

Constructor and Description
SimpleArray(T[] initial) Create an instance backed by an array.
SimpleArray(T[] initial, int size) Create an instance backed by an array with a specified number of preallocated elements.

Method Summary

Modifier and Type	Method and Description
void	add(T element) Add an element to the end of the list.
void	addAll(T[] src) Add all elements from an array.
private void	addAll(T[] src, int offset, int len) Add a portion of elements from an array.
protected int	calculateNewCapacity(int currentCapacity)
void	clear() Clear all elements.
void	copyTo(T[] dst, int offset) Copy all elements from the backing array to another array.
T[]	elements() Get an array with all elements.
T	get(int index) Get the element at the specified index.
java.util.Iterator<T>	iterator()
int	size() Get the number of stored elements.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

elements

private T[] elements

size

private int size

Constructor Detail

SimpleArray

public SimpleArray(T[] initial)

Create an instance backed by an array. The array content will be overwritten with elements that are subsequently added.

Parameters:

initial - array to use for storage

SimpleArray

public SimpleArray(T[] initial,
                   int size)

Create an instance backed by an array with a specified number of preallocated elements. The array content after the preallocated elements will be overwritten with elements that are subsequently added.

Parameters:

initial - array to use for storage

size - number of preallocated elements

Method Detail

get

public T get(int index)

Get the element at the specified index.

Parameters:

index - element index

Returns:

element at index

add

public void add(T element)

Add an element to the end of the list.

Parameters:

element - element to add

addAll

public void addAll(T[] src)

Add all elements from an array.

Parameters:

src - array containing elements to add

addAll

private void addAll(T[] src,
                    int offset,
                    int len)

Add a portion of elements from an array.

Parameters:

src - array containing elements to add

offset - offset in array to start adding elements from

len - number of elements from the array to add

copyTo

public void copyTo(T[] dst,
                   int offset)

Copy all elements from the backing array to another array. The destination array must be large enough to fit all elements.

Parameters:

dst - array to copy elements to

offset - starting position in the destination array

calculateNewCapacity

protected int calculateNewCapacity(int currentCapacity)

size

public int size()

Get the number of stored elements. Note that this is not the same as the size of the backing array.

Returns:

the number of stored elements

clear

public void clear()

Clear all elements. Note that the backing array is not cleared.

elements

public T[] elements()

Get an array with all elements. The array length will be equal to the number of elements.

Returns:

an array with all elements

iterator

public java.util.Iterator<T> iterator()

Specified by:

iterator in interface java.lang.Iterable<T>