org.javasimon.callback.lastsplits
Class CircularList<T>

java.lang.Object
  java.util.AbstractCollection<E>
      java.util.AbstractList<T>
          org.javasimon.callback.lastsplits.CircularList<T>

All Implemented Interfaces:

Iterable<T>, Collection<T>, List<T>

public class CircularList<T>
extends AbstractList<T>

Ring/circular buffer, fixed size FIFO list. Stores values as a fixed size array looping insertion point when array is full. Warnings:

• Only needed methods of the List interface have been implemented.
• This class is not thread safe

Since:

3.2

Author:

gquintana

Nested Class Summary

private class	CircularList.EmptyIterator Empty iterator used when the list is empty
private class	CircularList.MainIterator Main iterator user when the list contains at least one element

Field Summary

private T[]	elements Elements
private int	firstIndex Index of the the first element.
private int	lastIndex Index + 1 of the last element.
private int	size Number of element stored in this list.

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

CircularList(int capacity)
Contructor

Method Summary

boolean	add(T newElement) Add an element to the list, overwriting last added element when list's capacity is reached
boolean	addAll(Collection<? extends T> newElements) Insert a collection of elements, looping on them
void	clear() Removes all elements from the list
private int	convertIndex(int index) Converts an index starting from 0 into an index starting from first
private <X> void	copy(X[] elementsCopy) Copy elements in a target array
T	first() Get the first (inserted) element
T	get(int index) Get element by index
int	getCapacity() Get capacity (buffer size).
private int	incrementIndex(int index, int maxIndex) Increment an index
boolean	isEmpty() Tells whether the list is empty
private boolean	isFull()
Iterator<T>	iterator() Create a new iterator to browse elements
T	last() Get the last (inserted) element
T	removeFirst() Remove the first (inserted) element of the collection
int	size() Return the number of elements in the list
Object[]	toArray()
<T> T[]	toArray(T[] elementsCopy)

Methods inherited from class java.util.AbstractList

add, addAll, equals, hashCode, indexOf, lastIndexOf, listIterator, listIterator, remove, removeRange, set, subList

Methods inherited from class java.util.AbstractCollection

contains, containsAll, remove, removeAll, retainAll, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.List

contains, containsAll, remove, removeAll, retainAll

Field Detail

elements

private final T[] elements

Elements

lastIndex

private int lastIndex

Index + 1 of the last element. Or said differently index where will be added the next element

firstIndex

private int firstIndex

Index of the the first element. Or said differently index which will be removed when list capacity is achieved.

size

private int size

Number of element stored in this list.

Constructor Detail

CircularList

public CircularList(int capacity)

Contructor

Parameters:

capacity - Size of the ring buffer

Method Detail

getCapacity

public int getCapacity()

Get capacity (buffer size).

Returns:

capacity

convertIndex

private int convertIndex(int index)

Converts an index starting from 0 into an index starting from first

Parameters:

index - Index

Returns:

Index converted

get

public T get(int index)

Get element by index

Specified by:

get in interface List<T>

Specified by:

get in class AbstractList<T>

Parameters:

index - Index

Returns:

Element

size

public int size()

Return the number of elements in the list

Specified by:

size in interface Collection<T>

Specified by:

size in interface List<T>

Specified by:

size in class AbstractCollection<T>

Returns:

Size

isEmpty

public boolean isEmpty()

Tells whether the list is empty

Specified by:

isEmpty in interface Collection<T>

Specified by:

isEmpty in interface List<T>

Overrides:

isEmpty in class AbstractCollection<T>

Returns:

true if empty

incrementIndex

private int incrementIndex(int index,
                           int maxIndex)

Increment an index

Parameters:

index - Input index

maxIndex - Assigned value when capacity is reached

Returns:

Output index

add

public boolean add(T newElement)

Add an element to the list, overwriting last added element when list's capacity is reached

Specified by:

add in interface Collection<T>

Specified by:

add in interface List<T>

Overrides:

add in class AbstractList<T>

Parameters:

newElement - Element to add

Returns:

Always true

isFull

private boolean isFull()

addAll

public boolean addAll(Collection<? extends T> newElements)

Insert a collection of elements, looping on them

Specified by:

addAll in interface Collection<T>

Specified by:

addAll in interface List<T>

Overrides:

addAll in class AbstractCollection<T>

Parameters:

newElements - Collection of elements to add

Returns:

Always true

removeFirst

public T removeFirst()

Remove the first (inserted) element of the collection

Returns:

Removed element or null if any

first

public T first()

Get the first (inserted) element

Returns:

First element or null if any

last

public T last()

Get the last (inserted) element

Returns:

Last element or null if any

clear

public void clear()

Removes all elements from the list

Specified by:

clear in interface Collection<T>

Specified by:

clear in interface List<T>

Overrides:

clear in class AbstractList<T>

iterator

public Iterator<T> iterator()

Create a new iterator to browse elements

Specified by:

iterator in interface Iterable<T>

Specified by:

iterator in interface Collection<T>

Specified by:

iterator in interface List<T>

Overrides:

iterator in class AbstractList<T>

Returns:

Iterator

copy

private <X> void copy(X[] elementsCopy)

Copy elements in a target array

Parameters:

elementsCopy - Target array

toArray

public Object[] toArray()

Specified by:

toArray in interface Collection<T>

Specified by:

toArray in interface List<T>

Overrides:

toArray in class AbstractCollection<T>

toArray

public <T> T[] toArray(T[] elementsCopy)

Specified by:

toArray in interface Collection<T>

Specified by:

toArray in interface List<T>

Overrides:

toArray in class AbstractCollection<T>