Package org.apache.log4j.chainsaw

Class CyclicBufferList

java.lang.Object

java.util.AbstractCollection

java.util.AbstractList

org.apache.log4j.chainsaw.CyclicBufferList

All Implemented Interfaces:

Iterable, Collection, List

public class CyclicBufferList
extends AbstractList
implements List

CyclicBuffer implementation that is Object generic, and implements the List interface.

Original CyclicBuffer @author Ceki Gülcü

This implementation (although there's very little change) @author Paul Smith <psmith@apache.org>

Field Summary

Fields

Modifier and Type	Field	Description
(package private) Object[]	ea
(package private) int	first
(package private) int	last
(package private) int	maxSize
(package private) int	numElems

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

Constructors

Constructor	Description
CyclicBufferList()
CyclicBufferList(int maxSize)	Instantiate a new CyclicBuffer of at most maxSize events.

Method Summary

Modifier and Type	Method	Description
boolean	add(Object event)	Add an event as the last event in the buffer.
void	clear()
Object	get()	Get the oldest (first) element in the buffer.
Object	get(int i)	Get the ith oldest event currently in the buffer.
int	getLast()
int	getMaxSize()
Object	remove(int index)	Removes the element at the specified position in this list.
void	resize(int newSize)	Resize the cyclic buffer to newSize.
Object	set(int index, Object element)
int	size()	Get the number of elements in the buffer.

Methods inherited from class java.util.AbstractList

add, addAll, equals, hashCode, indexOf, iterator, lastIndexOf, listIterator, listIterator, removeRange, subList

Methods inherited from class java.util.AbstractCollection

addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from interface java.util.List

add, addAll, addAll, contains, containsAll, equals, hashCode, indexOf, isEmpty, iterator, lastIndexOf, listIterator, listIterator, remove, removeAll, replaceAll, retainAll, sort, spliterator, subList, toArray, toArray

Field Details

ea

Object[] ea

first

int first

last

int last

numElems

int numElems

maxSize

int maxSize

Constructor Details

CyclicBufferList

public CyclicBufferList(int maxSize)

Instantiate a new CyclicBuffer of at most maxSize events.

The maxSize argument must a positive integer.

Parameters:

maxSize - The maximum number of elements in the buffer.

CyclicBufferList

public CyclicBufferList()

Method Details

remove

public Object remove(int index)

Removes the element at the specified position in this list. Shifts any subsequent elements to the left (subtracts one from their indices).

Specified by:

remove in interface List

Overrides:

remove in class AbstractList

Parameters:

index - the index of the element to removed.

Returns:

the element that was removed from the list.

Throws:

IndexOutOfBoundsException - if index out of range (index < 0 || index >= size()).

set

public Object set(int index,
 Object element)

Specified by:

set in interface List

Overrides:

set in class AbstractList

add

public boolean add(Object event)

Add an event as the last event in the buffer.

Specified by:

add in interface Collection

Specified by:

add in interface List

Overrides:

add in class AbstractList

get

public Object get(int i)

Get the ith oldest event currently in the buffer. If i is outside the range 0 to the number of elements currently in the buffer, then null is returned.

Specified by:

get in interface List

Specified by:

get in class AbstractList

getMaxSize

public int getMaxSize()

getLast

public int getLast()

get

public Object get()

Get the oldest (first) element in the buffer. The oldest element is removed from the buffer.

size

public int size()

Get the number of elements in the buffer. This number is guaranteed to be in the range 0 to maxSize (inclusive).

Specified by:

size in interface Collection

Specified by:

size in interface List

Specified by:

size in class AbstractCollection

resize

public void resize(int newSize)

Resize the cyclic buffer to newSize.

Throws:

IllegalArgumentException - if newSize is negative.

clear

public void clear()

Specified by:

clear in interface Collection

Specified by:

clear in interface List

Overrides:

clear in class AbstractList