ch.qos.logback.core.helpers

Class CyclicBuffer<E>

java.lang.Object

ch.qos.logback.core.helpers.CyclicBuffer<E>

public class CyclicBuffer<E>
extends Object

CyclicBuffer holds values in a cyclic array.

It allows read access to any element in the buffer not just the first or last element.

Constructor Summary

Constructors

Constructor and Description
CyclicBuffer(CyclicBuffer<E> other)
CyclicBuffer(int maxSize) Instantiate a new CyclicBuffer of at most maxSize events.

Method Summary

Modifier and Type	Method and Description
void	add(E event) Add an event as the last event in the buffer.
List<E>	asList()
void	clear() Clears the buffer and resets all attributes.
E	get() Get the oldest (first) element in the buffer.
E	get(int i) Get the ith oldest event currently in the buffer.
int	getMaxSize()
int	length() Get the number of elements in the buffer.
void	resize(int newSize) Resize the cyclic buffer to newSize.

Methods inherited from class java.lang.Object

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

Constructor Detail

CyclicBuffer

public CyclicBuffer(int maxSize)
             throws IllegalArgumentException

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.

Throws:

IllegalArgumentException

CyclicBuffer

public CyclicBuffer(CyclicBuffer<E> other)

Method Detail

clear

public void clear()

Clears the buffer and resets all attributes.

add

public void add(E event)

Add an event as the last event in the buffer.

Parameters:

event - the log event

get

public E 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.

Parameters:

i - the index of the oldest event to fetch

Returns:

the event

getMaxSize

public int getMaxSize()

get

public E get()

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

Returns:

the element

asList

public List<E> asList()

length

public int length()

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

Returns:

the element count

resize

public void resize(int newSize)

Resize the cyclic buffer to newSize.

Parameters:

newSize - the desired size

Throws:

IllegalArgumentException - if newSize is negative.