org.apache.commons.collections.buffer
Class CircularFifoBuffer
java.lang.Object
|
+--java.util.AbstractCollection
|
+--org.apache.commons.collections.buffer.BoundedFifoBuffer
|
+--org.apache.commons.collections.buffer.CircularFifoBuffer
- All Implemented Interfaces:
- BoundedCollection, Buffer, Collection
- public class CircularFifoBuffer
- extends BoundedFifoBuffer
CircularFifoBuffer is a first in first out buffer with a fixed size that
replaces its oldest element if full.
The removal order of a CircularFifoBuffer
is based on the
insertion order; elements are removed in the same order in which they
were added. The iteration order is the same as the removal order.
The add(Object)
, BoundedFifoBuffer.remove()
and BoundedFifoBuffer.get()
operations
all perform in constant time. All other operations perform in linear
time or worse.
Note that this implementation is not synchronized. The following can be
used to provide synchronized access to your CircularFifoBuffer
:
Buffer fifo = BufferUtils.synchronizedBuffer(new CircularFifoBuffer());
This buffer prevents null objects from being added.
- Since:
- Commons Collections 3.0
- Version:
- $Revision: 1.2 $ $Date: 2004/01/14 21:43:08 $
- Author:
- Stefano Fornari, Stephen Colebourne
Method Summary |
boolean |
add(Object element)
If the buffer is full, the least recently added element is discarded so
that a new element can be inserted. |
CircularFifoBuffer
public CircularFifoBuffer()
- Constructor that creates a buffer with the default size of 32.
CircularFifoBuffer
public CircularFifoBuffer(int size)
- Constructor that creates a buffer with the specified size.
- Parameters:
size
- the size of the buffer (cannot be changed)- Throws:
IllegalArgumentException
- if the size is less than 1
CircularFifoBuffer
public CircularFifoBuffer(Collection coll)
- Constructor that creates a buffer from the specified collection.
The collection size also sets the buffer size
- Parameters:
coll
- the collection to copy into the buffer, may not be null- Throws:
NullPointerException
- if the collection is null
add
public boolean add(Object element)
- If the buffer is full, the least recently added element is discarded so
that a new element can be inserted.
- Overrides:
add
in class BoundedFifoBuffer
- Parameters:
element
- the element to add- Returns:
- true, always
Copyright © 2001-2004 Apache Software Foundation. All Rights Reserved.