public class UnboundedFifoBuffer extends AbstractCollection implements Buffer, Serializable
Buffer that can grow to any size.
According to performance testing, it exhibits a constant access time, but it
also outperforms ArrayList when used for the same purpose.
The removal order of an UnboundedFifoBuffer 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 remove() and get() operations perform in constant time.
The add(Object) operation performs in amortized 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 UnboundedFifoBuffer:
Buffer fifo = BufferUtils.synchronizedBuffer(new UnboundedFifoBuffer());
This buffer prevents null objects from being added.
This class is Serializable from Commons Collections 3.1.
| Modifier and Type | Field and Description |
|---|---|
protected Object[] |
buffer
The array of objects in the buffer.
|
protected int |
head
The current head index.
|
protected int |
tail
The current tail index.
|
| Constructor and Description |
|---|
UnboundedFifoBuffer()
Constructs an UnboundedFifoBuffer with the default number of elements.
|
UnboundedFifoBuffer(int initialSize)
Constructs an UnboundedFifoBuffer with the specified number of elements.
|
| Modifier and Type | Method and Description |
|---|---|
boolean |
add(Object obj)
Adds the given element to this buffer.
|
Object |
get()
Returns the next object in the buffer.
|
boolean |
isEmpty()
Returns true if this buffer is empty; false otherwise.
|
Iterator |
iterator()
Returns an iterator over this buffer's elements.
|
Object |
remove()
Removes the next object from the buffer
|
int |
size()
Returns the number of elements stored in the buffer.
|
addAll, clear, contains, containsAll, remove, removeAll, retainAll, toArray, toArray, toStringprotected transient Object[] buffer
protected transient int head
protected transient int tail
public UnboundedFifoBuffer()
new UnboundedFifoBuffer(32);
public UnboundedFifoBuffer(int initialSize)
initialSize - the initial size of the bufferIllegalArgumentException - if the size is less than 1public int size()
size in interface Collectionsize in class AbstractCollectionpublic boolean isEmpty()
isEmpty in interface CollectionisEmpty in class AbstractCollectionpublic boolean add(Object obj)
add in interface Collectionadd in class AbstractCollectionobj - the element to addNullPointerException - if the given element is nullpublic Object get()
get in interface BufferBufferUnderflowException - if this buffer is emptypublic Object remove()
remove in interface BufferBufferUnderflowException - if this buffer is emptypublic Iterator iterator()
iterator in interface Iterableiterator in interface Collectioniterator in class AbstractCollectionCopyright © 2001–2015 The Apache Software Foundation. All rights reserved.