org.apache.commons.collections.buffer
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 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.
Since: Commons Collections 3.0 (previously in main package v2.1)
Version: $Revision: 405927 $ $Date: 2006-05-12 23:57:03 +0100 (Fri, 12 May 2006) $
Field Summary | |
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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 Summary | |
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UnboundedFifoBuffer()
Constructs an UnboundedFifoBuffer with the default number of elements.
| |
UnboundedFifoBuffer(int initialSize)
Constructs an UnboundedFifoBuffer with the specified number of elements.
|
Method Summary | |
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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.
|
new UnboundedFifoBuffer(32);
Parameters: initialSize the initial size of the buffer
Throws: IllegalArgumentException if the size is less than 1
Parameters: obj the element to add
Returns: true, always
Throws: NullPointerException if the given element is null
Returns: the next object in the buffer
Throws: BufferUnderflowException if this buffer is empty
Returns: true if this buffer is empty
Returns: an iterator over this buffer's elements
Returns: the removed object
Throws: BufferUnderflowException if this buffer is empty
Returns: this buffer's size