Package org.apache.commons.collections.buffer

Class UnboundedFifoBuffer

java.lang.Object
java.util.AbstractCollection
org.apache.commons.collections.buffer.UnboundedFifoBuffer
All Implemented Interfaces:
Serializable, Iterable, Collection, Buffer
public class UnboundedFifoBuffer extends AbstractCollection implements Buffer, Serializable
UnboundedFifoBuffer is a very efficient implementation of 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.

Since:
Commons Collections 3.0 (previously in main package v2.1)
Version:
$Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
Author:
Avalon, Federico Barbieri, Berin Loritsch, Paul Jack, Stephen Colebourne, Andreas Schlosser, Thomas Knych, Jordan Krey
See Also:

  • Field Details

    • buffer

      protected transient Object[] buffer
      The array of objects in the buffer.

    • tail

      protected transient int tail
      The current tail index.

  • Constructor Details

    • UnboundedFifoBuffer

      public UnboundedFifoBuffer()
      Constructs an UnboundedFifoBuffer with the default number of elements. It is exactly the same as performing the following: 
         new UnboundedFifoBuffer(32);

    • UnboundedFifoBuffer

      public UnboundedFifoBuffer(int initialSize)
      Constructs an UnboundedFifoBuffer with the specified number of elements. The integer must be a positive integer.
      Parameters:
      initialSize - the initial size of the buffer
      Throws:
      IllegalArgumentException - if the size is less than 1

  • Method Details