org.apache.commons.collections
public class UnboundedFifoBuffer extends AbstractCollection implements Buffer
Deprecated: Moved to buffer subpackage. Due to be removed in v4.0.
UnboundedFifoBuffer is a very efficient buffer implementation. 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.
Since: Commons Collections 2.1
Version: $Revision: 219316 $ $Date: 2005-07-16 12:17:02 +0100 (Sat, 16 Jul 2005) $
Field Summary | |
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protected Object[] | m_buffer |
protected int | m_head |
protected int | m_tail |
Constructor Summary | |
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UnboundedFifoBuffer()
Constructs an UnboundedFifoBuffer with the default number of elements.
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UnboundedFifoBuffer(int initialSize)
Constructs an UnboundedFifoBuffer with the specified number of elements.
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Method Summary | |
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boolean | add(Object obj)
Adds the given element to this buffer.
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Object | get()
Returns the next object in the buffer.
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boolean | isEmpty()
Returns true if this buffer is empty; false otherwise.
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Iterator | iterator()
Returns an iterator over this buffer's elements.
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Object | remove()
Removes the next object from the buffer
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int | size()
Returns the number of elements stored in the buffer.
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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 BufferOverflowException if this buffer is full
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