Apache
/
commons-collections
mirror of https://github.com/apache/commons-collections.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Minor speed improvement 

Javadoc/copyright


git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/collections/trunk@131030 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Stephen Colebourne 2003-04-26 15:09:48 +00:00
parent 48b7814cf6
commit ad8bc0e6d9
1 changed files with 19 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
src/java/org/apache/commons/collections/BoundedFifoBuffer.java
View File

@ -1,13 +1,10 @@
/*
* $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//collections/src/java/org/apache/commons/collections/BoundedFifoBuffer.java,v 1.6 2002/11/24 16:23:21 scolebourne Exp $
* $Revision: 1.6 $
* $Date: 2002/11/24 16:23:21 $
*
* $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//collections/src/java/org/apache/commons/collections/BoundedFifoBuffer.java,v 1.7 2003/04/26 15:09:48 scolebourne Exp $
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999-2002 The Apache Software Foundation. All rights
* Copyright (c) 1999-2003 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
@ -65,6 +62,7 @@ import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.NoSuchElementException;
/**
* The BoundedFifoBuffer is a <strong>very</strong> efficient implementation of
* Buffer that does not alter the size of the buffer at runtime.
@ -86,18 +84,20 @@ import java.util.NoSuchElementException;
* This buffer prevents null objects from being added.
*
* @since 2.1
* @version $Revision: 1.7 $ $Date: 2003/04/26 15:09:48 $
*
* @author Avalon
* @author <a href="mailto:bloritsch@apache.org">Berin Loritsch</a>
* @author Paul Jack
* @author Stephen Colebourne
* @author <a href="herve.quiroz@esil.univ-mrs.fr">Herve Quiroz</a>
* @version $Id: BoundedFifoBuffer.java,v 1.6 2002/11/24 16:23:21 scolebourne Exp $
*/
public class BoundedFifoBuffer extends AbstractCollection implements Buffer, BoundedCollection {
private final Object[] m_elements;
private int m_start = 0;
private int m_end = 0;
private boolean m_full = false;
private final int maxElements;
/**
* Constructs a new <code>BoundedFifoBuffer</code> big enough to hold
@ -119,6 +119,7 @@ public class BoundedFifoBuffer extends AbstractCollection implements Buffer, Bou
throw new IllegalArgumentException("The size must be greater than 0");
}
m_elements = new Object[size];
maxElements = m_elements.length;
}
/**
@ -126,7 +127,8 @@ public class BoundedFifoBuffer extends AbstractCollection implements Buffer, Bou
* of the elements in the specified collection. That collection's
* elements will also be added to the buffer.
*
* @param coll the collection whose elements to add
* @param coll the collection whose elements to add, may not be null
* @throws NullPointerException if the collection is null
*/
public BoundedFifoBuffer(Collection coll) {
this(coll.size());
@ -142,9 +144,9 @@ public class BoundedFifoBuffer extends AbstractCollection implements Buffer, Bou
int size = 0;
if (m_end < m_start) {
size = m_elements.length - m_start + m_end;
size = maxElements - m_start + m_end;
} else if (m_end == m_start) {
size = (m_full ? m_elements.length : 0);
size = (m_full ? maxElements : 0);
} else {
size = m_end - m_start;
}
@ -167,7 +169,7 @@ public class BoundedFifoBuffer extends AbstractCollection implements Buffer, Bou
* @return <code>true</code> if the collection is full
*/
public boolean isFull() {
return size() == m_elements.length;
return size() == maxElements;
}
/**
@ -176,7 +178,7 @@ public class BoundedFifoBuffer extends AbstractCollection implements Buffer, Bou
* @return the maximum number of elements the collection can hold
*/
public int maxSize() {
return m_elements.length;
return maxElements;
}
/**
@ -203,12 +205,12 @@ public class BoundedFifoBuffer extends AbstractCollection implements Buffer, Bou
}
if (m_full) {
throw new BufferOverflowException("The buffer cannot hold more than " + m_elements.length + " objects.");
throw new BufferOverflowException("The buffer cannot hold more than " + maxElements + " objects.");
}
m_elements[m_end++] = element;
if (m_end >= m_elements.length) {
if (m_end >= maxElements) {
m_end = 0;
}
@ -249,7 +251,7 @@ public class BoundedFifoBuffer extends AbstractCollection implements Buffer, Bou
if (null != element) {
m_elements[m_start++] = null;
if (m_start >= m_elements.length) {
if (m_start >= maxElements) {
m_start = 0;
}
@ -267,7 +269,7 @@ public class BoundedFifoBuffer extends AbstractCollection implements Buffer, Bou
*/
private int increment(int index) {
index++;
if (index >= m_elements.length) {
if (index >= maxElements) {
index = 0;
}
return index;
@ -282,7 +284,7 @@ public class BoundedFifoBuffer extends AbstractCollection implements Buffer, Bou
private int decrement(int index) {
index--;
if (index < 0) {
index = m_elements.length - 1;
index = maxElements - 1;
}
return index;
}
@ -325,7 +327,7 @@ public class BoundedFifoBuffer extends AbstractCollection implements Buffer, Bou
// Other elements require us to shift the subsequent elements
int i = lastReturnedIndex + 1;
while (i != m_end) {
if (i >= m_elements.length) {
if (i >= maxElements) {
m_elements[i - 1] = m_elements[0];
i = 0;
} else {