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CIP4 JDF Library for JDF 1.x
/*
*
* The CIP4 Software License, Version 1.0
*
*
* Copyright (c) 2001-2024 The International Cooperation for the Integration of
* Processes in Prepress, Press and Postpress (CIP4). All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* The International Cooperation for the Integration of
* Processes in Prepress, Press and Postpress (www.cip4.org)"
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "CIP4" and "The International Cooperation for the Integration of
* Processes in Prepress, Press and Postpress" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact [email protected].
*
* 5. Products derived from this software may not be called "CIP4",
* nor may "CIP4" appear in their name, without prior written
* permission of the CIP4 organization
*
* Usage of this software in commercial products is subject to restrictions. For
* details please consult [email protected].
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE INTERNATIONAL COOPERATION FOR
* THE INTEGRATION OF PROCESSES IN PREPRESS, PRESS AND POSTPRESS OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the The International Cooperation for the Integration
* of Processes in Prepress, Press and Postpress and was
* originally based on software
* copyright (c) 1999-2001, Heidelberger Druckmaschinen AG
* copyright (c) 1999-2001, Agfa-Gevaert N.V.
*
* For more information on The International Cooperation for the
* Integration of Processes in Prepress, Press and Postpress , please see
*
*
* quick and dirty fast fifo built on a circular array May 26, 2009
* @param the element class to dump into the fifo
*/
public class FastFiFo
{
private final Object[] theArray;
private int first;
private int fill;
/**
* @param n size of the fifo
*
*/
public FastFiFo(final int n)
{
if (n <= 0)
{
throw new IllegalArgumentException("fifo must have positive # elements");
}
theArray = new Object[n];
for (int i = 0; i < n; i++)
{
theArray[i] = null;
}
first = 0;
fill = 0;
}
/**
* pushes an element into the back and returns the previous content of the cell
*
* @param back the element to push
* @return the element that has been replaced, null if we are not yet full
*/
synchronized public x push(final x back)
{
final int s = theArray.length;
x ret = null;
if (fill == s)
{
ret = pop();
}
theArray[(first + fill++) % s] = back;
return ret;
}
/**
* pops the first to go
*
* @return the first element, null if empty
*/
@SuppressWarnings("unchecked")
synchronized public x pop()
{
if (fill == 0)
{
return null;
}
final x ret = (x) theArray[first];
theArray[first] = null;
first = ++first % theArray.length;
fill--;
return ret;
}
/**
* peeks into the fifo from the beginning
*
* @param i the index of the element to peek
* @return the object at position i
*/
@SuppressWarnings("unchecked")
public x peek(final int i)
{
if (i >= fill)
{
return null;
}
return (x) theArray[(first + i) % theArray.length];
}
/**
* peeks into the fifo from the beginning
*
* @return a snapshot of the current fifo, null if empty
*/
@SuppressWarnings("unchecked")
synchronized public x[] peekArray()
{
if (fill == 0)
{
return null;
}
final x[] ret = (x[]) Array.newInstance(peek(0).getClass(), fill);
for (int i = 0; i < fill; i++)
{
ret[i] = peek(i);
}
return ret;
}
/**
* @see java.lang.Object#toString()
*/
@Override
public String toString()
{
return "FastFiFo : fill=" + fill + " first=" + first + "\n" + Arrays.toString(theArray);
}
/**
* @return the current number of elements
*/
public int getFill()
{
return fill;
}
/**
* @return the maximum total number of elements
*/
public int size()
{
return theArray.length;
}
}
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