Mega Code Archive
Array-List for integer objects
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/**
*
* JFreeReport : a free Java reporting library
*
*
* Project Info: http://reporting.pentaho.org/
*
* (C) Copyright 2001-2007, by Object Refinery Ltd, Pentaho Corporation and Contributors.
*
* This library is free software; you can redistribute it and/or modify it under the terms
* of the GNU Lesser General Public License as published by the Free Software Foundation;
* either version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
* ------------
* LongList.java
* ------------
* (C) Copyright 2001-2007, by Object Refinery Ltd, Pentaho Corporation and Contributors.
*/
import java.io.Serializable;
/**
* A Array-List for integer objects. Ints can be added to the list and will be stored in an int-array.
* <p/>
* Using this list for storing ints is much faster than creating java.lang.Long objects and storing them in an
* ArrayList.
* <p/>
* This list is not synchronized and does not implement the full List interface. In fact, this list can only be used to
* add new values or to clear the complete list.
*
* @author Thomas Morgner
*/
public class LongList implements Serializable, Cloneable
{
/**
* An empty array used to avoid object creation.
*/
private static final long[] EMPTY_ARRAY = new long[0];
/**
* The array holding the list data.
*/
private long[] data;
/**
* The size of the list.
*/
private int size;
/**
* The number of free slots added on every resize.
*/
private int increment;
/**
* Creates a new IntList with the given initial capacity. The capacity will also be used as increment value when
* extending the capacity of the list.
*
* @param capacity the initial capacity.
*/
public LongList(final int capacity)
{
data = new long[capacity];
increment = capacity;
}
/**
* Ensures, that the list backend can store at least <code>c</code> elements. This method does nothing, if the new
* capacity is less than the current capacity.
*
* @param c the new capacity of the list.
*/
private void ensureCapacity(final int c)
{
if (data.length <= c)
{
final long[] newData = new long[Math.max(data.length + increment, c + 1)];
System.arraycopy(data, 0, newData, 0, size);
data = newData;
}
}
/**
* Adds the given int value to the list.
*
* @param value the new value to be added.
*/
public void add(final long value)
{
ensureCapacity(size);
data[size] = value;
size += 1;
}
/**
* Adds the given int value to the list.
*
* @param value the new value to be defined.
* @param index the position of the valur that should be redefined.
*/
public void set(final int index, final long value)
{
ensureCapacity(index);
data[index] = value;
if (index >= size)
{
size = index + 1;
}
}
/**
* Returns the value at the given index.
*
* @param index the index
* @return the value at the given index
* @throws IndexOutOfBoundsException if the index is greater or equal to the list size or if the index is negative.
*/
public long get(final int index)
{
if (index >= size || index < 0)
{
throw new IndexOutOfBoundsException("Illegal Index: " + index + " Max:" + size);
}
return data[index];
}
/**
* Clears the list.
*/
public void clear()
{
size = 0;
}
/**
* Returns the number of elements in this list.
*
* @return the number of elements in the list
*/
public int size()
{
return size;
}
/**
* Copys the list contents into a new array.
*
* @return the list contents as array.
*/
public long[] toArray()
{
if (size == 0)
{
return LongList.EMPTY_ARRAY;
}
if (size == data.length)
{
return (long[]) data.clone();
}
final long[] retval = new long[size];
System.arraycopy(data, 0, retval, 0, size);
return retval;
}
/**
* Copys the list contents into a new array.
*
* @param retval the array that should receive the contents.
* @return the list contents as array.
*/
public long[] toArray(long[] retval)
{
if (retval == null || retval.length < size)
{
retval = new long[size];
}
System.arraycopy(data, 0, retval, 0, size);
return retval;
}
/**
* Creates a copy of this list.
*
* @return a copy of this list.
* @throws CloneNotSupportedException if something went wrong during the cloning.
*/
public Object clone() throws CloneNotSupportedException
{
final LongList intList = (LongList) super.clone();
intList.data = (long[]) data.clone();
return data;
}
}
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