LongList.java Source code

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Here is the source code for LongList.java

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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;
    }
}