/* ByteArrayComparator.java --
   Copyright (C) 2005 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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any later version.

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General Public License for more details.

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Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
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package gnu.CORBA;

import java.util.Arrays;
import java.util.Comparator;

/**
 * A byte array comparator for mapping with CORBA object keys.
 *
 * @author Audrius Meskauskas (AudriusA@Bioinformatics.org)
 */
public class ByteArrayComparator
  implements Comparator
{
  /**
   * Compare arrays first by absolute equality, then by length
   * and then (byte to byte) by content.
   *
   * @return 0 if arrays are equal, some comparison value otherwise.
   */
  public int compare(Object an_a, Object a_b)
  {
    if (an_a == a_b)
      return 0;

    byte[] a = null;
    byte[] b = null;
    try
      {
        a = (byte[]) an_a;
        b = (byte[]) a_b;
      }
    catch (Exception ex)
      {
        throw new InternalError(an_a.getClass().getName() + "," +
                                a_b.getClass().getName()
                               );
      }

    if (a.length != b.length)
      return a.length - b.length;
    else
      {
        // The array sizes must be equal.
        for (int i = 0; i < b.length; i++)
          {
            if (a [ i ] != b [ i ])
              return a [ i ] - b [ i ];
          }
      }

    return 0;
  }
}