/* 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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General Public License for more details.

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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
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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
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package gnu.CORBA;

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;
  }
}