strhash.c

/* strhash.c string hashing
 *
 * Copyright (c) 1994-2008 Carnegie Mellon University.  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 name "Carnegie Mellon University" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For permission or any legal
 *    details, please contact
 *      Carnegie Mellon University
 *      Center for Technology Transfer and Enterprise Creation
 *      4615 Forbes Avenue
 *      Suite 302
 *      Pittsburgh, PA  15213
 *      (412) 268-7393, fax: (412) 268-7395
 *      innovation@andrew.cmu.edu
 *
 * 4. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by Computing Services
 *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
 *
 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
 * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * $Id: strhash.c,v 1.5 2010/01/06 17:01:47 murch Exp $
 */

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <signal.h>
#include <stdlib.h>
#include <syslog.h>
#include <errno.h>

#include "assert.h"
#include "strhash.h"

unsigned strhash(const char *string)
{
      unsigned ret_val = 0;
      int i;

      while (*string)
      {
            i = (int) *string;
            ret_val ^= i;
            ret_val <<= 1;
            string ++;
      }
      return ret_val;
}