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Diff for /libaitcrc/src/hash.c between versions 1.1 and 1.2

version 1.1, 2010/06/13 16:29:03 version 1.2, 2011/04/28 20:28:20
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   /*************************************************************************
   * (C) 2009 AITNET ltd - Sofia/Bulgaria - <misho@aitbg.com>
   *  by Michael Pounov <misho@openbsd-bg.org>
   *
   * $Author$
   * $Id$
   *
   **************************************************************************
   The ELWIX and AITNET software is distributed under the following
   terms:
   
   All of the documentation and software included in the ELWIX and AITNET
   Releases is copyrighted by ELWIX - Sofia/Bulgaria <info@elwix.org>
   
   Copyright 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
           by Michael Pounov <misho@elwix.org>.  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. All advertising materials mentioning features or use of this software
      must display the following acknowledgement:
   This product includes software developed by Michael Pounov <misho@elwix.org>
   ELWIX - Embedded LightWeight unIX and its contributors.
   4. Neither the name of AITNET nor the names of its contributors
      may be used to endorse or promote products derived from this software
      without specific prior written permission.
   
   THIS SOFTWARE IS PROVIDED BY AITNET AND CONTRIBUTORS ``AS IS'' AND
   ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   SUCH DAMAGE.
   */
   #include "global.h"
   
   
   /*
    * hash_varchar() Compute index hash by variable length string
    * @csStr = Input data buffer
    * @nStrLen = Length of data buffer
    * @nVer = Version of algorythm; 0 - original, 1 - AITNET variant
    * return: Hash value
   */
   inline u_int
   hash_varchar(const char *csStr, int nStrLen, int nVer)
   {
           register u_int n, hash = 0;
           register int i;
   
           assert(csStr);
   
           for (i = 0; i < nStrLen; i++) {
                   n = 2 * hash + csStr[i];
                   if (!nVer) {
                           if (hash & 0x80000000)
                                   n ^= 0xC0A0A0D5;                // Polynom CRC-32 aviation
                   } else {
                           if (n & 1)                              // Misho ;) patch for better avalanche!!!
                                   n ^= 0xC0A0A0D5;                // Polynom CRC-32 aviation
                   }
                   hash = n;
           }
   
           return hash;
   }
   
   /*
    * hash_bernstein() Compute index hash by Bernstein
    * @csStr = Input data buffer
    * @nStrLen = Length of data buffer
    * @nVer = Version of algorythm; 0 - Bernstein, 1 - DJBX33A variant
    * return: Hash value
   */
   inline u_int
   hash_bernstein(const char *csStr, int nStrLen, int nVer)
   {
           register u_int hash = 5381;
           register int i;
   
           assert(csStr);
   
           for (i = 0; i < nStrLen; i++)
                   if (!nVer)
                           hash = ((hash << 5) + hash) + csStr[i];
                   else
                           hash = hash * 33 + csStr[i];            // DJBX33A
   
           return hash;
   }
   
   /*
    * hash_fnv1() Compute index hash by FNV-1
    * @csStr = Input data buffer
    * @nStrLen = Length of data buffer
    * @nVer = Version of algorythm; 0 - FNV-1, 1 - FNV-1a (best avalanche)
    * return: Hash value
   */
   inline u_int
   hash_fnv1(const char *csStr, int nStrLen, int nVer)
   {
           register u_int hash = 0x811c9dc5;                       // 2166136261
           register int i;
   
           assert(csStr);
   
           for (i = 0; i < nStrLen; i++)
                   if (!nVer) {                                    // FNV-1
                           hash *= 16777619;
                           hash ^= csStr[i];
                   } else {                                        // FNV-1a
                           hash ^= csStr[i];
                           hash *= 16777619;
                   }
   
           return hash;
   }
   
   /*
    * hash_jenkins() Compute index hash by Jenkins (one-at-a-time)
    * @csStr = Input data buffer
    * @nStrLen = Length of data buffer
    * return: Hash value
   */
   inline u_int
   hash_jenkins(const char *csStr, int nStrLen)
   {
           register u_int hash = 0;
           register int i;
   
           assert(csStr);
   
           for (i = 0; i < nStrLen; i++) {
                   hash += csStr[i];
                   hash += (hash << 10);
                   hash ^= (hash >> 6);
           }
           hash += (hash << 3);
           hash ^= (hash >> 11);
           hash += (hash << 15);
   
           return hash;
   }
   
   /*
    * hash_reddragon() Compute index hash by Red Dragon
    * @csStr = Input data buffer
    * @nStrLen = Length of data buffer
    * return: Hash value
   */
   inline u_int
   hash_reddragon(const char *csStr, int nStrLen)
   {
           register u_int g, hash;
           register int i;
   
           assert(csStr);
   
           for (hash = 0, i = 0; i < nStrLen; i++) {
                   hash = (hash << 4) + csStr[i];
                   if ((g = hash & 0xF0000000)) {
                           hash ^= g >> 24;
                           hash ^= g;
                   }
           }
   
           return hash;
   }
Removed from v.1.1  
changed lines
  Added in v.1.2

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