git.sur5r.net Git - cc65/blob - src/common/hashstr.c

   1 /*****************************************************************************/
   2 /*                                                                           */
   3 /*                                 hashstr.c                                 */
   4 /*                                                                           */
   5 /*                         Hash function for strings                         */
   6 /*                                                                           */
   7 /*                                                                           */
   8 /*                                                                           */
   9 /* (C) 1998-2008  Ullrich von Bassewitz                                      */
  10 /*                Roemerstrasse 52                                           */
  11 /*                D-70794 Filderstadt                                        */
  12 /* EMail:         uz@cc65.org                                                */
  13 /*                                                                           */
  14 /*                                                                           */
  15 /* This software is provided 'as-is', without any expressed or implied       */
  16 /* warranty.  In no event will the authors be held liable for any damages    */
  17 /* arising from the use of this software.                                    */
  18 /*                                                                           */
  19 /* Permission is granted to anyone to use this software for any purpose,     */
  20 /* including commercial applications, and to alter it and redistribute it    */
  21 /* freely, subject to the following restrictions:                            */
  22 /*                                                                           */
  23 /* 1. The origin of this software must not be misrepresented; you must not   */
  24 /*    claim that you wrote the original software. If you use this software   */
  25 /*    in a product, an acknowledgment in the product documentation would be  */
  26 /*    appreciated but is not required.                                       */
  27 /* 2. Altered source versions must be plainly marked as such, and must not   */
  28 /*    be misrepresented as being the original software.                      */
  29 /* 3. This notice may not be removed or altered from any source              */
  30 /*    distribution.                                                          */
  31 /*                                                                           */
  32 /*****************************************************************************/
  33
  34
  35
  36 /* common */
  37 #include "hashstr.h"
  38
  39
  40
  41 /*****************************************************************************/
  42 /*                                   Code                                    */
  43 /*****************************************************************************/
  44
  45
  46
  47 unsigned HashStr (const char* S)
  48 /* Return a hash value for the given string */
  49 {
  50     unsigned L, H;
  51
  52     /* Do the hash */
  53     H = L = 0;
  54     while (*S) {
  55         H = ((H << 3) ^ ((unsigned char) *S++)) + L++;
  56     }
  57     return H;
  58 }
  59
  60
  61
  62 unsigned HashBuf (const StrBuf* S)
  63 /* Return a hash value for the given string buffer */
  64 {
  65     unsigned I, L, H;
  66
  67     /* Do the hash */
  68     H = L = 0;
  69     for (I = 0; I < SB_GetLen (S); ++I) {
  70         H = ((H << 3) ^ ((unsigned char) SB_AtUnchecked (S, I))) + L++;
  71     }
  72     return H;
  73 }
  74
  75
  76