man_hash.c

   1 /*      $Id: man_hash.c,v 1.10 2009/06/18 10:32:00 kristaps Exp $ */
   2 /*
   3  * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@kth.se>
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17 #include <assert.h>
  18 #include <stdlib.h>
  19 #include <string.h>
  20
  21 #include "libman.h"
  22
  23
  24 /* ARGUSED */
  25 void
  26 man_hash_free(void *htab)
  27 {
  28
  29         free(htab);
  30 }
  31
  32
  33 /* ARGUSED */
  34 void *
  35 man_hash_alloc(void)
  36 {
  37         int             *htab;
  38         int              i, j, x;
  39
  40         /* Initialised to -1. */
  41
  42         htab = malloc(26 * 5 * sizeof(int));
  43         if (NULL == htab)
  44                 return(NULL);
  45         for (i = 0; i < 26 * 5; i++)
  46                 htab[i] = -1;
  47
  48         for (i = 0; i < MAN_MAX; i++) {
  49                 x = man_macronames[i][0];
  50
  51                 assert((x >= 65 && x <= 90) ||
  52                                 (x >= 97 && x <= 122));
  53
  54                 x -= (x <= 90) ? 65 : 97;
  55                 x *= 5;
  56
  57                 for (j = 0; j < 5; j++)
  58                         if (-1 == htab[x + j]) {
  59                                 htab[x + j] = i;
  60                                 break;
  61                         }
  62
  63                 assert(j < 5);
  64         }
  65
  66         return((void *)htab);
  67 }
  68
  69
  70 int
  71 man_hash_find(const void *arg, const char *tmp)
  72 {
  73         int              x, i, tok;
  74         const int       *htab;
  75
  76         htab = (const int *)arg;
  77
  78         if (0 == (x = tmp[0]))
  79                 return(MAN_MAX);
  80         if ( ! ((x >= 65 && x <= 90) || (x >= 97 && x <= 122)))
  81                 return(MAN_MAX);
  82
  83         x -= (x <= 90) ? 65 : 97;
  84         x *= 5;
  85
  86         for (i = 0; i < 5; i++) {
  87                 if (-1 == (tok = htab[x + i]))
  88                         return(MAN_MAX);
  89                 if (0 == strcmp(tmp, man_macronames[tok]))
  90                         return(tok);
  91         }
  92
  93         return(MAN_MAX);
  94 }
  95