mdoc_hash.c

   1 /*      $Id: mdoc_hash.c,v 1.12 2010/01/01 17:14:29 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 #ifdef HAVE_CONFIG_H
  18 #include "config.h"
  19 #endif
  20
  21 #include <sys/types.h>
  22
  23 #include <assert.h>
  24 #include <ctype.h>
  25 #include <limits.h>
  26 #include <stdlib.h>
  27 #include <stdio.h>
  28 #include <string.h>
  29
  30 #include "libmdoc.h"
  31
  32 static  u_char           table[27 * 12];
  33
  34 /*
  35  * XXX - this hash has global scope, so if intended for use as a library
  36  * with multiple callers, it will need re-invocation protection.
  37  */
  38 void
  39 mdoc_hash_init(void)
  40 {
  41         int              i, j, major;
  42         const char      *p;
  43
  44         memset(table, UCHAR_MAX, sizeof(table));
  45
  46         for (i = 0; i < MDOC_MAX; i++) {
  47                 p = mdoc_macronames[i];
  48
  49                 if (isalpha((u_char)p[1]))
  50                         major = 12 * (tolower((u_char)p[1]) - 97);
  51                 else
  52                         major = 12 * 26;
  53
  54                 for (j = 0; j < 12; j++)
  55                         if (UCHAR_MAX == table[major + j]) {
  56                                 table[major + j] = (u_char)i;
  57                                 break;
  58                         }
  59
  60                 assert(j < 12);
  61         }
  62 }
  63
  64 int
  65 mdoc_hash_find(const char *p)
  66 {
  67         int               major, i, j;
  68
  69         if (0 == p[0])
  70                 return(MDOC_MAX);
  71         if ( ! isalpha((u_char)p[0]) && '%' != p[0])
  72                 return(MDOC_MAX);
  73
  74         if (isalpha((u_char)p[1]))
  75                 major = 12 * (tolower((u_char)p[1]) - 97);
  76         else if ('1' == p[1])
  77                 major = 12 * 26;
  78         else
  79                 return(MDOC_MAX);
  80
  81         if (p[2] && p[3])
  82                 return(MDOC_MAX);
  83
  84         for (j = 0; j < 12; j++) {
  85                 if (UCHAR_MAX == (i = table[major + j]))
  86                         break;
  87                 if (0 == strcmp(p, mdoc_macronames[i]))
  88                         return(i);
  89         }
  90
  91         return(MDOC_MAX);
  92 }