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