contrib/mdocml/mdoc_hash.c

   1 /*      $Id: mdoc_hash.c,v 1.20 2014/04/20 16:46:05 schwarze Exp $ */
   2 /*
   3  * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@bsd.lv>
   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 "mdoc.h"
  31 #include "libmdoc.h"
  32
  33 static  unsigned char    table[27 * 12];
  34
  35
  36 /*
  37  * XXX - this hash has global scope, so if intended for use as a library
  38  * with multiple callers, it will need re-invocation protection.
  39  */
  40 void
  41 mdoc_hash_init(void)
  42 {
  43         int              i, j, major;
  44         const char      *p;
  45
  46         memset(table, UCHAR_MAX, sizeof(table));
  47
  48         for (i = 0; i < (int)MDOC_MAX; i++) {
  49                 p = mdoc_macronames[i];
  50
  51                 if (isalpha((unsigned char)p[1]))
  52                         major = 12 * (tolower((unsigned char)p[1]) - 97);
  53                 else
  54                         major = 12 * 26;
  55
  56                 for (j = 0; j < 12; j++)
  57                         if (UCHAR_MAX == table[major + j]) {
  58                                 table[major + j] = (unsigned char)i;
  59                                 break;
  60                         }
  61
  62                 assert(j < 12);
  63         }
  64 }
  65
  66 enum mdoct
  67 mdoc_hash_find(const char *p)
  68 {
  69         int               major, i, j;
  70
  71         if (0 == p[0])
  72                 return(MDOC_MAX);
  73         if ( ! isalpha((unsigned char)p[0]) && '%' != p[0])
  74                 return(MDOC_MAX);
  75
  76         if (isalpha((unsigned char)p[1]))
  77                 major = 12 * (tolower((unsigned char)p[1]) - 97);
  78         else if ('1' == p[1])
  79                 major = 12 * 26;
  80         else
  81                 return(MDOC_MAX);
  82
  83         if (p[2] && p[3])
  84                 return(MDOC_MAX);
  85
  86         for (j = 0; j < 12; j++) {
  87                 if (UCHAR_MAX == (i = table[major + j]))
  88                         break;
  89                 if (0 == strcmp(p, mdoc_macronames[i]))
  90                         return((enum mdoct)i);
  91         }
  92
  93         return(MDOC_MAX);
  94 }