cmd/mandoc/mdoc_hash.c

/*  $Id: mdoc_hash.c,v 1.26 2015/10/06 18:32:19 schwarze Exp $ */
/*
 * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@bsd.lv>
 * Copyright (c) 2015 Ingo Schwarze <schwarze@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#include "config.h"

#include <sys/types.h>

#include <assert.h>
#include <ctype.h>
#include <limits.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "roff.h"
#include "mdoc.h"
#include "libmdoc.h"

static  unsigned char    table[27 * 12];


void
mdoc_hash_init(void)
{
    int      i, j, major;
    const char  *p;

    if (*table != '\0')
        return;

    memset(table, UCHAR_MAX, sizeof(table));

    for (i = 0; i < (int)MDOC_MAX; i++) {
        p = mdoc_macronames[i];

        if (isalpha((unsigned char)p[1]))
            major = 12 * (tolower((unsigned char)p[1]) - 97);
        else
            major = 12 * 26;

        for (j = 0; j < 12; j++)
            if (UCHAR_MAX == table[major + j]) {
                table[major + j] = (unsigned char)i;
                break;
            }

        assert(j < 12);
    }
}

int
mdoc_hash_find(const char *p)
{
    int       major, i, j;

    if (0 == p[0])
        return TOKEN_NONE;
    if ( ! isalpha((unsigned char)p[0]) && '%' != p[0])
        return TOKEN_NONE;

    if (isalpha((unsigned char)p[1]))
        major = 12 * (tolower((unsigned char)p[1]) - 97);
    else if ('1' == p[1])
        major = 12 * 26;
    else
        return TOKEN_NONE;

    if (p[2] && p[3])
        return TOKEN_NONE;

    for (j = 0; j < 12; j++) {
        if (UCHAR_MAX == (i = table[major + j]))
            break;
        if (0 == strcmp(p, mdoc_macronames[i]))
            return i;
    }

    return TOKEN_NONE;
}