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Revision 1.36, Fri Apr 29 22:18:12 2011 UTC (12 years, 11 months ago) by kristaps
Branch: MAIN
Changes since 1.35: +21 -29 lines

Move "chars" interface out of out.h and into mandoc.h.  This doesn't
change any code but for renaming functions and types to be consistent
with other mandoc.h stuff.  The reason for moving into libmandoc is that
the rendering of special characters is part of mandoc itself---not an
external part.  From mandoc(1)'s perspective, this changes nothing, but
for other utilities, it's important to have these part of libmandoc.
Note this isn't documented [yet] in mandoc.3 because there are some
parts I'd like to change around beforehand.

/*	$Id: chars.c,v 1.36 2011/04/29 22:18:12 kristaps Exp $ */
/*
 * Copyright (c) 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
 * Copyright (c) 2011 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.
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

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

#include "mandoc.h"

#define	PRINT_HI	 126
#define	PRINT_LO	 32

struct	ln {
	struct ln	 *next;
	const char	 *code;
	const char	 *ascii;
	int		  unicode;
	int		  type;
#define	CHARS_CHAR	 (1 << 0)
#define	CHARS_STRING	 (1 << 1)
#define CHARS_BOTH	 (CHARS_CHAR | CHARS_STRING)
};

#define	LINES_MAX	  353

#define CHAR(in, ch, code) \
	{ NULL, (in), (ch), (code), CHARS_CHAR },
#define STRING(in, ch, code) \
	{ NULL, (in), (ch), (code), CHARS_STRING },
#define BOTH(in, ch, code) \
	{ NULL, (in), (ch), (code), CHARS_BOTH },

#define	CHAR_TBL_START	  static struct ln lines[LINES_MAX] = {
#define	CHAR_TBL_END	  };

#include "chars.in"

struct	mchars {
	enum mcharst	  type;
	struct ln	**htab;
};

static	inline int	  match(const struct ln *,
				const char *, size_t, int);
static	const struct ln	 *find(struct mchars *, const char *, size_t, int);

void
mchars_free(struct mchars *arg)
{

	free(arg->htab);
	free(arg);
}

struct mchars *
mchars_init(enum mcharst type)
{
	struct mchars	 *tab;
	struct ln	**htab;
	struct ln	 *pp;
	int		  i, hash;

	/*
	 * Constructs a very basic chaining hashtable.  The hash routine
	 * is simply the integral value of the first character.
	 * Subsequent entries are chained in the order they're processed
	 * (they're in-line re-ordered during lookup).
	 */

	tab = mandoc_malloc(sizeof(struct mchars));
	htab = mandoc_calloc(PRINT_HI - PRINT_LO + 1, sizeof(struct ln **));

	for (i = 0; i < LINES_MAX; i++) {
		hash = (int)lines[i].code[0] - PRINT_LO;

		if (NULL == (pp = htab[hash])) {
			htab[hash] = &lines[i];
			continue;
		}

		for ( ; pp->next; pp = pp->next)
			/* Scan ahead. */ ;
		pp->next = &lines[i];
	}

	tab->htab = htab;
	tab->type = type;
	return(tab);
}


/* 
 * Special character to Unicode codepoint.
 */
int
mchars_spec2cp(struct mchars *arg, const char *p, size_t sz)
{
	const struct ln	*ln;

	ln = find(arg, p, sz, CHARS_CHAR);
	if (NULL == ln)
		return(-1);
	return(ln->unicode);
}


/* 
 * Reserved word to Unicode codepoint.
 */
int
mchars_res2cp(struct mchars *arg, const char *p, size_t sz)
{
	const struct ln	*ln;

	ln = find(arg, p, sz, CHARS_STRING);
	if (NULL == ln)
		return(-1);
	return(ln->unicode);
}


/*
 * Numbered character to literal character,
 * represented as a null-terminated string for additional safety.
 */
const char *
mchars_num2char(const char *p, size_t sz)
{
	int		  i;
	static char	  c[2];

	if (sz > 3)
		return(NULL);
	i = atoi(p);
	if (i < 0 || i > 255)
		return(NULL);
	c[0] = (char)i;
	c[1] = '\0';
	return(c);
}


/* 
 * Special character to string array.
 */
const char *
mchars_spec2str(struct mchars *arg, const char *p, size_t sz, size_t *rsz)
{
	const struct ln	*ln;

	ln = find(arg, p, sz, CHARS_CHAR);
	if (NULL == ln)
		return(NULL);

	*rsz = strlen(ln->ascii);
	return(ln->ascii);
}


/* 
 * Reserved word to string array.
 */
const char *
mchars_res2str(struct mchars *arg, const char *p, size_t sz, size_t *rsz)
{
	const struct ln	*ln;

	ln = find(arg, p, sz, CHARS_STRING);
	if (NULL == ln)
		return(NULL);

	*rsz = strlen(ln->ascii);
	return(ln->ascii);
}

static const struct ln *
find(struct mchars *tab, const char *p, size_t sz, int type)
{
	struct ln	 *pp, *prev;
	struct ln	**htab;
	int		  hash;

	assert(p);
	if (0 == sz)
		return(NULL);

	if (p[0] < PRINT_LO || p[0] > PRINT_HI)
		return(NULL);

	/*
	 * Lookup the symbol in the symbol hash.  See ascii2htab for the
	 * hashtable specs.  This dynamically re-orders the hash chain
	 * to optimise for repeat hits.
	 */

	hash = (int)p[0] - PRINT_LO;
	htab = tab->htab;

	if (NULL == (pp = htab[hash]))
		return(NULL);

	for (prev = NULL; pp; pp = pp->next) {
		if ( ! match(pp, p, sz, type)) {
			prev = pp;
			continue;
		}

		if (prev) {
			prev->next = pp->next;
			pp->next = htab[hash];
			htab[hash] = pp;
		}

		return(pp);
	}

	return(NULL);
}

static inline int
match(const struct ln *ln, const char *p, size_t sz, int type)
{

	if ( ! (ln->type & type))
		return(0);
	if (strncmp(ln->code, p, sz))
		return(0);
	return('\0' == ln->code[(int)sz]);
}