1/*-
2 * Copyright (c) 1995 Alex Tatmanjants <alex@elvisti.kiev.ua>
3 *		at Electronni Visti IA, Kiev, Ukraine.
4 *			All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD: src/lib/libc/string/strxfrm.c,v 1.17 2008/10/19 09:10:44 delphij Exp $");
30
31#include "xlocale_private.h"
32
33#include <stdlib.h>
34#include <string.h>
35#include <wchar.h>
36#include <errno.h>
37#include "collate.h"
38
39/*
40 * In the non-POSIX case, we transform each character into a string of
41 * characters representing the character's priority.  Since char is usually
42 * signed, we are limited by 7 bits per byte.  To avoid zero, we need to add
43 * XFRM_OFFSET, so we can't use a full 7 bits.  For simplicity, we choose 6
44 * bits per byte.  We choose 4 bytes per character as a good compromise
45 * between maximum coverage and minimum size.  This gives 24 bits, or 16M
46 * priorities.  So we choose COLLATE_MAX_PRIORITY to be (2^24 - 1).  This
47 * this can be increased if more is needed.
48 */
49
50#define	XFRM_BYTES	4
51#define	XFRM_OFFSET	('0')	/* make all printable characters */
52#define	XFRM_SHIFT	6
53#define	XFRM_MASK	((1 << XFRM_SHIFT) - 1)
54
55static void
56xfrm(unsigned char *p, int pri)
57{
58
59	p[3] = (pri & XFRM_MASK) + XFRM_OFFSET;
60	pri >>= XFRM_SHIFT;
61	p[2] = (pri & XFRM_MASK) + XFRM_OFFSET;
62	pri >>= XFRM_SHIFT;
63	p[1] = (pri & XFRM_MASK) + XFRM_OFFSET;
64	pri >>= XFRM_SHIFT;
65	p[0] = (pri & XFRM_MASK) + XFRM_OFFSET;
66}
67
68size_t
69strxfrm_l(char * __restrict dest, const char * __restrict src, size_t len,
70    locale_t loc)
71{
72	size_t slen;
73	wchar_t *wcs, *xf[2];
74	int sverrno;
75
76	if (!*src && dest) {
77		if (len > 0)
78			*dest = '\0';
79		return 0;
80	}
81
82	NORMALIZE_LOCALE(loc);
83	if (loc->__collate_load_error || (wcs = __collate_mbstowcs(src, loc)) == NULL)
84		return strlcpy(dest, src, len);
85
86	__collate_xfrm(wcs, xf, loc);
87
88	slen = wcslen(xf[0]) * XFRM_BYTES;
89	if (xf[1])
90		slen += (wcslen(xf[1]) + 1) * XFRM_BYTES;
91	if (len > 0) {
92		wchar_t *w = xf[0];
93		int b = 0;
94		unsigned char buf[XFRM_BYTES];
95		unsigned char *bp;
96		while (len > 1) {
97			if (!b) {
98				if (!*w)
99					break;
100				xfrm(bp = buf, *w++);
101				b = XFRM_BYTES;
102			}
103			*dest++ = *(char *)bp++;
104			b--;
105			len--;
106		}
107		if ((w = xf[1]) != NULL) {
108			xfrm(bp = buf, 0);
109			b = XFRM_BYTES;
110			while (len > 1) {
111				if (!b)
112					break;
113				*dest++ = *(char *)bp++;
114				b--;
115				len--;
116			}
117			b = 0;
118			while (len > 1) {
119				if (!b) {
120					if (!*w)
121						break;
122					xfrm(bp = buf, *w++);
123					b = XFRM_BYTES;
124				}
125				*dest++ = *(char *)bp++;
126				b--;
127				len--;
128			}
129		}
130		*dest = 0;
131 	}
132	sverrno = errno;
133	free(wcs);
134	free(xf[0]);
135	free(xf[1]);
136	errno = sverrno;
137
138	return slen;
139}
140
141size_t
142strxfrm(char * __restrict dest, const char * __restrict src, size_t len)
143{
144	return strxfrm_l(dest, src, len, __current_locale());
145}
146