gettext_iconv.c revision 1.3 
1/*	$NetBSD: gettext_iconv.c,v 1.3 2004/01/18 08:54:02 yamt Exp $	*/
2
3/*-
4 * Copyright (c) 2004 Citrus Project,
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $Citrus$
29 */
30
31
32#include <sys/types.h>
33#include <sys/param.h>
34
35#include <errno.h>
36#include <iconv.h>
37#include <libintl.h>
38#include <langinfo.h>
39#include <search.h>
40#include <stdlib.h>
41#include <string.h>
42
43#include "libintl_local.h"
44
45struct cache {
46	const char *c_origmsg;
47	const char *c_resultmsg;
48};
49
50static const struct cache *cache_find(const char *, struct domainbinding *);
51static int cache_enter(const char *, const char *);
52static int cache_cmp(const void *, const void *);
53
54static void *cacheroot;
55
56/* ARGSUSED1 */
57static const struct cache *
58cache_find(const char *msg, struct domainbinding *db)
59{
60	struct cache key;
61	struct cache **c;
62
63	key.c_origmsg = msg;
64	c = tfind(&key, &cacheroot, cache_cmp);
65
66	return c ? *c : NULL;
67}
68
69static int
70cache_enter(const char *origmsg, const char *resultmsg)
71{
72	struct cache *c;
73
74	c = malloc(sizeof(*c));
75	if (c == NULL)
76		return -1;
77
78	c->c_origmsg = origmsg;
79	c->c_resultmsg = resultmsg;
80
81	if (tsearch(c, &cacheroot, cache_cmp) == NULL) {
82		free(c);
83		return -1;
84	}
85
86	return 0;
87}
88
89static int
90cache_cmp(const void *va, const void *vb)
91{
92	const struct cache *a = va;
93	const struct cache *b = vb;
94	int result;
95
96	result = a->c_origmsg - b->c_origmsg;
97
98	return result;
99}
100
101#define	GETTEXT_ICONV_MALLOC_CHUNK	(16*1024)
102
103const char *
104__gettext_iconv(const char *origmsg, struct domainbinding *db)
105{
106	const char *tocode;
107	const char *fromcode = db->mohandle.mo.mo_charset;
108	const struct cache *cache;
109	const char *result;
110	iconv_t cd;
111	const char *src;
112	char *dst;
113	size_t origlen;
114	size_t srclen;
115	size_t dstlen;
116	size_t nvalid;
117	int savederrno = errno;
118
119	/*
120	 * static buffer for converted texts.
121	 *
122	 * note:
123	 * we never free buffers once returned to callers.
124	 * because of interface design of gettext, we can't know
125	 * the lifetime of them.
126	 */
127	static char *buffer;
128	static size_t bufferlen;
129
130	tocode = db->codeset;
131	if (tocode == NULL) {
132		/*
133		 * codeset isn't specified explicitly by
134		 * bind_textdomain_codeset().
135		 * use current locale(LC_MESSAGE)'s codeset.
136		 *
137		 * XXX maybe wrong; it can mismatch with
138		 * environment variable setting.
139		 */
140		tocode = nl_langinfo(CODESET);
141	}
142
143	/*
144	 * shortcut if possible.
145	 * XXX should handle aliases
146	 */
147	if (!strcasecmp(tocode, fromcode))
148		return origmsg;
149
150	/* XXX LOCK */
151
152	/* XXX should detect change of tocode and purge caches? */
153
154	/*
155	 * see if we have already converted this message.
156	 */
157	cache = cache_find(origmsg, db);
158	if (cache) {
159		result = cache->c_resultmsg;
160		goto out;
161	}
162
163	origlen = strlen(origmsg) + 1;
164again:
165	cd = iconv_open(tocode, fromcode);
166	if (cd == (iconv_t)-1) {
167		result = origmsg;
168		goto out;
169	}
170
171	src = origmsg;
172	srclen = origlen;
173	dst = buffer;
174	dstlen = bufferlen;
175	nvalid = iconv(cd, &src, &srclen, &dst, &dstlen);
176	iconv_close(cd);
177
178	if (nvalid == (size_t)-1) {
179		/*
180		 * try to allocate a new buffer.
181		 *
182		 * just give up if GETTEXT_ICONV_MALLOC_CHUNK was not enough.
183		 */
184		if (errno == E2BIG &&
185		    bufferlen != GETTEXT_ICONV_MALLOC_CHUNK) {
186			buffer = malloc(GETTEXT_ICONV_MALLOC_CHUNK);
187			if (buffer) {
188				bufferlen = GETTEXT_ICONV_MALLOC_CHUNK;
189				goto again;
190			}
191		}
192
193		result = origmsg;
194	} else if (cache_enter(origmsg, buffer)) {
195		/*
196		 * failed to enter cache.  give up.
197		 */
198		result = origmsg;
199	} else {
200		size_t resultlen = dst - buffer;
201
202		result = buffer;
203		bufferlen -= resultlen;
204		buffer += resultlen;
205	}
206
207out:
208	/* XXX UNLOCK */
209	errno = savederrno;
210
211	return result;
212}
213