gitweb: use new Git::Repo API, and add optional caching
[git/gitweb-caching.git] / utf8.c
blobdc3735364f85273c2a119b994ddb405c09dc395c
1 #include "git-compat-util.h"
2 #include "utf8.h"
4 /* This code is originally from http://www.cl.cam.ac.uk/~mgk25/ucs/ */
6 struct interval {
7 int first;
8 int last;
9 };
11 /* auxiliary function for binary search in interval table */
12 static int bisearch(ucs_char_t ucs, const struct interval *table, int max)
14 int min = 0;
15 int mid;
17 if (ucs < table[0].first || ucs > table[max].last)
18 return 0;
19 while (max >= min) {
20 mid = (min + max) / 2;
21 if (ucs > table[mid].last)
22 min = mid + 1;
23 else if (ucs < table[mid].first)
24 max = mid - 1;
25 else
26 return 1;
29 return 0;
32 /* The following two functions define the column width of an ISO 10646
33 * character as follows:
35 * - The null character (U+0000) has a column width of 0.
37 * - Other C0/C1 control characters and DEL will lead to a return
38 * value of -1.
40 * - Non-spacing and enclosing combining characters (general
41 * category code Mn or Me in the Unicode database) have a
42 * column width of 0.
44 * - SOFT HYPHEN (U+00AD) has a column width of 1.
46 * - Other format characters (general category code Cf in the Unicode
47 * database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
49 * - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
50 * have a column width of 0.
52 * - Spacing characters in the East Asian Wide (W) or East Asian
53 * Full-width (F) category as defined in Unicode Technical
54 * Report #11 have a column width of 2.
56 * - All remaining characters (including all printable
57 * ISO 8859-1 and WGL4 characters, Unicode control characters,
58 * etc.) have a column width of 1.
60 * This implementation assumes that ucs_char_t characters are encoded
61 * in ISO 10646.
64 static int git_wcwidth(ucs_char_t ch)
67 * Sorted list of non-overlapping intervals of non-spacing characters,
68 * generated by
69 * "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c".
71 static const struct interval combining[] = {
72 { 0x0300, 0x0357 }, { 0x035D, 0x036F }, { 0x0483, 0x0486 },
73 { 0x0488, 0x0489 }, { 0x0591, 0x05A1 }, { 0x05A3, 0x05B9 },
74 { 0x05BB, 0x05BD }, { 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 },
75 { 0x05C4, 0x05C4 }, { 0x0600, 0x0603 }, { 0x0610, 0x0615 },
76 { 0x064B, 0x0658 }, { 0x0670, 0x0670 }, { 0x06D6, 0x06E4 },
77 { 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED }, { 0x070F, 0x070F },
78 { 0x0711, 0x0711 }, { 0x0730, 0x074A }, { 0x07A6, 0x07B0 },
79 { 0x0901, 0x0902 }, { 0x093C, 0x093C }, { 0x0941, 0x0948 },
80 { 0x094D, 0x094D }, { 0x0951, 0x0954 }, { 0x0962, 0x0963 },
81 { 0x0981, 0x0981 }, { 0x09BC, 0x09BC }, { 0x09C1, 0x09C4 },
82 { 0x09CD, 0x09CD }, { 0x09E2, 0x09E3 }, { 0x0A01, 0x0A02 },
83 { 0x0A3C, 0x0A3C }, { 0x0A41, 0x0A42 }, { 0x0A47, 0x0A48 },
84 { 0x0A4B, 0x0A4D }, { 0x0A70, 0x0A71 }, { 0x0A81, 0x0A82 },
85 { 0x0ABC, 0x0ABC }, { 0x0AC1, 0x0AC5 }, { 0x0AC7, 0x0AC8 },
86 { 0x0ACD, 0x0ACD }, { 0x0AE2, 0x0AE3 }, { 0x0B01, 0x0B01 },
87 { 0x0B3C, 0x0B3C }, { 0x0B3F, 0x0B3F }, { 0x0B41, 0x0B43 },
88 { 0x0B4D, 0x0B4D }, { 0x0B56, 0x0B56 }, { 0x0B82, 0x0B82 },
89 { 0x0BC0, 0x0BC0 }, { 0x0BCD, 0x0BCD }, { 0x0C3E, 0x0C40 },
90 { 0x0C46, 0x0C48 }, { 0x0C4A, 0x0C4D }, { 0x0C55, 0x0C56 },
91 { 0x0CBC, 0x0CBC }, { 0x0CBF, 0x0CBF }, { 0x0CC6, 0x0CC6 },
92 { 0x0CCC, 0x0CCD }, { 0x0D41, 0x0D43 }, { 0x0D4D, 0x0D4D },
93 { 0x0DCA, 0x0DCA }, { 0x0DD2, 0x0DD4 }, { 0x0DD6, 0x0DD6 },
94 { 0x0E31, 0x0E31 }, { 0x0E34, 0x0E3A }, { 0x0E47, 0x0E4E },
95 { 0x0EB1, 0x0EB1 }, { 0x0EB4, 0x0EB9 }, { 0x0EBB, 0x0EBC },
96 { 0x0EC8, 0x0ECD }, { 0x0F18, 0x0F19 }, { 0x0F35, 0x0F35 },
97 { 0x0F37, 0x0F37 }, { 0x0F39, 0x0F39 }, { 0x0F71, 0x0F7E },
98 { 0x0F80, 0x0F84 }, { 0x0F86, 0x0F87 }, { 0x0F90, 0x0F97 },
99 { 0x0F99, 0x0FBC }, { 0x0FC6, 0x0FC6 }, { 0x102D, 0x1030 },
100 { 0x1032, 0x1032 }, { 0x1036, 0x1037 }, { 0x1039, 0x1039 },
101 { 0x1058, 0x1059 }, { 0x1160, 0x11FF }, { 0x1712, 0x1714 },
102 { 0x1732, 0x1734 }, { 0x1752, 0x1753 }, { 0x1772, 0x1773 },
103 { 0x17B4, 0x17B5 }, { 0x17B7, 0x17BD }, { 0x17C6, 0x17C6 },
104 { 0x17C9, 0x17D3 }, { 0x17DD, 0x17DD }, { 0x180B, 0x180D },
105 { 0x18A9, 0x18A9 }, { 0x1920, 0x1922 }, { 0x1927, 0x1928 },
106 { 0x1932, 0x1932 }, { 0x1939, 0x193B }, { 0x200B, 0x200F },
107 { 0x202A, 0x202E }, { 0x2060, 0x2063 }, { 0x206A, 0x206F },
108 { 0x20D0, 0x20EA }, { 0x302A, 0x302F }, { 0x3099, 0x309A },
109 { 0xFB1E, 0xFB1E }, { 0xFE00, 0xFE0F }, { 0xFE20, 0xFE23 },
110 { 0xFEFF, 0xFEFF }, { 0xFFF9, 0xFFFB }, { 0x1D167, 0x1D169 },
111 { 0x1D173, 0x1D182 }, { 0x1D185, 0x1D18B },
112 { 0x1D1AA, 0x1D1AD }, { 0xE0001, 0xE0001 },
113 { 0xE0020, 0xE007F }, { 0xE0100, 0xE01EF }
116 /* test for 8-bit control characters */
117 if (ch == 0)
118 return 0;
119 if (ch < 32 || (ch >= 0x7f && ch < 0xa0))
120 return -1;
122 /* binary search in table of non-spacing characters */
123 if (bisearch(ch, combining, sizeof(combining)
124 / sizeof(struct interval) - 1))
125 return 0;
128 * If we arrive here, ch is neither a combining nor a C0/C1
129 * control character.
132 return 1 +
133 (ch >= 0x1100 &&
134 /* Hangul Jamo init. consonants */
135 (ch <= 0x115f ||
136 ch == 0x2329 || ch == 0x232a ||
137 /* CJK ... Yi */
138 (ch >= 0x2e80 && ch <= 0xa4cf &&
139 ch != 0x303f) ||
140 /* Hangul Syllables */
141 (ch >= 0xac00 && ch <= 0xd7a3) ||
142 /* CJK Compatibility Ideographs */
143 (ch >= 0xf900 && ch <= 0xfaff) ||
144 /* CJK Compatibility Forms */
145 (ch >= 0xfe30 && ch <= 0xfe6f) ||
146 /* Fullwidth Forms */
147 (ch >= 0xff00 && ch <= 0xff60) ||
148 (ch >= 0xffe0 && ch <= 0xffe6) ||
149 (ch >= 0x20000 && ch <= 0x2fffd) ||
150 (ch >= 0x30000 && ch <= 0x3fffd)));
154 * Pick one ucs character starting from the location *start points at,
155 * and return it, while updating the *start pointer to point at the
156 * end of that character. When remainder_p is not NULL, the location
157 * holds the number of bytes remaining in the string that we are allowed
158 * to pick from. Otherwise we are allowed to pick up to the NUL that
159 * would eventually appear in the string. *remainder_p is also reduced
160 * by the number of bytes we have consumed.
162 * If the string was not a valid UTF-8, *start pointer is set to NULL
163 * and the return value is undefined.
165 ucs_char_t pick_one_utf8_char(const char **start, size_t *remainder_p)
167 unsigned char *s = (unsigned char *)*start;
168 ucs_char_t ch;
169 size_t remainder, incr;
172 * A caller that assumes NUL terminated text can choose
173 * not to bother with the remainder length. We will
174 * stop at the first NUL.
176 remainder = (remainder_p ? *remainder_p : 999);
178 if (remainder < 1) {
179 goto invalid;
180 } else if (*s < 0x80) {
181 /* 0xxxxxxx */
182 ch = *s;
183 incr = 1;
184 } else if ((s[0] & 0xe0) == 0xc0) {
185 /* 110XXXXx 10xxxxxx */
186 if (remainder < 2 ||
187 (s[1] & 0xc0) != 0x80 ||
188 (s[0] & 0xfe) == 0xc0)
189 goto invalid;
190 ch = ((s[0] & 0x1f) << 6) | (s[1] & 0x3f);
191 incr = 2;
192 } else if ((s[0] & 0xf0) == 0xe0) {
193 /* 1110XXXX 10Xxxxxx 10xxxxxx */
194 if (remainder < 3 ||
195 (s[1] & 0xc0) != 0x80 ||
196 (s[2] & 0xc0) != 0x80 ||
197 /* overlong? */
198 (s[0] == 0xe0 && (s[1] & 0xe0) == 0x80) ||
199 /* surrogate? */
200 (s[0] == 0xed && (s[1] & 0xe0) == 0xa0) ||
201 /* U+FFFE or U+FFFF? */
202 (s[0] == 0xef && s[1] == 0xbf &&
203 (s[2] & 0xfe) == 0xbe))
204 goto invalid;
205 ch = ((s[0] & 0x0f) << 12) |
206 ((s[1] & 0x3f) << 6) | (s[2] & 0x3f);
207 incr = 3;
208 } else if ((s[0] & 0xf8) == 0xf0) {
209 /* 11110XXX 10XXxxxx 10xxxxxx 10xxxxxx */
210 if (remainder < 4 ||
211 (s[1] & 0xc0) != 0x80 ||
212 (s[2] & 0xc0) != 0x80 ||
213 (s[3] & 0xc0) != 0x80 ||
214 /* overlong? */
215 (s[0] == 0xf0 && (s[1] & 0xf0) == 0x80) ||
216 /* > U+10FFFF? */
217 (s[0] == 0xf4 && s[1] > 0x8f) || s[0] > 0xf4)
218 goto invalid;
219 ch = ((s[0] & 0x07) << 18) | ((s[1] & 0x3f) << 12) |
220 ((s[2] & 0x3f) << 6) | (s[3] & 0x3f);
221 incr = 4;
222 } else {
223 invalid:
224 *start = NULL;
225 return 0;
228 *start += incr;
229 if (remainder_p)
230 *remainder_p = remainder - incr;
231 return ch;
235 * This function returns the number of columns occupied by the character
236 * pointed to by the variable start. The pointer is updated to point at
237 * the next character. When remainder_p is not NULL, it points at the
238 * location that stores the number of remaining bytes we can use to pick
239 * a character (see pick_one_utf8_char() above).
241 int utf8_width(const char **start, size_t *remainder_p)
243 ucs_char_t ch = pick_one_utf8_char(start, remainder_p);
244 if (!*start)
245 return 0;
246 return git_wcwidth(ch);
249 int is_utf8(const char *text)
251 while (*text) {
252 if (*text == '\n' || *text == '\t' || *text == '\r') {
253 text++;
254 continue;
256 utf8_width(&text, NULL);
257 if (!text)
258 return 0;
260 return 1;
263 static void print_spaces(int count)
265 static const char s[] = " ";
266 while (count >= sizeof(s)) {
267 fwrite(s, sizeof(s) - 1, 1, stdout);
268 count -= sizeof(s) - 1;
270 fwrite(s, count, 1, stdout);
274 * Wrap the text, if necessary. The variable indent is the indent for the
275 * first line, indent2 is the indent for all other lines.
276 * If indent is negative, assume that already -indent columns have been
277 * consumed (and no extra indent is necessary for the first line).
279 int print_wrapped_text(const char *text, int indent, int indent2, int width)
281 int w = indent, assume_utf8 = is_utf8(text);
282 const char *bol = text, *space = NULL;
284 if (indent < 0) {
285 w = -indent;
286 space = text;
289 for (;;) {
290 char c = *text;
291 if (!c || isspace(c)) {
292 if (w < width || !space) {
293 const char *start = bol;
294 if (space)
295 start = space;
296 else
297 print_spaces(indent);
298 fwrite(start, text - start, 1, stdout);
299 if (!c)
300 return w;
301 else if (c == '\t')
302 w |= 0x07;
303 space = text;
304 w++;
305 text++;
307 else {
308 putchar('\n');
309 text = bol = space + isspace(*space);
310 space = NULL;
311 w = indent = indent2;
313 continue;
315 if (assume_utf8)
316 w += utf8_width(&text, NULL);
317 else {
318 w++;
319 text++;
324 int is_encoding_utf8(const char *name)
326 if (!name)
327 return 1;
328 if (!strcasecmp(name, "utf-8") || !strcasecmp(name, "utf8"))
329 return 1;
330 return 0;
334 * Given a buffer and its encoding, return it re-encoded
335 * with iconv. If the conversion fails, returns NULL.
337 #ifndef NO_ICONV
338 #ifdef OLD_ICONV
339 typedef const char * iconv_ibp;
340 #else
341 typedef char * iconv_ibp;
342 #endif
343 char *reencode_string(const char *in, const char *out_encoding, const char *in_encoding)
345 iconv_t conv;
346 size_t insz, outsz, outalloc;
347 char *out, *outpos;
348 iconv_ibp cp;
350 if (!in_encoding)
351 return NULL;
352 conv = iconv_open(out_encoding, in_encoding);
353 if (conv == (iconv_t) -1)
354 return NULL;
355 insz = strlen(in);
356 outsz = insz;
357 outalloc = outsz + 1; /* for terminating NUL */
358 out = xmalloc(outalloc);
359 outpos = out;
360 cp = (iconv_ibp)in;
362 while (1) {
363 size_t cnt = iconv(conv, &cp, &insz, &outpos, &outsz);
365 if (cnt == -1) {
366 size_t sofar;
367 if (errno != E2BIG) {
368 free(out);
369 iconv_close(conv);
370 return NULL;
372 /* insz has remaining number of bytes.
373 * since we started outsz the same as insz,
374 * it is likely that insz is not enough for
375 * converting the rest.
377 sofar = outpos - out;
378 outalloc = sofar + insz * 2 + 32;
379 out = xrealloc(out, outalloc);
380 outpos = out + sofar;
381 outsz = outalloc - sofar - 1;
383 else {
384 *outpos = '\0';
385 break;
388 iconv_close(conv);
389 return out;
391 #endif