| 1 | /* |
| 2 | * Copyright (c) 2012 Nicolas George |
| 3 | * |
| 4 | * This file is part of FFmpeg. |
| 5 | * |
| 6 | * FFmpeg is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU Lesser General Public |
| 8 | * License as published by the Free Software Foundation; either |
| 9 | * version 2.1 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * FFmpeg is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | * Lesser General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Lesser General Public |
| 17 | * License along with FFmpeg; if not, write to the Free Software |
| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 19 | */ |
| 20 | |
| 21 | #include <stdarg.h> |
| 22 | #include <stdio.h> |
| 23 | #include <string.h> |
| 24 | #include <time.h> |
| 25 | #include "avassert.h" |
| 26 | #include "avstring.h" |
| 27 | #include "bprint.h" |
| 28 | #include "common.h" |
| 29 | #include "compat/va_copy.h" |
| 30 | #include "error.h" |
| 31 | #include "mem.h" |
| 32 | |
| 33 | #define av_bprint_room(buf) ((buf)->size - FFMIN((buf)->len, (buf)->size)) |
| 34 | #define av_bprint_is_allocated(buf) ((buf)->str != (buf)->reserved_internal_buffer) |
| 35 | |
| 36 | static int av_bprint_alloc(AVBPrint *buf, unsigned room) |
| 37 | { |
| 38 | char *old_str, *new_str; |
| 39 | unsigned min_size, new_size; |
| 40 | |
| 41 | if (buf->size == buf->size_max) |
| 42 | return AVERROR(EIO); |
| 43 | if (!av_bprint_is_complete(buf)) |
| 44 | return AVERROR_INVALIDDATA; /* it is already truncated anyway */ |
| 45 | min_size = buf->len + 1 + FFMIN(UINT_MAX - buf->len - 1, room); |
| 46 | new_size = buf->size > buf->size_max / 2 ? buf->size_max : buf->size * 2; |
| 47 | if (new_size < min_size) |
| 48 | new_size = FFMIN(buf->size_max, min_size); |
| 49 | old_str = av_bprint_is_allocated(buf) ? buf->str : NULL; |
| 50 | new_str = av_realloc(old_str, new_size); |
| 51 | if (!new_str) |
| 52 | return AVERROR(ENOMEM); |
| 53 | if (!old_str) |
| 54 | memcpy(new_str, buf->str, buf->len + 1); |
| 55 | buf->str = new_str; |
| 56 | buf->size = new_size; |
| 57 | return 0; |
| 58 | } |
| 59 | |
| 60 | static void av_bprint_grow(AVBPrint *buf, unsigned extra_len) |
| 61 | { |
| 62 | /* arbitrary margin to avoid small overflows */ |
| 63 | extra_len = FFMIN(extra_len, UINT_MAX - 5 - buf->len); |
| 64 | buf->len += extra_len; |
| 65 | if (buf->size) |
| 66 | buf->str[FFMIN(buf->len, buf->size - 1)] = 0; |
| 67 | } |
| 68 | |
| 69 | void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max) |
| 70 | { |
| 71 | unsigned size_auto = (char *)buf + sizeof(*buf) - |
| 72 | buf->reserved_internal_buffer; |
| 73 | |
| 74 | if (size_max == 1) |
| 75 | size_max = size_auto; |
| 76 | buf->str = buf->reserved_internal_buffer; |
| 77 | buf->len = 0; |
| 78 | buf->size = FFMIN(size_auto, size_max); |
| 79 | buf->size_max = size_max; |
| 80 | *buf->str = 0; |
| 81 | if (size_init > buf->size) |
| 82 | av_bprint_alloc(buf, size_init - 1); |
| 83 | } |
| 84 | |
| 85 | void av_bprint_init_for_buffer(AVBPrint *buf, char *buffer, unsigned size) |
| 86 | { |
| 87 | buf->str = buffer; |
| 88 | buf->len = 0; |
| 89 | buf->size = size; |
| 90 | buf->size_max = size; |
| 91 | *buf->str = 0; |
| 92 | } |
| 93 | |
| 94 | void av_bprintf(AVBPrint *buf, const char *fmt, ...) |
| 95 | { |
| 96 | unsigned room; |
| 97 | char *dst; |
| 98 | va_list vl; |
| 99 | int extra_len; |
| 100 | |
| 101 | while (1) { |
| 102 | room = av_bprint_room(buf); |
| 103 | dst = room ? buf->str + buf->len : NULL; |
| 104 | va_start(vl, fmt); |
| 105 | extra_len = vsnprintf(dst, room, fmt, vl); |
| 106 | va_end(vl); |
| 107 | if (extra_len <= 0) |
| 108 | return; |
| 109 | if (extra_len < room) |
| 110 | break; |
| 111 | if (av_bprint_alloc(buf, extra_len)) |
| 112 | break; |
| 113 | } |
| 114 | av_bprint_grow(buf, extra_len); |
| 115 | } |
| 116 | |
| 117 | void av_vbprintf(AVBPrint *buf, const char *fmt, va_list vl_arg) |
| 118 | { |
| 119 | unsigned room; |
| 120 | char *dst; |
| 121 | int extra_len; |
| 122 | va_list vl; |
| 123 | |
| 124 | while (1) { |
| 125 | room = av_bprint_room(buf); |
| 126 | dst = room ? buf->str + buf->len : NULL; |
| 127 | va_copy(vl, vl_arg); |
| 128 | extra_len = vsnprintf(dst, room, fmt, vl); |
| 129 | va_end(vl); |
| 130 | if (extra_len <= 0) |
| 131 | return; |
| 132 | if (extra_len < room) |
| 133 | break; |
| 134 | if (av_bprint_alloc(buf, extra_len)) |
| 135 | break; |
| 136 | } |
| 137 | av_bprint_grow(buf, extra_len); |
| 138 | } |
| 139 | |
| 140 | void av_bprint_chars(AVBPrint *buf, char c, unsigned n) |
| 141 | { |
| 142 | unsigned room, real_n; |
| 143 | |
| 144 | while (1) { |
| 145 | room = av_bprint_room(buf); |
| 146 | if (n < room) |
| 147 | break; |
| 148 | if (av_bprint_alloc(buf, n)) |
| 149 | break; |
| 150 | } |
| 151 | if (room) { |
| 152 | real_n = FFMIN(n, room - 1); |
| 153 | memset(buf->str + buf->len, c, real_n); |
| 154 | } |
| 155 | av_bprint_grow(buf, n); |
| 156 | } |
| 157 | |
| 158 | void av_bprint_append_data(AVBPrint *buf, const char *data, unsigned size) |
| 159 | { |
| 160 | unsigned room, real_n; |
| 161 | |
| 162 | while (1) { |
| 163 | room = av_bprint_room(buf); |
| 164 | if (size < room) |
| 165 | break; |
| 166 | if (av_bprint_alloc(buf, size)) |
| 167 | break; |
| 168 | } |
| 169 | if (room) { |
| 170 | real_n = FFMIN(size, room - 1); |
| 171 | memcpy(buf->str + buf->len, data, real_n); |
| 172 | } |
| 173 | av_bprint_grow(buf, size); |
| 174 | } |
| 175 | |
| 176 | void av_bprint_strftime(AVBPrint *buf, const char *fmt, const struct tm *tm) |
| 177 | { |
| 178 | unsigned room; |
| 179 | size_t l; |
| 180 | |
| 181 | if (!*fmt) |
| 182 | return; |
| 183 | while (1) { |
| 184 | room = av_bprint_room(buf); |
| 185 | if (room && (l = strftime(buf->str + buf->len, room, fmt, tm))) |
| 186 | break; |
| 187 | /* strftime does not tell us how much room it would need: let us |
| 188 | retry with twice as much until the buffer is large enough */ |
| 189 | room = !room ? strlen(fmt) + 1 : |
| 190 | room <= INT_MAX / 2 ? room * 2 : INT_MAX; |
| 191 | if (av_bprint_alloc(buf, room)) { |
| 192 | /* impossible to grow, try to manage something useful anyway */ |
| 193 | room = av_bprint_room(buf); |
| 194 | if (room < 1024) { |
| 195 | /* if strftime fails because the buffer has (almost) reached |
| 196 | its maximum size, let us try in a local buffer; 1k should |
| 197 | be enough to format any real date+time string */ |
| 198 | char buf2[1024]; |
| 199 | if ((l = strftime(buf2, sizeof(buf2), fmt, tm))) { |
| 200 | av_bprintf(buf, "%s", buf2); |
| 201 | return; |
| 202 | } |
| 203 | } |
| 204 | if (room) { |
| 205 | /* if anything else failed and the buffer is not already |
| 206 | truncated, let us add a stock string and force truncation */ |
| 207 | static const char txt[] = "[truncated strftime output]"; |
| 208 | memset(buf->str + buf->len, '!', room); |
| 209 | memcpy(buf->str + buf->len, txt, FFMIN(sizeof(txt) - 1, room)); |
| 210 | av_bprint_grow(buf, room); /* force truncation */ |
| 211 | } |
| 212 | return; |
| 213 | } |
| 214 | } |
| 215 | av_bprint_grow(buf, l); |
| 216 | } |
| 217 | |
| 218 | void av_bprint_get_buffer(AVBPrint *buf, unsigned size, |
| 219 | unsigned char **mem, unsigned *actual_size) |
| 220 | { |
| 221 | if (size > av_bprint_room(buf)) |
| 222 | av_bprint_alloc(buf, size); |
| 223 | *actual_size = av_bprint_room(buf); |
| 224 | *mem = *actual_size ? buf->str + buf->len : NULL; |
| 225 | } |
| 226 | |
| 227 | void av_bprint_clear(AVBPrint *buf) |
| 228 | { |
| 229 | if (buf->len) { |
| 230 | *buf->str = 0; |
| 231 | buf->len = 0; |
| 232 | } |
| 233 | } |
| 234 | |
| 235 | int av_bprint_finalize(AVBPrint *buf, char **ret_str) |
| 236 | { |
| 237 | unsigned real_size = FFMIN(buf->len + 1, buf->size); |
| 238 | char *str; |
| 239 | int ret = 0; |
| 240 | |
| 241 | if (ret_str) { |
| 242 | if (av_bprint_is_allocated(buf)) { |
| 243 | str = av_realloc(buf->str, real_size); |
| 244 | if (!str) |
| 245 | str = buf->str; |
| 246 | buf->str = NULL; |
| 247 | } else { |
| 248 | str = av_malloc(real_size); |
| 249 | if (str) |
| 250 | memcpy(str, buf->str, real_size); |
| 251 | else |
| 252 | ret = AVERROR(ENOMEM); |
| 253 | } |
| 254 | *ret_str = str; |
| 255 | } else { |
| 256 | if (av_bprint_is_allocated(buf)) |
| 257 | av_freep(&buf->str); |
| 258 | } |
| 259 | buf->size = real_size; |
| 260 | return ret; |
| 261 | } |
| 262 | |
| 263 | #define WHITESPACES " \n\t" |
| 264 | |
| 265 | void av_bprint_escape(AVBPrint *dstbuf, const char *src, const char *special_chars, |
| 266 | enum AVEscapeMode mode, int flags) |
| 267 | { |
| 268 | const char *src0 = src; |
| 269 | |
| 270 | if (mode == AV_ESCAPE_MODE_AUTO) |
| 271 | mode = AV_ESCAPE_MODE_BACKSLASH; /* TODO: implement a heuristic */ |
| 272 | |
| 273 | switch (mode) { |
| 274 | case AV_ESCAPE_MODE_QUOTE: |
| 275 | /* enclose the string between '' */ |
| 276 | av_bprint_chars(dstbuf, '\'', 1); |
| 277 | for (; *src; src++) { |
| 278 | if (*src == '\'') |
| 279 | av_bprintf(dstbuf, "'\\''"); |
| 280 | else |
| 281 | av_bprint_chars(dstbuf, *src, 1); |
| 282 | } |
| 283 | av_bprint_chars(dstbuf, '\'', 1); |
| 284 | break; |
| 285 | |
| 286 | /* case AV_ESCAPE_MODE_BACKSLASH or unknown mode */ |
| 287 | default: |
| 288 | /* \-escape characters */ |
| 289 | for (; *src; src++) { |
| 290 | int is_first_last = src == src0 || !*(src+1); |
| 291 | int is_ws = !!strchr(WHITESPACES, *src); |
| 292 | int is_strictly_special = special_chars && strchr(special_chars, *src); |
| 293 | int is_special = |
| 294 | is_strictly_special || strchr("'\\", *src) || |
| 295 | (is_ws && (flags & AV_ESCAPE_FLAG_WHITESPACE)); |
| 296 | |
| 297 | if (is_strictly_special || |
| 298 | (!(flags & AV_ESCAPE_FLAG_STRICT) && |
| 299 | (is_special || (is_ws && is_first_last)))) |
| 300 | av_bprint_chars(dstbuf, '\\', 1); |
| 301 | av_bprint_chars(dstbuf, *src, 1); |
| 302 | } |
| 303 | break; |
| 304 | } |
| 305 | } |
| 306 | |
| 307 | #ifdef TEST |
| 308 | |
| 309 | #undef printf |
| 310 | |
| 311 | static void bprint_pascal(AVBPrint *b, unsigned size) |
| 312 | { |
| 313 | unsigned i, j; |
| 314 | unsigned p[42]; |
| 315 | |
| 316 | av_assert0(size < FF_ARRAY_ELEMS(p)); |
| 317 | |
| 318 | p[0] = 1; |
| 319 | av_bprintf(b, "%8d\n", 1); |
| 320 | for (i = 1; i <= size; i++) { |
| 321 | p[i] = 1; |
| 322 | for (j = i - 1; j > 0; j--) |
| 323 | p[j] = p[j] + p[j - 1]; |
| 324 | for (j = 0; j <= i; j++) |
| 325 | av_bprintf(b, "%8d", p[j]); |
| 326 | av_bprintf(b, "\n"); |
| 327 | } |
| 328 | } |
| 329 | |
| 330 | int main(void) |
| 331 | { |
| 332 | AVBPrint b; |
| 333 | char buf[256]; |
| 334 | struct tm testtime = { .tm_year = 100, .tm_mon = 11, .tm_mday = 20 }; |
| 335 | |
| 336 | av_bprint_init(&b, 0, -1); |
| 337 | bprint_pascal(&b, 5); |
| 338 | printf("Short text in unlimited buffer: %u/%u\n", (unsigned)strlen(b.str), b.len); |
| 339 | printf("%s\n", b.str); |
| 340 | av_bprint_finalize(&b, NULL); |
| 341 | |
| 342 | av_bprint_init(&b, 0, -1); |
| 343 | bprint_pascal(&b, 25); |
| 344 | printf("Long text in unlimited buffer: %u/%u\n", (unsigned)strlen(b.str), b.len); |
| 345 | av_bprint_finalize(&b, NULL); |
| 346 | |
| 347 | av_bprint_init(&b, 0, 2048); |
| 348 | bprint_pascal(&b, 25); |
| 349 | printf("Long text in limited buffer: %u/%u\n", (unsigned)strlen(b.str), b.len); |
| 350 | av_bprint_finalize(&b, NULL); |
| 351 | |
| 352 | av_bprint_init(&b, 0, 1); |
| 353 | bprint_pascal(&b, 5); |
| 354 | printf("Short text in automatic buffer: %u/%u\n", (unsigned)strlen(b.str), b.len); |
| 355 | |
| 356 | av_bprint_init(&b, 0, 1); |
| 357 | bprint_pascal(&b, 25); |
| 358 | printf("Long text in automatic buffer: %u/%u\n", (unsigned)strlen(b.str)/8*8, b.len); |
| 359 | /* Note that the size of the automatic buffer is arch-dependent. */ |
| 360 | |
| 361 | av_bprint_init(&b, 0, 0); |
| 362 | bprint_pascal(&b, 25); |
| 363 | printf("Long text count only buffer: %u/%u\n", (unsigned)strlen(b.str), b.len); |
| 364 | |
| 365 | av_bprint_init_for_buffer(&b, buf, sizeof(buf)); |
| 366 | bprint_pascal(&b, 25); |
| 367 | printf("Long text count only buffer: %u/%u\n", (unsigned)strlen(buf), b.len); |
| 368 | |
| 369 | av_bprint_init(&b, 0, -1); |
| 370 | av_bprint_strftime(&b, "%Y-%m-%d", &testtime); |
| 371 | printf("strftime full: %u/%u \"%s\"\n", (unsigned)strlen(buf), b.len, b.str); |
| 372 | av_bprint_finalize(&b, NULL); |
| 373 | |
| 374 | av_bprint_init(&b, 0, 8); |
| 375 | av_bprint_strftime(&b, "%Y-%m-%d", &testtime); |
| 376 | printf("strftime truncated: %u/%u \"%s\"\n", (unsigned)strlen(buf), b.len, b.str); |
| 377 | |
| 378 | return 0; |
| 379 | } |
| 380 | |
| 381 | #endif |