Daniel Veillard | bca22f4 | 2012-07-11 16:48:47 +0800 | [diff] [blame^] | 1 | /* |
| 2 | * buf.c: memory buffers for libxml2 |
| 3 | * |
| 4 | * new buffer structures and entry points to simplify the maintainance |
| 5 | * of libxml2 and ensure we keep good control over memory allocations |
| 6 | * and stay 64 bits clean. |
| 7 | * The new entry point use the xmlBufPtr opaque structure and |
| 8 | * xmlBuf...() counterparts to the old xmlBuf...() functions |
| 9 | * |
| 10 | * See Copyright for the status of this software. |
| 11 | * |
| 12 | * daniel@veillard.com |
| 13 | */ |
| 14 | |
| 15 | #define IN_LIBXML |
| 16 | #include "libxml.h" |
| 17 | |
| 18 | #include <string.h> /* for memset() only ! */ |
| 19 | #include <limits.h> |
| 20 | #ifdef HAVE_CTYPE_H |
| 21 | #include <ctype.h> |
| 22 | #endif |
| 23 | #ifdef HAVE_STDLIB_H |
| 24 | #include <stdlib.h> |
| 25 | #endif |
| 26 | |
| 27 | #include <libxml/tree.h> |
| 28 | #include <libxml/globals.h> |
| 29 | #include <libxml/tree.h> |
| 30 | #include "buf.h" |
| 31 | |
| 32 | /** |
| 33 | * xmlBuf: |
| 34 | * |
| 35 | * A buffer structure |
| 36 | */ |
| 37 | |
| 38 | struct _xmlBuf { |
| 39 | xmlChar *content; /* The buffer content UTF8 */ |
| 40 | size_t use; /* The buffer size used */ |
| 41 | size_t size; /* The buffer size */ |
| 42 | xmlBufferAllocationScheme alloc; /* The realloc method */ |
| 43 | xmlChar *contentIO; /* in IO mode we may have a different base */ |
| 44 | xmlBufferPtr buffer; /* wrapper for an old buffer */ |
| 45 | int error; /* an error code if a failure occured */ |
| 46 | }; |
| 47 | |
| 48 | /** |
| 49 | * xmlBufMemoryError: |
| 50 | * @extra: extra informations |
| 51 | * |
| 52 | * Handle an out of memory condition |
| 53 | * To be improved... |
| 54 | */ |
| 55 | static void |
| 56 | xmlBufMemoryError(xmlBufPtr buf, const char *extra) |
| 57 | { |
| 58 | __xmlSimpleError(XML_FROM_BUFFER, XML_ERR_NO_MEMORY, NULL, NULL, extra); |
| 59 | if ((buf) && (buf->error == 0)) |
| 60 | buf->error = XML_ERR_NO_MEMORY; |
| 61 | } |
| 62 | |
| 63 | /** |
| 64 | * xmlBufOverflowError: |
| 65 | * @extra: extra informations |
| 66 | * |
| 67 | * Handle a buffer overflow error |
| 68 | * To be improved... |
| 69 | */ |
| 70 | static void |
| 71 | xmlBufOverflowError(xmlBufPtr buf, const char *extra) |
| 72 | { |
| 73 | __xmlSimpleError(XML_FROM_BUFFER, XML_BUF_OVERFLOW, NULL, NULL, extra); |
| 74 | if ((buf) && (buf->error == 0)) |
| 75 | buf->error = XML_BUF_OVERFLOW; |
| 76 | } |
| 77 | |
| 78 | |
| 79 | /** |
| 80 | * xmlBufCreate: |
| 81 | * |
| 82 | * routine to create an XML buffer. |
| 83 | * returns the new structure. |
| 84 | */ |
| 85 | xmlBufPtr |
| 86 | xmlBufCreate(void) { |
| 87 | xmlBufPtr ret; |
| 88 | |
| 89 | ret = (xmlBufPtr) xmlMalloc(sizeof(xmlBuf)); |
| 90 | if (ret == NULL) { |
| 91 | xmlBufMemoryError(NULL, "creating buffer"); |
| 92 | return(NULL); |
| 93 | } |
| 94 | ret->use = 0; |
| 95 | ret->error = 0; |
| 96 | ret->buffer = NULL; |
| 97 | ret->size = xmlDefaultBufferSize; |
| 98 | ret->alloc = xmlBufferAllocScheme; |
| 99 | ret->content = (xmlChar *) xmlMallocAtomic(ret->size * sizeof(xmlChar)); |
| 100 | if (ret->content == NULL) { |
| 101 | xmlBufMemoryError(ret, "creating buffer"); |
| 102 | xmlFree(ret); |
| 103 | return(NULL); |
| 104 | } |
| 105 | ret->content[0] = 0; |
| 106 | ret->contentIO = NULL; |
| 107 | return(ret); |
| 108 | } |
| 109 | |
| 110 | /** |
| 111 | * xmlBufCreateSize: |
| 112 | * @size: initial size of buffer |
| 113 | * |
| 114 | * routine to create an XML buffer. |
| 115 | * returns the new structure. |
| 116 | */ |
| 117 | xmlBufPtr |
| 118 | xmlBufCreateSize(size_t size) { |
| 119 | xmlBufPtr ret; |
| 120 | |
| 121 | ret = (xmlBufPtr) xmlMalloc(sizeof(xmlBuf)); |
| 122 | if (ret == NULL) { |
| 123 | xmlBufMemoryError(NULL, "creating buffer"); |
| 124 | return(NULL); |
| 125 | } |
| 126 | ret->use = 0; |
| 127 | ret->error = 0; |
| 128 | ret->buffer = NULL; |
| 129 | ret->alloc = xmlBufferAllocScheme; |
| 130 | ret->size = (size ? size+2 : 0); /* +1 for ending null */ |
| 131 | if (ret->size){ |
| 132 | ret->content = (xmlChar *) xmlMallocAtomic(ret->size * sizeof(xmlChar)); |
| 133 | if (ret->content == NULL) { |
| 134 | xmlBufMemoryError(ret, "creating buffer"); |
| 135 | xmlFree(ret); |
| 136 | return(NULL); |
| 137 | } |
| 138 | ret->content[0] = 0; |
| 139 | } else |
| 140 | ret->content = NULL; |
| 141 | ret->contentIO = NULL; |
| 142 | return(ret); |
| 143 | } |
| 144 | |
| 145 | /** |
| 146 | * xmlBufDetach: |
| 147 | * @buf: the buffer |
| 148 | * |
| 149 | * Remove the string contained in a buffer and gie it back to the |
| 150 | * caller. The buffer is reset to an empty content. |
| 151 | * This doesn't work with immutable buffers as they can't be reset. |
| 152 | * |
| 153 | * Returns the previous string contained by the buffer. |
| 154 | */ |
| 155 | xmlChar * |
| 156 | xmlBufDetach(xmlBufPtr buf) { |
| 157 | xmlChar *ret; |
| 158 | |
| 159 | if (buf == NULL) |
| 160 | return(NULL); |
| 161 | if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) |
| 162 | return(NULL); |
| 163 | if (buf->buffer != NULL) |
| 164 | return(NULL); |
| 165 | if (buf->error) |
| 166 | return(NULL); |
| 167 | |
| 168 | ret = buf->content; |
| 169 | buf->content = NULL; |
| 170 | buf->size = 0; |
| 171 | buf->use = 0; |
| 172 | |
| 173 | return ret; |
| 174 | } |
| 175 | |
| 176 | |
| 177 | /** |
| 178 | * xmlBufCreateStatic: |
| 179 | * @mem: the memory area |
| 180 | * @size: the size in byte |
| 181 | * |
| 182 | * routine to create an XML buffer from an immutable memory area. |
| 183 | * The area won't be modified nor copied, and is expected to be |
| 184 | * present until the end of the buffer lifetime. |
| 185 | * |
| 186 | * returns the new structure. |
| 187 | */ |
| 188 | xmlBufPtr |
| 189 | xmlBufCreateStatic(void *mem, size_t size) { |
| 190 | xmlBufPtr ret; |
| 191 | |
| 192 | if ((mem == NULL) || (size == 0)) |
| 193 | return(NULL); |
| 194 | |
| 195 | ret = (xmlBufPtr) xmlMalloc(sizeof(xmlBuf)); |
| 196 | if (ret == NULL) { |
| 197 | xmlBufMemoryError(NULL, "creating buffer"); |
| 198 | return(NULL); |
| 199 | } |
| 200 | ret->use = size; |
| 201 | ret->size = size; |
| 202 | ret->alloc = XML_BUFFER_ALLOC_IMMUTABLE; |
| 203 | ret->content = (xmlChar *) mem; |
| 204 | ret->error = 0; |
| 205 | ret->buffer = NULL; |
| 206 | return(ret); |
| 207 | } |
| 208 | |
| 209 | /** |
| 210 | * |
| 211 | * |
| 212 | */ |
| 213 | int |
| 214 | xmlBufGetAllocationScheme(xmlBufPtr buf) { |
| 215 | if (buf == NULL) { |
| 216 | #ifdef DEBUG_BUFFER |
| 217 | xmlGenericError(xmlGenericErrorContext, |
| 218 | "xmlBufGetAllocationScheme: buf == NULL\n"); |
| 219 | #endif |
| 220 | return(-1); |
| 221 | } |
| 222 | return(buf->alloc); |
| 223 | } |
| 224 | |
| 225 | /** |
| 226 | * xmlBufSetAllocationScheme: |
| 227 | * @buf: the buffer to tune |
| 228 | * @scheme: allocation scheme to use |
| 229 | * |
| 230 | * Sets the allocation scheme for this buffer |
| 231 | * |
| 232 | * returns 0 in case of success and -1 in case of failure |
| 233 | */ |
| 234 | int |
| 235 | xmlBufSetAllocationScheme(xmlBufPtr buf, |
| 236 | xmlBufferAllocationScheme scheme) { |
| 237 | if (buf == NULL) { |
| 238 | #ifdef DEBUG_BUFFER |
| 239 | xmlGenericError(xmlGenericErrorContext, |
| 240 | "xmlBufSetAllocationScheme: buf == NULL\n"); |
| 241 | #endif |
| 242 | return(-1); |
| 243 | } |
| 244 | if ((buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) || |
| 245 | (buf->alloc == XML_BUFFER_ALLOC_IO)) |
| 246 | return(-1); |
| 247 | if ((scheme == XML_BUFFER_ALLOC_DOUBLEIT) || |
| 248 | (scheme == XML_BUFFER_ALLOC_EXACT) || |
| 249 | (scheme == XML_BUFFER_ALLOC_HYBRID) || |
| 250 | (scheme == XML_BUFFER_ALLOC_IMMUTABLE)) { |
| 251 | buf->alloc = scheme; |
| 252 | if (buf->buffer) |
| 253 | buf->buffer->alloc = scheme; |
| 254 | return(0); |
| 255 | } |
| 256 | /* |
| 257 | * Switching a buffer ALLOC_IO has the side effect of initializing |
| 258 | * the contentIO field with the current content |
| 259 | */ |
| 260 | if (scheme == XML_BUFFER_ALLOC_IO) { |
| 261 | buf->alloc = XML_BUFFER_ALLOC_IO; |
| 262 | buf->contentIO = buf->content; |
| 263 | } |
| 264 | return(-1); |
| 265 | } |
| 266 | |
| 267 | /** |
| 268 | * xmlBufFree: |
| 269 | * @buf: the buffer to free |
| 270 | * |
| 271 | * Frees an XML buffer. It frees both the content and the structure which |
| 272 | * encapsulate it. |
| 273 | */ |
| 274 | void |
| 275 | xmlBufFree(xmlBufPtr buf) { |
| 276 | if (buf == NULL) { |
| 277 | #ifdef DEBUG_BUFFER |
| 278 | xmlGenericError(xmlGenericErrorContext, |
| 279 | "xmlBufFree: buf == NULL\n"); |
| 280 | #endif |
| 281 | return; |
| 282 | } |
| 283 | |
| 284 | if ((buf->alloc == XML_BUFFER_ALLOC_IO) && |
| 285 | (buf->contentIO != NULL)) { |
| 286 | xmlFree(buf->contentIO); |
| 287 | } else if ((buf->content != NULL) && |
| 288 | (buf->alloc != XML_BUFFER_ALLOC_IMMUTABLE)) { |
| 289 | xmlFree(buf->content); |
| 290 | } |
| 291 | xmlFree(buf); |
| 292 | } |
| 293 | |
| 294 | /** |
| 295 | * xmlBufEmpty: |
| 296 | * @buf: the buffer |
| 297 | * |
| 298 | * empty a buffer. |
| 299 | */ |
| 300 | void |
| 301 | xmlBufEmpty(xmlBufPtr buf) { |
| 302 | if (buf == NULL) return; |
| 303 | if (buf->content == NULL) return; |
| 304 | buf->use = 0; |
| 305 | if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) { |
| 306 | buf->content = BAD_CAST ""; |
| 307 | } else if ((buf->alloc == XML_BUFFER_ALLOC_IO) && |
| 308 | (buf->contentIO != NULL)) { |
| 309 | size_t start_buf = buf->content - buf->contentIO; |
| 310 | |
| 311 | buf->size += start_buf; |
| 312 | buf->content = buf->contentIO; |
| 313 | buf->content[0] = 0; |
| 314 | } else { |
| 315 | buf->content[0] = 0; |
| 316 | } |
| 317 | } |
| 318 | |
| 319 | /** |
| 320 | * xmlBufShrink: |
| 321 | * @buf: the buffer to dump |
| 322 | * @len: the number of xmlChar to remove |
| 323 | * |
| 324 | * Remove the beginning of an XML buffer. |
| 325 | * NOTE that this routine behaviour differs from xmlBufferShrink() |
| 326 | * as it will return 0 on error instead of -1 due to size_t being |
| 327 | * used as the return type. |
| 328 | * |
| 329 | * Returns the number of byte removed or 0 in case of failure |
| 330 | */ |
| 331 | size_t |
| 332 | xmlBufShrink(xmlBufPtr buf, size_t len) { |
| 333 | if (buf == NULL) return(0); |
| 334 | if (len == 0) return(0); |
| 335 | if (len > buf->use) return(0); |
| 336 | |
| 337 | buf->use -= len; |
| 338 | if ((buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) || |
| 339 | ((buf->alloc == XML_BUFFER_ALLOC_IO) && (buf->contentIO != NULL))) { |
| 340 | /* |
| 341 | * we just move the content pointer, but also make sure |
| 342 | * the perceived buffer size has shrinked accordingly |
| 343 | */ |
| 344 | buf->content += len; |
| 345 | buf->size -= len; |
| 346 | |
| 347 | /* |
| 348 | * sometimes though it maybe be better to really shrink |
| 349 | * on IO buffers |
| 350 | */ |
| 351 | if ((buf->alloc == XML_BUFFER_ALLOC_IO) && (buf->contentIO != NULL)) { |
| 352 | size_t start_buf = buf->content - buf->contentIO; |
| 353 | if (start_buf >= buf->size) { |
| 354 | memmove(buf->contentIO, &buf->content[0], buf->use); |
| 355 | buf->content = buf->contentIO; |
| 356 | buf->content[buf->use] = 0; |
| 357 | buf->size += start_buf; |
| 358 | } |
| 359 | } |
| 360 | } else { |
| 361 | memmove(buf->content, &buf->content[len], buf->use); |
| 362 | buf->content[buf->use] = 0; |
| 363 | } |
| 364 | return(len); |
| 365 | } |
| 366 | |
| 367 | /** |
| 368 | * xmlBufGrowInternal: |
| 369 | * @buf: the buffer |
| 370 | * @len: the minimum free size to allocate |
| 371 | * |
| 372 | * Grow the available space of an XML buffer, @len is the target value |
| 373 | * Error checking should be done on buf->error since using the return |
| 374 | * value doesn't work that well |
| 375 | * |
| 376 | * Returns 0 in case of error or the length made available otherwise |
| 377 | */ |
| 378 | static size_t |
| 379 | xmlBufGrowInternal(xmlBufPtr buf, size_t len) { |
| 380 | size_t size; |
| 381 | xmlChar *newbuf; |
| 382 | |
| 383 | if (buf == NULL) return(0); |
| 384 | |
| 385 | if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return(0); |
| 386 | if (buf->use + len < buf->size) |
| 387 | return(buf->size - buf->use); |
| 388 | |
| 389 | /* |
| 390 | * Windows has a BIG problem on realloc timing, so we try to double |
| 391 | * the buffer size (if that's enough) (bug 146697) |
| 392 | * Apparently BSD too, and it's probably best for linux too |
| 393 | * On an embedded system this may be something to change |
| 394 | */ |
| 395 | #if 1 |
| 396 | if (buf->size > (size_t) len) |
| 397 | size = buf->size * 2; |
| 398 | else |
| 399 | size = buf->use + len + 100; |
| 400 | #else |
| 401 | size = buf->use + len + 100; |
| 402 | #endif |
| 403 | |
| 404 | if ((buf->alloc == XML_BUFFER_ALLOC_IO) && (buf->contentIO != NULL)) { |
| 405 | size_t start_buf = buf->content - buf->contentIO; |
| 406 | |
| 407 | newbuf = (xmlChar *) xmlRealloc(buf->contentIO, start_buf + size); |
| 408 | if (newbuf == NULL) { |
| 409 | xmlBufMemoryError(buf, "growing buffer"); |
| 410 | return(0); |
| 411 | } |
| 412 | buf->contentIO = newbuf; |
| 413 | buf->content = newbuf + start_buf; |
| 414 | } else { |
| 415 | newbuf = (xmlChar *) xmlRealloc(buf->content, size); |
| 416 | if (newbuf == NULL) { |
| 417 | xmlBufMemoryError(buf, "growing buffer"); |
| 418 | return(0); |
| 419 | } |
| 420 | buf->content = newbuf; |
| 421 | } |
| 422 | buf->size = size; |
| 423 | return(buf->size - buf->use); |
| 424 | } |
| 425 | |
| 426 | /** |
| 427 | * xmlBufGrow: |
| 428 | * @buf: the buffer |
| 429 | * @len: the minimum free size to allocate |
| 430 | * |
| 431 | * Grow the available space of an XML buffer, @len is the target value |
| 432 | * This is been kept compatible with xmlBufferGrow() as much as possible |
| 433 | * |
| 434 | * Returns -1 in case of error or the length made available otherwise |
| 435 | */ |
| 436 | int |
| 437 | xmlBufGrow(xmlBufPtr buf, int len) { |
| 438 | size_t ret; |
| 439 | |
| 440 | if ((buf == NULL) || (len < 0)) return(-1); |
| 441 | if (len == 0) |
| 442 | return(0); |
| 443 | ret = xmlBufGrowInternal(buf, len); |
| 444 | if (buf->error != 0) |
| 445 | return(-1); |
| 446 | return((int) ret); |
| 447 | } |
| 448 | |
| 449 | /** |
| 450 | * xmlBufInflate: |
| 451 | * @buf: the buffer |
| 452 | * @len: the minimum extra free size to allocate |
| 453 | * |
| 454 | * Grow the available space of an XML buffer, adding at least @len bytes |
| 455 | * |
| 456 | * Returns 0 if successful or -1 in case of error |
| 457 | */ |
| 458 | int |
| 459 | xmlBufInflate(xmlBufPtr buf, size_t len) { |
| 460 | if (buf == NULL) return(-1); |
| 461 | xmlBufGrowInternal(buf, len + buf->size); |
| 462 | if (buf->error) |
| 463 | return(-1); |
| 464 | return(0); |
| 465 | } |
| 466 | |
| 467 | /** |
| 468 | * xmlBufDump: |
| 469 | * @file: the file output |
| 470 | * @buf: the buffer to dump |
| 471 | * |
| 472 | * Dumps an XML buffer to a FILE *. |
| 473 | * Returns the number of #xmlChar written |
| 474 | */ |
| 475 | size_t |
| 476 | xmlBufDump(FILE *file, xmlBufPtr buf) { |
| 477 | size_t ret; |
| 478 | |
| 479 | if (buf == NULL) { |
| 480 | #ifdef DEBUG_BUFFER |
| 481 | xmlGenericError(xmlGenericErrorContext, |
| 482 | "xmlBufDump: buf == NULL\n"); |
| 483 | #endif |
| 484 | return(0); |
| 485 | } |
| 486 | if (buf->content == NULL) { |
| 487 | #ifdef DEBUG_BUFFER |
| 488 | xmlGenericError(xmlGenericErrorContext, |
| 489 | "xmlBufDump: buf->content == NULL\n"); |
| 490 | #endif |
| 491 | return(0); |
| 492 | } |
| 493 | if (file == NULL) |
| 494 | file = stdout; |
| 495 | ret = fwrite(buf->content, sizeof(xmlChar), buf->use, file); |
| 496 | return(ret); |
| 497 | } |
| 498 | |
| 499 | /** |
| 500 | * xmlBufContent: |
| 501 | * @buf: the buffer |
| 502 | * |
| 503 | * Function to extract the content of a buffer |
| 504 | * |
| 505 | * Returns the internal content |
| 506 | */ |
| 507 | |
| 508 | xmlChar * |
| 509 | xmlBufContent(const xmlBufPtr buf) |
| 510 | { |
| 511 | if(!buf) |
| 512 | return NULL; |
| 513 | |
| 514 | return(buf->content); |
| 515 | } |
| 516 | |
| 517 | /** |
| 518 | * xmlBufEnd: |
| 519 | * @buf: the buffer |
| 520 | * |
| 521 | * Function to extract the end of the content of a buffer |
| 522 | * |
| 523 | * Returns the end of the internal content or NULL in case of error |
| 524 | */ |
| 525 | |
| 526 | xmlChar * |
| 527 | xmlBufEnd(const xmlBufPtr buf) |
| 528 | { |
| 529 | if(!buf) |
| 530 | return NULL; |
| 531 | |
| 532 | return(&buf->content[buf->use]); |
| 533 | } |
| 534 | |
| 535 | /** |
| 536 | * xmlBufAddLen: |
| 537 | * @buf: the buffer |
| 538 | * @len: the size which were added at the end |
| 539 | * |
| 540 | * Sometime data may be added at the end of the buffer without |
| 541 | * using the xmlBuf APIs that is used to expand the used space |
| 542 | * and set the zero terminating at the end of the buffer |
| 543 | * |
| 544 | * Returns -1 in case of error and 0 otherwise |
| 545 | */ |
| 546 | int |
| 547 | xmlBufAddLen(xmlBufPtr buf, size_t len) { |
| 548 | if ((buf == NULL) || (len > (buf->size - buf->use))) |
| 549 | return(-1); |
| 550 | buf->use += len; |
| 551 | if (buf->size > buf->use) |
| 552 | buf->content[buf->use] = 0; |
| 553 | else |
| 554 | return(-1); |
| 555 | return(0); |
| 556 | } |
| 557 | |
| 558 | /** |
| 559 | * xmlBufErase: |
| 560 | * @buf: the buffer |
| 561 | * @len: the size to erase at the end |
| 562 | * |
| 563 | * Sometime data need to be erased at the end of the buffer |
| 564 | * |
| 565 | * Returns -1 in case of error and 0 otherwise |
| 566 | */ |
| 567 | int |
| 568 | xmlBufErase(xmlBufPtr buf, size_t len) { |
| 569 | if ((buf == NULL) || (len > buf->use)) |
| 570 | return(-1); |
| 571 | buf->use -= len; |
| 572 | buf->content[buf->use] = 0; |
| 573 | return(0); |
| 574 | } |
| 575 | |
| 576 | /** |
| 577 | * xmlBufLength: |
| 578 | * @buf: the buffer |
| 579 | * |
| 580 | * Function to get the length of a buffer |
| 581 | * |
| 582 | * Returns the length of data in the internal content |
| 583 | */ |
| 584 | |
| 585 | size_t |
| 586 | xmlBufLength(const xmlBufPtr buf) |
| 587 | { |
| 588 | if (!buf) |
| 589 | return 0; |
| 590 | |
| 591 | return(buf->use); |
| 592 | } |
| 593 | |
| 594 | /** |
| 595 | * xmlBufUse: |
| 596 | * @buf: the buffer |
| 597 | * |
| 598 | * Function to get the length of a buffer |
| 599 | * |
| 600 | * Returns the length of data in the internal content |
| 601 | */ |
| 602 | |
| 603 | size_t |
| 604 | xmlBufUse(const xmlBufPtr buf) |
| 605 | { |
| 606 | if (!buf) |
| 607 | return 0; |
| 608 | |
| 609 | return(buf->use); |
| 610 | } |
| 611 | |
| 612 | /** |
| 613 | * xmlBufAvail: |
| 614 | * @buf: the buffer |
| 615 | * |
| 616 | * Function to find how much free space is allocated but not |
| 617 | * used in the buffer. It does not account for the terminating zero |
| 618 | * usually needed |
| 619 | * |
| 620 | * Returns the amount or 0 if none or an error occured |
| 621 | */ |
| 622 | |
| 623 | size_t |
| 624 | xmlBufAvail(const xmlBufPtr buf) |
| 625 | { |
| 626 | if (!buf) |
| 627 | return 0; |
| 628 | |
| 629 | return(buf->size - buf->use); |
| 630 | } |
| 631 | |
| 632 | /** |
| 633 | * xmlBufIsEmpty: |
| 634 | * @buf: the buffer |
| 635 | * |
| 636 | * Tell if a buffer is empty |
| 637 | * |
| 638 | * Returns 0 if no, 1 if yes and -1 in case of error |
| 639 | */ |
| 640 | int |
| 641 | xmlBufIsEmpty(const xmlBufPtr buf) |
| 642 | { |
| 643 | if(!buf) |
| 644 | return(-1); |
| 645 | |
| 646 | return(buf->use == 0); |
| 647 | } |
| 648 | |
| 649 | /** |
| 650 | * xmlBufResize: |
| 651 | * @buf: the buffer to resize |
| 652 | * @size: the desired size |
| 653 | * |
| 654 | * Resize a buffer to accommodate minimum size of @size. |
| 655 | * |
| 656 | * Returns 0 in case of problems, 1 otherwise |
| 657 | */ |
| 658 | int |
| 659 | xmlBufResize(xmlBufPtr buf, size_t size) |
| 660 | { |
| 661 | unsigned int newSize; |
| 662 | xmlChar* rebuf = NULL; |
| 663 | size_t start_buf; |
| 664 | |
| 665 | if (buf == NULL) |
| 666 | return(0); |
| 667 | |
| 668 | if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return(0); |
| 669 | |
| 670 | /* Don't resize if we don't have to */ |
| 671 | if (size < buf->size) |
| 672 | return 1; |
| 673 | |
| 674 | /* figure out new size */ |
| 675 | switch (buf->alloc){ |
| 676 | case XML_BUFFER_ALLOC_IO: |
| 677 | case XML_BUFFER_ALLOC_DOUBLEIT: |
| 678 | /*take care of empty case*/ |
| 679 | newSize = (buf->size ? buf->size*2 : size + 10); |
| 680 | while (size > newSize) { |
| 681 | if (newSize > UINT_MAX / 2) { |
| 682 | xmlBufMemoryError(buf, "growing buffer"); |
| 683 | return 0; |
| 684 | } |
| 685 | newSize *= 2; |
| 686 | } |
| 687 | break; |
| 688 | case XML_BUFFER_ALLOC_EXACT: |
| 689 | newSize = size+10; |
| 690 | break; |
| 691 | case XML_BUFFER_ALLOC_HYBRID: |
| 692 | if (buf->use < BASE_BUFFER_SIZE) |
| 693 | newSize = size; |
| 694 | else { |
| 695 | newSize = buf->size * 2; |
| 696 | while (size > newSize) { |
| 697 | if (newSize > UINT_MAX / 2) { |
| 698 | xmlBufMemoryError(buf, "growing buffer"); |
| 699 | return 0; |
| 700 | } |
| 701 | newSize *= 2; |
| 702 | } |
| 703 | } |
| 704 | break; |
| 705 | |
| 706 | default: |
| 707 | newSize = size+10; |
| 708 | break; |
| 709 | } |
| 710 | |
| 711 | if ((buf->alloc == XML_BUFFER_ALLOC_IO) && (buf->contentIO != NULL)) { |
| 712 | start_buf = buf->content - buf->contentIO; |
| 713 | |
| 714 | if (start_buf > newSize) { |
| 715 | /* move data back to start */ |
| 716 | memmove(buf->contentIO, buf->content, buf->use); |
| 717 | buf->content = buf->contentIO; |
| 718 | buf->content[buf->use] = 0; |
| 719 | buf->size += start_buf; |
| 720 | } else { |
| 721 | rebuf = (xmlChar *) xmlRealloc(buf->contentIO, start_buf + newSize); |
| 722 | if (rebuf == NULL) { |
| 723 | xmlBufMemoryError(buf, "growing buffer"); |
| 724 | return 0; |
| 725 | } |
| 726 | buf->contentIO = rebuf; |
| 727 | buf->content = rebuf + start_buf; |
| 728 | } |
| 729 | } else { |
| 730 | if (buf->content == NULL) { |
| 731 | rebuf = (xmlChar *) xmlMallocAtomic(newSize); |
| 732 | } else if (buf->size - buf->use < 100) { |
| 733 | rebuf = (xmlChar *) xmlRealloc(buf->content, newSize); |
| 734 | } else { |
| 735 | /* |
| 736 | * if we are reallocating a buffer far from being full, it's |
| 737 | * better to make a new allocation and copy only the used range |
| 738 | * and free the old one. |
| 739 | */ |
| 740 | rebuf = (xmlChar *) xmlMallocAtomic(newSize); |
| 741 | if (rebuf != NULL) { |
| 742 | memcpy(rebuf, buf->content, buf->use); |
| 743 | xmlFree(buf->content); |
| 744 | rebuf[buf->use] = 0; |
| 745 | } |
| 746 | } |
| 747 | if (rebuf == NULL) { |
| 748 | xmlBufMemoryError(buf, "growing buffer"); |
| 749 | return 0; |
| 750 | } |
| 751 | buf->content = rebuf; |
| 752 | } |
| 753 | buf->size = newSize; |
| 754 | |
| 755 | return 1; |
| 756 | } |
| 757 | |
| 758 | /** |
| 759 | * xmlBufAdd: |
| 760 | * @buf: the buffer to dump |
| 761 | * @str: the #xmlChar string |
| 762 | * @len: the number of #xmlChar to add |
| 763 | * |
| 764 | * Add a string range to an XML buffer. if len == -1, the length of |
| 765 | * str is recomputed. |
| 766 | * |
| 767 | * Returns 0 successful, a positive error code number otherwise |
| 768 | * and -1 in case of internal or API error. |
| 769 | */ |
| 770 | int |
| 771 | xmlBufAdd(xmlBufPtr buf, const xmlChar *str, int len) { |
| 772 | unsigned int needSize; |
| 773 | |
| 774 | if ((str == NULL) || (buf == NULL)) { |
| 775 | return -1; |
| 776 | } |
| 777 | if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return -1; |
| 778 | if (len < -1) { |
| 779 | #ifdef DEBUG_BUFFER |
| 780 | xmlGenericError(xmlGenericErrorContext, |
| 781 | "xmlBufAdd: len < 0\n"); |
| 782 | #endif |
| 783 | return -1; |
| 784 | } |
| 785 | if (len == 0) return 0; |
| 786 | |
| 787 | if (len < 0) |
| 788 | len = xmlStrlen(str); |
| 789 | |
| 790 | if (len < 0) return -1; |
| 791 | if (len == 0) return 0; |
| 792 | |
| 793 | needSize = buf->use + len + 2; |
| 794 | if (needSize > buf->size){ |
| 795 | if (!xmlBufResize(buf, needSize)){ |
| 796 | xmlBufMemoryError(buf, "growing buffer"); |
| 797 | return XML_ERR_NO_MEMORY; |
| 798 | } |
| 799 | } |
| 800 | |
| 801 | memmove(&buf->content[buf->use], str, len*sizeof(xmlChar)); |
| 802 | buf->use += len; |
| 803 | buf->content[buf->use] = 0; |
| 804 | return 0; |
| 805 | } |
| 806 | |
| 807 | /** |
| 808 | * xmlBufAddHead: |
| 809 | * @buf: the buffer |
| 810 | * @str: the #xmlChar string |
| 811 | * @len: the number of #xmlChar to add |
| 812 | * |
| 813 | * Add a string range to the beginning of an XML buffer. |
| 814 | * if len == -1, the length of @str is recomputed. |
| 815 | * |
| 816 | * Returns 0 successful, a positive error code number otherwise |
| 817 | * and -1 in case of internal or API error. |
| 818 | */ |
| 819 | int |
| 820 | xmlBufAddHead(xmlBufPtr buf, const xmlChar *str, int len) { |
| 821 | unsigned int needSize; |
| 822 | |
| 823 | if (buf == NULL) |
| 824 | return(-1); |
| 825 | if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return -1; |
| 826 | if (str == NULL) { |
| 827 | #ifdef DEBUG_BUFFER |
| 828 | xmlGenericError(xmlGenericErrorContext, |
| 829 | "xmlBufAddHead: str == NULL\n"); |
| 830 | #endif |
| 831 | return -1; |
| 832 | } |
| 833 | if (len < -1) { |
| 834 | #ifdef DEBUG_BUFFER |
| 835 | xmlGenericError(xmlGenericErrorContext, |
| 836 | "xmlBufAddHead: len < 0\n"); |
| 837 | #endif |
| 838 | return -1; |
| 839 | } |
| 840 | if (len == 0) return 0; |
| 841 | |
| 842 | if (len < 0) |
| 843 | len = xmlStrlen(str); |
| 844 | |
| 845 | if (len <= 0) return -1; |
| 846 | |
| 847 | if ((buf->alloc == XML_BUFFER_ALLOC_IO) && (buf->contentIO != NULL)) { |
| 848 | size_t start_buf = buf->content - buf->contentIO; |
| 849 | |
| 850 | if (start_buf > (unsigned int) len) { |
| 851 | /* |
| 852 | * We can add it in the space previously shrinked |
| 853 | */ |
| 854 | buf->content -= len; |
| 855 | memmove(&buf->content[0], str, len); |
| 856 | buf->use += len; |
| 857 | buf->size += len; |
| 858 | return(0); |
| 859 | } |
| 860 | } |
| 861 | needSize = buf->use + len + 2; |
| 862 | if (needSize > buf->size){ |
| 863 | if (!xmlBufResize(buf, needSize)){ |
| 864 | xmlBufMemoryError(buf, "growing buffer"); |
| 865 | return XML_ERR_NO_MEMORY; |
| 866 | } |
| 867 | } |
| 868 | |
| 869 | memmove(&buf->content[len], &buf->content[0], buf->use); |
| 870 | memmove(&buf->content[0], str, len); |
| 871 | buf->use += len; |
| 872 | buf->content[buf->use] = 0; |
| 873 | return 0; |
| 874 | } |
| 875 | |
| 876 | /** |
| 877 | * xmlBufCat: |
| 878 | * @buf: the buffer to add to |
| 879 | * @str: the #xmlChar string |
| 880 | * |
| 881 | * Append a zero terminated string to an XML buffer. |
| 882 | * |
| 883 | * Returns 0 successful, a positive error code number otherwise |
| 884 | * and -1 in case of internal or API error. |
| 885 | */ |
| 886 | int |
| 887 | xmlBufCat(xmlBufPtr buf, const xmlChar *str) { |
| 888 | if (buf == NULL) |
| 889 | return(-1); |
| 890 | if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return -1; |
| 891 | if (str == NULL) return -1; |
| 892 | return xmlBufAdd(buf, str, -1); |
| 893 | } |
| 894 | |
| 895 | /** |
| 896 | * xmlBufCCat: |
| 897 | * @buf: the buffer to dump |
| 898 | * @str: the C char string |
| 899 | * |
| 900 | * Append a zero terminated C string to an XML buffer. |
| 901 | * |
| 902 | * Returns 0 successful, a positive error code number otherwise |
| 903 | * and -1 in case of internal or API error. |
| 904 | */ |
| 905 | int |
| 906 | xmlBufCCat(xmlBufPtr buf, const char *str) { |
| 907 | const char *cur; |
| 908 | |
| 909 | if (buf == NULL) |
| 910 | return(-1); |
| 911 | if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return -1; |
| 912 | if (str == NULL) { |
| 913 | #ifdef DEBUG_BUFFER |
| 914 | xmlGenericError(xmlGenericErrorContext, |
| 915 | "xmlBufCCat: str == NULL\n"); |
| 916 | #endif |
| 917 | return -1; |
| 918 | } |
| 919 | for (cur = str;*cur != 0;cur++) { |
| 920 | if (buf->use + 10 >= buf->size) { |
| 921 | if (!xmlBufResize(buf, buf->use+10)){ |
| 922 | xmlBufMemoryError(buf, "growing buffer"); |
| 923 | return XML_ERR_NO_MEMORY; |
| 924 | } |
| 925 | } |
| 926 | buf->content[buf->use++] = *cur; |
| 927 | } |
| 928 | buf->content[buf->use] = 0; |
| 929 | return 0; |
| 930 | } |
| 931 | |
| 932 | /** |
| 933 | * xmlBufWriteCHAR: |
| 934 | * @buf: the XML buffer |
| 935 | * @string: the string to add |
| 936 | * |
| 937 | * routine which manages and grows an output buffer. This one adds |
| 938 | * xmlChars at the end of the buffer. |
| 939 | * |
| 940 | * Returns 0 if successful, a positive error code number otherwise |
| 941 | * and -1 in case of internal or API error. |
| 942 | */ |
| 943 | int |
| 944 | xmlBufWriteCHAR(xmlBufPtr buf, const xmlChar *string) { |
| 945 | if (buf == NULL) |
| 946 | return(-1); |
| 947 | if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) |
| 948 | return(-1); |
| 949 | return(xmlBufCat(buf, string)); |
| 950 | } |
| 951 | |
| 952 | /** |
| 953 | * xmlBufWriteChar: |
| 954 | * @buf: the XML buffer output |
| 955 | * @string: the string to add |
| 956 | * |
| 957 | * routine which manage and grows an output buffer. This one add |
| 958 | * C chars at the end of the array. |
| 959 | * |
| 960 | * Returns 0 if successful, a positive error code number otherwise |
| 961 | * and -1 in case of internal or API error. |
| 962 | */ |
| 963 | int |
| 964 | xmlBufWriteChar(xmlBufPtr buf, const char *string) { |
| 965 | if (buf == NULL) |
| 966 | return(-1); |
| 967 | if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) |
| 968 | return(-1); |
| 969 | return(xmlBufCCat(buf, string)); |
| 970 | } |
| 971 | |
| 972 | |
| 973 | /** |
| 974 | * xmlBufWriteQuotedString: |
| 975 | * @buf: the XML buffer output |
| 976 | * @string: the string to add |
| 977 | * |
| 978 | * routine which manage and grows an output buffer. This one writes |
| 979 | * a quoted or double quoted #xmlChar string, checking first if it holds |
| 980 | * quote or double-quotes internally |
| 981 | * |
| 982 | * Returns 0 if successful, a positive error code number otherwise |
| 983 | * and -1 in case of internal or API error. |
| 984 | */ |
| 985 | int |
| 986 | xmlBufWriteQuotedString(xmlBufPtr buf, const xmlChar *string) { |
| 987 | const xmlChar *cur, *base; |
| 988 | if (buf == NULL) |
| 989 | return(-1); |
| 990 | if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) |
| 991 | return(-1); |
| 992 | if (xmlStrchr(string, '\"')) { |
| 993 | if (xmlStrchr(string, '\'')) { |
| 994 | #ifdef DEBUG_BUFFER |
| 995 | xmlGenericError(xmlGenericErrorContext, |
| 996 | "xmlBufWriteQuotedString: string contains quote and double-quotes !\n"); |
| 997 | #endif |
| 998 | xmlBufCCat(buf, "\""); |
| 999 | base = cur = string; |
| 1000 | while(*cur != 0){ |
| 1001 | if(*cur == '"'){ |
| 1002 | if (base != cur) |
| 1003 | xmlBufAdd(buf, base, cur - base); |
| 1004 | xmlBufAdd(buf, BAD_CAST """, 6); |
| 1005 | cur++; |
| 1006 | base = cur; |
| 1007 | } |
| 1008 | else { |
| 1009 | cur++; |
| 1010 | } |
| 1011 | } |
| 1012 | if (base != cur) |
| 1013 | xmlBufAdd(buf, base, cur - base); |
| 1014 | xmlBufCCat(buf, "\""); |
| 1015 | } |
| 1016 | else{ |
| 1017 | xmlBufCCat(buf, "\'"); |
| 1018 | xmlBufCat(buf, string); |
| 1019 | xmlBufCCat(buf, "\'"); |
| 1020 | } |
| 1021 | } else { |
| 1022 | xmlBufCCat(buf, "\""); |
| 1023 | xmlBufCat(buf, string); |
| 1024 | xmlBufCCat(buf, "\""); |
| 1025 | } |
| 1026 | return(0); |
| 1027 | } |
| 1028 | |
| 1029 | /** |
| 1030 | * xmlBufFromBuffer: |
| 1031 | * @buffer: incoming old buffer to convert to a new one |
| 1032 | * |
| 1033 | * Helper routine to switch from the old buffer structures in use |
| 1034 | * in various APIs. It creates a wrapper xmlBufPtr which will be |
| 1035 | * used for internal processing until the xmlBufBackToBuffer() is |
| 1036 | * issued. |
| 1037 | * |
| 1038 | * Returns a new xmlBufPtr unless the call failed and NULL is returned |
| 1039 | */ |
| 1040 | xmlBufPtr |
| 1041 | xmlBufFromBuffer(xmlBufferPtr buffer) { |
| 1042 | xmlBufPtr ret; |
| 1043 | |
| 1044 | if (buffer == NULL) |
| 1045 | return(NULL); |
| 1046 | |
| 1047 | ret = (xmlBufPtr) xmlMalloc(sizeof(xmlBuf)); |
| 1048 | if (ret == NULL) { |
| 1049 | xmlBufMemoryError(NULL, "creating buffer"); |
| 1050 | return(NULL); |
| 1051 | } |
| 1052 | ret->use = buffer->use; |
| 1053 | ret->size = buffer->size; |
| 1054 | ret->error = 0; |
| 1055 | ret->buffer = buffer; |
| 1056 | ret->alloc = buffer->alloc; |
| 1057 | ret->content = buffer->content; |
| 1058 | ret->contentIO = buffer->contentIO; |
| 1059 | |
| 1060 | return(ret); |
| 1061 | } |
| 1062 | |
| 1063 | /** |
| 1064 | * xmlBufBackToBuffer: |
| 1065 | * @buf: new buffer wrapping the old one |
| 1066 | * |
| 1067 | * Function to be called once internal processing had been done to |
| 1068 | * update back the buffer provided by the user. This can lead to |
| 1069 | * a failure in case the size accumulated in the xmlBuf is larger |
| 1070 | * than what an xmlBuffer can support on 64 bits (INT_MAX) |
| 1071 | * The xmlBufPtr @buf wrapper is deallocated by this call in any case. |
| 1072 | * |
| 1073 | * Returns the old xmlBufferPtr unless the call failed and NULL is returned |
| 1074 | */ |
| 1075 | xmlBufferPtr |
| 1076 | xmlBufBackToBuffer(xmlBufPtr buf) { |
| 1077 | xmlBufferPtr ret; |
| 1078 | |
| 1079 | if (buf == NULL) |
| 1080 | return(NULL); |
| 1081 | if (buf->buffer == NULL) { |
| 1082 | xmlBufFree(buf); |
| 1083 | return(NULL); |
| 1084 | } |
| 1085 | |
| 1086 | ret = buf->buffer; |
| 1087 | /* |
| 1088 | * What to do in case of error in the buffer ??? |
| 1089 | */ |
| 1090 | if (buf->use > INT_MAX) { |
| 1091 | /* |
| 1092 | * Worse case, we really allocated and used more than the |
| 1093 | * maximum allowed memory for an xmlBuffer on this architecture. |
| 1094 | * Keep the buffer but provide a truncated size value. |
| 1095 | */ |
| 1096 | xmlBufOverflowError(buf, "Used size too big for xmlBuffer"); |
| 1097 | ret->use = INT_MAX; |
| 1098 | ret->size = INT_MAX; |
| 1099 | } else if (buf->size > INT_MAX) { |
| 1100 | /* |
| 1101 | * milder case, we allocated more than the maximum allowed memory |
| 1102 | * for an xmlBuffer on this architecture, but used less than the |
| 1103 | * limit. |
| 1104 | * Keep the buffer but provide a truncated size value. |
| 1105 | */ |
| 1106 | xmlBufOverflowError(buf, "Allocated size too big for xmlBuffer"); |
| 1107 | ret->size = INT_MAX; |
| 1108 | } |
| 1109 | ret->use = (int) buf->use; |
| 1110 | ret->size = (int) buf->size; |
| 1111 | ret->alloc = buf->alloc; |
| 1112 | ret->content = buf->content; |
| 1113 | ret->contentIO = buf->contentIO; |
| 1114 | xmlFree(buf); |
| 1115 | return(ret); |
| 1116 | } |
| 1117 | |
| 1118 | /** |
| 1119 | * xmlBufMergeBuffer: |
| 1120 | * @buf: an xmlBufPtr |
| 1121 | * @buffer: the buffer to consume into @buf |
| 1122 | * |
| 1123 | * The content of @buffer is appended to @buf and @buffer is freed |
| 1124 | * |
| 1125 | * Returns -1 in case of error, 0 otherwise, in any case @buffer is freed |
| 1126 | */ |
| 1127 | int |
| 1128 | xmlBufMergeBuffer(xmlBufPtr buf, xmlBufferPtr buffer) { |
| 1129 | int ret; |
| 1130 | |
| 1131 | if (buffer == NULL) |
| 1132 | return(0); |
| 1133 | if ((buf != NULL) && (buffer->content != NULL) && (buffer->use > 0)) { |
| 1134 | ret = xmlBufAdd(buf, buffer->content, buffer->use); |
| 1135 | } |
| 1136 | xmlBufferFree(buffer); |
| 1137 | return(ret); |
| 1138 | } |