1 /*
2 * buf.c: memory buffers for libxml2
3 *
4 * new buffer structures and entry points to simplify the maintenance
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 #include <ctype.h>
21 #include <stdlib.h>
22
23 #include <libxml/tree.h>
24 #include <libxml/parserInternals.h> /* for XML_MAX_TEXT_LENGTH */
25
26 #include "private/buf.h"
27 #include "private/error.h"
28
29 #ifndef SIZE_MAX
30 #define SIZE_MAX ((size_t) -1)
31 #endif
32
33 #define WITH_BUFFER_COMPAT
34
35 /**
36 * xmlBuf:
37 *
38 * A buffer structure. The base of the structure is somehow compatible
39 * with struct _xmlBuffer to limit risks on application which accessed
40 * directly the input->buf->buffer structures.
41 */
42
43 struct _xmlBuf {
44 xmlChar *content; /* The buffer content UTF8 */
45 unsigned int compat_use; /* for binary compatibility */
46 unsigned int compat_size; /* for binary compatibility */
47 xmlBufferAllocationScheme alloc; /* The realloc method */
48 xmlChar *contentIO; /* in IO mode we may have a different base */
49 size_t use; /* The buffer size used */
50 size_t size; /* The buffer size */
51 xmlBufferPtr buffer; /* wrapper for an old buffer */
52 int error; /* an error code if a failure occurred */
53 };
54
55 #ifdef WITH_BUFFER_COMPAT
56 /*
57 * Macro for compatibility with xmlBuffer to be used after an xmlBuf
58 * is updated. This makes sure the compat fields are updated too.
59 */
60 #define UPDATE_COMPAT(buf) \
61 if (buf->size < INT_MAX) buf->compat_size = buf->size; \
62 else buf->compat_size = INT_MAX; \
63 if (buf->use < INT_MAX) buf->compat_use = buf->use; \
64 else buf->compat_use = INT_MAX;
65
66 /*
67 * Macro for compatibility with xmlBuffer to be used in all the xmlBuf
68 * entry points, it checks that the compat fields have not been modified
69 * by direct call to xmlBuffer function from code compiled before 2.9.0 .
70 */
71 #define CHECK_COMPAT(buf) \
72 if (buf->size != (size_t) buf->compat_size) \
73 if (buf->compat_size < INT_MAX) \
74 buf->size = buf->compat_size; \
75 if (buf->use != (size_t) buf->compat_use) \
76 if (buf->compat_use < INT_MAX) \
77 buf->use = buf->compat_use;
78
79 #else /* ! WITH_BUFFER_COMPAT */
80 #define UPDATE_COMPAT(buf)
81 #define CHECK_COMPAT(buf)
82 #endif /* WITH_BUFFER_COMPAT */
83
84 /**
85 * xmlBufMemoryError:
86 * @extra: extra information
87 *
88 * Handle an out of memory condition
89 * To be improved...
90 */
91 static void
92 xmlBufMemoryError(xmlBufPtr buf, const char *extra)
93 {
94 __xmlSimpleError(XML_FROM_BUFFER, XML_ERR_NO_MEMORY, NULL, NULL, extra);
95 if ((buf) && (buf->error == 0))
96 buf->error = XML_ERR_NO_MEMORY;
97 }
98
99 /**
100 * xmlBufOverflowError:
101 * @extra: extra information
102 *
103 * Handle a buffer overflow error
104 * To be improved...
105 */
106 static void
107 xmlBufOverflowError(xmlBufPtr buf, const char *extra)
108 {
109 __xmlSimpleError(XML_FROM_BUFFER, XML_BUF_OVERFLOW, NULL, NULL, extra);
110 if ((buf) && (buf->error == 0))
111 buf->error = XML_BUF_OVERFLOW;
112 }
113
114
115 /**
116 * xmlBufCreate:
117 *
118 * routine to create an XML buffer.
119 * returns the new structure.
120 */
121 xmlBufPtr
122 xmlBufCreate(void) {
123 xmlBufPtr ret;
124
125 ret = (xmlBufPtr) xmlMalloc(sizeof(xmlBuf));
126 if (ret == NULL) {
127 xmlBufMemoryError(NULL, "creating buffer");
128 return(NULL);
129 }
130 ret->use = 0;
131 ret->error = 0;
132 ret->buffer = NULL;
133 ret->size = xmlDefaultBufferSize;
134 UPDATE_COMPAT(ret);
135 ret->alloc = xmlBufferAllocScheme;
136 ret->content = (xmlChar *) xmlMallocAtomic(ret->size);
137 if (ret->content == NULL) {
138 xmlBufMemoryError(ret, "creating buffer");
139 xmlFree(ret);
140 return(NULL);
141 }
142 ret->content[0] = 0;
143 ret->contentIO = NULL;
144 return(ret);
145 }
146
147 /**
148 * xmlBufCreateSize:
149 * @size: initial size of buffer
150 *
151 * routine to create an XML buffer.
152 * returns the new structure.
153 */
154 xmlBufPtr
155 xmlBufCreateSize(size_t size) {
156 xmlBufPtr ret;
157
158 if (size == SIZE_MAX)
159 return(NULL);
160 ret = (xmlBufPtr) xmlMalloc(sizeof(xmlBuf));
161 if (ret == NULL) {
162 xmlBufMemoryError(NULL, "creating buffer");
163 return(NULL);
164 }
165 ret->use = 0;
166 ret->error = 0;
167 ret->buffer = NULL;
168 ret->alloc = xmlBufferAllocScheme;
169 ret->size = (size ? size + 1 : 0); /* +1 for ending null */
170 UPDATE_COMPAT(ret);
171 if (ret->size){
172 ret->content = (xmlChar *) xmlMallocAtomic(ret->size);
173 if (ret->content == NULL) {
174 xmlBufMemoryError(ret, "creating buffer");
175 xmlFree(ret);
176 return(NULL);
177 }
178 ret->content[0] = 0;
179 } else
180 ret->content = NULL;
181 ret->contentIO = NULL;
182 return(ret);
183 }
184
185 /**
186 * xmlBufDetach:
187 * @buf: the buffer
188 *
189 * Remove the string contained in a buffer and give it back to the
190 * caller. The buffer is reset to an empty content.
191 * This doesn't work with immutable buffers as they can't be reset.
192 *
193 * Returns the previous string contained by the buffer.
194 */
195 xmlChar *
196 xmlBufDetach(xmlBufPtr buf) {
197 xmlChar *ret;
198
199 if (buf == NULL)
200 return(NULL);
201 if (buf->buffer != NULL)
202 return(NULL);
203 if (buf->error)
204 return(NULL);
205
206 ret = buf->content;
207 buf->content = NULL;
208 buf->size = 0;
209 buf->use = 0;
210 UPDATE_COMPAT(buf);
211
212 return ret;
213 }
214
215 /**
216 * xmlBufGetAllocationScheme:
217 * @buf: the buffer
218 *
219 * Get the buffer allocation scheme
220 *
221 * Returns the scheme or -1 in case of error
222 */
223 int
224 xmlBufGetAllocationScheme(xmlBufPtr buf) {
225 if (buf == NULL) {
226 return(-1);
227 }
228 return(buf->alloc);
229 }
230
231 /**
232 * xmlBufSetAllocationScheme:
233 * @buf: the buffer to tune
234 * @scheme: allocation scheme to use
235 *
236 * Sets the allocation scheme for this buffer
237 *
238 * returns 0 in case of success and -1 in case of failure
239 */
240 int
241 xmlBufSetAllocationScheme(xmlBufPtr buf,
242 xmlBufferAllocationScheme scheme) {
243 if ((buf == NULL) || (buf->error != 0)) {
244 return(-1);
245 }
246 if (buf->alloc == XML_BUFFER_ALLOC_IO)
247 return(-1);
248 if ((scheme == XML_BUFFER_ALLOC_DOUBLEIT) ||
249 (scheme == XML_BUFFER_ALLOC_EXACT) ||
250 (scheme == XML_BUFFER_ALLOC_HYBRID) ||
251 (scheme == XML_BUFFER_ALLOC_BOUNDED)) {
252 buf->alloc = scheme;
253 if (buf->buffer)
254 buf->buffer->alloc = scheme;
255 return(0);
256 }
257 /*
258 * Switching a buffer ALLOC_IO has the side effect of initializing
259 * the contentIO field with the current content
260 */
261 if (scheme == XML_BUFFER_ALLOC_IO) {
262 buf->alloc = XML_BUFFER_ALLOC_IO;
263 buf->contentIO = buf->content;
264 }
265 return(-1);
266 }
267
268 /**
269 * xmlBufFree:
270 * @buf: the buffer to free
271 *
272 * Frees an XML buffer. It frees both the content and the structure which
273 * encapsulate it.
274 */
275 void
276 xmlBufFree(xmlBufPtr buf) {
277 if (buf == NULL) {
278 return;
279 }
280
281 if ((buf->alloc == XML_BUFFER_ALLOC_IO) &&
282 (buf->contentIO != NULL)) {
283 xmlFree(buf->contentIO);
284 } else if (buf->content != NULL) {
285 xmlFree(buf->content);
286 }
287 xmlFree(buf);
288 }
289
290 /**
291 * xmlBufEmpty:
292 * @buf: the buffer
293 *
294 * empty a buffer.
295 */
296 void
297 xmlBufEmpty(xmlBufPtr buf) {
298 if ((buf == NULL) || (buf->error != 0)) return;
299 if (buf->content == NULL) return;
300 CHECK_COMPAT(buf)
301 buf->use = 0;
302 if ((buf->alloc == XML_BUFFER_ALLOC_IO) &&
303 (buf->contentIO != NULL)) {
304 size_t start_buf = buf->content - buf->contentIO;
305
306 buf->size += start_buf;
307 buf->content = buf->contentIO;
308 buf->content[0] = 0;
309 } else {
310 buf->content[0] = 0;
311 }
312 UPDATE_COMPAT(buf)
313 }
314
315 /**
316 * xmlBufShrink:
317 * @buf: the buffer to dump
318 * @len: the number of xmlChar to remove
319 *
320 * Remove the beginning of an XML buffer.
321 * NOTE that this routine behaviour differs from xmlBufferShrink()
322 * as it will return 0 on error instead of -1 due to size_t being
323 * used as the return type.
324 *
325 * Returns the number of byte removed or 0 in case of failure
326 */
327 size_t
328 xmlBufShrink(xmlBufPtr buf, size_t len) {
329 if ((buf == NULL) || (buf->error != 0)) return(0);
330 CHECK_COMPAT(buf)
331 if (len == 0) return(0);
332 if (len > buf->use) return(0);
333
334 buf->use -= len;
335 if ((buf->alloc == XML_BUFFER_ALLOC_IO) && (buf->contentIO != NULL)) {
336 /*
337 * we just move the content pointer, but also make sure
338 * the perceived buffer size has shrunk accordingly
339 */
340 buf->content += len;
341 buf->size -= len;
342
343 /*
344 * sometimes though it maybe be better to really shrink
345 * on IO buffers
346 */
347 if ((buf->alloc == XML_BUFFER_ALLOC_IO) && (buf->contentIO != NULL)) {
348 size_t start_buf = buf->content - buf->contentIO;
349 if (start_buf >= buf->size) {
350 memmove(buf->contentIO, &buf->content[0], buf->use);
351 buf->content = buf->contentIO;
352 buf->content[buf->use] = 0;
353 buf->size += start_buf;
354 }
355 }
356 } else {
357 memmove(buf->content, &buf->content[len], buf->use);
358 buf->content[buf->use] = 0;
359 }
360 UPDATE_COMPAT(buf)
361 return(len);
362 }
363
364 /**
365 * xmlBufGrowInternal:
366 * @buf: the buffer
367 * @len: the minimum free size to allocate
368 *
369 * Grow the available space of an XML buffer, @len is the target value
370 * Error checking should be done on buf->error since using the return
371 * value doesn't work that well
372 *
373 * Returns 0 in case of error or the length made available otherwise
374 */
375 static size_t
376 xmlBufGrowInternal(xmlBufPtr buf, size_t len) {
377 size_t size;
378 xmlChar *newbuf;
379
380 if ((buf == NULL) || (buf->error != 0)) return(0);
381 CHECK_COMPAT(buf)
382
383 if (len < buf->size - buf->use)
384 return(buf->size - buf->use - 1);
385 if (len >= SIZE_MAX - buf->use) {
386 xmlBufMemoryError(buf, "growing buffer past SIZE_MAX");
387 return(0);
388 }
389
390 if (buf->size > (size_t) len) {
391 size = buf->size > SIZE_MAX / 2 ? SIZE_MAX : buf->size * 2;
392 } else {
393 size = buf->use + len;
394 size = size > SIZE_MAX - 100 ? SIZE_MAX : size + 100;
395 }
396
397 if (buf->alloc == XML_BUFFER_ALLOC_BOUNDED) {
398 /*
399 * Used to provide parsing limits
400 */
401 if ((buf->use + len + 1 >= XML_MAX_TEXT_LENGTH) ||
402 (buf->size >= XML_MAX_TEXT_LENGTH)) {
403 xmlBufMemoryError(buf, "buffer error: text too long\n");
404 return(0);
405 }
406 if (size >= XML_MAX_TEXT_LENGTH)
407 size = XML_MAX_TEXT_LENGTH;
408 }
409 if ((buf->alloc == XML_BUFFER_ALLOC_IO) && (buf->contentIO != NULL)) {
410 size_t start_buf = buf->content - buf->contentIO;
411
412 newbuf = (xmlChar *) xmlRealloc(buf->contentIO, start_buf + size);
413 if (newbuf == NULL) {
414 xmlBufMemoryError(buf, "growing buffer");
415 return(0);
416 }
417 buf->contentIO = newbuf;
418 buf->content = newbuf + start_buf;
419 } else {
420 newbuf = (xmlChar *) xmlRealloc(buf->content, size);
421 if (newbuf == NULL) {
422 xmlBufMemoryError(buf, "growing buffer");
423 return(0);
424 }
425 buf->content = newbuf;
426 }
427 buf->size = size;
428 UPDATE_COMPAT(buf)
429 return(buf->size - buf->use - 1);
430 }
431
432 /**
433 * xmlBufGrow:
434 * @buf: the buffer
435 * @len: the minimum free size to allocate
436 *
437 * Grow the available space of an XML buffer, @len is the target value
438 * This is been kept compatible with xmlBufferGrow() as much as possible
439 *
440 * Returns -1 in case of error or the length made available otherwise
441 */
442 int
443 xmlBufGrow(xmlBufPtr buf, int len) {
444 size_t ret;
445
446 if ((buf == NULL) || (len < 0)) return(-1);
447 if (len == 0)
448 return(0);
449 ret = xmlBufGrowInternal(buf, len);
450 if (buf->error != 0)
451 return(-1);
452 return(ret > INT_MAX ? INT_MAX : ret);
453 }
454
455 /**
456 * xmlBufDump:
457 * @file: the file output
458 * @buf: the buffer to dump
459 *
460 * Dumps an XML buffer to a FILE *.
461 * Returns the number of #xmlChar written
462 */
463 size_t
464 xmlBufDump(FILE *file, xmlBufPtr buf) {
465 size_t ret;
466
467 if ((buf == NULL) || (buf->error != 0)) {
468 return(0);
469 }
470 if (buf->content == NULL) {
471 return(0);
472 }
473 CHECK_COMPAT(buf)
474 if (file == NULL)
475 file = stdout;
476 ret = fwrite(buf->content, 1, buf->use, file);
477 return(ret);
478 }
479
480 /**
481 * xmlBufContent:
482 * @buf: the buffer
483 *
484 * Function to extract the content of a buffer
485 *
486 * Returns the internal content
487 */
488
489 xmlChar *
490 xmlBufContent(const xmlBuf *buf)
491 {
492 if ((!buf) || (buf->error))
493 return NULL;
494
495 return(buf->content);
496 }
497
498 /**
499 * xmlBufEnd:
500 * @buf: the buffer
501 *
502 * Function to extract the end of the content of a buffer
503 *
504 * Returns the end of the internal content or NULL in case of error
505 */
506
507 xmlChar *
508 xmlBufEnd(xmlBufPtr buf)
509 {
510 if ((!buf) || (buf->error))
511 return NULL;
512 CHECK_COMPAT(buf)
513
514 return(&buf->content[buf->use]);
515 }
516
517 /**
518 * xmlBufAddLen:
519 * @buf: the buffer
520 * @len: the size which were added at the end
521 *
522 * Sometime data may be added at the end of the buffer without
523 * using the xmlBuf APIs that is used to expand the used space
524 * and set the zero terminating at the end of the buffer
525 *
526 * Returns -1 in case of error and 0 otherwise
527 */
528 int
529 xmlBufAddLen(xmlBufPtr buf, size_t len) {
530 if ((buf == NULL) || (buf->error))
531 return(-1);
532 CHECK_COMPAT(buf)
533 if (len >= (buf->size - buf->use))
534 return(-1);
535 buf->use += len;
536 buf->content[buf->use] = 0;
537 UPDATE_COMPAT(buf)
538 return(0);
539 }
540
541 /**
542 * xmlBufLength:
543 * @buf: the buffer
544 *
545 * Function to get the length of a buffer
546 *
547 * Returns the length of data in the internal content
548 */
549
550 size_t
551 xmlBufLength(const xmlBufPtr buf)
552 {
553 if ((!buf) || (buf->error))
554 return 0;
555 CHECK_COMPAT(buf)
556
557 return(buf->use);
558 }
559
560 /**
561 * xmlBufUse:
562 * @buf: the buffer
563 *
564 * Function to get the length of a buffer
565 *
566 * Returns the length of data in the internal content
567 */
568
569 size_t
570 xmlBufUse(const xmlBufPtr buf)
571 {
572 if ((!buf) || (buf->error))
573 return 0;
574 CHECK_COMPAT(buf)
575
576 return(buf->use);
577 }
578
579 /**
580 * xmlBufAvail:
581 * @buf: the buffer
582 *
583 * Function to find how much free space is allocated but not
584 * used in the buffer. It reserves one byte for the NUL
585 * terminator character that is usually needed, so there is
586 * no need to subtract 1 from the result anymore.
587 *
588 * Returns the amount, or 0 if none or if an error occurred.
589 */
590
591 size_t
592 xmlBufAvail(const xmlBufPtr buf)
593 {
594 if ((!buf) || (buf->error))
595 return 0;
596 CHECK_COMPAT(buf)
597
598 return((buf->size > buf->use) ? (buf->size - buf->use - 1) : 0);
599 }
600
601 /**
602 * xmlBufIsEmpty:
603 * @buf: the buffer
604 *
605 * Tell if a buffer is empty
606 *
607 * Returns 0 if no, 1 if yes and -1 in case of error
608 */
609 int
610 xmlBufIsEmpty(const xmlBufPtr buf)
611 {
612 if ((!buf) || (buf->error))
613 return(-1);
614 CHECK_COMPAT(buf)
615
616 return(buf->use == 0);
617 }
618
619 /**
620 * xmlBufResize:
621 * @buf: the buffer to resize
622 * @size: the desired size
623 *
624 * Resize a buffer to accommodate minimum size of @size.
625 *
626 * Returns 0 in case of problems, 1 otherwise
627 */
628 int
629 xmlBufResize(xmlBufPtr buf, size_t size)
630 {
631 size_t newSize;
632 xmlChar* rebuf = NULL;
633 size_t start_buf;
634
635 if ((buf == NULL) || (buf->error))
636 return(0);
637 CHECK_COMPAT(buf)
638
639 if (buf->alloc == XML_BUFFER_ALLOC_BOUNDED) {
640 /*
641 * Used to provide parsing limits
642 */
643 if (size >= XML_MAX_TEXT_LENGTH) {
644 xmlBufMemoryError(buf, "buffer error: text too long\n");
645 return(0);
646 }
647 }
648
649 /* Don't resize if we don't have to */
650 if (size < buf->size)
651 return 1;
652
653 /* figure out new size */
654 switch (buf->alloc){
655 case XML_BUFFER_ALLOC_IO:
656 case XML_BUFFER_ALLOC_DOUBLEIT:
657 /*take care of empty case*/
658 if (buf->size == 0) {
659 newSize = (size > SIZE_MAX - 10 ? SIZE_MAX : size + 10);
660 } else {
661 newSize = buf->size;
662 }
663 while (size > newSize) {
664 if (newSize > SIZE_MAX / 2) {
665 xmlBufMemoryError(buf, "growing buffer");
666 return 0;
667 }
668 newSize *= 2;
669 }
670 break;
671 case XML_BUFFER_ALLOC_EXACT:
672 newSize = (size > SIZE_MAX - 10 ? SIZE_MAX : size + 10);
673 break;
674 case XML_BUFFER_ALLOC_HYBRID:
675 if (buf->use < BASE_BUFFER_SIZE)
676 newSize = size;
677 else {
678 newSize = buf->size;
679 while (size > newSize) {
680 if (newSize > SIZE_MAX / 2) {
681 xmlBufMemoryError(buf, "growing buffer");
682 return 0;
683 }
684 newSize *= 2;
685 }
686 }
687 break;
688
689 default:
690 newSize = (size > SIZE_MAX - 10 ? SIZE_MAX : size + 10);
691 break;
692 }
693
694 if ((buf->alloc == XML_BUFFER_ALLOC_IO) && (buf->contentIO != NULL)) {
695 start_buf = buf->content - buf->contentIO;
696
697 if (start_buf > newSize) {
698 /* move data back to start */
699 memmove(buf->contentIO, buf->content, buf->use);
700 buf->content = buf->contentIO;
701 buf->content[buf->use] = 0;
702 buf->size += start_buf;
703 } else {
704 rebuf = (xmlChar *) xmlRealloc(buf->contentIO, start_buf + newSize);
705 if (rebuf == NULL) {
706 xmlBufMemoryError(buf, "growing buffer");
707 return 0;
708 }
709 buf->contentIO = rebuf;
710 buf->content = rebuf + start_buf;
711 }
712 } else {
713 if (buf->content == NULL) {
714 rebuf = (xmlChar *) xmlMallocAtomic(newSize);
715 buf->use = 0;
716 if (rebuf != NULL)
717 rebuf[buf->use] = 0;
718 } else if (buf->size - buf->use < 100) {
719 rebuf = (xmlChar *) xmlRealloc(buf->content, newSize);
720 } else {
721 /*
722 * if we are reallocating a buffer far from being full, it's
723 * better to make a new allocation and copy only the used range
724 * and free the old one.
725 */
726 rebuf = (xmlChar *) xmlMallocAtomic(newSize);
727 if (rebuf != NULL) {
728 memcpy(rebuf, buf->content, buf->use);
729 xmlFree(buf->content);
730 rebuf[buf->use] = 0;
731 }
732 }
733 if (rebuf == NULL) {
734 xmlBufMemoryError(buf, "growing buffer");
735 return 0;
736 }
737 buf->content = rebuf;
738 }
739 buf->size = newSize;
740 UPDATE_COMPAT(buf)
741
742 return 1;
743 }
744
745 /**
746 * xmlBufAdd:
747 * @buf: the buffer to dump
748 * @str: the #xmlChar string
749 * @len: the number of #xmlChar to add
750 *
751 * Add a string range to an XML buffer. if len == -1, the length of
752 * str is recomputed.
753 *
754 * Returns 0 successful, a positive error code number otherwise
755 * and -1 in case of internal or API error.
756 */
757 int
758 xmlBufAdd(xmlBufPtr buf, const xmlChar *str, int len) {
759 size_t needSize;
760
761 if ((str == NULL) || (buf == NULL) || (buf->error))
762 return -1;
763 CHECK_COMPAT(buf)
764
765 if (len < -1) {
766 return -1;
767 }
768 if (len == 0) return 0;
769
770 if (len < 0)
771 len = xmlStrlen(str);
772
773 if (len < 0) return -1;
774 if (len == 0) return 0;
775
776 /* Note that both buf->size and buf->use can be zero here. */
777 if ((size_t) len >= buf->size - buf->use) {
778 if ((size_t) len >= SIZE_MAX - buf->use) {
779 xmlBufMemoryError(buf, "growing buffer past SIZE_MAX");
780 return(-1);
781 }
782 needSize = buf->use + len + 1;
783 if (buf->alloc == XML_BUFFER_ALLOC_BOUNDED) {
784 /*
785 * Used to provide parsing limits
786 */
787 if (needSize >= XML_MAX_TEXT_LENGTH) {
788 xmlBufMemoryError(buf, "buffer error: text too long\n");
789 return(-1);
790 }
791 }
792 if (!xmlBufResize(buf, needSize)){
793 xmlBufMemoryError(buf, "growing buffer");
794 return XML_ERR_NO_MEMORY;
795 }
796 }
797
798 memmove(&buf->content[buf->use], str, len);
799 buf->use += len;
800 buf->content[buf->use] = 0;
801 UPDATE_COMPAT(buf)
802 return 0;
803 }
804
805 /**
806 * xmlBufCat:
807 * @buf: the buffer to add to
808 * @str: the #xmlChar string
809 *
810 * Append a zero terminated string to an XML buffer.
811 *
812 * Returns 0 successful, a positive error code number otherwise
813 * and -1 in case of internal or API error.
814 */
815 int
816 xmlBufCat(xmlBufPtr buf, const xmlChar *str) {
817 if ((buf == NULL) || (buf->error))
818 return(-1);
819 CHECK_COMPAT(buf)
820 if (str == NULL) return -1;
821 return xmlBufAdd(buf, str, -1);
822 }
823
824 /**
825 * xmlBufCCat:
826 * @buf: the buffer to dump
827 * @str: the C char string
828 *
829 * Append a zero terminated C string to an XML buffer.
830 *
831 * Returns 0 successful, a positive error code number otherwise
832 * and -1 in case of internal or API error.
833 */
834 int
835 xmlBufCCat(xmlBufPtr buf, const char *str) {
836 return xmlBufCat(buf, (const xmlChar *) str);
837 }
838
839 /**
840 * xmlBufWriteQuotedString:
841 * @buf: the XML buffer output
842 * @string: the string to add
843 *
844 * routine which manage and grows an output buffer. This one writes
845 * a quoted or double quoted #xmlChar string, checking first if it holds
846 * quote or double-quotes internally
847 *
848 * Returns 0 if successful, a positive error code number otherwise
849 * and -1 in case of internal or API error.
850 */
851 int
852 xmlBufWriteQuotedString(xmlBufPtr buf, const xmlChar *string) {
853 const xmlChar *cur, *base;
854 if ((buf == NULL) || (buf->error))
855 return(-1);
856 CHECK_COMPAT(buf)
857 if (xmlStrchr(string, '\"')) {
858 if (xmlStrchr(string, '\'')) {
859 xmlBufCCat(buf, "\"");
860 base = cur = string;
861 while(*cur != 0){
862 if(*cur == '"'){
863 if (base != cur)
864 xmlBufAdd(buf, base, cur - base);
865 xmlBufAdd(buf, BAD_CAST """, 6);
866 cur++;
867 base = cur;
868 }
869 else {
870 cur++;
871 }
872 }
873 if (base != cur)
874 xmlBufAdd(buf, base, cur - base);
875 xmlBufCCat(buf, "\"");
876 }
877 else{
878 xmlBufCCat(buf, "\'");
879 xmlBufCat(buf, string);
880 xmlBufCCat(buf, "\'");
881 }
882 } else {
883 xmlBufCCat(buf, "\"");
884 xmlBufCat(buf, string);
885 xmlBufCCat(buf, "\"");
886 }
887 return(0);
888 }
889
890 /**
891 * xmlBufFromBuffer:
892 * @buffer: incoming old buffer to convert to a new one
893 *
894 * Helper routine to switch from the old buffer structures in use
895 * in various APIs. It creates a wrapper xmlBufPtr which will be
896 * used for internal processing until the xmlBufBackToBuffer() is
897 * issued.
898 *
899 * Returns a new xmlBufPtr unless the call failed and NULL is returned
900 */
901 xmlBufPtr
902 xmlBufFromBuffer(xmlBufferPtr buffer) {
903 xmlBufPtr ret;
904
905 if (buffer == NULL)
906 return(NULL);
907
908 ret = (xmlBufPtr) xmlMalloc(sizeof(xmlBuf));
909 if (ret == NULL) {
910 xmlBufMemoryError(NULL, "creating buffer");
911 return(NULL);
912 }
913 ret->use = buffer->use;
914 ret->size = buffer->size;
915 UPDATE_COMPAT(ret);
916 ret->error = 0;
917 ret->buffer = buffer;
918 ret->alloc = buffer->alloc;
919 ret->content = buffer->content;
920 ret->contentIO = buffer->contentIO;
921
922 return(ret);
923 }
924
925 /**
926 * xmlBufBackToBuffer:
927 * @buf: new buffer wrapping the old one
928 *
929 * Function to be called once internal processing had been done to
930 * update back the buffer provided by the user. This can lead to
931 * a failure in case the size accumulated in the xmlBuf is larger
932 * than what an xmlBuffer can support on 64 bits (INT_MAX)
933 * The xmlBufPtr @buf wrapper is deallocated by this call in any case.
934 *
935 * Returns the old xmlBufferPtr unless the call failed and NULL is returned
936 */
937 xmlBufferPtr
938 xmlBufBackToBuffer(xmlBufPtr buf) {
939 xmlBufferPtr ret;
940
941 if (buf == NULL)
942 return(NULL);
943 CHECK_COMPAT(buf)
944 if ((buf->error) || (buf->buffer == NULL)) {
945 xmlBufFree(buf);
946 return(NULL);
947 }
948
949 ret = buf->buffer;
950 /*
951 * What to do in case of error in the buffer ???
952 */
953 if (buf->use > INT_MAX) {
954 /*
955 * Worse case, we really allocated and used more than the
956 * maximum allowed memory for an xmlBuffer on this architecture.
957 * Keep the buffer but provide a truncated size value.
958 */
959 xmlBufOverflowError(buf, "Used size too big for xmlBuffer");
960 ret->use = INT_MAX;
961 ret->size = INT_MAX;
962 } else if (buf->size > INT_MAX) {
963 /*
964 * milder case, we allocated more than the maximum allowed memory
965 * for an xmlBuffer on this architecture, but used less than the
966 * limit.
967 * Keep the buffer but provide a truncated size value.
968 */
969 xmlBufOverflowError(buf, "Allocated size too big for xmlBuffer");
970 ret->use = buf->use;
971 ret->size = INT_MAX;
972 } else {
973 ret->use = buf->use;
974 ret->size = buf->size;
975 }
976 ret->alloc = buf->alloc;
977 ret->content = buf->content;
978 ret->contentIO = buf->contentIO;
979 xmlFree(buf);
980 return(ret);
981 }
982
983 /**
984 * xmlBufMergeBuffer:
985 * @buf: an xmlBufPtr
986 * @buffer: the buffer to consume into @buf
987 *
988 * The content of @buffer is appended to @buf and @buffer is freed
989 *
990 * Returns -1 in case of error, 0 otherwise, in any case @buffer is freed
991 */
992 int
993 xmlBufMergeBuffer(xmlBufPtr buf, xmlBufferPtr buffer) {
994 int ret = 0;
995
996 if ((buf == NULL) || (buf->error)) {
997 xmlBufferFree(buffer);
998 return(-1);
999 }
1000 CHECK_COMPAT(buf)
1001 if ((buffer != NULL) && (buffer->content != NULL) &&
1002 (buffer->use > 0)) {
1003 ret = xmlBufAdd(buf, buffer->content, buffer->use);
1004 }
1005 xmlBufferFree(buffer);
1006 return(ret);
1007 }
1008
1009 /**
1010 * xmlBufResetInput:
1011 * @buf: an xmlBufPtr
1012 * @input: an xmlParserInputPtr
1013 *
1014 * Update the input to use the current set of pointers from the buffer.
1015 *
1016 * Returns -1 in case of error, 0 otherwise
1017 */
1018 int
1019 xmlBufResetInput(xmlBufPtr buf, xmlParserInputPtr input) {
1020 if (input == NULL)
1021 return(-1);
1022 if ((buf == NULL) || (buf->error)) {
1023 input->base = input->cur = input->end = BAD_CAST "";
1024 return(-1);
1025 }
1026 CHECK_COMPAT(buf)
1027 input->base = input->cur = buf->content;
1028 input->end = &buf->content[buf->use];
1029 return(0);
1030 }
1031
1032 /**
1033 * xmlBufUpdateInput:
1034 * @buf: an xmlBufPtr
1035 * @input: an xmlParserInputPtr
1036 * @pos: the cur value relative to the beginning of the buffer
1037 *
1038 * Update the input to use the base and cur relative to the buffer
1039 * after a possible reallocation of its content
1040 *
1041 * Returns -1 in case of error, 0 otherwise
1042 */
1043 int
1044 xmlBufUpdateInput(xmlBufPtr buf, xmlParserInputPtr input, size_t pos) {
1045 if (input == NULL)
1046 return(-1);
1047 /*
1048 * TODO: It might be safer to keep using the buffer content if there
1049 * was an error.
1050 */
1051 if ((buf == NULL) || (buf->error)) {
1052 input->base = input->cur = input->end = BAD_CAST "";
1053 return(-1);
1054 }
1055 CHECK_COMPAT(buf)
1056 input->base = buf->content;
1057 input->cur = input->base + pos;
1058 input->end = &buf->content[buf->use];
1059 return(0);
1060 }
1061