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1 | |
2 | /* pngmem.c - stub functions for memory allocation | |
3 | * | |
a626cc03 | 4 | * libpng 1.0.3 - January 14, 1999 |
c801d85f KB |
5 | * For conditions of distribution and use, see copyright notice in png.h |
6 | * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. | |
7 | * Copyright (c) 1996, 1997 Andreas Dilger | |
a626cc03 | 8 | * Copyright (c) 1998, 1999 Glenn Randers-Pehrson |
c801d85f | 9 | * |
a626cc03 RR |
10 | * This file provides a location for all memory allocation. Users who |
11 | * need special memory handling are expected to supply replacement | |
12 | * functions for png_malloc() and png_free(), and to use | |
13 | * png_create_read_struct_2() and png_create_write_struct_2() to | |
14 | * identify the replacement functions. | |
c801d85f KB |
15 | */ |
16 | ||
17 | #define PNG_INTERNAL | |
a626cc03 | 18 | #include "png.h" |
c801d85f KB |
19 | |
20 | /* Borland DOS special memory handler */ | |
21 | #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__) | |
22 | /* if you change this, be sure to change the one in png.h also */ | |
23 | ||
24 | /* Allocate memory for a png_struct. The malloc and memset can be replaced | |
25 | by a single call to calloc() if this is thought to improve performance. */ | |
26 | png_voidp | |
27 | png_create_struct(int type) | |
28 | { | |
a626cc03 RR |
29 | #ifdef PNG_USER_MEM_SUPPORTED |
30 | return (png_create_struct_2(type, NULL)); | |
31 | } | |
32 | ||
33 | /* Alternate version of png_create_struct, for use with user-defined malloc. */ | |
34 | png_voidp | |
35 | png_create_struct_2(int type, png_malloc_ptr malloc_fn) | |
36 | { | |
37 | #endif /* PNG_USER_MEM_SUPPORTED */ | |
c801d85f KB |
38 | png_size_t size; |
39 | png_voidp struct_ptr; | |
40 | ||
41 | if (type == PNG_STRUCT_INFO) | |
42 | size = sizeof(png_info); | |
43 | else if (type == PNG_STRUCT_PNG) | |
44 | size = sizeof(png_struct); | |
45 | else | |
46 | return ((png_voidp)NULL); | |
47 | ||
a626cc03 RR |
48 | #ifdef PNG_USER_MEM_SUPPORTED |
49 | if(malloc_fn != NULL) | |
50 | { | |
51 | if ((struct_ptr = (*(malloc_fn))(NULL, size)) != NULL) | |
52 | png_memset(struct_ptr, 0, size); | |
53 | return (struct_ptr); | |
54 | } | |
55 | #endif /* PNG_USER_MEM_SUPPORTED */ | |
c801d85f KB |
56 | if ((struct_ptr = (png_voidp)farmalloc(size)) != NULL) |
57 | { | |
58 | png_memset(struct_ptr, 0, size); | |
59 | } | |
c801d85f KB |
60 | return (struct_ptr); |
61 | } | |
62 | ||
63 | ||
64 | /* Free memory allocated by a png_create_struct() call */ | |
65 | void | |
66 | png_destroy_struct(png_voidp struct_ptr) | |
67 | { | |
a626cc03 RR |
68 | #ifdef PNG_USER_MEM_SUPPORTED |
69 | png_destroy_struct_2(struct_ptr, (png_free_ptr)NULL); | |
70 | } | |
71 | ||
72 | /* Free memory allocated by a png_create_struct() call */ | |
73 | void | |
74 | png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn) | |
75 | { | |
76 | #endif | |
c801d85f KB |
77 | if (struct_ptr != NULL) |
78 | { | |
a626cc03 RR |
79 | #ifdef PNG_USER_MEM_SUPPORTED |
80 | if(free_fn != NULL) | |
81 | { | |
82 | png_struct dummy_struct; | |
83 | png_structp png_ptr = &dummy_struct; | |
84 | (*(free_fn))(png_ptr, struct_ptr); | |
85 | struct_ptr = NULL; | |
86 | return; | |
87 | } | |
88 | #endif /* PNG_USER_MEM_SUPPORTED */ | |
c801d85f KB |
89 | farfree (struct_ptr); |
90 | struct_ptr = NULL; | |
91 | } | |
92 | } | |
93 | ||
94 | /* Allocate memory. For reasonable files, size should never exceed | |
95 | * 64K. However, zlib may allocate more then 64K if you don't tell | |
96 | * it not to. See zconf.h and png.h for more information. zlib does | |
97 | * need to allocate exactly 64K, so whatever you call here must | |
98 | * have the ability to do that. | |
99 | * | |
100 | * Borland seems to have a problem in DOS mode for exactly 64K. | |
a626cc03 | 101 | * It gives you a segment with an offset of 8 (perhaps to store its |
c801d85f KB |
102 | * memory stuff). zlib doesn't like this at all, so we have to |
103 | * detect and deal with it. This code should not be needed in | |
104 | * Windows or OS/2 modes, and only in 16 bit mode. This code has | |
105 | * been updated by Alexander Lehmann for version 0.89 to waste less | |
106 | * memory. | |
107 | * | |
108 | * Note that we can't use png_size_t for the "size" declaration, | |
109 | * since on some systems a png_size_t is a 16-bit quantity, and as a | |
110 | * result, we would be truncating potentially larger memory requests | |
111 | * (which should cause a fatal error) and introducing major problems. | |
112 | */ | |
113 | png_voidp | |
a626cc03 | 114 | png_malloc(png_structp png_ptr, png_uint_32 size) |
c801d85f | 115 | { |
a626cc03 | 116 | #ifndef PNG_USER_MEM_SUPPORTED |
c801d85f | 117 | png_voidp ret; |
a626cc03 | 118 | #endif |
c801d85f KB |
119 | if (png_ptr == NULL || size == 0) |
120 | return ((png_voidp)NULL); | |
121 | ||
a626cc03 RR |
122 | #ifdef PNG_USER_MEM_SUPPORTED |
123 | if(png_ptr->malloc_fn != NULL) | |
124 | return ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size)); | |
125 | else | |
126 | return png_malloc_default(png_ptr, size); | |
127 | } | |
128 | ||
129 | png_voidp | |
130 | png_malloc_default(png_structp png_ptr, png_uint_32 size) | |
131 | { | |
132 | png_voidp ret; | |
133 | #endif /* PNG_USER_MEM_SUPPORTED */ | |
134 | ||
c801d85f KB |
135 | #ifdef PNG_MAX_MALLOC_64K |
136 | if (size > (png_uint_32)65536L) | |
137 | png_error(png_ptr, "Cannot Allocate > 64K"); | |
138 | #endif | |
139 | ||
140 | if (size == (png_uint_32)65536L) | |
141 | { | |
142 | if (png_ptr->offset_table == NULL) | |
143 | { | |
144 | /* try to see if we need to do any of this fancy stuff */ | |
145 | ret = farmalloc(size); | |
146 | if (ret == NULL || ((png_size_t)ret & 0xffff)) | |
147 | { | |
148 | int num_blocks; | |
149 | png_uint_32 total_size; | |
150 | png_bytep table; | |
151 | int i; | |
152 | png_byte huge * hptr; | |
153 | ||
154 | if (ret != NULL) | |
155 | { | |
156 | farfree(ret); | |
157 | ret = NULL; | |
158 | } | |
159 | ||
160 | num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14)); | |
161 | if (num_blocks < 1) | |
162 | num_blocks = 1; | |
163 | if (png_ptr->zlib_mem_level >= 7) | |
164 | num_blocks += (int)(1 << (png_ptr->zlib_mem_level - 7)); | |
165 | else | |
166 | num_blocks++; | |
167 | ||
168 | total_size = ((png_uint_32)65536L) * (png_uint_32)num_blocks+16; | |
169 | ||
170 | table = farmalloc(total_size); | |
171 | ||
172 | if (table == NULL) | |
173 | { | |
174 | png_error(png_ptr, "Out Of Memory."); /* Note "O" and "M" */ | |
175 | } | |
176 | ||
177 | if ((png_size_t)table & 0xfff0) | |
178 | { | |
179 | png_error(png_ptr, "Farmalloc didn't return normalized pointer"); | |
180 | } | |
181 | ||
182 | png_ptr->offset_table = table; | |
183 | png_ptr->offset_table_ptr = farmalloc(num_blocks * | |
184 | sizeof (png_bytep)); | |
185 | ||
186 | if (png_ptr->offset_table_ptr == NULL) | |
187 | { | |
188 | png_error(png_ptr, "Out Of memory."); | |
189 | } | |
190 | ||
191 | hptr = (png_byte huge *)table; | |
192 | if ((png_size_t)hptr & 0xf) | |
193 | { | |
194 | hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L); | |
195 | hptr += 16L; | |
196 | } | |
197 | for (i = 0; i < num_blocks; i++) | |
198 | { | |
199 | png_ptr->offset_table_ptr[i] = (png_bytep)hptr; | |
200 | hptr += (png_uint_32)65536L; | |
201 | } | |
202 | ||
203 | png_ptr->offset_table_number = num_blocks; | |
204 | png_ptr->offset_table_count = 0; | |
205 | png_ptr->offset_table_count_free = 0; | |
206 | } | |
207 | } | |
208 | ||
209 | if (png_ptr->offset_table_count >= png_ptr->offset_table_number) | |
210 | png_error(png_ptr, "Out of Memory."); | |
211 | ||
212 | ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++]; | |
213 | } | |
214 | else | |
215 | ret = farmalloc(size); | |
216 | ||
217 | if (ret == NULL) | |
218 | { | |
219 | png_error(png_ptr, "Out of memory."); /* Note "o" and "m" */ | |
220 | } | |
221 | ||
222 | return (ret); | |
223 | } | |
224 | ||
a626cc03 | 225 | /* free a pointer allocated by png_malloc(). In the default |
c801d85f KB |
226 | configuration, png_ptr is not used, but is passed in case it |
227 | is needed. If ptr is NULL, return without taking any action. */ | |
228 | void | |
a626cc03 | 229 | png_free(png_structp png_ptr, png_voidp ptr) |
c801d85f KB |
230 | { |
231 | if (png_ptr == NULL || ptr == NULL) | |
232 | return; | |
233 | ||
a626cc03 RR |
234 | #ifdef PNG_USER_MEM_SUPPORTED |
235 | if (png_ptr->free_fn != NULL) | |
236 | { | |
237 | (*(png_ptr->free_fn))(png_ptr, ptr); | |
238 | ptr = NULL; | |
239 | return; | |
240 | } | |
241 | else png_free_default(png_ptr, ptr); | |
242 | } | |
243 | ||
244 | void | |
245 | png_free_default(png_structp png_ptr, png_voidp ptr) | |
246 | { | |
247 | #endif /* PNG_USER_MEM_SUPPORTED */ | |
248 | ||
c801d85f KB |
249 | if (png_ptr->offset_table != NULL) |
250 | { | |
251 | int i; | |
252 | ||
253 | for (i = 0; i < png_ptr->offset_table_count; i++) | |
254 | { | |
255 | if (ptr == png_ptr->offset_table_ptr[i]) | |
256 | { | |
257 | ptr = NULL; | |
258 | png_ptr->offset_table_count_free++; | |
259 | break; | |
260 | } | |
261 | } | |
262 | if (png_ptr->offset_table_count_free == png_ptr->offset_table_count) | |
263 | { | |
264 | farfree(png_ptr->offset_table); | |
265 | farfree(png_ptr->offset_table_ptr); | |
266 | png_ptr->offset_table = NULL; | |
267 | png_ptr->offset_table_ptr = NULL; | |
268 | } | |
269 | } | |
270 | ||
271 | if (ptr != NULL) | |
272 | { | |
273 | farfree(ptr); | |
274 | ptr = NULL; | |
275 | } | |
276 | } | |
277 | ||
278 | #else /* Not the Borland DOS special memory handler */ | |
279 | ||
280 | /* Allocate memory for a png_struct or a png_info. The malloc and | |
281 | memset can be replaced by a single call to calloc() if this is thought | |
282 | to improve performance noticably.*/ | |
283 | png_voidp | |
284 | png_create_struct(int type) | |
285 | { | |
a626cc03 RR |
286 | #ifdef PNG_USER_MEM_SUPPORTED |
287 | return (png_create_struct_2(type, NULL)); | |
288 | } | |
289 | ||
290 | /* Allocate memory for a png_struct or a png_info. The malloc and | |
291 | memset can be replaced by a single call to calloc() if this is thought | |
292 | to improve performance noticably.*/ | |
293 | png_voidp | |
294 | png_create_struct_2(int type, png_malloc_ptr malloc_fn) | |
295 | { | |
296 | #endif /* PNG_USER_MEM_SUPPORTED */ | |
c801d85f KB |
297 | png_size_t size; |
298 | png_voidp struct_ptr; | |
299 | ||
300 | if (type == PNG_STRUCT_INFO) | |
301 | size = sizeof(png_info); | |
302 | else if (type == PNG_STRUCT_PNG) | |
303 | size = sizeof(png_struct); | |
304 | else | |
305 | return ((png_voidp)NULL); | |
306 | ||
a626cc03 RR |
307 | #ifdef PNG_USER_MEM_SUPPORTED |
308 | if(malloc_fn != NULL) | |
309 | { | |
310 | if ((struct_ptr = (*(malloc_fn))(NULL, size)) != NULL) | |
311 | png_memset(struct_ptr, 0, size); | |
312 | return (struct_ptr); | |
313 | } | |
314 | #endif /* PNG_USER_MEM_SUPPORTED */ | |
315 | ||
c801d85f KB |
316 | #if defined(__TURBOC__) && !defined(__FLAT__) |
317 | if ((struct_ptr = (png_voidp)farmalloc(size)) != NULL) | |
318 | #else | |
319 | # if defined(_MSC_VER) && defined(MAXSEG_64K) | |
320 | if ((struct_ptr = (png_voidp)halloc(size,1)) != NULL) | |
321 | # else | |
322 | if ((struct_ptr = (png_voidp)malloc(size)) != NULL) | |
323 | # endif | |
324 | #endif | |
325 | { | |
326 | png_memset(struct_ptr, 0, size); | |
327 | } | |
328 | ||
329 | return (struct_ptr); | |
330 | } | |
331 | ||
332 | ||
333 | /* Free memory allocated by a png_create_struct() call */ | |
334 | void | |
335 | png_destroy_struct(png_voidp struct_ptr) | |
336 | { | |
a626cc03 RR |
337 | #ifdef PNG_USER_MEM_SUPPORTED |
338 | png_destroy_struct_2(struct_ptr, (png_free_ptr)NULL); | |
339 | } | |
340 | ||
341 | /* Free memory allocated by a png_create_struct() call */ | |
342 | void | |
343 | png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn) | |
344 | { | |
345 | #endif /* PNG_USER_MEM_SUPPORTED */ | |
c801d85f KB |
346 | if (struct_ptr != NULL) |
347 | { | |
a626cc03 RR |
348 | #ifdef PNG_USER_MEM_SUPPORTED |
349 | if(free_fn != NULL) | |
350 | { | |
351 | png_struct dummy_struct; | |
352 | png_structp png_ptr = &dummy_struct; | |
353 | (*(free_fn))(png_ptr, struct_ptr); | |
354 | struct_ptr = NULL; | |
355 | return; | |
356 | } | |
357 | #endif /* PNG_USER_MEM_SUPPORTED */ | |
c801d85f KB |
358 | #if defined(__TURBOC__) && !defined(__FLAT__) |
359 | farfree(struct_ptr); | |
a626cc03 | 360 | struct_ptr = NULL; |
c801d85f KB |
361 | #else |
362 | # if defined(_MSC_VER) && defined(MAXSEG_64K) | |
363 | hfree(struct_ptr); | |
a626cc03 | 364 | struct_ptr = NULL; |
c801d85f KB |
365 | # else |
366 | free(struct_ptr); | |
a626cc03 | 367 | struct_ptr = NULL; |
c801d85f KB |
368 | # endif |
369 | #endif | |
370 | } | |
371 | } | |
372 | ||
373 | ||
374 | /* Allocate memory. For reasonable files, size should never exceed | |
375 | 64K. However, zlib may allocate more then 64K if you don't tell | |
376 | it not to. See zconf.h and png.h for more information. zlib does | |
377 | need to allocate exactly 64K, so whatever you call here must | |
378 | have the ability to do that. */ | |
379 | ||
380 | png_voidp | |
a626cc03 | 381 | png_malloc(png_structp png_ptr, png_uint_32 size) |
c801d85f | 382 | { |
a626cc03 | 383 | #ifndef PNG_USER_MEM_SUPPORTED |
c801d85f | 384 | png_voidp ret; |
a626cc03 | 385 | #endif |
c801d85f KB |
386 | if (png_ptr == NULL || size == 0) |
387 | return ((png_voidp)NULL); | |
388 | ||
a626cc03 RR |
389 | #ifdef PNG_USER_MEM_SUPPORTED |
390 | if(png_ptr->malloc_fn != NULL) | |
391 | return ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size)); | |
392 | else | |
393 | return (png_malloc_default(png_ptr, size)); | |
394 | } | |
395 | png_voidp | |
396 | png_malloc_default(png_structp png_ptr, png_uint_32 size) | |
397 | { | |
398 | png_voidp ret; | |
399 | #endif /* PNG_USER_MEM_SUPPORTED */ | |
400 | ||
c801d85f KB |
401 | #ifdef PNG_MAX_MALLOC_64K |
402 | if (size > (png_uint_32)65536L) | |
403 | png_error(png_ptr, "Cannot Allocate > 64K"); | |
404 | #endif | |
405 | ||
406 | #if defined(__TURBOC__) && !defined(__FLAT__) | |
407 | ret = farmalloc(size); | |
408 | #else | |
409 | # if defined(_MSC_VER) && defined(MAXSEG_64K) | |
410 | ret = halloc(size, 1); | |
411 | # else | |
412 | ret = malloc((size_t)size); | |
413 | # endif | |
414 | #endif | |
415 | ||
416 | if (ret == NULL) | |
417 | { | |
418 | png_error(png_ptr, "Out of Memory"); | |
419 | } | |
420 | ||
421 | return (ret); | |
422 | } | |
423 | ||
a626cc03 RR |
424 | /* Free a pointer allocated by png_malloc(). If ptr is NULL, return |
425 | without taking any action. */ | |
c801d85f | 426 | void |
a626cc03 | 427 | png_free(png_structp png_ptr, png_voidp ptr) |
c801d85f KB |
428 | { |
429 | if (png_ptr == NULL || ptr == NULL) | |
430 | return; | |
431 | ||
a626cc03 RR |
432 | #ifdef PNG_USER_MEM_SUPPORTED |
433 | if (png_ptr->free_fn != NULL) | |
434 | { | |
435 | (*(png_ptr->free_fn))(png_ptr, ptr); | |
436 | ptr = NULL; | |
437 | return; | |
438 | } | |
439 | else png_free_default(png_ptr, ptr); | |
440 | } | |
441 | void | |
442 | png_free_default(png_structp png_ptr, png_voidp ptr) | |
443 | { | |
444 | #endif /* PNG_USER_MEM_SUPPORTED */ | |
445 | ||
c801d85f KB |
446 | #if defined(__TURBOC__) && !defined(__FLAT__) |
447 | farfree(ptr); | |
a626cc03 | 448 | ptr = NULL; |
c801d85f KB |
449 | #else |
450 | # if defined(_MSC_VER) && defined(MAXSEG_64K) | |
451 | hfree(ptr); | |
a626cc03 | 452 | ptr = NULL; |
c801d85f KB |
453 | # else |
454 | free(ptr); | |
a626cc03 | 455 | ptr = NULL; |
c801d85f KB |
456 | # endif |
457 | #endif | |
458 | } | |
459 | ||
460 | #endif /* Not Borland DOS special memory handler */ | |
461 | ||
462 | png_voidp | |
463 | png_memcpy_check (png_structp png_ptr, png_voidp s1, png_voidp s2, | |
464 | png_uint_32 length) | |
465 | { | |
466 | png_size_t size; | |
467 | ||
468 | size = (png_size_t)length; | |
469 | if ((png_uint_32)size != length) | |
470 | png_error(png_ptr,"Overflow in png_memcpy_check."); | |
a626cc03 | 471 | |
c801d85f KB |
472 | return(png_memcpy (s1, s2, size)); |
473 | } | |
474 | ||
475 | png_voidp | |
476 | png_memset_check (png_structp png_ptr, png_voidp s1, int value, | |
477 | png_uint_32 length) | |
478 | { | |
479 | png_size_t size; | |
480 | ||
481 | size = (png_size_t)length; | |
482 | if ((png_uint_32)size != length) | |
483 | png_error(png_ptr,"Overflow in png_memset_check."); | |
484 | ||
485 | return (png_memset (s1, value, size)); | |
486 | ||
487 | } | |
a626cc03 RR |
488 | |
489 | #ifdef PNG_USER_MEM_SUPPORTED | |
490 | /* This function is called when the application wants to use another method | |
491 | * of allocating and freeing memory. | |
492 | */ | |
493 | void | |
494 | png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr | |
495 | malloc_fn, png_free_ptr free_fn) | |
496 | { | |
497 | png_ptr->mem_ptr = mem_ptr; | |
498 | png_ptr->malloc_fn = malloc_fn; | |
499 | png_ptr->free_fn = free_fn; | |
500 | } | |
501 | ||
502 | /* This function returns a pointer to the mem_ptr associated with the user | |
503 | * functions. The application should free any memory associated with this | |
504 | * pointer before png_write_destroy and png_read_destroy are called. | |
505 | */ | |
506 | png_voidp | |
507 | png_get_mem_ptr(png_structp png_ptr) | |
508 | { | |
509 | return ((png_voidp)png_ptr->mem_ptr); | |
510 | } | |
511 | #endif /* PNG_USER_MEM_SUPPORTED */ |