2 /* pngmem.c - stub functions for memory allocation
4 * Last changed in libpng 1.5.7 [December 15, 2011]
5 * Copyright (c) 1998-2011 Glenn Randers-Pehrson
6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
9 * This code is released under the libpng license.
10 * For conditions of distribution and use, see the disclaimer
11 * and license in png.h
13 * This file provides a location for all memory allocation. Users who
14 * need special memory handling are expected to supply replacement
15 * functions for png_malloc() and png_free(), and to use
16 * png_create_read_struct_2() and png_create_write_struct_2() to
17 * identify the replacement functions.
22 #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
24 /* Borland DOS special memory handler */
25 #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
26 /* If you change this, be sure to change the one in png.h also */
28 /* Allocate memory for a png_struct. The malloc and memset can be replaced
29 by a single call to calloc() if this is thought to improve performance. */
30 PNG_FUNCTION(png_voidp /* PRIVATE */,
31 png_create_struct,(int type),PNG_ALLOCATED)
33 # ifdef PNG_USER_MEM_SUPPORTED
34 return (png_create_struct_2(type, NULL, NULL));
37 /* Alternate version of png_create_struct, for use with user-defined malloc. */
38 PNG_FUNCTION(png_voidp /* PRIVATE */,
39 png_create_struct_2,(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr),
42 # endif /* PNG_USER_MEM_SUPPORTED */
46 if (type == PNG_STRUCT_INFO)
47 size = png_sizeof(png_info);
49 else if (type == PNG_STRUCT_PNG)
50 size = png_sizeof(png_struct);
53 return (png_get_copyright(NULL));
55 # ifdef PNG_USER_MEM_SUPPORTED
56 if (malloc_fn != NULL)
58 png_struct dummy_struct;
59 memset(&dummy_struct, 0, sizeof dummy_struct);
60 dummy_struct.mem_ptr=mem_ptr;
61 struct_ptr = (*(malloc_fn))(&dummy_struct, (png_alloc_size_t)size);
65 # endif /* PNG_USER_MEM_SUPPORTED */
66 struct_ptr = (png_voidp)farmalloc(size);
67 if (struct_ptr != NULL)
68 png_memset(struct_ptr, 0, size);
73 /* Free memory allocated by a png_create_struct() call */
75 png_destroy_struct(png_voidp struct_ptr)
77 # ifdef PNG_USER_MEM_SUPPORTED
78 png_destroy_struct_2(struct_ptr, NULL, NULL);
81 /* Free memory allocated by a png_create_struct() call */
83 png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
87 if (struct_ptr != NULL)
89 # ifdef PNG_USER_MEM_SUPPORTED
92 png_struct dummy_struct;
93 memset(&dummy_struct, 0, sizeof dummy_struct);
94 dummy_struct.mem_ptr=mem_ptr;
95 (*(free_fn))(&dummy_struct, struct_ptr);
99 # endif /* PNG_USER_MEM_SUPPORTED */
100 farfree (struct_ptr);
104 /* Allocate memory. For reasonable files, size should never exceed
105 * 64K. However, zlib may allocate more then 64K if you don't tell
106 * it not to. See zconf.h and png.h for more information. zlib does
107 * need to allocate exactly 64K, so whatever you call here must
108 * have the ability to do that.
110 * Borland seems to have a problem in DOS mode for exactly 64K.
111 * It gives you a segment with an offset of 8 (perhaps to store its
112 * memory stuff). zlib doesn't like this at all, so we have to
113 * detect and deal with it. This code should not be needed in
114 * Windows or OS/2 modes, and only in 16 bit mode. This code has
115 * been updated by Alexander Lehmann for version 0.89 to waste less
118 * Note that we can't use png_size_t for the "size" declaration,
119 * since on some systems a png_size_t is a 16-bit quantity, and as a
120 * result, we would be truncating potentially larger memory requests
121 * (which should cause a fatal error) and introducing major problems.
123 PNG_FUNCTION(png_voidp,PNGAPI
124 png_calloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
128 ret = (png_malloc(png_ptr, size));
131 png_memset(ret,0,(png_size_t)size);
136 PNG_FUNCTION(png_voidp,PNGAPI
137 png_malloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
141 if (png_ptr == NULL || size == 0)
144 # ifdef PNG_USER_MEM_SUPPORTED
145 if (png_ptr->malloc_fn != NULL)
146 ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size));
149 ret = (png_malloc_default(png_ptr, size));
151 if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
152 png_error(png_ptr, "Out of memory");
157 PNG_FUNCTION(png_voidp,PNGAPI
158 png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
161 # endif /* PNG_USER_MEM_SUPPORTED */
163 if (png_ptr == NULL || size == 0)
166 # ifdef PNG_MAX_MALLOC_64K
167 if (size > (png_uint_32)65536L)
169 png_warning(png_ptr, "Cannot Allocate > 64K");
176 if (size != (size_t)size)
179 else if (size == (png_uint_32)65536L)
181 if (png_ptr->offset_table == NULL)
183 /* Try to see if we need to do any of this fancy stuff */
184 ret = farmalloc(size);
185 if (ret == NULL || ((png_size_t)ret & 0xffff))
188 png_uint_32 total_size;
190 int i, mem_level, window_bits;
191 png_byte huge * hptr;
201 png_ptr->zlib_window_bits >= png_ptr->zlib_text_window_bits ?
202 png_ptr->zlib_window_bits : png_ptr->zlib_text_window_bits;
204 if (window_bits > 14)
205 num_blocks = (int)(1 << (window_bits - 14));
211 png_ptr->zlib_mem_level >= png_ptr->zlib_text_mem_level ?
212 png_ptr->zlib_mem_level : png_ptr->zlib_text_mem_level;
215 num_blocks += (int)(1 << (mem_level - 7));
220 total_size = ((png_uint_32)65536L) * (png_uint_32)num_blocks+16;
222 table = farmalloc(total_size);
226 # ifndef PNG_USER_MEM_SUPPORTED
227 if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
228 png_error(png_ptr, "Out Of Memory"); /* Note "O", "M" */
231 png_warning(png_ptr, "Out Of Memory");
236 if ((png_size_t)table & 0xfff0)
238 # ifndef PNG_USER_MEM_SUPPORTED
239 if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
241 "Farmalloc didn't return normalized pointer");
245 "Farmalloc didn't return normalized pointer");
250 png_ptr->offset_table = table;
251 png_ptr->offset_table_ptr = farmalloc(num_blocks *
252 png_sizeof(png_bytep));
254 if (png_ptr->offset_table_ptr == NULL)
256 # ifndef PNG_USER_MEM_SUPPORTED
257 if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
258 png_error(png_ptr, "Out Of memory"); /* Note "O", "m" */
261 png_warning(png_ptr, "Out Of memory");
266 hptr = (png_byte huge *)table;
267 if ((png_size_t)hptr & 0xf)
269 hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
270 hptr = hptr + 16L; /* "hptr += 16L" fails on Turbo C++ 3.0 */
273 for (i = 0; i < num_blocks; i++)
275 png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
276 hptr = hptr + (png_uint_32)65536L; /* "+=" fails on TC++3.0 */
279 png_ptr->offset_table_number = num_blocks;
280 png_ptr->offset_table_count = 0;
281 png_ptr->offset_table_count_free = 0;
285 if (png_ptr->offset_table_count >= png_ptr->offset_table_number)
287 # ifndef PNG_USER_MEM_SUPPORTED
288 if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
289 png_error(png_ptr, "Out of Memory"); /* Note "O" and "M" */
292 png_warning(png_ptr, "Out of Memory");
297 ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++];
301 ret = farmalloc(size);
303 # ifndef PNG_USER_MEM_SUPPORTED
306 if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
307 png_error(png_ptr, "Out of memory"); /* Note "o" and "m" */
310 png_warning(png_ptr, "Out of memory"); /* Note "o" and "m" */
317 /* Free a pointer allocated by png_malloc(). In the default
318 * configuration, png_ptr is not used, but is passed in case it
319 * is needed. If ptr is NULL, return without taking any action.
322 png_free(png_structp png_ptr, png_voidp ptr)
324 if (png_ptr == NULL || ptr == NULL)
327 # ifdef PNG_USER_MEM_SUPPORTED
328 if (png_ptr->free_fn != NULL)
330 (*(png_ptr->free_fn))(png_ptr, ptr);
335 png_free_default(png_ptr, ptr);
339 png_free_default(png_structp png_ptr, png_voidp ptr)
341 # endif /* PNG_USER_MEM_SUPPORTED */
343 if (png_ptr == NULL || ptr == NULL)
346 if (png_ptr->offset_table != NULL)
350 for (i = 0; i < png_ptr->offset_table_count; i++)
352 if (ptr == png_ptr->offset_table_ptr[i])
355 png_ptr->offset_table_count_free++;
359 if (png_ptr->offset_table_count_free == png_ptr->offset_table_count)
361 farfree(png_ptr->offset_table);
362 farfree(png_ptr->offset_table_ptr);
363 png_ptr->offset_table = NULL;
364 png_ptr->offset_table_ptr = NULL;
372 #else /* Not the Borland DOS special memory handler */
374 /* Allocate memory for a png_struct or a png_info. The malloc and
375 memset can be replaced by a single call to calloc() if this is thought
376 to improve performance noticably. */
377 PNG_FUNCTION(png_voidp /* PRIVATE */,
378 png_create_struct,(int type),PNG_ALLOCATED)
380 # ifdef PNG_USER_MEM_SUPPORTED
381 return (png_create_struct_2(type, NULL, NULL));
384 /* Allocate memory for a png_struct or a png_info. The malloc and
385 memset can be replaced by a single call to calloc() if this is thought
386 to improve performance noticably. */
387 PNG_FUNCTION(png_voidp /* PRIVATE */,
388 png_create_struct_2,(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr),
391 # endif /* PNG_USER_MEM_SUPPORTED */
393 png_voidp struct_ptr;
395 if (type == PNG_STRUCT_INFO)
396 size = png_sizeof(png_info);
398 else if (type == PNG_STRUCT_PNG)
399 size = png_sizeof(png_struct);
404 # ifdef PNG_USER_MEM_SUPPORTED
405 if (malloc_fn != NULL)
407 png_struct dummy_struct;
408 png_structp png_ptr = &dummy_struct;
409 png_ptr->mem_ptr=mem_ptr;
410 struct_ptr = (*(malloc_fn))(png_ptr, size);
412 if (struct_ptr != NULL)
413 png_memset(struct_ptr, 0, size);
417 # endif /* PNG_USER_MEM_SUPPORTED */
419 # if defined(__TURBOC__) && !defined(__FLAT__)
420 struct_ptr = (png_voidp)farmalloc(size);
422 # if defined(_MSC_VER) && defined(MAXSEG_64K)
423 struct_ptr = (png_voidp)halloc(size, 1);
425 struct_ptr = (png_voidp)malloc(size);
429 if (struct_ptr != NULL)
430 png_memset(struct_ptr, 0, size);
436 /* Free memory allocated by a png_create_struct() call */
438 png_destroy_struct(png_voidp struct_ptr)
440 # ifdef PNG_USER_MEM_SUPPORTED
441 png_destroy_struct_2(struct_ptr, NULL, NULL);
444 /* Free memory allocated by a png_create_struct() call */
446 png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
449 # endif /* PNG_USER_MEM_SUPPORTED */
450 if (struct_ptr != NULL)
452 # ifdef PNG_USER_MEM_SUPPORTED
455 png_struct dummy_struct;
456 png_structp png_ptr = &dummy_struct;
457 png_ptr->mem_ptr=mem_ptr;
458 (*(free_fn))(png_ptr, struct_ptr);
461 # endif /* PNG_USER_MEM_SUPPORTED */
462 # if defined(__TURBOC__) && !defined(__FLAT__)
466 # if defined(_MSC_VER) && defined(MAXSEG_64K)
477 /* Allocate memory. For reasonable files, size should never exceed
478 * 64K. However, zlib may allocate more then 64K if you don't tell
479 * it not to. See zconf.h and png.h for more information. zlib does
480 * need to allocate exactly 64K, so whatever you call here must
481 * have the ability to do that.
484 PNG_FUNCTION(png_voidp,PNGAPI
485 png_calloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
489 ret = (png_malloc(png_ptr, size));
492 png_memset(ret,0,(png_size_t)size);
497 PNG_FUNCTION(png_voidp,PNGAPI
498 png_malloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
502 # ifdef PNG_USER_MEM_SUPPORTED
503 if (png_ptr == NULL || size == 0)
506 if (png_ptr->malloc_fn != NULL)
507 ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size));
510 ret = (png_malloc_default(png_ptr, size));
512 if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
513 png_error(png_ptr, "Out of Memory");
518 PNG_FUNCTION(png_voidp,PNGAPI
519 png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
522 # endif /* PNG_USER_MEM_SUPPORTED */
524 if (png_ptr == NULL || size == 0)
527 # ifdef PNG_MAX_MALLOC_64K
528 if (size > (png_uint_32)65536L)
530 # ifndef PNG_USER_MEM_SUPPORTED
531 if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
532 png_error(png_ptr, "Cannot Allocate > 64K");
540 /* Check for overflow */
541 # if defined(__TURBOC__) && !defined(__FLAT__)
543 if (size != (unsigned long)size)
547 ret = farmalloc(size);
550 # if defined(_MSC_VER) && defined(MAXSEG_64K)
551 if (size != (unsigned long)size)
555 ret = halloc(size, 1);
558 if (size != (size_t)size)
562 ret = malloc((size_t)size);
566 # ifndef PNG_USER_MEM_SUPPORTED
567 if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
568 png_error(png_ptr, "Out of Memory");
574 /* Free a pointer allocated by png_malloc(). If ptr is NULL, return
575 * without taking any action.
578 png_free(png_structp png_ptr, png_voidp ptr)
580 if (png_ptr == NULL || ptr == NULL)
583 # ifdef PNG_USER_MEM_SUPPORTED
584 if (png_ptr->free_fn != NULL)
586 (*(png_ptr->free_fn))(png_ptr, ptr);
591 png_free_default(png_ptr, ptr);
595 png_free_default(png_structp png_ptr, png_voidp ptr)
597 if (png_ptr == NULL || ptr == NULL)
600 # endif /* PNG_USER_MEM_SUPPORTED */
602 # if defined(__TURBOC__) && !defined(__FLAT__)
606 # if defined(_MSC_VER) && defined(MAXSEG_64K)
615 #endif /* Not Borland DOS special memory handler */
617 /* This function was added at libpng version 1.2.3. The png_malloc_warn()
618 * function will set up png_malloc() to issue a png_warning and return NULL
619 * instead of issuing a png_error, if it fails to allocate the requested
622 PNG_FUNCTION(png_voidp,PNGAPI
623 png_malloc_warn,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
626 png_uint_32 save_flags;
630 save_flags = png_ptr->flags;
631 png_ptr->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
632 ptr = (png_voidp)png_malloc((png_structp)png_ptr, size);
633 png_ptr->flags=save_flags;
638 #ifdef PNG_USER_MEM_SUPPORTED
639 /* This function is called when the application wants to use another method
640 * of allocating and freeing memory.
643 png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr
644 malloc_fn, png_free_ptr free_fn)
648 png_ptr->mem_ptr = mem_ptr;
649 png_ptr->malloc_fn = malloc_fn;
650 png_ptr->free_fn = free_fn;
654 /* This function returns a pointer to the mem_ptr associated with the user
655 * functions. The application should free any memory associated with this
656 * pointer before png_write_destroy and png_read_destroy are called.
659 png_get_mem_ptr(png_const_structp png_ptr)
664 return ((png_voidp)png_ptr->mem_ptr);
666 #endif /* PNG_USER_MEM_SUPPORTED */
667 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */