2 /* pngmem.c - stub functions for memory allocation
4 * Last changed in libpng 1.5.1 [February 3, 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 png_structp png_ptr = &dummy_struct;
60 png_ptr->mem_ptr=mem_ptr;
61 struct_ptr = (*(malloc_fn))(png_ptr, (png_uint_32)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 png_structp png_ptr = &dummy_struct;
94 png_ptr->mem_ptr=mem_ptr;
95 (*(free_fn))(png_ptr, 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, (png_size_t)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;
191 png_byte huge * hptr;
199 if (png_ptr->zlib_window_bits > 14)
200 num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14));
205 if (png_ptr->zlib_mem_level >= 7)
206 num_blocks += (int)(1 << (png_ptr->zlib_mem_level - 7));
211 total_size = ((png_uint_32)65536L) * (png_uint_32)num_blocks+16;
213 table = farmalloc(total_size);
217 # ifndef PNG_USER_MEM_SUPPORTED
218 if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
219 png_error(png_ptr, "Out Of Memory"); /* Note "O", "M" */
222 png_warning(png_ptr, "Out Of Memory");
227 if ((png_size_t)table & 0xfff0)
229 # ifndef PNG_USER_MEM_SUPPORTED
230 if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
232 "Farmalloc didn't return normalized pointer");
236 "Farmalloc didn't return normalized pointer");
241 png_ptr->offset_table = table;
242 png_ptr->offset_table_ptr = farmalloc(num_blocks *
243 png_sizeof(png_bytep));
245 if (png_ptr->offset_table_ptr == NULL)
247 # ifndef PNG_USER_MEM_SUPPORTED
248 if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
249 png_error(png_ptr, "Out Of memory"); /* Note "O", "m" */
252 png_warning(png_ptr, "Out Of memory");
257 hptr = (png_byte huge *)table;
258 if ((png_size_t)hptr & 0xf)
260 hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
261 hptr = hptr + 16L; /* "hptr += 16L" fails on Turbo C++ 3.0 */
264 for (i = 0; i < num_blocks; i++)
266 png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
267 hptr = hptr + (png_uint_32)65536L; /* "+=" fails on TC++3.0 */
270 png_ptr->offset_table_number = num_blocks;
271 png_ptr->offset_table_count = 0;
272 png_ptr->offset_table_count_free = 0;
276 if (png_ptr->offset_table_count >= png_ptr->offset_table_number)
278 # ifndef PNG_USER_MEM_SUPPORTED
279 if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
280 png_error(png_ptr, "Out of Memory"); /* Note "o" and "M" */
283 png_warning(png_ptr, "Out of Memory");
288 ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++];
292 ret = farmalloc(size);
294 # ifndef PNG_USER_MEM_SUPPORTED
297 if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
298 png_error(png_ptr, "Out of memory"); /* Note "o" and "m" */
301 png_warning(png_ptr, "Out of memory"); /* Note "o" and "m" */
308 /* Free a pointer allocated by png_malloc(). In the default
309 * configuration, png_ptr is not used, but is passed in case it
310 * is needed. If ptr is NULL, return without taking any action.
313 png_free(png_structp png_ptr, png_voidp ptr)
315 if (png_ptr == NULL || ptr == NULL)
318 # ifdef PNG_USER_MEM_SUPPORTED
319 if (png_ptr->free_fn != NULL)
321 (*(png_ptr->free_fn))(png_ptr, ptr);
326 png_free_default(png_ptr, ptr);
330 png_free_default(png_structp png_ptr, png_voidp ptr)
332 # endif /* PNG_USER_MEM_SUPPORTED */
334 if (png_ptr == NULL || ptr == NULL)
337 if (png_ptr->offset_table != NULL)
341 for (i = 0; i < png_ptr->offset_table_count; i++)
343 if (ptr == png_ptr->offset_table_ptr[i])
346 png_ptr->offset_table_count_free++;
350 if (png_ptr->offset_table_count_free == png_ptr->offset_table_count)
352 farfree(png_ptr->offset_table);
353 farfree(png_ptr->offset_table_ptr);
354 png_ptr->offset_table = NULL;
355 png_ptr->offset_table_ptr = NULL;
363 #else /* Not the Borland DOS special memory handler */
365 /* Allocate memory for a png_struct or a png_info. The malloc and
366 memset can be replaced by a single call to calloc() if this is thought
367 to improve performance noticably. */
368 PNG_FUNCTION(png_voidp /* PRIVATE */,
369 png_create_struct,(int type),PNG_ALLOCATED)
371 # ifdef PNG_USER_MEM_SUPPORTED
372 return (png_create_struct_2(type, NULL, NULL));
375 /* Allocate memory for a png_struct or a png_info. The malloc and
376 memset can be replaced by a single call to calloc() if this is thought
377 to improve performance noticably. */
378 PNG_FUNCTION(png_voidp /* PRIVATE */,
379 png_create_struct_2,(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr),
382 # endif /* PNG_USER_MEM_SUPPORTED */
384 png_voidp struct_ptr;
386 if (type == PNG_STRUCT_INFO)
387 size = png_sizeof(png_info);
389 else if (type == PNG_STRUCT_PNG)
390 size = png_sizeof(png_struct);
395 # ifdef PNG_USER_MEM_SUPPORTED
396 if (malloc_fn != NULL)
398 png_struct dummy_struct;
399 png_structp png_ptr = &dummy_struct;
400 png_ptr->mem_ptr=mem_ptr;
401 struct_ptr = (*(malloc_fn))(png_ptr, size);
403 if (struct_ptr != NULL)
404 png_memset(struct_ptr, 0, size);
408 # endif /* PNG_USER_MEM_SUPPORTED */
410 # if defined(__TURBOC__) && !defined(__FLAT__)
411 struct_ptr = (png_voidp)farmalloc(size);
413 # if defined(_MSC_VER) && defined(MAXSEG_64K)
414 struct_ptr = (png_voidp)halloc(size, 1);
416 struct_ptr = (png_voidp)malloc(size);
420 if (struct_ptr != NULL)
421 png_memset(struct_ptr, 0, size);
427 /* Free memory allocated by a png_create_struct() call */
429 png_destroy_struct(png_voidp struct_ptr)
431 # ifdef PNG_USER_MEM_SUPPORTED
432 png_destroy_struct_2(struct_ptr, NULL, NULL);
435 /* Free memory allocated by a png_create_struct() call */
437 png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
440 # endif /* PNG_USER_MEM_SUPPORTED */
441 if (struct_ptr != NULL)
443 # ifdef PNG_USER_MEM_SUPPORTED
446 png_struct dummy_struct;
447 png_structp png_ptr = &dummy_struct;
448 png_ptr->mem_ptr=mem_ptr;
449 (*(free_fn))(png_ptr, struct_ptr);
452 # endif /* PNG_USER_MEM_SUPPORTED */
453 # if defined(__TURBOC__) && !defined(__FLAT__)
457 # if defined(_MSC_VER) && defined(MAXSEG_64K)
468 /* Allocate memory. For reasonable files, size should never exceed
469 * 64K. However, zlib may allocate more then 64K if you don't tell
470 * it not to. See zconf.h and png.h for more information. zlib does
471 * need to allocate exactly 64K, so whatever you call here must
472 * have the ability to do that.
475 PNG_FUNCTION(png_voidp,PNGAPI
476 png_calloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
480 ret = (png_malloc(png_ptr, size));
483 png_memset(ret,0,(png_size_t)size);
488 PNG_FUNCTION(png_voidp,PNGAPI
489 png_malloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
493 # ifdef PNG_USER_MEM_SUPPORTED
494 if (png_ptr == NULL || size == 0)
497 if (png_ptr->malloc_fn != NULL)
498 ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size));
501 ret = (png_malloc_default(png_ptr, size));
503 if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
504 png_error(png_ptr, "Out of Memory");
509 PNG_FUNCTION(png_voidp,PNGAPI
510 png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
513 # endif /* PNG_USER_MEM_SUPPORTED */
515 if (png_ptr == NULL || size == 0)
518 # ifdef PNG_MAX_MALLOC_64K
519 if (size > (png_uint_32)65536L)
521 # ifndef PNG_USER_MEM_SUPPORTED
522 if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
523 png_error(png_ptr, "Cannot Allocate > 64K");
531 /* Check for overflow */
532 # if defined(__TURBOC__) && !defined(__FLAT__)
534 if (size != (unsigned long)size)
538 ret = farmalloc(size);
541 # if defined(_MSC_VER) && defined(MAXSEG_64K)
542 if (size != (unsigned long)size)
546 ret = halloc(size, 1);
549 if (size != (size_t)size)
553 ret = malloc((size_t)size);
557 # ifndef PNG_USER_MEM_SUPPORTED
558 if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
559 png_error(png_ptr, "Out of Memory");
565 /* Free a pointer allocated by png_malloc(). If ptr is NULL, return
566 * without taking any action.
569 png_free(png_structp png_ptr, png_voidp ptr)
571 if (png_ptr == NULL || ptr == NULL)
574 # ifdef PNG_USER_MEM_SUPPORTED
575 if (png_ptr->free_fn != NULL)
577 (*(png_ptr->free_fn))(png_ptr, ptr);
582 png_free_default(png_ptr, ptr);
586 png_free_default(png_structp png_ptr, png_voidp ptr)
588 if (png_ptr == NULL || ptr == NULL)
591 # endif /* PNG_USER_MEM_SUPPORTED */
593 # if defined(__TURBOC__) && !defined(__FLAT__)
597 # if defined(_MSC_VER) && defined(MAXSEG_64K)
606 #endif /* Not Borland DOS special memory handler */
608 /* This function was added at libpng version 1.2.3. The png_malloc_warn()
609 * function will set up png_malloc() to issue a png_warning and return NULL
610 * instead of issuing a png_error, if it fails to allocate the requested
613 PNG_FUNCTION(png_voidp,PNGAPI
614 png_malloc_warn,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
617 png_uint_32 save_flags;
621 save_flags = png_ptr->flags;
622 png_ptr->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
623 ptr = (png_voidp)png_malloc((png_structp)png_ptr, size);
624 png_ptr->flags=save_flags;
629 #ifdef PNG_USER_MEM_SUPPORTED
630 /* This function is called when the application wants to use another method
631 * of allocating and freeing memory.
634 png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr
635 malloc_fn, png_free_ptr free_fn)
639 png_ptr->mem_ptr = mem_ptr;
640 png_ptr->malloc_fn = malloc_fn;
641 png_ptr->free_fn = free_fn;
645 /* This function returns a pointer to the mem_ptr associated with the user
646 * functions. The application should free any memory associated with this
647 * pointer before png_write_destroy and png_read_destroy are called.
650 png_get_mem_ptr(png_const_structp png_ptr)
655 return ((png_voidp)png_ptr->mem_ptr);
657 #endif /* PNG_USER_MEM_SUPPORTED */
658 #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */