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/src/FreeImage/Source/LibPNG/pngmem.c

https://bitbucket.org/cabalistic/ogredeps/
C | 667 lines | 467 code | 122 blank | 78 comment | 162 complexity | aa9a43db2e454926bd7e658271b29592 MD5 | raw file
  1
  2/* pngmem.c - stub functions for memory allocation
  3 *
  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.)
  8 *
  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
 12 *
 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.
 18 */
 19
 20#include "pngpriv.h"
 21
 22#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
 23
 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 */
 27
 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. */
 30PNG_FUNCTION(png_voidp /* PRIVATE */,
 31png_create_struct,(int type),PNG_ALLOCATED)
 32{
 33#  ifdef PNG_USER_MEM_SUPPORTED
 34   return (png_create_struct_2(type, NULL, NULL));
 35}
 36
 37/* Alternate version of png_create_struct, for use with user-defined malloc. */
 38PNG_FUNCTION(png_voidp /* PRIVATE */,
 39png_create_struct_2,(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr),
 40   PNG_ALLOCATED)
 41{
 42#  endif /* PNG_USER_MEM_SUPPORTED */
 43   png_size_t size;
 44   png_voidp struct_ptr;
 45
 46   if (type == PNG_STRUCT_INFO)
 47      size = png_sizeof(png_info);
 48
 49   else if (type == PNG_STRUCT_PNG)
 50      size = png_sizeof(png_struct);
 51
 52   else
 53      return (png_get_copyright(NULL));
 54
 55#  ifdef PNG_USER_MEM_SUPPORTED
 56   if (malloc_fn != NULL)
 57   {
 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);
 62   }
 63
 64   else
 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);
 69
 70   return (struct_ptr);
 71}
 72
 73/* Free memory allocated by a png_create_struct() call */
 74void /* PRIVATE */
 75png_destroy_struct(png_voidp struct_ptr)
 76{
 77#  ifdef PNG_USER_MEM_SUPPORTED
 78   png_destroy_struct_2(struct_ptr, NULL, NULL);
 79}
 80
 81/* Free memory allocated by a png_create_struct() call */
 82void /* PRIVATE */
 83png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
 84    png_voidp mem_ptr)
 85{
 86#  endif
 87   if (struct_ptr != NULL)
 88   {
 89#  ifdef PNG_USER_MEM_SUPPORTED
 90      if (free_fn != NULL)
 91      {
 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);
 96         return;
 97      }
 98
 99#  endif /* PNG_USER_MEM_SUPPORTED */
100      farfree (struct_ptr);
101   }
102}
103
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.
109 *
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
116 * memory.
117 *
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.
122 */
123PNG_FUNCTION(png_voidp,PNGAPI
124png_calloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
125{
126   png_voidp ret;
127
128   ret = (png_malloc(png_ptr, size));
129
130   if (ret != NULL)
131      png_memset(ret,0,(png_size_t)size);
132
133   return (ret);
134}
135
136PNG_FUNCTION(png_voidp,PNGAPI
137png_malloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
138{
139   png_voidp ret;
140
141   if (png_ptr == NULL || size == 0)
142      return (NULL);
143
144#  ifdef PNG_USER_MEM_SUPPORTED
145   if (png_ptr->malloc_fn != NULL)
146      ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size));
147
148   else
149      ret = (png_malloc_default(png_ptr, size));
150
151   if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
152       png_error(png_ptr, "Out of memory");
153
154   return (ret);
155}
156
157PNG_FUNCTION(png_voidp,PNGAPI
158png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
159{
160   png_voidp ret;
161#  endif /* PNG_USER_MEM_SUPPORTED */
162
163   if (png_ptr == NULL || size == 0)
164      return (NULL);
165
166#  ifdef PNG_MAX_MALLOC_64K
167   if (size > (png_uint_32)65536L)
168   {
169      png_warning(png_ptr, "Cannot Allocate > 64K");
170      ret = NULL;
171   }
172
173   else
174#  endif
175
176   if (size != (size_t)size)
177      ret = NULL;
178
179   else if (size == (png_uint_32)65536L)
180   {
181      if (png_ptr->offset_table == NULL)
182      {
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))
186         {
187            int num_blocks;
188            png_uint_32 total_size;
189            png_bytep table;
190            int i, mem_level, window_bits;
191            png_byte huge * hptr;
192            int window_bits
193
194            if (ret != NULL)
195            {
196               farfree(ret);
197               ret = NULL;
198            }
199
200            window_bits =
201                png_ptr->zlib_window_bits >= png_ptr->zlib_text_window_bits ?
202                png_ptr->zlib_window_bits : png_ptr->zlib_text_window_bits;
203
204            if (window_bits > 14)
205               num_blocks = (int)(1 << (window_bits - 14));
206
207            else
208               num_blocks = 1;
209
210            mem_level =
211                png_ptr->zlib_mem_level >= png_ptr->zlib_text_mem_level ?
212                png_ptr->zlib_mem_level : png_ptr->zlib_text_mem_level;
213
214            if (mem_level >= 7)
215               num_blocks += (int)(1 << (mem_level - 7));
216
217            else
218               num_blocks++;
219
220            total_size = ((png_uint_32)65536L) * (png_uint_32)num_blocks+16;
221
222            table = farmalloc(total_size);
223
224            if (table == NULL)
225            {
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" */
229
230               else
231                  png_warning(png_ptr, "Out Of Memory");
232#  endif
233               return (NULL);
234            }
235
236            if ((png_size_t)table & 0xfff0)
237            {
238#  ifndef PNG_USER_MEM_SUPPORTED
239               if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
240                  png_error(png_ptr,
241                    "Farmalloc didn't return normalized pointer");
242
243               else
244                  png_warning(png_ptr,
245                    "Farmalloc didn't return normalized pointer");
246#  endif
247               return (NULL);
248            }
249
250            png_ptr->offset_table = table;
251            png_ptr->offset_table_ptr = farmalloc(num_blocks *
252               png_sizeof(png_bytep));
253
254            if (png_ptr->offset_table_ptr == NULL)
255            {
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" */
259
260               else
261                  png_warning(png_ptr, "Out Of memory");
262#  endif
263               return (NULL);
264            }
265
266            hptr = (png_byte huge *)table;
267            if ((png_size_t)hptr & 0xf)
268            {
269               hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
270               hptr = hptr + 16L;  /* "hptr += 16L" fails on Turbo C++ 3.0 */
271            }
272
273            for (i = 0; i < num_blocks; i++)
274            {
275               png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
276               hptr = hptr + (png_uint_32)65536L;  /* "+=" fails on TC++3.0 */
277            }
278
279            png_ptr->offset_table_number = num_blocks;
280            png_ptr->offset_table_count = 0;
281            png_ptr->offset_table_count_free = 0;
282         }
283      }
284
285      if (png_ptr->offset_table_count >= png_ptr->offset_table_number)
286      {
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" */
290
291         else
292            png_warning(png_ptr, "Out of Memory");
293#  endif
294         return (NULL);
295      }
296
297      ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++];
298   }
299
300   else
301      ret = farmalloc(size);
302
303#  ifndef PNG_USER_MEM_SUPPORTED
304   if (ret == NULL)
305   {
306      if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
307         png_error(png_ptr, "Out of memory"); /* Note "o" and "m" */
308
309      else
310         png_warning(png_ptr, "Out of memory"); /* Note "o" and "m" */
311   }
312#  endif
313
314   return (ret);
315}
316
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.
320 */
321void PNGAPI
322png_free(png_structp png_ptr, png_voidp ptr)
323{
324   if (png_ptr == NULL || ptr == NULL)
325      return;
326
327#  ifdef PNG_USER_MEM_SUPPORTED
328   if (png_ptr->free_fn != NULL)
329   {
330      (*(png_ptr->free_fn))(png_ptr, ptr);
331      return;
332   }
333
334   else
335      png_free_default(png_ptr, ptr);
336}
337
338void PNGAPI
339png_free_default(png_structp png_ptr, png_voidp ptr)
340{
341#  endif /* PNG_USER_MEM_SUPPORTED */
342
343   if (png_ptr == NULL || ptr == NULL)
344      return;
345
346   if (png_ptr->offset_table != NULL)
347   {
348      int i;
349
350      for (i = 0; i < png_ptr->offset_table_count; i++)
351      {
352         if (ptr == png_ptr->offset_table_ptr[i])
353         {
354            ptr = NULL;
355            png_ptr->offset_table_count_free++;
356            break;
357         }
358      }
359      if (png_ptr->offset_table_count_free == png_ptr->offset_table_count)
360      {
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;
365      }
366   }
367
368   if (ptr != NULL)
369      farfree(ptr);
370}
371
372#else /* Not the Borland DOS special memory handler */
373
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. */
377PNG_FUNCTION(png_voidp /* PRIVATE */,
378png_create_struct,(int type),PNG_ALLOCATED)
379{
380#  ifdef PNG_USER_MEM_SUPPORTED
381   return (png_create_struct_2(type, NULL, NULL));
382}
383
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. */
387PNG_FUNCTION(png_voidp /* PRIVATE */,
388png_create_struct_2,(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr),
389   PNG_ALLOCATED)
390{
391#  endif /* PNG_USER_MEM_SUPPORTED */
392   png_size_t size;
393   png_voidp struct_ptr;
394
395   if (type == PNG_STRUCT_INFO)
396      size = png_sizeof(png_info);
397
398   else if (type == PNG_STRUCT_PNG)
399      size = png_sizeof(png_struct);
400
401   else
402      return (NULL);
403
404#  ifdef PNG_USER_MEM_SUPPORTED
405   if (malloc_fn != NULL)
406   {
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);
411
412      if (struct_ptr != NULL)
413         png_memset(struct_ptr, 0, size);
414
415      return (struct_ptr);
416   }
417#  endif /* PNG_USER_MEM_SUPPORTED */
418
419#  if defined(__TURBOC__) && !defined(__FLAT__)
420   struct_ptr = (png_voidp)farmalloc(size);
421#  else
422#    if defined(_MSC_VER) && defined(MAXSEG_64K)
423   struct_ptr = (png_voidp)halloc(size, 1);
424#    else
425   struct_ptr = (png_voidp)malloc(size);
426#    endif
427#  endif
428
429   if (struct_ptr != NULL)
430      png_memset(struct_ptr, 0, size);
431
432   return (struct_ptr);
433}
434
435
436/* Free memory allocated by a png_create_struct() call */
437void /* PRIVATE */
438png_destroy_struct(png_voidp struct_ptr)
439{
440#  ifdef PNG_USER_MEM_SUPPORTED
441   png_destroy_struct_2(struct_ptr, NULL, NULL);
442}
443
444/* Free memory allocated by a png_create_struct() call */
445void /* PRIVATE */
446png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
447    png_voidp mem_ptr)
448{
449#  endif /* PNG_USER_MEM_SUPPORTED */
450   if (struct_ptr != NULL)
451   {
452#  ifdef PNG_USER_MEM_SUPPORTED
453      if (free_fn != NULL)
454      {
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);
459         return;
460      }
461#  endif /* PNG_USER_MEM_SUPPORTED */
462#  if defined(__TURBOC__) && !defined(__FLAT__)
463      farfree(struct_ptr);
464
465#  else
466#    if defined(_MSC_VER) && defined(MAXSEG_64K)
467      hfree(struct_ptr);
468
469#    else
470      free(struct_ptr);
471
472#    endif
473#  endif
474   }
475}
476
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.
482 */
483
484PNG_FUNCTION(png_voidp,PNGAPI
485png_calloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
486{
487   png_voidp ret;
488
489   ret = (png_malloc(png_ptr, size));
490
491   if (ret != NULL)
492      png_memset(ret,0,(png_size_t)size);
493
494   return (ret);
495}
496
497PNG_FUNCTION(png_voidp,PNGAPI
498png_malloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
499{
500   png_voidp ret;
501
502#  ifdef PNG_USER_MEM_SUPPORTED
503   if (png_ptr == NULL || size == 0)
504      return (NULL);
505
506   if (png_ptr->malloc_fn != NULL)
507      ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size));
508
509   else
510      ret = (png_malloc_default(png_ptr, size));
511
512   if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
513       png_error(png_ptr, "Out of Memory");
514
515   return (ret);
516}
517
518PNG_FUNCTION(png_voidp,PNGAPI
519png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
520{
521   png_voidp ret;
522#  endif /* PNG_USER_MEM_SUPPORTED */
523
524   if (png_ptr == NULL || size == 0)
525      return (NULL);
526
527#  ifdef PNG_MAX_MALLOC_64K
528   if (size > (png_uint_32)65536L)
529   {
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");
533
534      else
535#    endif
536         return NULL;
537   }
538#  endif
539
540   /* Check for overflow */
541#  if defined(__TURBOC__) && !defined(__FLAT__)
542
543   if (size != (unsigned long)size)
544      ret = NULL;
545
546   else
547      ret = farmalloc(size);
548
549#  else
550#    if defined(_MSC_VER) && defined(MAXSEG_64K)
551   if (size != (unsigned long)size)
552      ret = NULL;
553
554   else
555      ret = halloc(size, 1);
556
557#    else
558   if (size != (size_t)size)
559      ret = NULL;
560
561   else
562      ret = malloc((size_t)size);
563#    endif
564#  endif
565
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");
569#  endif
570
571   return (ret);
572}
573
574/* Free a pointer allocated by png_malloc().  If ptr is NULL, return
575 * without taking any action.
576 */
577void PNGAPI
578png_free(png_structp png_ptr, png_voidp ptr)
579{
580   if (png_ptr == NULL || ptr == NULL)
581      return;
582
583#  ifdef PNG_USER_MEM_SUPPORTED
584   if (png_ptr->free_fn != NULL)
585   {
586      (*(png_ptr->free_fn))(png_ptr, ptr);
587      return;
588   }
589
590   else
591      png_free_default(png_ptr, ptr);
592}
593
594void PNGAPI
595png_free_default(png_structp png_ptr, png_voidp ptr)
596{
597   if (png_ptr == NULL || ptr == NULL)
598      return;
599
600#  endif /* PNG_USER_MEM_SUPPORTED */
601
602#  if defined(__TURBOC__) && !defined(__FLAT__)
603   farfree(ptr);
604
605#  else
606#    if defined(_MSC_VER) && defined(MAXSEG_64K)
607   hfree(ptr);
608
609#    else
610   free(ptr);
611
612#    endif
613#  endif
614}
615#endif /* Not Borland DOS special memory handler */
616
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
620 * memory.
621 */
622PNG_FUNCTION(png_voidp,PNGAPI
623png_malloc_warn,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
624{
625   png_voidp ptr;
626   png_uint_32 save_flags;
627   if (png_ptr == NULL)
628      return (NULL);
629
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;
634   return(ptr);
635}
636
637
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.
641 */
642void PNGAPI
643png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr
644  malloc_fn, png_free_ptr free_fn)
645{
646   if (png_ptr != NULL)
647   {
648      png_ptr->mem_ptr = mem_ptr;
649      png_ptr->malloc_fn = malloc_fn;
650      png_ptr->free_fn = free_fn;
651   }
652}
653
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.
657 */
658png_voidp PNGAPI
659png_get_mem_ptr(png_const_structp png_ptr)
660{
661   if (png_ptr == NULL)
662      return (NULL);
663
664   return ((png_voidp)png_ptr->mem_ptr);
665}
666#endif /* PNG_USER_MEM_SUPPORTED */
667#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */