pngmem.c 16.7 KB
Newer Older
1 2 3

/* pngmem.c - stub functions for memory allocation
 *
4 5
 * Last changed in libpng 1.2.37 [June 4, 2009]
 * Copyright (c) 1998-2009 Glenn Randers-Pehrson
6 7 8
 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
 *
9 10 11 12
 * This code is released under the libpng license.
 * For conditions of distribution and use, see the disclaimer
 * and license in png.h
 *
13 14 15 16 17 18 19 20 21
 * This file provides a location for all memory allocation.  Users who
 * need special memory handling are expected to supply replacement
 * functions for png_malloc() and png_free(), and to use
 * png_create_read_struct_2() and png_create_write_struct_2() to
 * identify the replacement functions.
 */

#define PNG_INTERNAL
#include "png.h"
22 23
#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)

24 25
/* Borland DOS special memory handler */
#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
26
/* If you change this, be sure to change the one in png.h also */
27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45

/* Allocate memory for a png_struct.  The malloc and memset can be replaced
   by a single call to calloc() if this is thought to improve performance. */
png_voidp /* PRIVATE */
png_create_struct(int type)
{
#ifdef PNG_USER_MEM_SUPPORTED
   return (png_create_struct_2(type, png_malloc_ptr_NULL, png_voidp_NULL));
}

/* Alternate version of png_create_struct, for use with user-defined malloc. */
png_voidp /* PRIVATE */
png_create_struct_2(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr)
{
#endif /* PNG_USER_MEM_SUPPORTED */
   png_size_t size;
   png_voidp struct_ptr;

   if (type == PNG_STRUCT_INFO)
46
      size = png_sizeof(png_info);
47
   else if (type == PNG_STRUCT_PNG)
48
      size = png_sizeof(png_struct);
49
   else
50
      return (png_get_copyright(NULL));
51 52

#ifdef PNG_USER_MEM_SUPPORTED
53
   if (malloc_fn != NULL)
54 55 56 57 58 59 60 61
   {
      png_struct dummy_struct;
      png_structp png_ptr = &dummy_struct;
      png_ptr->mem_ptr=mem_ptr;
      struct_ptr = (*(malloc_fn))(png_ptr, (png_uint_32)size);
   }
   else
#endif /* PNG_USER_MEM_SUPPORTED */
62
   struct_ptr = (png_voidp)farmalloc(size);
63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84
   if (struct_ptr != NULL)
      png_memset(struct_ptr, 0, size);
   return (struct_ptr);
}

/* Free memory allocated by a png_create_struct() call */
void /* PRIVATE */
png_destroy_struct(png_voidp struct_ptr)
{
#ifdef PNG_USER_MEM_SUPPORTED
   png_destroy_struct_2(struct_ptr, png_free_ptr_NULL, png_voidp_NULL);
}

/* Free memory allocated by a png_create_struct() call */
void /* PRIVATE */
png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
    png_voidp mem_ptr)
{
#endif
   if (struct_ptr != NULL)
   {
#ifdef PNG_USER_MEM_SUPPORTED
85
      if (free_fn != NULL)
86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116
      {
         png_struct dummy_struct;
         png_structp png_ptr = &dummy_struct;
         png_ptr->mem_ptr=mem_ptr;
         (*(free_fn))(png_ptr, struct_ptr);
         return;
      }
#endif /* PNG_USER_MEM_SUPPORTED */
      farfree (struct_ptr);
   }
}

/* Allocate memory.  For reasonable files, size should never exceed
 * 64K.  However, zlib may allocate more then 64K if you don't tell
 * it not to.  See zconf.h and png.h for more information. zlib does
 * need to allocate exactly 64K, so whatever you call here must
 * have the ability to do that.
 *
 * Borland seems to have a problem in DOS mode for exactly 64K.
 * It gives you a segment with an offset of 8 (perhaps to store its
 * memory stuff).  zlib doesn't like this at all, so we have to
 * detect and deal with it.  This code should not be needed in
 * Windows or OS/2 modes, and only in 16 bit mode.  This code has
 * been updated by Alexander Lehmann for version 0.89 to waste less
 * memory.
 *
 * Note that we can't use png_size_t for the "size" declaration,
 * since on some systems a png_size_t is a 16-bit quantity, and as a
 * result, we would be truncating potentially larger memory requests
 * (which should cause a fatal error) and introducing major problems.
 */
117

118 119 120 121
png_voidp PNGAPI
png_malloc(png_structp png_ptr, png_uint_32 size)
{
   png_voidp ret;
122

123 124 125 126
   if (png_ptr == NULL || size == 0)
      return (NULL);

#ifdef PNG_USER_MEM_SUPPORTED
127 128
   if (png_ptr->malloc_fn != NULL)
      ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size));
129
   else
130
      ret = (png_malloc_default(png_ptr, size));
131 132 133
   if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
       png_error(png_ptr, "Out of memory!");
   return (ret);
134 135 136 137 138 139 140 141
}

png_voidp PNGAPI
png_malloc_default(png_structp png_ptr, png_uint_32 size)
{
   png_voidp ret;
#endif /* PNG_USER_MEM_SUPPORTED */

142 143 144
   if (png_ptr == NULL || size == 0)
      return (NULL);

145 146
#ifdef PNG_MAX_MALLOC_64K
   if (size > (png_uint_32)65536L)
147 148 149 150 151
   {
      png_warning(png_ptr, "Cannot Allocate > 64K");
      ret = NULL;
   }
   else
152 153
#endif

154
   if (size != (size_t)size)
155
      ret = NULL;
156
   else if (size == (png_uint_32)65536L)
157 158 159
   {
      if (png_ptr->offset_table == NULL)
      {
160
         /* Try to see if we need to do any of this fancy stuff */
161 162 163 164 165 166 167 168 169 170 171 172 173 174 175
         ret = farmalloc(size);
         if (ret == NULL || ((png_size_t)ret & 0xffff))
         {
            int num_blocks;
            png_uint_32 total_size;
            png_bytep table;
            int i;
            png_byte huge * hptr;

            if (ret != NULL)
            {
               farfree(ret);
               ret = NULL;
            }

176
            if (png_ptr->zlib_window_bits > 14)
177 178 179 180 181 182 183 184 185 186 187 188 189 190
               num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14));
            else
               num_blocks = 1;
            if (png_ptr->zlib_mem_level >= 7)
               num_blocks += (int)(1 << (png_ptr->zlib_mem_level - 7));
            else
               num_blocks++;

            total_size = ((png_uint_32)65536L) * (png_uint_32)num_blocks+16;

            table = farmalloc(total_size);

            if (table == NULL)
            {
191 192 193 194 195 196 197
#ifndef PNG_USER_MEM_SUPPORTED
               if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
                  png_error(png_ptr, "Out Of Memory."); /* Note "O" and "M" */
               else
                  png_warning(png_ptr, "Out Of Memory.");
#endif
               return (NULL);
198 199 200 201
            }

            if ((png_size_t)table & 0xfff0)
            {
202 203 204 205 206 207 208 209 210
#ifndef PNG_USER_MEM_SUPPORTED
               if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
                  png_error(png_ptr,
                    "Farmalloc didn't return normalized pointer");
               else
                  png_warning(png_ptr,
                    "Farmalloc didn't return normalized pointer");
#endif
               return (NULL);
211 212 213 214
            }

            png_ptr->offset_table = table;
            png_ptr->offset_table_ptr = farmalloc(num_blocks *
215
               png_sizeof(png_bytep));
216 217 218

            if (png_ptr->offset_table_ptr == NULL)
            {
219 220 221 222 223 224 225
#ifndef PNG_USER_MEM_SUPPORTED
               if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
                  png_error(png_ptr, "Out Of memory."); /* Note "O" and "M" */
               else
                  png_warning(png_ptr, "Out Of memory.");
#endif
               return (NULL);
226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246
            }

            hptr = (png_byte huge *)table;
            if ((png_size_t)hptr & 0xf)
            {
               hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
               hptr = hptr + 16L;  /* "hptr += 16L" fails on Turbo C++ 3.0 */
            }
            for (i = 0; i < num_blocks; i++)
            {
               png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
               hptr = hptr + (png_uint_32)65536L;  /* "+=" fails on TC++3.0 */
            }

            png_ptr->offset_table_number = num_blocks;
            png_ptr->offset_table_count = 0;
            png_ptr->offset_table_count_free = 0;
         }
      }

      if (png_ptr->offset_table_count >= png_ptr->offset_table_number)
247 248 249 250 251 252 253 254 255
      {
#ifndef PNG_USER_MEM_SUPPORTED
         if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
            png_error(png_ptr, "Out of Memory."); /* Note "o" and "M" */
         else
            png_warning(png_ptr, "Out of Memory.");
#endif
         return (NULL);
      }
256 257 258 259 260 261

      ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++];
   }
   else
      ret = farmalloc(size);

262
#ifndef PNG_USER_MEM_SUPPORTED
263 264
   if (ret == NULL)
   {
265 266 267 268
      if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
         png_error(png_ptr, "Out of memory."); /* Note "o" and "m" */
      else
         png_warning(png_ptr, "Out of memory."); /* Note "o" and "m" */
269
   }
270
#endif
271 272 273 274

   return (ret);
}

275 276 277 278
/* Free a pointer allocated by png_malloc().  In the default
 * configuration, png_ptr is not used, but is passed in case it
 * is needed.  If ptr is NULL, return without taking any action.
 */
279 280 281 282 283 284 285 286 287 288 289 290
void PNGAPI
png_free(png_structp png_ptr, png_voidp ptr)
{
   if (png_ptr == NULL || ptr == NULL)
      return;

#ifdef PNG_USER_MEM_SUPPORTED
   if (png_ptr->free_fn != NULL)
   {
      (*(png_ptr->free_fn))(png_ptr, ptr);
      return;
   }
291 292
   else
      png_free_default(png_ptr, ptr);
293 294 295 296 297 298 299
}

void PNGAPI
png_free_default(png_structp png_ptr, png_voidp ptr)
{
#endif /* PNG_USER_MEM_SUPPORTED */

300 301
   if (png_ptr == NULL || ptr == NULL)
      return;
302

303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334
   if (png_ptr->offset_table != NULL)
   {
      int i;

      for (i = 0; i < png_ptr->offset_table_count; i++)
      {
         if (ptr == png_ptr->offset_table_ptr[i])
         {
            ptr = NULL;
            png_ptr->offset_table_count_free++;
            break;
         }
      }
      if (png_ptr->offset_table_count_free == png_ptr->offset_table_count)
      {
         farfree(png_ptr->offset_table);
         farfree(png_ptr->offset_table_ptr);
         png_ptr->offset_table = NULL;
         png_ptr->offset_table_ptr = NULL;
      }
   }

   if (ptr != NULL)
   {
      farfree(ptr);
   }
}

#else /* Not the Borland DOS special memory handler */

/* Allocate memory for a png_struct or a png_info.  The malloc and
   memset can be replaced by a single call to calloc() if this is thought
335
   to improve performance noticably. */
336 337 338 339 340 341 342 343 344
png_voidp /* PRIVATE */
png_create_struct(int type)
{
#ifdef PNG_USER_MEM_SUPPORTED
   return (png_create_struct_2(type, png_malloc_ptr_NULL, png_voidp_NULL));
}

/* Allocate memory for a png_struct or a png_info.  The malloc and
   memset can be replaced by a single call to calloc() if this is thought
345
   to improve performance noticably. */
346 347 348 349 350 351 352 353
png_voidp /* PRIVATE */
png_create_struct_2(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr)
{
#endif /* PNG_USER_MEM_SUPPORTED */
   png_size_t size;
   png_voidp struct_ptr;

   if (type == PNG_STRUCT_INFO)
354
      size = png_sizeof(png_info);
355
   else if (type == PNG_STRUCT_PNG)
356
      size = png_sizeof(png_struct);
357 358 359 360
   else
      return (NULL);

#ifdef PNG_USER_MEM_SUPPORTED
361
   if (malloc_fn != NULL)
362 363 364 365 366 367 368 369 370 371 372 373
   {
      png_struct dummy_struct;
      png_structp png_ptr = &dummy_struct;
      png_ptr->mem_ptr=mem_ptr;
      struct_ptr = (*(malloc_fn))(png_ptr, size);
      if (struct_ptr != NULL)
         png_memset(struct_ptr, 0, size);
      return (struct_ptr);
   }
#endif /* PNG_USER_MEM_SUPPORTED */

#if defined(__TURBOC__) && !defined(__FLAT__)
374
   struct_ptr = (png_voidp)farmalloc(size);
375 376
#else
# if defined(_MSC_VER) && defined(MAXSEG_64K)
377
   struct_ptr = (png_voidp)halloc(size, 1);
378
# else
379
   struct_ptr = (png_voidp)malloc(size);
380 381
# endif
#endif
382
   if (struct_ptr != NULL)
383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405
      png_memset(struct_ptr, 0, size);

   return (struct_ptr);
}


/* Free memory allocated by a png_create_struct() call */
void /* PRIVATE */
png_destroy_struct(png_voidp struct_ptr)
{
#ifdef PNG_USER_MEM_SUPPORTED
   png_destroy_struct_2(struct_ptr, png_free_ptr_NULL, png_voidp_NULL);
}

/* Free memory allocated by a png_create_struct() call */
void /* PRIVATE */
png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn,
    png_voidp mem_ptr)
{
#endif /* PNG_USER_MEM_SUPPORTED */
   if (struct_ptr != NULL)
   {
#ifdef PNG_USER_MEM_SUPPORTED
406
      if (free_fn != NULL)
407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427
      {
         png_struct dummy_struct;
         png_structp png_ptr = &dummy_struct;
         png_ptr->mem_ptr=mem_ptr;
         (*(free_fn))(png_ptr, struct_ptr);
         return;
      }
#endif /* PNG_USER_MEM_SUPPORTED */
#if defined(__TURBOC__) && !defined(__FLAT__)
      farfree(struct_ptr);
#else
# if defined(_MSC_VER) && defined(MAXSEG_64K)
      hfree(struct_ptr);
# else
      free(struct_ptr);
# endif
#endif
   }
}

/* Allocate memory.  For reasonable files, size should never exceed
428 429 430 431 432 433
 * 64K.  However, zlib may allocate more then 64K if you don't tell
 * it not to.  See zconf.h and png.h for more information.  zlib does
 * need to allocate exactly 64K, so whatever you call here must
 * have the ability to do that.
 */

434 435 436 437 438

png_voidp PNGAPI
png_malloc(png_structp png_ptr, png_uint_32 size)
{
   png_voidp ret;
439 440

#ifdef PNG_USER_MEM_SUPPORTED
441 442 443
   if (png_ptr == NULL || size == 0)
      return (NULL);

444 445
   if (png_ptr->malloc_fn != NULL)
      ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size));
446
   else
447
      ret = (png_malloc_default(png_ptr, size));
448 449 450
   if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
       png_error(png_ptr, "Out of Memory!");
   return (ret);
451
}
452 453

png_voidp PNGAPI
454 455 456 457 458
png_malloc_default(png_structp png_ptr, png_uint_32 size)
{
   png_voidp ret;
#endif /* PNG_USER_MEM_SUPPORTED */

459 460 461
   if (png_ptr == NULL || size == 0)
      return (NULL);

462 463
#ifdef PNG_MAX_MALLOC_64K
   if (size > (png_uint_32)65536L)
464 465
   {
#ifndef PNG_USER_MEM_SUPPORTED
466
      if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
467 468 469 470 471
         png_error(png_ptr, "Cannot Allocate > 64K");
      else
#endif
         return NULL;
   }
472 473
#endif

474
   /* Check for overflow */
475
#if defined(__TURBOC__) && !defined(__FLAT__)
476 477 478 479
   if (size != (unsigned long)size)
      ret = NULL;
   else
      ret = farmalloc(size);
480 481
#else
# if defined(_MSC_VER) && defined(MAXSEG_64K)
482 483 484 485
   if (size != (unsigned long)size)
      ret = NULL;
   else
      ret = halloc(size, 1);
486
# else
487 488 489 490
   if (size != (size_t)size)
      ret = NULL;
   else
      ret = malloc((size_t)size);
491 492 493
# endif
#endif

494 495
#ifndef PNG_USER_MEM_SUPPORTED
   if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0)
496
      png_error(png_ptr, "Out of Memory");
497
#endif
498 499 500 501 502

   return (ret);
}

/* Free a pointer allocated by png_malloc().  If ptr is NULL, return
503 504
 * without taking any action.
 */
505 506 507 508 509 510 511 512 513 514 515 516
void PNGAPI
png_free(png_structp png_ptr, png_voidp ptr)
{
   if (png_ptr == NULL || ptr == NULL)
      return;

#ifdef PNG_USER_MEM_SUPPORTED
   if (png_ptr->free_fn != NULL)
   {
      (*(png_ptr->free_fn))(png_ptr, ptr);
      return;
   }
517 518
   else
      png_free_default(png_ptr, ptr);
519
}
520
void PNGAPI
521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540
png_free_default(png_structp png_ptr, png_voidp ptr)
{
   if (png_ptr == NULL || ptr == NULL)
      return;

#endif /* PNG_USER_MEM_SUPPORTED */

#if defined(__TURBOC__) && !defined(__FLAT__)
   farfree(ptr);
#else
# if defined(_MSC_VER) && defined(MAXSEG_64K)
   hfree(ptr);
# else
   free(ptr);
# endif
#endif
}

#endif /* Not Borland DOS special memory handler */

541 542 543 544 545 546 547 548 549 550 551 552
#if defined(PNG_1_0_X)
#  define png_malloc_warn png_malloc
#else
/* This function was added at libpng version 1.2.3.  The png_malloc_warn()
 * function will set up png_malloc() to issue a png_warning and return NULL
 * instead of issuing a png_error, if it fails to allocate the requested
 * memory.
 */
png_voidp PNGAPI
png_malloc_warn(png_structp png_ptr, png_uint_32 size)
{
   png_voidp ptr;
553
   png_uint_32 save_flags;
554 555
   if (png_ptr == NULL)
      return (NULL);
556

557
   save_flags = png_ptr->flags;
558 559 560 561 562 563 564 565
   png_ptr->flags|=PNG_FLAG_MALLOC_NULL_MEM_OK;
   ptr = (png_voidp)png_malloc((png_structp)png_ptr, size);
   png_ptr->flags=save_flags;
   return(ptr);
}
#endif

png_voidp PNGAPI
566 567 568 569 570 571 572
png_memcpy_check (png_structp png_ptr, png_voidp s1, png_voidp s2,
   png_uint_32 length)
{
   png_size_t size;

   size = (png_size_t)length;
   if ((png_uint_32)size != length)
573
      png_error(png_ptr, "Overflow in png_memcpy_check.");
574 575 576 577

   return(png_memcpy (s1, s2, size));
}

578
png_voidp PNGAPI
579 580 581 582 583 584 585
png_memset_check (png_structp png_ptr, png_voidp s1, int value,
   png_uint_32 length)
{
   png_size_t size;

   size = (png_size_t)length;
   if ((png_uint_32)size != length)
586
      png_error(png_ptr, "Overflow in png_memset_check.");
587 588 589 590 591 592 593 594 595 596 597 598 599

   return (png_memset (s1, value, size));

}

#ifdef PNG_USER_MEM_SUPPORTED
/* This function is called when the application wants to use another method
 * of allocating and freeing memory.
 */
void PNGAPI
png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr
  malloc_fn, png_free_ptr free_fn)
{
600 601 602 603 604
   if (png_ptr != NULL)
   {
      png_ptr->mem_ptr = mem_ptr;
      png_ptr->malloc_fn = malloc_fn;
      png_ptr->free_fn = free_fn;
605
   }
606 607 608 609 610 611 612 613 614
}

/* This function returns a pointer to the mem_ptr associated with the user
 * functions.  The application should free any memory associated with this
 * pointer before png_write_destroy and png_read_destroy are called.
 */
png_voidp PNGAPI
png_get_mem_ptr(png_structp png_ptr)
{
615 616
   if (png_ptr == NULL)
      return (NULL);
617 618 619
   return ((png_voidp)png_ptr->mem_ptr);
}
#endif /* PNG_USER_MEM_SUPPORTED */
620
#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */