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/* pngmem.c - stub functions for memory allocation
* * Last changed in libpng 1.5.1 [February 3, 2011] * Copyright (c) 1998-2011 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * * This code is released under the libpng license. * For conditions of distribution and use, see the disclaimer * and license in png.h * * 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. */
#include "pngpriv.h"
#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
/* Borland DOS special memory handler */ #if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
/* If you change this, be sure to change the one in png.h also */
/* 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_FUNCTION(png_voidp /* PRIVATE */, png_create_struct,(int type),PNG_ALLOCATED) { # ifdef PNG_USER_MEM_SUPPORTED
return (png_create_struct_2(type, NULL, NULL)); }
/* Alternate version of png_create_struct, for use with user-defined malloc. */ PNG_FUNCTION(png_voidp /* PRIVATE */, png_create_struct_2,(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr), PNG_ALLOCATED) { # endif /* PNG_USER_MEM_SUPPORTED */
png_size_t size; png_voidp struct_ptr;
if (type == PNG_STRUCT_INFO) size = png_sizeof(png_info);
else if (type == PNG_STRUCT_PNG) size = png_sizeof(png_struct);
else return (png_get_copyright(NULL));
# ifdef PNG_USER_MEM_SUPPORTED
if (malloc_fn != NULL) { 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 */
struct_ptr = (png_voidp)farmalloc(size); 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, NULL, 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
if (free_fn != NULL) { 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. */ PNG_FUNCTION(png_voidp,PNGAPI png_calloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) { png_voidp ret;
ret = (png_malloc(png_ptr, size));
if (ret != NULL) png_memset(ret,0,(png_size_t)size);
return (ret); }
PNG_FUNCTION(png_voidp,PNGAPI png_malloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) { png_voidp ret;
if (png_ptr == NULL || size == 0) return (NULL);
# ifdef PNG_USER_MEM_SUPPORTED
if (png_ptr->malloc_fn != NULL) ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size));
else ret = (png_malloc_default(png_ptr, size));
if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) png_error(png_ptr, "Out of memory");
return (ret); }
PNG_FUNCTION(png_voidp,PNGAPI png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) { png_voidp ret; # endif /* PNG_USER_MEM_SUPPORTED */
if (png_ptr == NULL || size == 0) return (NULL);
# ifdef PNG_MAX_MALLOC_64K
if (size > (png_uint_32)65536L) { png_warning(png_ptr, "Cannot Allocate > 64K"); ret = NULL; }
else # endif
if (size != (size_t)size) ret = NULL;
else if (size == (png_uint_32)65536L) { if (png_ptr->offset_table == NULL) { /* Try to see if we need to do any of this fancy stuff */ 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; }
if (png_ptr->zlib_window_bits > 14) 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) { # 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", "M" */
else png_warning(png_ptr, "Out Of Memory"); # endif
return (NULL); }
if ((png_size_t)table & 0xfff0) { # 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); }
png_ptr->offset_table = table; png_ptr->offset_table_ptr = farmalloc(num_blocks * png_sizeof(png_bytep));
if (png_ptr->offset_table_ptr == NULL) { # 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", "m" */
else png_warning(png_ptr, "Out Of memory"); # endif
return (NULL); }
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) { # 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); }
ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++]; }
else ret = farmalloc(size);
# ifndef PNG_USER_MEM_SUPPORTED
if (ret == NULL) { 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" */ } # endif
return (ret); }
/* 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. */ 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; }
else png_free_default(png_ptr, ptr); }
void PNGAPI png_free_default(png_structp png_ptr, png_voidp ptr) { # endif /* PNG_USER_MEM_SUPPORTED */
if (png_ptr == NULL || ptr == NULL) return;
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 to improve performance noticably. */ PNG_FUNCTION(png_voidp /* PRIVATE */, png_create_struct,(int type),PNG_ALLOCATED) { # ifdef PNG_USER_MEM_SUPPORTED
return (png_create_struct_2(type, NULL, 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 to improve performance noticably. */ PNG_FUNCTION(png_voidp /* PRIVATE */, png_create_struct_2,(int type, png_malloc_ptr malloc_fn, png_voidp mem_ptr), PNG_ALLOCATED) { # endif /* PNG_USER_MEM_SUPPORTED */
png_size_t size; png_voidp struct_ptr;
if (type == PNG_STRUCT_INFO) size = png_sizeof(png_info);
else if (type == PNG_STRUCT_PNG) size = png_sizeof(png_struct);
else return (NULL);
# ifdef PNG_USER_MEM_SUPPORTED
if (malloc_fn != NULL) { 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__)
struct_ptr = (png_voidp)farmalloc(size); # else
# if defined(_MSC_VER) && defined(MAXSEG_64K)
struct_ptr = (png_voidp)halloc(size, 1); # else
struct_ptr = (png_voidp)malloc(size); # endif
# endif
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, NULL, 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
if (free_fn != NULL) { 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
* 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. */
PNG_FUNCTION(png_voidp,PNGAPI png_calloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) { png_voidp ret;
ret = (png_malloc(png_ptr, size));
if (ret != NULL) png_memset(ret,0,(png_size_t)size);
return (ret); }
PNG_FUNCTION(png_voidp,PNGAPI png_malloc,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) { png_voidp ret;
# ifdef PNG_USER_MEM_SUPPORTED
if (png_ptr == NULL || size == 0) return (NULL);
if (png_ptr->malloc_fn != NULL) ret = ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, (png_size_t)size));
else ret = (png_malloc_default(png_ptr, size));
if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) png_error(png_ptr, "Out of Memory");
return (ret); }
PNG_FUNCTION(png_voidp,PNGAPI png_malloc_default,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) { png_voidp ret; # endif /* PNG_USER_MEM_SUPPORTED */
if (png_ptr == NULL || size == 0) return (NULL);
# ifdef PNG_MAX_MALLOC_64K
if (size > (png_uint_32)65536L) { # ifndef PNG_USER_MEM_SUPPORTED
if ((png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) png_error(png_ptr, "Cannot Allocate > 64K");
else # endif
return NULL; } # endif
/* Check for overflow */ # if defined(__TURBOC__) && !defined(__FLAT__)
if (size != (unsigned long)size) ret = NULL;
else ret = farmalloc(size);
# else
# if defined(_MSC_VER) && defined(MAXSEG_64K)
if (size != (unsigned long)size) ret = NULL;
else ret = halloc(size, 1);
# else
if (size != (size_t)size) ret = NULL;
else ret = malloc((size_t)size); # endif
# endif
# ifndef PNG_USER_MEM_SUPPORTED
if (ret == NULL && (png_ptr->flags&PNG_FLAG_MALLOC_NULL_MEM_OK) == 0) png_error(png_ptr, "Out of Memory"); # endif
return (ret); }
/* Free a pointer allocated by png_malloc(). If ptr is NULL, return
* without taking any action. */ 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; }
else png_free_default(png_ptr, ptr); }
void PNGAPI 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 */
/* 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_FUNCTION(png_voidp,PNGAPI png_malloc_warn,(png_structp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) { png_voidp ptr; png_uint_32 save_flags; if (png_ptr == NULL) return (NULL);
save_flags = png_ptr->flags; 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); }
#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) { if (png_ptr != NULL) { png_ptr->mem_ptr = mem_ptr; png_ptr->malloc_fn = malloc_fn; png_ptr->free_fn = free_fn; } }
/* 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_const_structp png_ptr) { if (png_ptr == NULL) return (NULL);
return ((png_voidp)png_ptr->mem_ptr); } #endif /* PNG_USER_MEM_SUPPORTED */
#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
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