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/* pngmem.c - stub functions for memory allocation
*
* Last changed in libpng 1.2.13 November 13, 2006
* For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1998-2006 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 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"
#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
/* 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_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
to improve performance noticably. */
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)
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(_MSC_VER) && defined(MAXSEG_64K)
struct_ptr = (png_voidp)halloc(size,1);
#else
struct_ptr = (png_voidp)malloc(size);
#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, 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
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(_MSC_VER) && defined(MAXSEG_64K)
hfree(struct_ptr);
#else
free(struct_ptr);
#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_voidp PNGAPI
png_malloc(png_structp png_ptr, png_uint_32 size)
{
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_voidp PNGAPI
png_malloc_default(png_structp png_ptr, png_uint_32 size)
{
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(_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
#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(_MSC_VER) && defined(MAXSEG_64K)
hfree(ptr);
#else
free(ptr);
#endif
}
#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;
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);
}
#endif
png_voidp PNGAPI
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)
png_error(png_ptr,"Overflow in png_memcpy_check.");
return(png_memcpy (s1, s2, size));
}
png_voidp PNGAPI
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)
png_error(png_ptr,"Overflow in png_memset_check.");
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)
{
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_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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