504 lines
13 KiB
C
504 lines
13 KiB
C
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/* pngmem.c - stub functions for memory allocation
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*
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* libpng 1.0.10beta1 - March 14, 2001
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* For conditions of distribution and use, see copyright notice in png.h
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* Copyright (c) 1998-2001 Glenn Randers-Pehrson
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* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
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* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
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*
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* This file provides a location for all memory allocation. Users who
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* need special memory handling are expected to supply replacement
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* functions for png_malloc() and png_free(), and to use
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* png_create_read_struct_2() and png_create_write_struct_2() to
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* identify the replacement functions.
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*/
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#define PNG_INTERNAL
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#include "png.h"
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/* Borland DOS special memory handler */
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#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
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/* if you change this, be sure to change the one in png.h also */
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/* Allocate memory for a png_struct. The malloc and memset can be replaced
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by a single call to calloc() if this is thought to improve performance. */
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png_voidp /* PRIVATE */
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png_create_struct(int type)
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{
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#ifdef PNG_USER_MEM_SUPPORTED
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return (png_create_struct_2(type, NULL));
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}
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/* Alternate version of png_create_struct, for use with user-defined malloc. */
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png_voidp /* PRIVATE */
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png_create_struct_2(int type, png_malloc_ptr malloc_fn)
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{
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#endif /* PNG_USER_MEM_SUPPORTED */
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png_size_t size;
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png_voidp struct_ptr;
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if (type == PNG_STRUCT_INFO)
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size = sizeof(png_info);
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else if (type == PNG_STRUCT_PNG)
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size = sizeof(png_struct);
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else
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return ((png_voidp)NULL);
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#ifdef PNG_USER_MEM_SUPPORTED
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if(malloc_fn != NULL)
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{
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if ((struct_ptr = (*(malloc_fn))(NULL, size)) != NULL)
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png_memset(struct_ptr, 0, size);
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return (struct_ptr);
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}
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#endif /* PNG_USER_MEM_SUPPORTED */
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if ((struct_ptr = (png_voidp)farmalloc(size)) != NULL)
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{
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png_memset(struct_ptr, 0, size);
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}
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return (struct_ptr);
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}
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/* Free memory allocated by a png_create_struct() call */
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void /* PRIVATE */
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png_destroy_struct(png_voidp struct_ptr)
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{
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#ifdef PNG_USER_MEM_SUPPORTED
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png_destroy_struct_2(struct_ptr, (png_free_ptr)NULL);
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}
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/* Free memory allocated by a png_create_struct() call */
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void /* PRIVATE */
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png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn)
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{
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#endif
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if (struct_ptr != NULL)
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{
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#ifdef PNG_USER_MEM_SUPPORTED
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if(free_fn != NULL)
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{
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png_struct dummy_struct;
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png_structp png_ptr = &dummy_struct;
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(*(free_fn))(png_ptr, struct_ptr);
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return;
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}
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#endif /* PNG_USER_MEM_SUPPORTED */
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farfree (struct_ptr);
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}
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}
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/* Allocate memory. For reasonable files, size should never exceed
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* 64K. However, zlib may allocate more then 64K if you don't tell
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* it not to. See zconf.h and png.h for more information. zlib does
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* need to allocate exactly 64K, so whatever you call here must
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* have the ability to do that.
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*
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* Borland seems to have a problem in DOS mode for exactly 64K.
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* It gives you a segment with an offset of 8 (perhaps to store its
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* memory stuff). zlib doesn't like this at all, so we have to
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* detect and deal with it. This code should not be needed in
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* Windows or OS/2 modes, and only in 16 bit mode. This code has
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* been updated by Alexander Lehmann for version 0.89 to waste less
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* memory.
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*
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* Note that we can't use png_size_t for the "size" declaration,
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* since on some systems a png_size_t is a 16-bit quantity, and as a
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* result, we would be truncating potentially larger memory requests
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* (which should cause a fatal error) and introducing major problems.
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*/
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png_voidp PNGAPI
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png_malloc(png_structp png_ptr, png_uint_32 size)
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{
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#ifndef PNG_USER_MEM_SUPPORTED
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png_voidp ret;
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#endif
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if (png_ptr == NULL || size == 0)
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return ((png_voidp)NULL);
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#ifdef PNG_USER_MEM_SUPPORTED
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if(png_ptr->malloc_fn != NULL)
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return ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size));
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else
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return png_malloc_default(png_ptr, size);
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}
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png_voidp PNGAPI
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png_malloc_default(png_structp png_ptr, png_uint_32 size)
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{
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png_voidp ret;
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#endif /* PNG_USER_MEM_SUPPORTED */
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#ifdef PNG_MAX_MALLOC_64K
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if (size > (png_uint_32)65536L)
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png_error(png_ptr, "Cannot Allocate > 64K");
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#endif
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if (size == (png_uint_32)65536L)
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{
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if (png_ptr->offset_table == NULL)
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{
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/* try to see if we need to do any of this fancy stuff */
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ret = farmalloc(size);
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if (ret == NULL || ((png_size_t)ret & 0xffff))
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{
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int num_blocks;
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png_uint_32 total_size;
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png_bytep table;
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int i;
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png_byte huge * hptr;
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if (ret != NULL)
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{
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farfree(ret);
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ret = NULL;
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}
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if(png_ptr->zlib_window_bits > 14)
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num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14));
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else
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num_blocks = 1;
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if (png_ptr->zlib_mem_level >= 7)
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num_blocks += (int)(1 << (png_ptr->zlib_mem_level - 7));
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else
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num_blocks++;
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total_size = ((png_uint_32)65536L) * (png_uint_32)num_blocks+16;
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table = farmalloc(total_size);
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if (table == NULL)
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{
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png_error(png_ptr, "Out Of Memory."); /* Note "O" and "M" */
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}
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if ((png_size_t)table & 0xfff0)
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{
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png_error(png_ptr, "Farmalloc didn't return normalized pointer");
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}
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png_ptr->offset_table = table;
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png_ptr->offset_table_ptr = farmalloc(num_blocks *
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sizeof (png_bytep));
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if (png_ptr->offset_table_ptr == NULL)
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{
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png_error(png_ptr, "Out Of memory.");
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}
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hptr = (png_byte huge *)table;
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if ((png_size_t)hptr & 0xf)
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{
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hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
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hptr = hptr + 16L; /* "hptr += 16L" fails on Turbo C++ 3.0 */
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}
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for (i = 0; i < num_blocks; i++)
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{
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png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
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hptr = hptr + (png_uint_32)65536L; /* "+=" fails on TC++3.0 */
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}
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png_ptr->offset_table_number = num_blocks;
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png_ptr->offset_table_count = 0;
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png_ptr->offset_table_count_free = 0;
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}
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}
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if (png_ptr->offset_table_count >= png_ptr->offset_table_number)
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png_error(png_ptr, "Out of Memory.");
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ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++];
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}
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else
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ret = farmalloc(size);
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if (ret == NULL)
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{
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png_error(png_ptr, "Out of memory."); /* Note "o" and "m" */
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}
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return (ret);
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}
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/* free a pointer allocated by png_malloc(). In the default
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configuration, png_ptr is not used, but is passed in case it
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is needed. If ptr is NULL, return without taking any action. */
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void PNGAPI
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png_free(png_structp png_ptr, png_voidp ptr)
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{
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if (png_ptr == NULL || ptr == NULL)
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return;
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#ifdef PNG_USER_MEM_SUPPORTED
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if (png_ptr->free_fn != NULL)
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{
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(*(png_ptr->free_fn))(png_ptr, ptr);
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return;
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}
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else png_free_default(png_ptr, ptr);
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}
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void PNGAPI
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png_free_default(png_structp png_ptr, png_voidp ptr)
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{
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#endif /* PNG_USER_MEM_SUPPORTED */
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if (png_ptr->offset_table != NULL)
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{
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int i;
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for (i = 0; i < png_ptr->offset_table_count; i++)
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{
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if (ptr == png_ptr->offset_table_ptr[i])
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{
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ptr = NULL;
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png_ptr->offset_table_count_free++;
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break;
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}
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}
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if (png_ptr->offset_table_count_free == png_ptr->offset_table_count)
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{
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farfree(png_ptr->offset_table);
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farfree(png_ptr->offset_table_ptr);
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png_ptr->offset_table = NULL;
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png_ptr->offset_table_ptr = NULL;
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}
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}
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if (ptr != NULL)
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{
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farfree(ptr);
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}
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}
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#else /* Not the Borland DOS special memory handler */
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/* Allocate memory for a png_struct or a png_info. The malloc and
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memset can be replaced by a single call to calloc() if this is thought
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to improve performance noticably.*/
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png_voidp /* PRIVATE */
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png_create_struct(int type)
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{
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#ifdef PNG_USER_MEM_SUPPORTED
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return (png_create_struct_2(type, NULL));
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}
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/* Allocate memory for a png_struct or a png_info. The malloc and
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memset can be replaced by a single call to calloc() if this is thought
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to improve performance noticably.*/
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png_voidp /* PRIVATE */
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png_create_struct_2(int type, png_malloc_ptr malloc_fn)
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{
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#endif /* PNG_USER_MEM_SUPPORTED */
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png_size_t size;
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png_voidp struct_ptr;
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if (type == PNG_STRUCT_INFO)
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size = sizeof(png_info);
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else if (type == PNG_STRUCT_PNG)
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size = sizeof(png_struct);
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else
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return ((png_voidp)NULL);
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#ifdef PNG_USER_MEM_SUPPORTED
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if(malloc_fn != NULL)
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{
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if ((struct_ptr = (*(malloc_fn))(NULL, size)) != NULL)
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png_memset(struct_ptr, 0, size);
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return (struct_ptr);
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}
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#endif /* PNG_USER_MEM_SUPPORTED */
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#if defined(__TURBOC__) && !defined(__FLAT__)
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if ((struct_ptr = (png_voidp)farmalloc(size)) != NULL)
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#else
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# if defined(_MSC_VER) && defined(MAXSEG_64K)
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if ((struct_ptr = (png_voidp)halloc(size,1)) != NULL)
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# else
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if ((struct_ptr = (png_voidp)malloc(size)) != NULL)
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# endif
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#endif
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{
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png_memset(struct_ptr, 0, size);
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}
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return (struct_ptr);
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}
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/* Free memory allocated by a png_create_struct() call */
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void /* PRIVATE */
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png_destroy_struct(png_voidp struct_ptr)
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{
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#ifdef PNG_USER_MEM_SUPPORTED
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png_destroy_struct_2(struct_ptr, (png_free_ptr)NULL);
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}
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/* Free memory allocated by a png_create_struct() call */
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void /* PRIVATE */
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png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn)
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{
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#endif /* PNG_USER_MEM_SUPPORTED */
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if (struct_ptr != NULL)
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{
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#ifdef PNG_USER_MEM_SUPPORTED
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if(free_fn != NULL)
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{
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png_struct dummy_struct;
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png_structp png_ptr = &dummy_struct;
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(*(free_fn))(png_ptr, struct_ptr);
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return;
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}
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#endif /* PNG_USER_MEM_SUPPORTED */
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#if defined(__TURBOC__) && !defined(__FLAT__)
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farfree(struct_ptr);
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#else
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# if defined(_MSC_VER) && defined(MAXSEG_64K)
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hfree(struct_ptr);
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# else
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free(struct_ptr);
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# endif
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#endif
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}
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}
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/* Allocate memory. For reasonable files, size should never exceed
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64K. However, zlib may allocate more then 64K if you don't tell
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it not to. See zconf.h and png.h for more information. zlib does
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need to allocate exactly 64K, so whatever you call here must
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have the ability to do that. */
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png_voidp PNGAPI
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png_malloc(png_structp png_ptr, png_uint_32 size)
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{
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#ifndef PNG_USER_MEM_SUPPORTED
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png_voidp ret;
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#endif
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if (png_ptr == NULL || size == 0)
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return ((png_voidp)NULL);
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#ifdef PNG_USER_MEM_SUPPORTED
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if(png_ptr->malloc_fn != NULL)
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return ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size));
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else
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return (png_malloc_default(png_ptr, size));
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}
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png_voidp /* PRIVATE */
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png_malloc_default(png_structp png_ptr, png_uint_32 size)
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{
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png_voidp ret;
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#endif /* PNG_USER_MEM_SUPPORTED */
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#ifdef PNG_MAX_MALLOC_64K
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if (size > (png_uint_32)65536L)
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png_error(png_ptr, "Cannot Allocate > 64K");
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#endif
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#if defined(__TURBOC__) && !defined(__FLAT__)
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ret = farmalloc(size);
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#else
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# if defined(_MSC_VER) && defined(MAXSEG_64K)
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ret = halloc(size, 1);
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# else
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ret = malloc((size_t)size);
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# endif
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#endif
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if (ret == NULL)
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{
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png_error(png_ptr, "Out of Memory");
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}
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return (ret);
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}
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/* Free a pointer allocated by png_malloc(). If ptr is NULL, return
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without taking any action. */
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void PNGAPI
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png_free(png_structp png_ptr, png_voidp ptr)
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{
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if (png_ptr == NULL || ptr == NULL)
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return;
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#ifdef PNG_USER_MEM_SUPPORTED
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if (png_ptr->free_fn != NULL)
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{
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(*(png_ptr->free_fn))(png_ptr, ptr);
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return;
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}
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else png_free_default(png_ptr, ptr);
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}
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void /* PRIVATE */
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png_free_default(png_structp png_ptr, png_voidp ptr)
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{
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if (png_ptr == NULL || ptr == NULL)
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return;
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#endif /* PNG_USER_MEM_SUPPORTED */
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#if defined(__TURBOC__) && !defined(__FLAT__)
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farfree(ptr);
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#else
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# if defined(_MSC_VER) && defined(MAXSEG_64K)
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hfree(ptr);
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# else
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free(ptr);
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# endif
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#endif
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}
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#endif /* Not Borland DOS special memory handler */
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png_voidp /* PRIVATE */
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png_memcpy_check (png_structp png_ptr, png_voidp s1, png_voidp s2,
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png_uint_32 length)
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{
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png_size_t size;
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size = (png_size_t)length;
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if ((png_uint_32)size != length)
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png_error(png_ptr,"Overflow in png_memcpy_check.");
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return(png_memcpy (s1, s2, size));
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}
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png_voidp /* PRIVATE */
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png_memset_check (png_structp png_ptr, png_voidp s1, int value,
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png_uint_32 length)
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{
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png_size_t size;
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size = (png_size_t)length;
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if ((png_uint_32)size != length)
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png_error(png_ptr,"Overflow in png_memset_check.");
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return (png_memset (s1, value, size));
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}
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#ifdef PNG_USER_MEM_SUPPORTED
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/* This function is called when the application wants to use another method
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* of allocating and freeing memory.
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*/
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void PNGAPI
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png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr
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malloc_fn, png_free_ptr free_fn)
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{
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png_ptr->mem_ptr = mem_ptr;
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png_ptr->malloc_fn = malloc_fn;
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png_ptr->free_fn = free_fn;
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}
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/* This function returns a pointer to the mem_ptr associated with the user
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* functions. The application should free any memory associated with this
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* pointer before png_write_destroy and png_read_destroy are called.
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*/
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png_voidp PNGAPI
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png_get_mem_ptr(png_structp png_ptr)
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{
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return ((png_voidp)png_ptr->mem_ptr);
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}
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#endif /* PNG_USER_MEM_SUPPORTED */
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