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Imported from libpng-0.87.tar

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This commit is contained in:
Guy Schalnat
1996-01-16 01:51:56 -06:00
committed by Glenn Randers-Pehrson
parent 69b1448f19
commit 4ee97b0891
22 changed files with 1210 additions and 863 deletions
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196
pngmem.c
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@@ -1,41 +1,199 @@
/* pngmem.c - stub functions for memory allocation
libpng 1.0 beta 2 - version 0.86
libpng 1.0 beta 2 - version 0.87
For conditions of distribution and use, see copyright notice in png.h
Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
January 10, 1996
January 15, 1996
This file provides a location for all memory allocation. Users which
need special memory handling are expected to modify the code in this file
to meet their needs. See the instructions at each function. */
to meet their needs. See the instructions at each function. */
#define PNG_INTERNAL
#include "png.h"
/* 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 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. */
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 it's
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.
*/
png_voidp
png_large_malloc(png_structp png_ptr, png_uint_32 size)
{
png_voidp ret;
if (!png_ptr || !size)
return ((voidp)0);
#ifdef PNG_MAX_MALLOC_64K
if (size > (png_uint_32)65536L)
png_error(png_ptr, "Cannot Allocate > 64K");
#endif
if (size == (png_uint_32)(65536L))
{
if (!png_ptr->offset_table)
{
/* try to see if we need to do any of this fancy stuff */
ret = farmalloc(size);
if (!ret || ((long)ret & 0xffff))
{
int num_blocks;
png_uint_32 total_size;
png_bytep table;
int i;
png_byte huge * hptr;
if (ret)
farfree(ret);
ret = 0;
num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14));
if (num_blocks < 1)
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;
table = farmalloc(total_size);
if (!table)
{
png_error(png_ptr, "Out of Memory");
}
if ((long)table & 0xffff)
{
farfree(table);
total_size += (png_uint_32)65536L;
}
table = farmalloc(total_size);
if (!table)
{
png_error(png_ptr, "Out of Memory");
}
png_ptr->offset_table = table;
png_ptr->offset_table_ptr = farmalloc(
num_blocks * sizeof (png_bytep));
hptr = (png_byte huge *)table;
if ((long)hptr & 0xffff)
{
hptr = (png_byte huge *)((long)(hptr) & 0xffff0000L);
hptr += 65536L;
}
for (i = 0; i < num_blocks; i++)
{
png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
hptr += 65536L;
}
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)
png_error(png_ptr, "Out of Memory");
ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++];
}
}
else
ret = farmalloc(size);
if (ret == NULL)
{
png_error(png_ptr, "Out of Memory");
}
return ret;
}
/* free a pointer allocated by png_large_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
png_large_free(png_structp png_ptr, png_voidp ptr)
{
if (!png_ptr)
return;
if (ptr != NULL)
{
if (png_ptr->offset_table)
{
int i;
for (i = 0; i < png_ptr->offset_table_count; i++)
{
if (ptr == png_ptr->offset_table_ptr[i])
{
ptr = 0;
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 = 0;
png_ptr->offset_table_ptr = 0;
}
}
if (ptr)
farfree(ptr);
}
}
#else /* Not the Borland DOS special memory handler */
/* 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
png_large_malloc(png_structp png_ptr, png_uint_32 size)
{
png_voidp ret;
if (!png_ptr || !size)
png_voidp ret;
if (!png_ptr || !size)
return ((voidp)0);
#ifdef PNG_MAX_MALLOC_64K
if (size > (png_uint_32)65536L)
png_error(png_ptr, "Cannot Allocate > 64K");
if (size > (png_uint_32)65536L)
png_error(png_ptr, "Cannot Allocate > 64K");
#endif
#if defined(__TURBOC__) && !defined(__FLAT__)
ret = farmalloc(size);
#else
# if defined(_MSC_VER) && defined(MAXSEG_64K)
ret = halloc(size, 1);
# else
ret = malloc(size);
# endif
#endif
if (ret == NULL)
@@ -43,7 +201,7 @@ png_large_malloc(png_structp png_ptr, png_uint_32 size)
png_error(png_ptr, "Out of Memory");
}
return ret;
return ret;
}
/* free a pointer allocated by png_large_malloc(). In the default
@@ -60,15 +218,22 @@ png_large_free(png_structp png_ptr, png_voidp ptr)
#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 */
/* Allocate memory. This is called for smallish blocks only It
should not get anywhere near 64K. On segmented machines, this
must come from the local heap (for zlib). */
must come from the local heap (for zlib). Currently, zlib is
the only one that uses this, so you should only get one call
to this, and that a small block. */
void *
png_malloc(png_structp png_ptr, png_uint_32 size)
{
@@ -96,7 +261,8 @@ png_malloc(png_structp png_ptr, png_uint_32 size)
}
/* Reallocate memory. This will not get near 64K on a
even marginally reasonable file. */
even marginally reasonable file. This is not used in
the current version of the library. */
void *
png_realloc(png_structp png_ptr, void * ptr, png_uint_32 size,
png_uint_32 old_size)