void PNGAPI
png_set_compression_buffer_size(png_structrp png_ptr, png_size_t size)
{
if (png_ptr == NULL)
return;
if (size == 0 || size > PNG_UINT_31_MAX)
png_error(png_ptr, "invalid compression buffer size");
# ifdef PNG_SEQUENTIAL_READ_SUPPORTED
if ((png_ptr->mode & PNG_IS_READ_STRUCT) != 0)
{
png_ptr->IDAT_read_size = (png_uint_32)size; /* checked above */
return;
}
# endif
# ifdef PNG_WRITE_SUPPORTED
if ((png_ptr->mode & PNG_IS_READ_STRUCT) == 0)
{
if (png_ptr->zowner != 0)
{
png_warning(png_ptr,
"Compression buffer size cannot be changed because it is in use");
return;
}
#ifndef __COVERITY__
/* Some compilers complain that this is always false. However, it
* can be true when integer overflow happens.
*/
if (size > ZLIB_IO_MAX)
{
png_warning(png_ptr,
"Compression buffer size limited to system maximum");
size = ZLIB_IO_MAX; /* must fit */
}
#endif
if (size < 6)
{
/* Deflate will potentially go into an infinite loop on a SYNC_FLUSH
* if this is permitted.
*/
png_warning(png_ptr,
"Compression buffer size cannot be reduced below 6");
return;
}
if (png_ptr->zbuffer_size != size)
{
png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list);
png_ptr->zbuffer_size = (uInt)size;
}
}
# endif
}
void PNGAPI
png_set_compression_buffer_size(png_structrp png_ptr, uint size)
{
if (png_ptr == NULL)
return;
if (size == 0 || size > PNG_UINT_31_MAX)
png_error(png_ptr, "invalid compression buffer size");
# ifdef PNG_SEQUENTIAL_READ_SUPPORTED
if (png_ptr->mode & PNG_IS_READ_STRUCT)
{
png_ptr->IDAT_read_size = (u32)size; /* checked above */
return;
}
# endif
# ifdef PNG_WRITE_SUPPORTED
if (!(png_ptr->mode & PNG_IS_READ_STRUCT))
{
if (png_ptr->zowner != 0)
{
png_warning(png_ptr,
"Compression buffer size cannot be changed because it is in use");
return;
}
if (size > ZLIB_IO_MAX)
{
png_warning(png_ptr,
"Compression buffer size limited to system maximum");
size = ZLIB_IO_MAX; /* must fit */
}
else if (size < 6)
{
/* Deflate will potentially go into an infinite loop on a SYNC_FLUSH
* if this is permitted.
*/
png_warning(png_ptr,
"Compression buffer size cannot be reduced below 6");
return;
}
if (png_ptr->zbuffer_size != size)
{
png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list);
png_ptr->zbuffer_size = (uInt)size;
}
}
# endif
}
