/* pngrio.c - functions for data input
*
- * Last changed in libpng 1.4.1 [February 25, 2010]
- * Copyright (c) 1998-2010 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.0 [February 14, 2013]
+ * Copyright (c) 1998-2013 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.)
*
* libpng use it at run time with png_set_read_fn(...).
*/
-#define PNG_NO_PEDANTIC_WARNINGS
-#include "png.h"
-#ifdef PNG_READ_SUPPORTED
#include "pngpriv.h"
+#ifdef PNG_READ_SUPPORTED
+
/* Read the data from whatever input you are using. The default routine
* reads from a file pointer. Note that this routine sometimes gets called
* with very small lengths, so you should implement some kind of simple
* to read more then 64K on a 16 bit machine.
*/
void /* PRIVATE */
-png_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
+png_read_data(png_structrp png_ptr, png_bytep data, png_size_t length)
{
png_debug1(4, "reading %d bytes", (int)length);
-
+
if (png_ptr->read_data_fn != NULL)
(*(png_ptr->read_data_fn))(png_ptr, data, length);
+
else
png_error(png_ptr, "Call to NULL read function");
}
* read_data function and use it at run time with png_set_read_fn(), rather
* than changing the library.
*/
-#ifndef USE_FAR_KEYWORD
-void PNGAPI
+void PNGCBAPI
png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
{
png_size_t check;
if (png_ptr == NULL)
return;
+
/* fread() returns 0 on error, so it is OK to store this in a png_size_t
* instead of an int, which is what fread() actually returns.
*/
- check = fread(data, 1, length, (png_FILE_p)png_ptr->io_ptr);
+ check = fread(data, 1, length, png_voidcast(png_FILE_p, png_ptr->io_ptr));
if (check != length)
png_error(png_ptr, "Read Error");
}
-#else
-/* This is the model-independent version. Since the standard I/O library
- can't handle far buffers in the medium and small models, we have to copy
- the data.
-*/
-
-#define NEAR_BUF_SIZE 1024
-#define MIN(a,b) (a <= b ? a : b)
-
-static void PNGAPI
-png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length)
-{
- png_size_t check;
- png_byte *n_data;
- png_FILE_p io_ptr;
-
- if (png_ptr == NULL)
- return;
- /* Check if data really is near. If so, use usual code. */
- n_data = (png_byte *)CVT_PTR_NOCHECK(data);
- io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
- if ((png_bytep)n_data == data)
- {
- check = fread(n_data, 1, length, io_ptr);
- }
- else
- {
- png_byte buf[NEAR_BUF_SIZE];
- png_size_t read, remaining, err;
- check = 0;
- remaining = length;
- do
- {
- read = MIN(NEAR_BUF_SIZE, remaining);
- err = fread(buf, 1, read, io_ptr);
- png_memcpy(data, buf, read); /* copy far buffer to near buffer */
- if (err != read)
- break;
- else
- check += err;
- data += read;
- remaining -= read;
- }
- while (remaining != 0);
- }
- if ((png_uint_32)check != (png_uint_32)length)
- png_error(png_ptr, "read Error");
-}
-#endif
#endif
/* This function allows the application to supply a new input function
* for libpng if standard C streams aren't being used.
*
* This function takes as its arguments:
+ *
* png_ptr - pointer to a png input data structure
+ *
* io_ptr - pointer to user supplied structure containing info about
* the input functions. May be NULL.
+ *
* read_data_fn - pointer to a new input function that takes as its
* arguments a pointer to a png_struct, a pointer to
* a location where input data can be stored, and a 32-bit
* be used.
*/
void PNGAPI
-png_set_read_fn(png_structp png_ptr, png_voidp io_ptr,
+png_set_read_fn(png_structrp png_ptr, png_voidp io_ptr,
png_rw_ptr read_data_fn)
{
if (png_ptr == NULL)
return;
+
png_ptr->io_ptr = io_ptr;
#ifdef PNG_STDIO_SUPPORTED
if (read_data_fn != NULL)
png_ptr->read_data_fn = read_data_fn;
+
else
png_ptr->read_data_fn = png_default_read_data;
#else
{
png_ptr->write_data_fn = NULL;
png_warning(png_ptr,
- "It's an error to set both read_data_fn and write_data_fn in the ");
- png_warning(png_ptr,
- "same structure. Resetting write_data_fn to NULL");
+ "Can't set both read_data_fn and write_data_fn in the"
+ " same structure");
}
#ifdef PNG_WRITE_FLUSH_SUPPORTED