XFA: Upgrade libpng to 1.6.20.

third_party/lpng_v163/pngwio.c

-
-/* pngwio.c - functions for data output
- *
- * 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.)
- *
- * This code is released under the libpng license.
- * For conditions of distribution and use, see the disclaimer
- * and license in png.h
- *
- * This file provides a location for all output.  Users who need
- * special handling are expected to write functions that have the same
- * arguments as these and perform similar functions, but that possibly
- * use different output methods.  Note that you shouldn't change these
- * functions, but rather write replacement functions and then change
- * them at run time with png_set_write_fn(...).
- */
-#include "pngpriv.h"
-
-#ifdef PNG_WRITE_SUPPORTED
-
-/* Write the data to whatever output you are using.  The default routine
- * writes to a file pointer.  Note that this routine sometimes gets called
- * with very small lengths, so you should implement some kind of simple
- * buffering if you are using unbuffered writes.  This should never be asked
- * to write more than 64K on a 16 bit machine.
- */
-
-void /* PRIVATE */
-png_write_data(png_structrp png_ptr, png_const_bytep data, png_size_t length)
-{
-   /* NOTE: write_data_fn must not change the buffer! */
-   if (png_ptr->write_data_fn != NULL )
-      (*(png_ptr->write_data_fn))(png_ptr, png_constcast(png_bytep,data),
-         length);
-
-   else
-      png_error(png_ptr, "Call to NULL write function");
-}
-
-#ifdef PNG_STDIO_SUPPORTED
-/* This is the function that does the actual writing of data.  If you are
- * not writing to a standard C stream, you should create a replacement
- * write_data function and use it at run time with png_set_write_fn(), rather
- * than changing the library.
- */
-void PNGCBAPI
-png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
-{
-   png_size_t check;
-
-   if (png_ptr == NULL)
-      return;
-
-   check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr));
-
-   if (check != length)
-      png_error(png_ptr, "Write Error");
-}
-#endif
-
-/* This function is called to output any data pending writing (normally
- * to disk).  After png_flush is called, there should be no data pending
- * writing in any buffers.
- */
-#ifdef PNG_WRITE_FLUSH_SUPPORTED
-void /* PRIVATE */
-png_flush(png_structrp png_ptr)
-{
-   if (png_ptr->output_flush_fn != NULL)
-      (*(png_ptr->output_flush_fn))(png_ptr);
-}
-
-#  ifdef PNG_STDIO_SUPPORTED
-void PNGCBAPI
-png_default_flush(png_structp png_ptr)
-{
-   png_FILE_p io_ptr;
-
-   if (png_ptr == NULL)
-      return;
-
-   io_ptr = png_voidcast(png_FILE_p, (png_ptr->io_ptr));
-   fflush(io_ptr);
-}
-#  endif
-#endif
-
-/* This function allows the application to supply new output functions for
- * libpng if standard C streams aren't being used.
- *
- * This function takes as its arguments:
- * png_ptr       - pointer to a png output data structure
- * io_ptr        - pointer to user supplied structure containing info about
- *                 the output functions.  May be NULL.
- * write_data_fn - pointer to a new output function that takes as its
- *                 arguments a pointer to a png_struct, a pointer to
- *                 data to be written, and a 32-bit unsigned int that is
- *                 the number of bytes to be written.  The new write
- *                 function should call png_error(png_ptr, "Error msg")
- *                 to exit and output any fatal error messages.  May be
- *                 NULL, in which case libpng's default function will
- *                 be used.
- * flush_data_fn - pointer to a new flush function that takes as its
- *                 arguments a pointer to a png_struct.  After a call to
- *                 the flush function, there should be no data in any buffers
- *                 or pending transmission.  If the output method doesn't do
- *                 any buffering of output, a function prototype must still be
- *                 supplied although it doesn't have to do anything.  If
- *                 PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile
- *                 time, output_flush_fn will be ignored, although it must be
- *                 supplied for compatibility.  May be NULL, in which case
- *                 libpng's default function will be used, if
- *                 PNG_WRITE_FLUSH_SUPPORTED is defined.  This is not
- *                 a good idea if io_ptr does not point to a standard
- *                 *FILE structure.
- */
-void PNGAPI
-png_set_write_fn(png_structrp png_ptr, png_voidp io_ptr,
-    png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
-{
-   if (png_ptr == NULL)
-      return;
-
-   png_ptr->io_ptr = io_ptr;
-
-#ifdef PNG_STDIO_SUPPORTED
-   if (write_data_fn != NULL)
-      png_ptr->write_data_fn = write_data_fn;
-
-   else
-      png_ptr->write_data_fn = png_default_write_data;
-#else
-   png_ptr->write_data_fn = write_data_fn;
-#endif
-
-#ifdef PNG_WRITE_FLUSH_SUPPORTED
-#  ifdef PNG_STDIO_SUPPORTED
-
-   if (output_flush_fn != NULL)
-      png_ptr->output_flush_fn = output_flush_fn;
-
-   else
-      png_ptr->output_flush_fn = png_default_flush;
-
-#  else
-   png_ptr->output_flush_fn = output_flush_fn;
-#  endif
-#endif /* PNG_WRITE_FLUSH_SUPPORTED */
-
-   /* It is an error to read while writing a png file */
-   if (png_ptr->read_data_fn != NULL)
-   {
-      png_ptr->read_data_fn = NULL;
-
-      png_warning(png_ptr,
-          "Can't set both read_data_fn and write_data_fn in the"
-          " same structure");
-   }
-}
-#endif /* PNG_WRITE_SUPPORTED */