libpng 1.6.3

third_party/libpng/pngrio.c

 
 /* pngrio.c - functions for data input
  *
- * Last changed in libpng 1.2.43 [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.)
  *
  * 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 input.  Users who need
  * special handling are expected to write a function that has the same
  * arguments as this and performs a similar function, but that possibly
  * has a different input method.  Note that you shouldn't change this
  * function, but rather write a replacement function and then make
  * libpng use it at run time with png_set_read_fn(...).
  */
 
-#define PNG_INTERNAL
-#define PNG_NO_PEDANTIC_WARNINGS
-#include "png.h"
+#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
  * buffering if you are using unbuffered reads.  This should never be asked
  * 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");
 }
 
 #ifdef PNG_STDIO_SUPPORTED
 /* This is the function that does the actual reading of data.  If you are
  * not reading from a standard C stream, you should create a replacement
  * 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.
     */
-#ifdef _WIN32_WCE
-   if ( !ReadFile((HANDLE)(png_ptr->io_ptr), data, length, &check, NULL) )
-      check = 0;
-#else
-   check = (png_size_t)fread(data, (png_size_t)1, length,
-      (png_FILE_p)png_ptr->io_ptr);
-#endif
+   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)
-{
-   int 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)
-   {
-#ifdef _WIN32_WCE
-      if ( !ReadFile((HANDLE)(png_ptr->io_ptr), data, length, &check,
-          NULL) )
-         check = 0;
-#else
-      check = fread(n_data, 1, length, io_ptr);
-#endif
-   }
-   else
-   {
-      png_byte buf[NEAR_BUF_SIZE];
-      png_size_t read, remaining, err;
-      check = 0;
-      remaining = length;
-      do
-      {
-         read = MIN(NEAR_BUF_SIZE, remaining);
-#ifdef _WIN32_WCE
-         if ( !ReadFile((HANDLE)(io_ptr), buf, read, &err, NULL) )
-            err = 0;
-#else
-         err = fread(buf, (png_size_t)1, read, io_ptr);
-#endif
-         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
  *                unsigned int that is the number of bytes to be read.
  *                To exit and output any fatal error messages the new write
  *                function should call png_error(png_ptr, "Error msg").
  *                May be NULL, in which case libpng's default function will
  *                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->read_data_fn = read_data_fn;
 #endif
 
    /* It is an error to write to a read device */
    if (png_ptr->write_data_fn != NULL)
    {
       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
    png_ptr->output_flush_fn = NULL;
 #endif
 }
 #endif /* PNG_READ_SUPPORTED */