/* pngwio.c - functions for data output
*
- * libpng 1.2.6 - August 15, 2004
- * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2004 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 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
* them at run time with png_set_write_fn(...).
*/
-#define PNG_INTERNAL
-#include "png.h"
+#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. */
+ * 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_structp png_ptr, png_bytep data, png_size_t length)
+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, data, length);
+ (*(png_ptr->write_data_fn))(png_ptr, png_constcast(png_bytep,data),
+ length);
+
else
png_error(png_ptr, "Call to NULL write function");
}
-#if !defined(PNG_NO_STDIO)
+#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. */
-#ifndef USE_FAR_KEYWORD
-void PNGAPI
+ * 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_uint_32 check;
-
-#if defined(_WIN32_WCE)
- if ( !WriteFile((HANDLE)(png_ptr->io_ptr), data, length, &check, NULL) )
- check = 0;
-#else
- check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr));
-#endif
- if (check != length)
- png_error(png_ptr, "Write 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.
-*/
+ png_size_t check;
-#define NEAR_BUF_SIZE 1024
-#define MIN(a,b) (a <= b ? a : b)
+ if (png_ptr == NULL)
+ return;
-void PNGAPI
-png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length)
-{
- png_uint_32 check;
- png_byte *near_data; /* Needs to be "png_byte *" instead of "png_bytep" */
- png_FILE_p io_ptr;
+ check = fwrite(data, 1, length, (png_FILE_p)(png_ptr->io_ptr));
- /* Check if data really is near. If so, use usual code. */
- near_data = (png_byte *)CVT_PTR_NOCHECK(data);
- io_ptr = (png_FILE_p)CVT_PTR(png_ptr->io_ptr);
- if ((png_bytep)near_data == data)
- {
-#if defined(_WIN32_WCE)
- if ( !WriteFile(io_ptr, near_data, length, &check, NULL) )
- check = 0;
-#else
- check = fwrite(near_data, 1, length, io_ptr);
-#endif
- }
- else
- {
- png_byte buf[NEAR_BUF_SIZE];
- png_size_t written, remaining, err;
- check = 0;
- remaining = length;
- do
- {
- written = MIN(NEAR_BUF_SIZE, remaining);
- png_memcpy(buf, data, written); /* copy far buffer to near buffer */
-#if defined(_WIN32_WCE)
- if ( !WriteFile(io_ptr, buf, written, &err, NULL) )
- err = 0;
-#else
- err = fwrite(buf, 1, written, io_ptr);
-#endif
- if (err != written)
- break;
- else
- check += err;
- data += written;
- remaining -= written;
- }
- while (remaining != 0);
- }
if (check != length)
png_error(png_ptr, "Write Error");
}
-
-#endif
#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. */
-#if defined(PNG_WRITE_FLUSH_SUPPORTED)
+ * 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_structp png_ptr)
+png_flush(png_structrp png_ptr)
{
if (png_ptr->output_flush_fn != NULL)
(*(png_ptr->output_flush_fn))(png_ptr);
}
-#if !defined(PNG_NO_STDIO)
-void PNGAPI
+# ifdef PNG_STDIO_SUPPORTED
+void PNGCBAPI
png_default_flush(png_structp png_ptr)
{
-#if !defined(_WIN32_WCE)
png_FILE_p io_ptr;
- io_ptr = (png_FILE_p)CVT_PTR((png_ptr->io_ptr));
- if (io_ptr != NULL)
- fflush(io_ptr);
-#endif
+
+ if (png_ptr == NULL)
+ return;
+
+ io_ptr = png_voidcast(png_FILE_p, (png_ptr->io_ptr));
+ fflush(io_ptr);
}
-#endif
+# 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.
- 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 ouput, 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. */
+ * 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_structp png_ptr, png_voidp io_ptr,
- png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)
+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;
-#if !defined(PNG_NO_STDIO)
+#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
-#if defined(PNG_WRITE_FLUSH_SUPPORTED)
-#if !defined(PNG_NO_STDIO)
+#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
+
+# else
png_ptr->output_flush_fn = output_flush_fn;
-#endif
+# 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,
- "Attempted to set both read_data_fn and write_data_fn in");
- png_warning(png_ptr,
- "the same structure. Resetting read_data_fn to NULL.");
+ "Can't set both read_data_fn and write_data_fn in the"
+ " same structure");
}
}
-
-#if defined(USE_FAR_KEYWORD)
-#if defined(_MSC_VER)
-void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check)
-{
- void *near_ptr;
- void FAR *far_ptr;
- FP_OFF(near_ptr) = FP_OFF(ptr);
- far_ptr = (void FAR *)near_ptr;
- if(check != 0)
- if(FP_SEG(ptr) != FP_SEG(far_ptr))
- png_error(png_ptr,"segment lost in conversion");
- return(near_ptr);
-}
-# else
-void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check)
-{
- void *near_ptr;
- void FAR *far_ptr;
- near_ptr = (void FAR *)ptr;
- far_ptr = (void FAR *)near_ptr;
- if(check != 0)
- if(far_ptr != ptr)
- png_error(png_ptr,"segment lost in conversion");
- return(near_ptr);
-}
-# endif
-# endif
#endif /* PNG_WRITE_SUPPORTED */
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