/************************************************************
* lib_libfwrite.c
*
* Copyright (C) 2007 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name Gregory Nutt nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
************************************************************/
/************************************************************
* Compilation Switches
************************************************************/
/************************************************************
* Included Files
************************************************************/
#include <nuttx/config.h> /* for CONFIG_STDIO_BUFFER_SIZE */
#include <stdio.h>
#include <errno.h>
#include "lib_internal.h"
/************************************************************
* Definitions
************************************************************/
/************************************************************
* Private Type Declarations
************************************************************/
/************************************************************
* Private Function Prototypes
************************************************************/
/************************************************************
* Global Constant Data
************************************************************/
/************************************************************
* Global Variables
************************************************************/
/************************************************************
* Private Constant Data
************************************************************/
/************************************************************
* Private Variables
************************************************************/
/************************************************************
* Global Functions
************************************************************/
/************************************************************
* lib_fwrite
************************************************************/
#if CONFIG_NFILE_STREAMS > 0
ssize_t lib_fwrite(const void *ptr, size_t count, FILE *stream)
#if CONFIG_STDIO_BUFFER_SIZE > 0
{
const unsigned char *start = ptr;
const unsigned char *src = ptr;
ssize_t bytes_written;
unsigned char *dest;
/* Make sure that writing to this stream is allowed */
if ((!stream) || ((stream->fs_oflags & O_WROK) == 0))
{
*get_errno_ptr() = EBADF;
bytes_written = -1;
}
else
{
/* Loop until all of the bytes have been buffered */
lib_take_semaphore(stream);
while (count > 0)
{
/* Determine the number of bytes left in the buffer */
size_t gulp_size = stream->fs_bufend - stream->fs_bufpos;
/* Will the user data fit into the amount of buffer space
* that we have left?
*/
if (gulp_size > count)
{
/* Yes, clip the gulp to the size of the user data */
gulp_size = count;
}
/* Adjust the number of bytes remaining to be transferred
* on the next pass through the loop (might be zero).
*/
count -= gulp_size;
/* Transfer the data into the buffer */
for (dest = stream->fs_bufpos; gulp_size > 0; gulp_size--)
{
*dest++ = *src++;
}
stream->fs_bufpos = dest;
/* Is the buffer full? */
if (dest >= stream->fs_bufend)
{
/* flush the buffered data to the IO stream */
int bytes_buffered = fflush(stream);
if (bytes_buffered < 0)
{
bytes_written = bytes_buffered;
goto err_out;
}
}
}
bytes_written = src - start;
err_out:
lib_give_semaphore(stream);
}
return bytes_written;
}
#else
{
return write(stream->fs_filedes, ptr, count);
}
#endif /* CONFIG_STDIO_BUFFER_SIZE */
#endif /* CONFIG_NFILE_STREAMS */
