/****************************************************************************
* apps/graphics/tiff/tiff_utils.c
*
* Copyright (C) 2011 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 NuttX 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <unistd.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <apps/tiff.h>
#include "tiff_internal.h"
/****************************************************************************
* Pre-Processor Definitions
****************************************************************************/
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: tiff_put16 and tiff_put32
*
* Description:
* Put 16 and 32 values in the correct byte order at the specified position.
*
* Input Parameters:
* dest - The location to store the multi-byte data
* value - The value to be stored
*
* Returned Value:
* None
*
****************************************************************************/
void tiff_put16(FAR uint8_t *dest, uint16_t value)
{
#ifdef CONFIG_ENDIAN_BIG
*dest++ = (uint8_t)(value >> 8);
*dest = (uint8_t)(value & 0xff);
#else
*dest++ = (uint8_t)(value & 0xff);
*dest = (uint8_t)(value >> 8);
#endif
}
void tiff_put32(FAR uint8_t *dest, uint32_t value)
{
#ifdef CONFIG_ENDIAN_BIG
tiff_put16(dest, (uint16_t)(value >> 16));
tiff_put16(dest+2, (uint16_t)(value & 0xffff));
#else
tiff_put16(dest, (uint16_t)(value & 0xffff));
tiff_put16(dest+2, (uint16_t)(value >> 16));
#endif
}
/****************************************************************************
* Name: tiff_write
*
* Description:
* Write TIFF data to the specified file
*
* Input Parameters:
* fd - Open file descriptor to write to
* buffer - Read-only buffer containing the data to be written
* count - The number of bytes to write
*
* Returned Value:
* Zero (OK) on success. A negated errno value on failure.
*
****************************************************************************/
int tiff_write(int fd, FAR void *buffer, size_t count)
{
ssize_t nbytes;
int errval;
/* This loop retries the write until either: (1) it completes successfully,
* or (2) until an irrecoverble error occurs.
*/
while (count > 0)
{
/* Do the write */
nbytes = write(fd, buffer, count);
/* Check for an error */
if (nbytes < 0)
{
/* EINTR is not an error.. this just means that the write was
* interrupted by a signal.
*/
errval = errno;
if (errval != EINTR)
{
/* Other errors are bad news and we will break out with an error */
return -errval;
}
}
/* What if the the write returns some number of bytes other than the requested number? */
else
{
DEBUGASSERT(nbytes < count && nbytes != 0);
count -= nbytes;
}
}
return OK;
}
