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nuttx-apps/graphics/tiff/tiff_utils.c

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/****************************************************************************
* apps/graphics/tiff/tiff_utils.c
*
* Copyright (C) 2011 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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 <string.h>
#include <unistd.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include "graphics/tiff.h"
#include "tiff_internal.h"
/****************************************************************************
* Pre-Processor Definitions
****************************************************************************/
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: tiff_put/get16/32
*
* Description:
* Put and get 16 and 32 values in the correct byte order at the specified
* position.
*
* Input Parameters:
* dest - The location to store the multi-byte data (put only)
* src - The location to get the multi-byte data (get only)
* value - The value to be stored (put only)
*
* Returned Value:
* None (put)
* The extracted value (get)
*
****************************************************************************/
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
}
uint16_t tiff_get16(FAR uint8_t *src)
{
#ifdef CONFIG_ENDIAN_BIG
return (uint16_t)src[0] << 8 | (uint16_t)src[1];
#else
return (uint16_t)src[1] << 8 | (uint16_t)src[0];
#endif
}
uint32_t tiff_get32(FAR uint8_t *src)
{
#ifdef CONFIG_ENDIAN_BIG
return (uint32_t)tiff_get16(src) << 16 | (uint32_t)tiff_get16(src+2);
#else
return (uint32_t)tiff_get16(src+2) << 16 | (uint32_t)tiff_get16(src);
#endif
}
/****************************************************************************
* Name: tiff_read
*
* Description:
* Read TIFF data from the specified file
*
* Input Parameters:
* fd - Open file descriptor to read from
* buffer - Read-only buffer containing the data to be written
* count - The number of bytes to write
*
* Returned Value:
* On success, then number of bytes read; Zero is returned on EOF.
* Otherwise, a negated errno value on failure.
*
****************************************************************************/
ssize_t tiff_read(int fd, FAR void *buffer, size_t count)
{
size_t ntotal;
ssize_t nbytes;
int errval;
/* This loop retries the write until either: (1) it completes successfully,
* or (2) until an irrecoverble error occurs.
*/
for (ntotal = 0; ntotal < count; )
{
/* Do the read. The number of bytes left to read is the total
* requested size (count) minus the amount that we have already read
* (ntotal).
*/
nbytes = read(fd, buffer, count-ntotal);
/* 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;
}
}
/* Zero is a special case and means that the end of file was encountered. */
else if (nbytes == 0)
{
break;
}
/* What if read returns some number of bytes other than the requested number?
* This probably means that the end-of-file will be encountered the next time
* that we call read().
*/
else
{
buffer += nbytes;
ntotal += nbytes;
}
}
return ntotal;
}
/****************************************************************************
* 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 const 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 write returns some number of bytes other than the requested number? */
else
{
DEBUGASSERT(nbytes == count);
buffer += nbytes;
count -= nbytes;
}
}
return OK;
}
/****************************************************************************
* Name: tiff_putint16
*
* Description:
* Write two bytes to the outfile.
*
* Input Parameters:
* fd - File descriptor to be used.
* value - The 2-byte, uint16_t value to write
*
* Returned Value:
* Zero (OK) on success. A negated errno value on failure.
*
****************************************************************************/
int tiff_putint16(int fd, uint16_t value)
{
uint8_t bytes[2];
/* Write the two bytes to the output file */
tiff_put16(bytes, value);
return tiff_write(fd, bytes, 2);
}
/****************************************************************************
* Name: tiff_putint32
*
* Description:
* Write four bytes to the outfile.
*
* Input Parameters:
* fd - File descriptor to be used.
* value - The 4-byte, uint32_t value to write
*
* Returned Value:
* Zero (OK) on success. A negated errno value on failure.
*
****************************************************************************/
int tiff_putint32(int fd, uint32_t value)
{
uint8_t bytes[4];
/* Write the four bytes to the output file */
tiff_put32(bytes, value);
return tiff_write(fd, bytes, 4);
}
/****************************************************************************
* Name: tiff_putstring
*
* Description:
* Write a string of fixed length to the outfile.
*
* Input Parameters:
* fd - File descriptor to be used.
* string - A pointer to the memory containing the string
* len - The length of the string (including the NUL terminator)
*
* Returned Value:
* Zero (OK) on success. A negated errno value on failure.
*
****************************************************************************/
int tiff_putstring(int fd, FAR const char *string, int len)
{
#ifdef CONFIG_DEBUG_GRAPHICS
int actual = strlen(string);
DEBUGASSERT(len = actual+1);
#endif
return tiff_write(fd, string, len);
}
/****************************************************************************
* Name: tiff_wordalign
*
* Description:
* Pad a file with zeros as necessary to achieve word alignament.
*
* Input Parameters:
* fd - File descriptor to be used.
* size - The current size of the file
*
* Returned Value:
* The new size of the file on success. A negated errno value on failure.
*
****************************************************************************/
ssize_t tiff_wordalign(int fd, size_t size)
{
unsigned int remainder;
int ret;
remainder = size & 3;
if (remainder > 0)
{
unsigned int nbytes = 4 - remainder;
uint32_t value = 0;
ret = tiff_write(fd, &value, nbytes);
if (ret < 0)
{
return (ssize_t)ret;
}
size += nbytes;
}
return size;
}
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