/*************************************************************************
* (C) 2010 AITNET ltd - Sofia/Bulgaria - <misho@aitnet.org>
*  by Michael Pounov <misho@elwix.org>
*
* $Author: misho $
* $Id: aio.c,v 1.4 2012/03/29 01:31:33 misho Exp $
*
**************************************************************************
The ELWIX and AITNET software is distributed under the following
terms:

All of the documentation and software included in the ELWIX and AITNET
Releases is copyrighted by ELWIX - Sofia/Bulgaria <info@elwix.org>

Copyright 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
	by Michael Pounov <misho@elwix.org>.  All rights reserved.

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. All advertising materials mentioning features or use of this software
   must display the following acknowledgement:
This product includes software developed by Michael Pounov <misho@elwix.org>
ELWIX - Embedded LightWeight unIX and its contributors.
4. Neither the name of AITNET 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 AITNET 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 REGENTS 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.
*/
#include "global.h"


/*
 * io_rread() Raw VFS read function
 *
 * @fd = File handle
 * @buf = Read buffer
 * @nbytes = Read buffer size
 * @offset = Read from position, if -1 read nbytes from current position
 * @update = Update file handle position !0
 * return: -1 error or !=-1 readed bytes
 */
inline int
io_rread(int fd, void * __restrict buf, size_t nbytes, off_t offset, int update)
{
	int ret;
#ifdef AIO_OPS
	off_t old = 0;
	struct aiocb acb;
#endif

	if (!buf) {
		io_SetErr(EINVAL, "Error:: invalid arguments ...\n");
		return -1;
	}
	if (!nbytes)
		return 0;
	if (offset == -1) {
		offset = lseek(fd, 0, SEEK_CUR);
		if (offset == -1) {
			LOGERR;
			return -1;
		}
	}

#ifdef AIO_OPS
	/* This made for generate EOF for file */
	if (!update && (old = lseek(fd, 0, SEEK_CUR)) == -1) {
		LOGERR;
		return -1;
	}
	if (offset >= lseek(fd, 0, SEEK_END))
		return 0;
	if (!update)
		lseek(fd, old, SEEK_SET);

	memset(buf, 0, nbytes);
	memset(&acb, 0, sizeof acb);
	acb.aio_fildes = fd;
	acb.aio_nbytes = nbytes;
	acb.aio_buf = buf;
	acb.aio_offset = offset;

	if (aio_read(&acb) == -1) {
		LOGERR;
		return -1;
	}

	while (aio_error(&acb) == EINPROGRESS);
	ret = aio_return(&acb);
	if (ret == -1) {
		LOGERR;
		return -1;
	} else
		ret = acb.aio_nbytes;
#else
	ret = pread(fd, buf, nbytes, offset);
	if (ret == -1) {
		LOGERR;
		return -1;
	}
#endif

	if (update)
		lseek(fd, offset + ret, SEEK_SET);

	return ret;
}

/*
 * io_rwrite() Raw VFS write function
 *
 * @fd = File handle
 * @buf = Write buffer
 * @nbytes = Write bytes from buffer
 * @offset = Write at position, if -1 write nbytes from current position
 * @update = Update file handle position !0
 * return: -1 error or !=-1 writed bytes
 */
inline int
io_rwrite(int fd, void * __restrict buf, size_t nbytes, off_t offset, int update)
{
	int ret;
#ifdef AIO_OPS
	struct aiocb acb;
#endif

	if (!buf) {
		io_SetErr(EINVAL, "Error:: invalid arguments ...\n");
		return -1;
	}
	if (!nbytes)
		return 0;
	if (offset == -1) {
		offset = lseek(fd, 0, SEEK_CUR);
		if (offset == -1) {
			LOGERR;
			return -1;
		}
	}

#ifdef AIO_OPS
	memset(&acb, 0, sizeof acb);
	acb.aio_fildes = fd;
	acb.aio_nbytes = nbytes;
	acb.aio_buf = buf;
	acb.aio_offset = offset;

	if (aio_write(&acb) == -1) {
		LOGERR;
		return -1;
	}

	while (aio_error(&acb) == EINPROGRESS);
	ret = aio_return(&acb);
	if (ret == -1) {
		LOGERR;
		return -1;
	} else
		ret = acb.aio_nbytes;
#else
	ret = pwrite(fd, buf, nbytes, offset);
	if (ret == -1) {
		LOGERR;
		return -1;
	}
#endif

	if (update)
		lseek(fd, offset + ret, SEEK_SET);


	return ret;
}