/* $NetBSD: atomic.c,v 1.2 2007/06/25 21:38:43 joerg Exp $ */

/*-
 * Copyright (c) 2007 Joerg Sonnenberger <joerg@NetBSD.org>.
 * All rights reserved.
 *
 * This code was developed as part of Google's Summer of Code 2007 program.
 *
 * 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.
 *
 * 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 HOLDERS 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 <nbcompat.h>

#include <nbcompat/stat.h>
#include <nbcompat/err.h>
#include <fcntl.h>
#include <nbcompat/limits.h>
#include <nbcompat/string.h>
#include <nbcompat/unistd.h>

#include "pbulk.h"

ssize_t
atomic_read(int fd, void *real_buf, size_t bytes)
{
	char *buf = real_buf;
	ssize_t len;
	ssize_t ret;

	len = 0;

	do {
		ret = read(fd, buf, bytes);
		if (ret == -1)
			return ret;
		buf += ret;
		len += ret;
		bytes -= ret;
	} while (ret != 0 && bytes != 0);

	return len;
}

ssize_t
atomic_write(int fd, const void *real_buf, size_t bytes)
{
	const char *buf = real_buf;
	ssize_t len;
	ssize_t ret;

	len = 0;

	do {
		ret = write(fd, buf, bytes);
		if (ret == -1)
			return ret;
		buf += ret;
		len += ret;
		bytes -= ret;
	} while (ret != 0 && bytes != 0);

	return len;
}