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// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab
/*
* Ceph - scalable distributed file system
*
* Copyright (C) 2011 New Dream Network
*
* This is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 2.1, as published by the Free Software
* Foundation. See file COPYING.
*
*/
#define _XOPEN_SOURCE 500
#include <unistd.h>
#include <errno.h>
#include "safe_io.h"
ssize_t safe_read(int fd, void *buf, size_t count)
{
ssize_t r;
size_t cnt = 0;
while (cnt < count) {
r = read(fd, buf, count - cnt);
if (r <= 0) {
if (r == 0) {
// EOF
return cnt;
}
if (errno == EINTR)
continue;
return -errno;
}
cnt += r;
buf = (char *)buf + r;
}
return cnt;
}
ssize_t safe_read_exact(int fd, void *buf, size_t count)
{
ssize_t ret = safe_read(fd, buf, count);
if (ret < 0)
return ret;
if ((size_t)ret != count)
return -EDOM;
return 0;
}
ssize_t safe_write(int fd, const void *buf, size_t count)
{
ssize_t r;
while (count > 0) {
r = write(fd, buf, count);
if (r < 0) {
if (errno == EINTR)
continue;
return -errno;
}
count -= r;
buf = (char *)buf + r;
}
return 0;
}
ssize_t safe_pread(int fd, void *buf, size_t count, off_t offset)
{
ssize_t r;
size_t cnt = 0;
char *b = (char*)buf;
while (cnt < count) {
r = pread(fd, b + cnt, count - cnt, offset + cnt);
if (r <= 0) {
if (r == 0) {
// EOF
return cnt;
}
if (errno == EINTR)
continue;
return -errno;
}
cnt += r;
}
return cnt;
}
ssize_t safe_pread_exact(int fd, void *buf, size_t count, off_t offset)
{
ssize_t ret = safe_pread(fd, buf, count, offset);
if (ret < 0)
return ret;
if ((size_t)ret != count)
return -EDOM;
return 0;
}
ssize_t safe_pwrite(int fd, const void *buf, size_t count, off_t offset)
{
ssize_t r;
while (count > 0) {
r = pwrite(fd, buf, count, offset);
if (r < 0) {
if (errno == EINTR)
continue;
return -errno;
}
count -= r;
buf = (char *)buf + r;
offset += r;
}
return 0;
}
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