SysUio.cpp File Reference

#include <folly/portability/SysUio.h>
#include <errno.h>
#include <stdio.h>
#include <folly/ScopeGuard.h>
#include <folly/portability/Sockets.h>
#include <folly/portability/SysFile.h>
#include <folly/portability/Unistd.h>

Go to the source code of this file.

Functions
template<class F , class... Args>
static int	wrapPositional (F f, int fd, off_t offset, Args...args)
ssize_t	preadv (int fd, const iovec *iov, int count, off_t offset)
ssize_t	pwritev (int fd, const iovec *iov, int count, off_t offset)

Function Documentation

ssize_t preadv	(	int	fd,
		const iovec *	iov,
		int	count,
		off_t	offset
	)

Definition at line 52 of file SysUio.cpp.

References wrapPositional().

Referenced by folly::preadvFull().

                                                                             {
  return wrapPositional(readv, fd, offset, iov, count);
}

ssize_t pwritev	(	int	fd,
		const iovec *	iov,
		int	count,
		off_t	offset
	)

Definition at line 58 of file SysUio.cpp.

References count, folly::kIovMax, fizz::detail::read(), SCOPE_EXIT, wrapPositional(), and fizz::detail::write().

Referenced by folly::pwritevFull().

                                                                              {
  return wrapPositional(writev, fd, offset, iov, count);
}

template<class F , class... Args>

static int wrapPositional ( F  f, int  fd, off_t  offset, Args...  args  )

static

Definition at line 28 of file SysUio.cpp.

References f.

Referenced by preadv(), and pwritev().

                                                                   {
  off_t origLoc = lseek(fd, 0, SEEK_CUR);
  if (origLoc == off_t(-1)) {
    return -1;
  }
  if (lseek(fd, offset, SEEK_SET) == off_t(-1)) {
    return -1;
  }

  int res = (int)f(fd, args...);

  int curErrNo = errno;
  if (lseek(fd, origLoc, SEEK_SET) == off_t(-1)) {
    if (res == -1) {
      errno = curErrNo;
    }
    return -1;
  }
  errno = curErrNo;

  return res;
}