/* POSIX compatible read() function.

   Copyright (C) 2008-2017 Free Software Foundation, Inc.

   Written by Bruno Haible <bruno@clisp.org>, 2011.

   This program is free software: you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include <config.h>

/* Specification.  */

#include <unistd.h>

#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__

# include <errno.h>

# include <io.h>

# define WIN32_LEAN_AND_MEAN  /* avoid including junk */

# include <windows.h>

# if HAVE_MSVC_INVALID_PARAMETER_HANDLER

#  include "msvc-inval.h"

# endif

# if GNULIB_MSVC_NOTHROW

#  include "msvc-nothrow.h"

# else

#  include <io.h>

# endif

# undef read

# if HAVE_MSVC_INVALID_PARAMETER_HANDLER

static ssize_t

read_nothrow (int fd, void *buf, size_t count)

{

  ssize_t result;

  TRY_MSVC_INVAL

    {

      result = read (fd, buf, count);

    }

  CATCH_MSVC_INVAL

    {

      result = -1;

      errno = EBADF;

    }

  DONE_MSVC_INVAL;

  return result;

}

# else

#  define read_nothrow read

# endif

ssize_t

rpl_read (int fd, void *buf, size_t count)

{

  ssize_t ret = read_nothrow (fd, buf, count);

# if GNULIB_NONBLOCKING

  if (ret < 0

      && GetLastError () == ERROR_NO_DATA)

    {

      HANDLE h = (HANDLE) _get_osfhandle (fd);

      if (GetFileType (h) == FILE_TYPE_PIPE)

        {

          /* h is a pipe or socket.  */

          DWORD state;

          if (GetNamedPipeHandleState (h, &state, NULL, NULL, NULL, NULL, 0)

              && (state & PIPE_NOWAIT) != 0)

            /* h is a pipe in non-blocking mode.

               Change errno from EINVAL to EAGAIN.  */

            errno = EAGAIN;

        }

    }

# endif

  return ret;

}

#endif