/* data-fd.c - A file descripor based data object.

   Copyright (C) 2002, 2004 g10 Code GmbH

   This file is part of GPGME.

   GPGME is free software; you can redistribute it and/or modify it

   under the terms of the GNU Lesser General Public License as

   published by the Free Software Foundation; either version 2.1 of

   the License, or (at your option) any later version.

   GPGME 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

   Lesser General Public License for more details.

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

   License along with this program; if not, write to the Free Software

   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA

   02111-1307, USA.  */

#if HAVE_CONFIG_H

#include <config.h>

#endif

#ifdef HAVE_UNISTD_H

# include <unistd.h>

#endif

#ifdef HAVE_SYS_TYPES_H

# include <sys/types.h>

#endif

#include "debug.h"

#include "data.h"

#if defined(HAVE_W32CE_SYSTEM) && !defined(__MINGW32CE__)

/* We need to provide replacements for read, write and lseek.  They

   are taken from the cegcc runtime files, written by Pedro Alves

   <pedro_alves@portugalmail.pt> in Feb 2007 and placed in the public

   domain. (cf. cegcc/src/mingw/mingwex/wince/)  */

#include <windows.h>

static int

read (int fildes, void *buf, unsigned int bufsize)

{

  DWORD NumberOfBytesRead;

  if (bufsize > 0x7fffffff)

    bufsize = 0x7fffffff;

  if (!ReadFile ((HANDLE) fildes, buf, bufsize, &NumberOfBytesRead, NULL))

    return -1;

  return (int) NumberOfBytesRead;

}

static int

write (int fildes, const void *buf, unsigned int bufsize)

{

  DWORD NumberOfBytesWritten;

  if (bufsize > 0x7fffffff)

    bufsize = 0x7fffffff;

  if (!WriteFile ((HANDLE) fildes, buf, bufsize, &NumberOfBytesWritten, NULL))

    return -1;

  return (int) NumberOfBytesWritten;

}

static long

lseek (int fildes, long offset, int whence)

{

  DWORD mode;

  switch (whence)

    {

    case SEEK_SET:

      mode = FILE_BEGIN;

      break;

    case SEEK_CUR:

      mode = FILE_CURRENT;

      break;

    case SEEK_END:

      mode = FILE_END;

      break;

    default:

      /* Specify an invalid mode so SetFilePointer catches it.  */

      mode = (DWORD)-1;

    }

  return (long) SetFilePointer ((HANDLE) fildes, offset, NULL, mode);

}

#endif /*HAVE_W32CE_SYSTEM && !__MINGW32CE__*/

static gpgme_ssize_t

fd_read (gpgme_data_t dh, void *buffer, size_t size)

{

  return read (dh->data.fd, buffer, size);

}

static gpgme_ssize_t

fd_write (gpgme_data_t dh, const void *buffer, size_t size)

{

  return write (dh->data.fd, buffer, size);

}

static gpgme_off_t

fd_seek (gpgme_data_t dh, gpgme_off_t offset, int whence)

{

  return lseek (dh->data.fd, offset, whence);

}

static int

fd_get_fd (gpgme_data_t dh)

{

  return (dh->data.fd);

}

static struct _gpgme_data_cbs fd_cbs =

  {

    fd_read,

    fd_write,

    fd_seek,

    NULL,

    fd_get_fd

  };

gpgme_error_t

gpgme_data_new_from_fd (gpgme_data_t *r_dh, int fd)

{

  gpgme_error_t err;

  TRACE_BEG1 (DEBUG_DATA, "gpgme_data_new_from_fd", r_dh, "fd=0x%x", fd);

  err = _gpgme_data_new (r_dh, &fd_cbs);

  if (err)

    return TRACE_ERR (err);

  (*r_dh)->data.fd = fd;

  return TRACE_SUC1 ("dh=%p", *r_dh);

}