/* data-stream.c - A stream based data object.

 * Copyright (C) 2002, 2004, 2018 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, see <https://www.gnu.org/licenses/>.

 * SPDX-License-Identifier: LGPL-2.1+

 */

#if HAVE_CONFIG_H

#include <config.h>

#endif

#include <stdio.h>

#ifdef HAVE_SYS_TYPES_H

# include <sys/types.h>

#endif

#include "debug.h"

#include "data.h"

static gpgme_ssize_t

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

{

  size_t amt = gpgrt_fread (buffer, 1, size, dh->data.e_stream);

  if (amt > 0)

    return amt;

  return gpgrt_ferror (dh->data.e_stream) ? -1 : 0;

}

static gpgme_ssize_t

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

{

  size_t amt = gpgrt_fwrite (buffer, 1, size, dh->data.e_stream);

  if (amt > 0)

    return amt;

  return gpgrt_ferror (dh->data.e_stream) ? -1 : 0;

}

static gpgme_off_t

stream_es_seek (gpgme_data_t dh, gpgme_off_t offset, int whence)

{

  int err;

  err = gpgrt_fseeko (dh->data.e_stream, offset, whence);

  if (err)

    return -1;

  return gpgrt_ftello (dh->data.e_stream);

}

static int

stream_es_get_fd (gpgme_data_t dh)

{

  gpgrt_fflush (dh->data.e_stream);

  return gpgrt_fileno (dh->data.e_stream);

}

static struct _gpgme_data_cbs stream_es_cbs =

  {

    stream_es_read,

    stream_es_write,

    stream_es_seek,

    NULL,

    stream_es_get_fd

  };

gpgme_error_t

gpgme_data_new_from_estream (gpgme_data_t *r_dh, gpgrt_stream_t stream)

{

  gpgme_error_t err;

  TRACE_BEG  (DEBUG_DATA, "gpgme_data_new_from_estream", r_dh, "estream=%p",

	      stream);

  err = _gpgme_data_new (r_dh, &stream_es_cbs);

  if (err)

    return TRACE_ERR (err);

  (*r_dh)->data.e_stream = stream;

  TRACE_SUC ("dh=%p", *r_dh);

  return 0;

}