/* GIO - GLib Input, Output and Streaming Library

 * 

 * Copyright (C) 2006-2007 Red Hat, Inc.

 *

 * This library 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.

 *

 * This library 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 library; if not, see <http://www.gnu.org/licenses/>.

 *

 * Author: Alexander Larsson <alexl@redhat.com>

 */

#include "config.h"

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <errno.h>

#include <glib.h>

#include <glib/gstdio.h>

#include "gcancellable.h"

#include "gioerror.h"

#include "glocalfileinputstream.h"

#include "glocalfileinfo.h"

#include "glibintl.h"

#ifdef G_OS_UNIX

#include <unistd.h>

#include "glib-unix.h"

#include "gfiledescriptorbased.h"

#endif

#ifdef G_OS_WIN32

#include <io.h>

#endif

struct _GLocalFileInputStreamPrivate {

  int fd;

  guint do_close : 1;

};

#ifdef G_OS_UNIX

static void       g_file_descriptor_based_iface_init   (GFileDescriptorBasedIface *iface);

#endif

#define g_local_file_input_stream_get_type _g_local_file_input_stream_get_type

#ifdef G_OS_UNIX

G_DEFINE_TYPE_WITH_CODE (GLocalFileInputStream, g_local_file_input_stream, G_TYPE_FILE_INPUT_STREAM,

                         G_ADD_PRIVATE (GLocalFileInputStream)

			 G_IMPLEMENT_INTERFACE (G_TYPE_FILE_DESCRIPTOR_BASED,

						g_file_descriptor_based_iface_init))

#else

G_DEFINE_TYPE_WITH_CODE (GLocalFileInputStream, g_local_file_input_stream, G_TYPE_FILE_INPUT_STREAM,

                         G_ADD_PRIVATE (GLocalFileInputStream))

#endif

static gssize     g_local_file_input_stream_read       (GInputStream      *stream,

							void              *buffer,

							gsize              count,

							GCancellable      *cancellable,

							GError           **error);

static gssize     g_local_file_input_stream_skip       (GInputStream      *stream,

							gsize              count,

							GCancellable      *cancellable,

							GError           **error);

static gboolean   g_local_file_input_stream_close      (GInputStream      *stream,

							GCancellable      *cancellable,

							GError           **error);

static goffset    g_local_file_input_stream_tell       (GFileInputStream  *stream);

static gboolean   g_local_file_input_stream_can_seek   (GFileInputStream  *stream);

static gboolean   g_local_file_input_stream_seek       (GFileInputStream  *stream,

							goffset            offset,

							GSeekType          type,

							GCancellable      *cancellable,

							GError           **error);

static GFileInfo *g_local_file_input_stream_query_info (GFileInputStream  *stream,

							const char        *attributes,

							GCancellable      *cancellable,

							GError           **error);

#ifdef G_OS_UNIX

static int        g_local_file_input_stream_get_fd     (GFileDescriptorBased *stream);

#endif

void

_g_local_file_input_stream_set_do_close (GLocalFileInputStream *in,

					  gboolean do_close)

{

  in->priv->do_close = do_close;

}

static void

g_local_file_input_stream_class_init (GLocalFileInputStreamClass *klass)

{

  GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);

  GFileInputStreamClass *file_stream_class = G_FILE_INPUT_STREAM_CLASS (klass);

  stream_class->read_fn = g_local_file_input_stream_read;

  stream_class->skip = g_local_file_input_stream_skip;

  stream_class->close_fn = g_local_file_input_stream_close;

  file_stream_class->tell = g_local_file_input_stream_tell;

  file_stream_class->can_seek = g_local_file_input_stream_can_seek;

  file_stream_class->seek = g_local_file_input_stream_seek;

  file_stream_class->query_info = g_local_file_input_stream_query_info;

}

#ifdef G_OS_UNIX

static void

g_file_descriptor_based_iface_init (GFileDescriptorBasedIface *iface)

{

  iface->get_fd = g_local_file_input_stream_get_fd;

}

#endif

static void

g_local_file_input_stream_init (GLocalFileInputStream *info)

{

  info->priv = g_local_file_input_stream_get_instance_private (info);

  info->priv->do_close = TRUE;

}

GFileInputStream *

_g_local_file_input_stream_new (int fd)

{

  GLocalFileInputStream *stream;

  stream = g_object_new (G_TYPE_LOCAL_FILE_INPUT_STREAM, NULL);

  stream->priv->fd = fd;

  return G_FILE_INPUT_STREAM (stream);

}

static gssize

g_local_file_input_stream_read (GInputStream  *stream,

				void          *buffer,

				gsize          count,

				GCancellable  *cancellable,

				GError       **error)

{

  GLocalFileInputStream *file;

  gssize res;

  file = G_LOCAL_FILE_INPUT_STREAM (stream);

  res = -1;

  while (1)

    {

      if (g_cancellable_set_error_if_cancelled (cancellable, error))

	break;

      res = read (file->priv->fd, buffer, count);

      if (res == -1)

	{

          int errsv = errno;

	  if (errsv == EINTR)

	    continue;

	  g_set_error (error, G_IO_ERROR,

		       g_io_error_from_errno (errsv),

		       _("Error reading from file: %s"),

		       g_strerror (errsv));

	}

      break;

    }

  return res;

}

static gssize

g_local_file_input_stream_skip (GInputStream  *stream,

				gsize          count,

				GCancellable  *cancellable,

				GError       **error)

{

  off_t start, end;

  GLocalFileInputStream *file;

  file = G_LOCAL_FILE_INPUT_STREAM (stream);

  if (g_cancellable_set_error_if_cancelled (cancellable, error))

    return -1;

  start = lseek (file->priv->fd, 0, SEEK_CUR);

  if (start == -1)

    {

      int errsv = errno;

      g_set_error (error, G_IO_ERROR,

		   g_io_error_from_errno (errsv),

		   _("Error seeking in file: %s"),

		   g_strerror (errsv));

      return -1;

    }

  end = lseek (file->priv->fd, 0, SEEK_END);

  if (end == -1)

    {

      int errsv = errno;

      g_set_error (error, G_IO_ERROR,

		   g_io_error_from_errno (errsv),

		   _("Error seeking in file: %s"),

		   g_strerror (errsv));

      return -1;

    }

  if (end - start > count)

    {

      end = lseek (file->priv->fd, count - (end - start), SEEK_CUR);

      if (end == -1)

	{

	  int errsv = errno;

	  g_set_error (error, G_IO_ERROR,

		       g_io_error_from_errno (errsv),

		       _("Error seeking in file: %s"),

		       g_strerror (errsv));

	  return -1;

	}

    }

  return end - start;

}

static gboolean

g_local_file_input_stream_close (GInputStream  *stream,

				 GCancellable  *cancellable,

				 GError       **error)

{

  GLocalFileInputStream *file;

  file = G_LOCAL_FILE_INPUT_STREAM (stream);

  if (!file->priv->do_close)

    return TRUE;

  if (file->priv->fd == -1)

    return TRUE;

  if (!g_close (file->priv->fd, NULL))

    {

      int errsv = errno;

      g_set_error (error, G_IO_ERROR,

                   g_io_error_from_errno (errsv),

                   _("Error closing file: %s"),

                   g_strerror (errsv));

      return FALSE;

    }

  return TRUE;

}

static goffset

g_local_file_input_stream_tell (GFileInputStream *stream)

{

  GLocalFileInputStream *file;

  off_t pos;

  file = G_LOCAL_FILE_INPUT_STREAM (stream);

  pos = lseek (file->priv->fd, 0, SEEK_CUR);

  if (pos == (off_t)-1)

    return 0;

  return pos;

}

static gboolean

g_local_file_input_stream_can_seek (GFileInputStream *stream)

{

  GLocalFileInputStream *file;

  off_t pos;

  file = G_LOCAL_FILE_INPUT_STREAM (stream);

  pos = lseek (file->priv->fd, 0, SEEK_CUR);

  if (pos == (off_t)-1 && errno == ESPIPE)

    return FALSE;

  return TRUE;

}

static int

seek_type_to_lseek (GSeekType type)

{

  switch (type)

    {

    default:

    case G_SEEK_CUR:

      return SEEK_CUR;

    case G_SEEK_SET:

      return SEEK_SET;

    case G_SEEK_END:

      return SEEK_END;

    }

}

static gboolean

g_local_file_input_stream_seek (GFileInputStream  *stream,

				goffset            offset,

				GSeekType          type,

				GCancellable      *cancellable,

				GError           **error)

{

  GLocalFileInputStream *file;

  off_t pos;

  file = G_LOCAL_FILE_INPUT_STREAM (stream);

  pos = lseek (file->priv->fd, offset, seek_type_to_lseek (type));

  if (pos == (off_t)-1)

    {

      int errsv = errno;

      g_set_error (error, G_IO_ERROR,

		   g_io_error_from_errno (errsv),

		   _("Error seeking in file: %s"),

		   g_strerror (errsv));

      return FALSE;

    }

  return TRUE;

}

static GFileInfo *

g_local_file_input_stream_query_info (GFileInputStream  *stream,

				      const char        *attributes,

				      GCancellable      *cancellable,

				      GError           **error)

{

  GLocalFileInputStream *file;

  file = G_LOCAL_FILE_INPUT_STREAM (stream);

  if (g_cancellable_set_error_if_cancelled (cancellable, error))

    return NULL;

  return _g_local_file_info_get_from_fd (file->priv->fd,

					 attributes,

					 error);

}

#ifdef G_OS_UNIX

static int

g_local_file_input_stream_get_fd (GFileDescriptorBased *fd_based)

{

  GLocalFileInputStream *stream = G_LOCAL_FILE_INPUT_STREAM (fd_based);

  return stream->priv->fd;

}

#endif