(root)/
glib-2.79.0/
gio/
glocalfileinputstream.c
       1  /* GIO - GLib Input, Output and Streaming Library
       2   * 
       3   * Copyright (C) 2006-2007 Red Hat, Inc.
       4   *
       5   * SPDX-License-Identifier: LGPL-2.1-or-later
       6   *
       7   * This library is free software; you can redistribute it and/or
       8   * modify it under the terms of the GNU Lesser General Public
       9   * License as published by the Free Software Foundation; either
      10   * version 2.1 of the License, or (at your option) any later version.
      11   *
      12   * This library is distributed in the hope that it will be useful,
      13   * but WITHOUT ANY WARRANTY; without even the implied warranty of
      14   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      15   * Lesser General Public License for more details.
      16   *
      17   * You should have received a copy of the GNU Lesser General
      18   * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
      19   *
      20   * Author: Alexander Larsson <alexl@redhat.com>
      21   */
      22  
      23  #include "config.h"
      24  
      25  #include <sys/types.h>
      26  #include <sys/stat.h>
      27  #include <fcntl.h>
      28  #include <errno.h>
      29  
      30  #include <glib.h>
      31  #include <glib/gstdio.h>
      32  #include "gcancellable.h"
      33  #include "gioerror.h"
      34  #include "glocalfileinputstream.h"
      35  #include "glocalfileinfo.h"
      36  #include "glibintl.h"
      37  
      38  #ifdef G_OS_UNIX
      39  #include <unistd.h>
      40  #include "glib-unix.h"
      41  #include "gfiledescriptorbased.h"
      42  #endif
      43  
      44  #ifdef G_OS_WIN32
      45  #include <io.h>
      46  #endif
      47  
      48  struct _GLocalFileInputStreamPrivate {
      49    int fd;
      50    guint do_close : 1;
      51  };
      52  
      53  #ifdef G_OS_UNIX
      54  static void       g_file_descriptor_based_iface_init   (GFileDescriptorBasedIface *iface);
      55  #endif
      56  
      57  #define g_local_file_input_stream_get_type _g_local_file_input_stream_get_type
      58  #ifdef G_OS_UNIX
      59  G_DEFINE_TYPE_WITH_CODE (GLocalFileInputStream, g_local_file_input_stream, G_TYPE_FILE_INPUT_STREAM,
      60                           G_ADD_PRIVATE (GLocalFileInputStream)
      61  			 G_IMPLEMENT_INTERFACE (G_TYPE_FILE_DESCRIPTOR_BASED,
      62  						g_file_descriptor_based_iface_init))
      63  #else
      64  G_DEFINE_TYPE_WITH_CODE (GLocalFileInputStream, g_local_file_input_stream, G_TYPE_FILE_INPUT_STREAM,
      65                           G_ADD_PRIVATE (GLocalFileInputStream))
      66  #endif
      67  
      68  static gssize     g_local_file_input_stream_read       (GInputStream      *stream,
      69  							void              *buffer,
      70  							gsize              count,
      71  							GCancellable      *cancellable,
      72  							GError           **error);
      73  static gboolean   g_local_file_input_stream_close      (GInputStream      *stream,
      74  							GCancellable      *cancellable,
      75  							GError           **error);
      76  static goffset    g_local_file_input_stream_tell       (GFileInputStream  *stream);
      77  static gboolean   g_local_file_input_stream_can_seek   (GFileInputStream  *stream);
      78  static gboolean   g_local_file_input_stream_seek       (GFileInputStream  *stream,
      79  							goffset            offset,
      80  							GSeekType          type,
      81  							GCancellable      *cancellable,
      82  							GError           **error);
      83  static GFileInfo *g_local_file_input_stream_query_info (GFileInputStream  *stream,
      84  							const char        *attributes,
      85  							GCancellable      *cancellable,
      86  							GError           **error);
      87  #ifdef G_OS_UNIX
      88  static int        g_local_file_input_stream_get_fd     (GFileDescriptorBased *stream);
      89  #endif
      90  
      91  void
      92  _g_local_file_input_stream_set_do_close (GLocalFileInputStream *in,
      93  					  gboolean do_close)
      94  {
      95    in->priv->do_close = do_close;
      96  }
      97  
      98  static void
      99  g_local_file_input_stream_class_init (GLocalFileInputStreamClass *klass)
     100  {
     101    GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
     102    GFileInputStreamClass *file_stream_class = G_FILE_INPUT_STREAM_CLASS (klass);
     103  
     104    stream_class->read_fn = g_local_file_input_stream_read;
     105    stream_class->close_fn = g_local_file_input_stream_close;
     106    file_stream_class->tell = g_local_file_input_stream_tell;
     107    file_stream_class->can_seek = g_local_file_input_stream_can_seek;
     108    file_stream_class->seek = g_local_file_input_stream_seek;
     109    file_stream_class->query_info = g_local_file_input_stream_query_info;
     110  }
     111  
     112  #ifdef G_OS_UNIX
     113  static void
     114  g_file_descriptor_based_iface_init (GFileDescriptorBasedIface *iface)
     115  {
     116    iface->get_fd = g_local_file_input_stream_get_fd;
     117  }
     118  #endif
     119  
     120  static void
     121  g_local_file_input_stream_init (GLocalFileInputStream *info)
     122  {
     123    info->priv = g_local_file_input_stream_get_instance_private (info);
     124    info->priv->do_close = TRUE;
     125  }
     126  
     127  GFileInputStream *
     128  _g_local_file_input_stream_new (int fd)
     129  {
     130    GLocalFileInputStream *stream;
     131  
     132    stream = g_object_new (G_TYPE_LOCAL_FILE_INPUT_STREAM, NULL);
     133    stream->priv->fd = fd;
     134    
     135    return G_FILE_INPUT_STREAM (stream);
     136  }
     137  
     138  static gssize
     139  g_local_file_input_stream_read (GInputStream  *stream,
     140  				void          *buffer,
     141  				gsize          count,
     142  				GCancellable  *cancellable,
     143  				GError       **error)
     144  {
     145    GLocalFileInputStream *file;
     146    gssize res;
     147  
     148    file = G_LOCAL_FILE_INPUT_STREAM (stream);
     149  
     150    res = -1;
     151    while (1)
     152      {
     153        if (g_cancellable_set_error_if_cancelled (cancellable, error))
     154  	break;
     155        res = read (file->priv->fd, buffer, count);
     156        if (res == -1)
     157  	{
     158            int errsv = errno;
     159  
     160  	  if (errsv == EINTR)
     161  	    continue;
     162  	  
     163  	  g_set_error (error, G_IO_ERROR,
     164  		       g_io_error_from_errno (errsv),
     165  		       _("Error reading from file: %s"),
     166  		       g_strerror (errsv));
     167  	}
     168        
     169        break;
     170      }
     171    
     172    return res;
     173  }
     174  
     175  static gboolean
     176  g_local_file_input_stream_close (GInputStream  *stream,
     177  				 GCancellable  *cancellable,
     178  				 GError       **error)
     179  {
     180    GLocalFileInputStream *file;
     181  
     182    file = G_LOCAL_FILE_INPUT_STREAM (stream);
     183  
     184    if (!file->priv->do_close)
     185      return TRUE;
     186  
     187    if (file->priv->fd == -1)
     188      return TRUE;
     189  
     190    if (!g_close (file->priv->fd, NULL))
     191      {
     192        int errsv = errno;
     193        
     194        g_set_error (error, G_IO_ERROR,
     195                     g_io_error_from_errno (errsv),
     196                     _("Error closing file: %s"),
     197                     g_strerror (errsv));
     198        return FALSE;
     199      }
     200  
     201    return TRUE;
     202  }
     203  
     204  
     205  static goffset
     206  g_local_file_input_stream_tell (GFileInputStream *stream)
     207  {
     208    GLocalFileInputStream *file;
     209    off_t pos;
     210  
     211    file = G_LOCAL_FILE_INPUT_STREAM (stream);
     212    
     213    pos = lseek (file->priv->fd, 0, SEEK_CUR);
     214  
     215    if (pos == (off_t)-1)
     216      return 0;
     217    
     218    return pos;
     219  }
     220  
     221  static gboolean
     222  g_local_file_input_stream_can_seek (GFileInputStream *stream)
     223  {
     224    GLocalFileInputStream *file;
     225    off_t pos;
     226  
     227    file = G_LOCAL_FILE_INPUT_STREAM (stream);
     228    
     229    pos = lseek (file->priv->fd, 0, SEEK_CUR);
     230  
     231    if (pos == (off_t)-1 && errno == ESPIPE)
     232      return FALSE;
     233    
     234    return TRUE;
     235  }
     236  
     237  static int
     238  seek_type_to_lseek (GSeekType type)
     239  {
     240    switch (type)
     241      {
     242      default:
     243      case G_SEEK_CUR:
     244        return SEEK_CUR;
     245        
     246      case G_SEEK_SET:
     247        return SEEK_SET;
     248        
     249      case G_SEEK_END:
     250        return SEEK_END;
     251      }
     252  }
     253  
     254  static gboolean
     255  g_local_file_input_stream_seek (GFileInputStream  *stream,
     256  				goffset            offset,
     257  				GSeekType          type,
     258  				GCancellable      *cancellable,
     259  				GError           **error)
     260  {
     261    GLocalFileInputStream *file;
     262    off_t pos;
     263  
     264    file = G_LOCAL_FILE_INPUT_STREAM (stream);
     265  
     266    pos = lseek (file->priv->fd, offset, seek_type_to_lseek (type));
     267  
     268    if (pos == (off_t)-1)
     269      {
     270        int errsv = errno;
     271  
     272        g_set_error (error, G_IO_ERROR,
     273  		   g_io_error_from_errno (errsv),
     274  		   _("Error seeking in file: %s"),
     275  		   g_strerror (errsv));
     276        return FALSE;
     277      }
     278    
     279    return TRUE;
     280  }
     281  
     282  static GFileInfo *
     283  g_local_file_input_stream_query_info (GFileInputStream  *stream,
     284  				      const char        *attributes,
     285  				      GCancellable      *cancellable,
     286  				      GError           **error)
     287  {
     288    GLocalFileInputStream *file;
     289  
     290    file = G_LOCAL_FILE_INPUT_STREAM (stream);
     291  
     292    if (g_cancellable_set_error_if_cancelled (cancellable, error))
     293      return NULL;
     294    
     295    return _g_local_file_info_get_from_fd (file->priv->fd,
     296  					 attributes,
     297  					 error);
     298  }
     299  
     300  #ifdef G_OS_UNIX
     301  static int
     302  g_local_file_input_stream_get_fd (GFileDescriptorBased *fd_based)
     303  {
     304    GLocalFileInputStream *stream = G_LOCAL_FILE_INPUT_STREAM (fd_based);
     305    return stream->priv->fd;
     306  }
     307  #endif