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