gio/glocalfileinputstream.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2006-2007 Red Hat, Inc.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this library; if not, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  18  * Boston, MA 02111-1307, USA.
  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 #ifdef HAVE_UNISTD_H
  29 #include <unistd.h>
  30 #endif
  31 #include <errno.h>
  32
  33 #include <glib.h>
  34 #include <glib/gstdio.h>
  35 #include "gcancellable.h"
  36 #include "gioerror.h"
  37 #include "glocalfileinputstream.h"
  38 #include "glocalfileinfo.h"
  39 #include "glibintl.h"
  40
  41 #ifdef G_OS_UNIX
  42 #include "gfiledescriptorbased.h"
  43 #endif
  44
  45 #ifdef G_OS_WIN32
  46 #include <io.h>
  47 #endif
  48
  49
  50
  51 #ifdef G_OS_UNIX
  52 static void       g_file_descriptor_based_iface_init   (GFileDescriptorBasedIface *iface);
  53 #endif
  54
  55 #define g_local_file_input_stream_get_type _g_local_file_input_stream_get_type
  56 #ifdef G_OS_UNIX
  57 G_DEFINE_TYPE_WITH_CODE (GLocalFileInputStream, g_local_file_input_stream, G_TYPE_FILE_INPUT_STREAM,
  58                          G_IMPLEMENT_INTERFACE (G_TYPE_FILE_DESCRIPTOR_BASED,
  59                                                 g_file_descriptor_based_iface_init)
  60 );
  61 #else
  62 G_DEFINE_TYPE_WITH_CODE (GLocalFileInputStream, g_local_file_input_stream, G_TYPE_FILE_INPUT_STREAM,);
  63 #endif
  64
  65 struct _GLocalFileInputStreamPrivate {
  66   int fd;
  67   guint do_close : 1;
  68 };
  69
  70 static gssize     g_local_file_input_stream_read       (GInputStream      *stream,
  71                                                         void              *buffer,
  72                                                         gsize              count,
  73                                                         GCancellable      *cancellable,
  74                                                         GError           **error);
  75 static gssize     g_local_file_input_stream_skip       (GInputStream      *stream,
  76                                                         gsize              count,
  77                                                         GCancellable      *cancellable,
  78                                                         GError           **error);
  79 static gboolean   g_local_file_input_stream_close      (GInputStream      *stream,
  80                                                         GCancellable      *cancellable,
  81                                                         GError           **error);
  82 static goffset    g_local_file_input_stream_tell       (GFileInputStream  *stream);
  83 static gboolean   g_local_file_input_stream_can_seek   (GFileInputStream  *stream);
  84 static gboolean   g_local_file_input_stream_seek       (GFileInputStream  *stream,
  85                                                         goffset            offset,
  86                                                         GSeekType          type,
  87                                                         GCancellable      *cancellable,
  88                                                         GError           **error);
  89 static GFileInfo *g_local_file_input_stream_query_info (GFileInputStream  *stream,
  90                                                         const char        *attributes,
  91                                                         GCancellable      *cancellable,
  92                                                         GError           **error);
  93 #ifdef G_OS_UNIX
  94 static int        g_local_file_input_stream_get_fd     (GFileDescriptorBased *stream);
  95 #endif
  96
  97 static void
  98 g_local_file_input_stream_finalize (GObject *object)
  99 {
 100   G_OBJECT_CLASS (g_local_file_input_stream_parent_class)->finalize (object);
 101 }
 102
 103 void
 104 _g_local_file_input_stream_set_do_close (GLocalFileInputStream *in,
 105                                           gboolean do_close)
 106 {
 107   in->priv->do_close = do_close;
 108 }
 109
 110 static void
 111 g_local_file_input_stream_class_init (GLocalFileInputStreamClass *klass)
 112 {
 113   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 114   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
 115   GFileInputStreamClass *file_stream_class = G_FILE_INPUT_STREAM_CLASS (klass);
 116
 117   g_type_class_add_private (klass, sizeof (GLocalFileInputStreamPrivate));
 118
 119   gobject_class->finalize = g_local_file_input_stream_finalize;
 120
 121   stream_class->read_fn = g_local_file_input_stream_read;
 122   stream_class->skip = g_local_file_input_stream_skip;
 123   stream_class->close_fn = g_local_file_input_stream_close;
 124   file_stream_class->tell = g_local_file_input_stream_tell;
 125   file_stream_class->can_seek = g_local_file_input_stream_can_seek;
 126   file_stream_class->seek = g_local_file_input_stream_seek;
 127   file_stream_class->query_info = g_local_file_input_stream_query_info;
 128 }
 129
 130 #ifdef G_OS_UNIX
 131 static void
 132 g_file_descriptor_based_iface_init (GFileDescriptorBasedIface *iface)
 133 {
 134   iface->get_fd = g_local_file_input_stream_get_fd;
 135 }
 136 #endif
 137
 138 static void
 139 g_local_file_input_stream_init (GLocalFileInputStream *info)
 140 {
 141   info->priv = G_TYPE_INSTANCE_GET_PRIVATE (info,
 142                                             G_TYPE_LOCAL_FILE_INPUT_STREAM,
 143                                             GLocalFileInputStreamPrivate);
 144   info->priv->do_close = TRUE;
 145 }
 146
 147 GFileInputStream *
 148 _g_local_file_input_stream_new (int fd)
 149 {
 150   GLocalFileInputStream *stream;
 151
 152   stream = g_object_new (G_TYPE_LOCAL_FILE_INPUT_STREAM, NULL);
 153   stream->priv->fd = fd;
 154
 155   return G_FILE_INPUT_STREAM (stream);
 156 }
 157
 158 static gssize
 159 g_local_file_input_stream_read (GInputStream  *stream,
 160                                 void          *buffer,
 161                                 gsize          count,
 162                                 GCancellable  *cancellable,
 163                                 GError       **error)
 164 {
 165   GLocalFileInputStream *file;
 166   gssize res;
 167
 168   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 169
 170   res = -1;
 171   while (1)
 172     {
 173       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 174         break;
 175       res = read (file->priv->fd, buffer, count);
 176       if (res == -1)
 177         {
 178           int errsv = errno;
 179
 180           if (errsv == EINTR)
 181             continue;
 182
 183           g_set_error (error, G_IO_ERROR,
 184                        g_io_error_from_errno (errsv),
 185                        _("Error reading from file: %s"),
 186                        g_strerror (errsv));
 187         }
 188
 189       break;
 190     }
 191
 192   return res;
 193 }
 194
 195 static gssize
 196 g_local_file_input_stream_skip (GInputStream  *stream,
 197                                 gsize          count,
 198                                 GCancellable  *cancellable,
 199                                 GError       **error)
 200 {
 201   off_t res, start;
 202   GLocalFileInputStream *file;
 203
 204   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 205
 206   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 207     return -1;
 208
 209   start = lseek (file->priv->fd, 0, SEEK_CUR);
 210   if (start == -1)
 211     {
 212       int errsv = errno;
 213
 214       g_set_error (error, G_IO_ERROR,
 215                    g_io_error_from_errno (errsv),
 216                    _("Error seeking in file: %s"),
 217                    g_strerror (errsv));
 218       return -1;
 219     }
 220
 221   res = lseek (file->priv->fd, count, SEEK_CUR);
 222   if (res == -1)
 223     {
 224       int errsv = errno;
 225
 226       g_set_error (error, G_IO_ERROR,
 227                    g_io_error_from_errno (errsv),
 228                    _("Error seeking in file: %s"),
 229                    g_strerror (errsv));
 230       return -1;
 231     }
 232
 233   return res - start;
 234 }
 235
 236 static gboolean
 237 g_local_file_input_stream_close (GInputStream  *stream,
 238                                  GCancellable  *cancellable,
 239                                  GError       **error)
 240 {
 241   GLocalFileInputStream *file;
 242   int res;
 243
 244   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 245
 246   if (!file->priv->do_close)
 247     return TRUE;
 248
 249   if (file->priv->fd == -1)
 250     return TRUE;
 251
 252   while (1)
 253     {
 254       res = close (file->priv->fd);
 255       if (res == -1)
 256         {
 257           int errsv = errno;
 258
 259           g_set_error (error, G_IO_ERROR,
 260                        g_io_error_from_errno (errsv),
 261                        _("Error closing file: %s"),
 262                        g_strerror (errsv));
 263         }
 264       break;
 265     }
 266
 267   return res != -1;
 268 }
 269
 270
 271 static goffset
 272 g_local_file_input_stream_tell (GFileInputStream *stream)
 273 {
 274   GLocalFileInputStream *file;
 275   off_t pos;
 276
 277   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 278
 279   pos = lseek (file->priv->fd, 0, SEEK_CUR);
 280
 281   if (pos == (off_t)-1)
 282     return 0;
 283
 284   return pos;
 285 }
 286
 287 static gboolean
 288 g_local_file_input_stream_can_seek (GFileInputStream *stream)
 289 {
 290   GLocalFileInputStream *file;
 291   off_t pos;
 292
 293   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 294
 295   pos = lseek (file->priv->fd, 0, SEEK_CUR);
 296
 297   if (pos == (off_t)-1 && errno == ESPIPE)
 298     return FALSE;
 299
 300   return TRUE;
 301 }
 302
 303 static int
 304 seek_type_to_lseek (GSeekType type)
 305 {
 306   switch (type)
 307     {
 308     default:
 309     case G_SEEK_CUR:
 310       return SEEK_CUR;
 311
 312     case G_SEEK_SET:
 313       return SEEK_SET;
 314
 315     case G_SEEK_END:
 316       return SEEK_END;
 317     }
 318 }
 319
 320 static gboolean
 321 g_local_file_input_stream_seek (GFileInputStream  *stream,
 322                                 goffset            offset,
 323                                 GSeekType          type,
 324                                 GCancellable      *cancellable,
 325                                 GError           **error)
 326 {
 327   GLocalFileInputStream *file;
 328   off_t pos;
 329
 330   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 331
 332   pos = lseek (file->priv->fd, offset, seek_type_to_lseek (type));
 333
 334   if (pos == (off_t)-1)
 335     {
 336       int errsv = errno;
 337
 338       g_set_error (error, G_IO_ERROR,
 339                    g_io_error_from_errno (errsv),
 340                    _("Error seeking in file: %s"),
 341                    g_strerror (errsv));
 342       return FALSE;
 343     }
 344
 345   return TRUE;
 346 }
 347
 348 static GFileInfo *
 349 g_local_file_input_stream_query_info (GFileInputStream  *stream,
 350                                       const char        *attributes,
 351                                       GCancellable      *cancellable,
 352                                       GError           **error)
 353 {
 354   GLocalFileInputStream *file;
 355
 356   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 357
 358   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 359     return NULL;
 360
 361   return _g_local_file_info_get_from_fd (file->priv->fd,
 362                                          attributes,
 363                                          error);
 364 }
 365
 366 #ifdef G_OS_UNIX
 367 static int
 368 g_local_file_input_stream_get_fd (GFileDescriptorBased *fd_based)
 369 {
 370   GLocalFileInputStream *stream = G_LOCAL_FILE_INPUT_STREAM (fd_based);
 371   return stream->priv->fd;
 372 }
 373 #endif