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_WIN32
  42 #include <io.h>
  43 #endif
  44
  45 #include "gioalias.h"
  46
  47 #define g_local_file_input_stream_get_type _g_local_file_input_stream_get_type
  48 G_DEFINE_TYPE (GLocalFileInputStream, g_local_file_input_stream, G_TYPE_FILE_INPUT_STREAM);
  49
  50 struct _GLocalFileInputStreamPrivate {
  51   int fd;
  52   guint do_close : 1;
  53 };
  54
  55 static gssize     g_local_file_input_stream_read       (GInputStream      *stream,
  56                                                         void              *buffer,
  57                                                         gsize              count,
  58                                                         GCancellable      *cancellable,
  59                                                         GError           **error);
  60 static gssize     g_local_file_input_stream_skip       (GInputStream      *stream,
  61                                                         gsize              count,
  62                                                         GCancellable      *cancellable,
  63                                                         GError           **error);
  64 static gboolean   g_local_file_input_stream_close      (GInputStream      *stream,
  65                                                         GCancellable      *cancellable,
  66                                                         GError           **error);
  67 static goffset    g_local_file_input_stream_tell       (GFileInputStream  *stream);
  68 static gboolean   g_local_file_input_stream_can_seek   (GFileInputStream  *stream);
  69 static gboolean   g_local_file_input_stream_seek       (GFileInputStream  *stream,
  70                                                         goffset            offset,
  71                                                         GSeekType          type,
  72                                                         GCancellable      *cancellable,
  73                                                         GError           **error);
  74 static GFileInfo *g_local_file_input_stream_query_info (GFileInputStream  *stream,
  75                                                         const char        *attributes,
  76                                                         GCancellable      *cancellable,
  77                                                         GError           **error);
  78
  79 static void
  80 g_local_file_input_stream_finalize (GObject *object)
  81 {
  82   GLocalFileInputStream *file;
  83
  84   file = G_LOCAL_FILE_INPUT_STREAM (object);
  85
  86   G_OBJECT_CLASS (g_local_file_input_stream_parent_class)->finalize (object);
  87 }
  88
  89 void
  90 _g_local_file_input_stream_set_do_close (GLocalFileInputStream *in,
  91                                           gboolean do_close)
  92 {
  93   in->priv->do_close = do_close;
  94 }
  95
  96 static void
  97 g_local_file_input_stream_class_init (GLocalFileInputStreamClass *klass)
  98 {
  99   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 100   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
 101   GFileInputStreamClass *file_stream_class = G_FILE_INPUT_STREAM_CLASS (klass);
 102
 103   g_type_class_add_private (klass, sizeof (GLocalFileInputStreamPrivate));
 104
 105   gobject_class->finalize = g_local_file_input_stream_finalize;
 106
 107   stream_class->read_fn = g_local_file_input_stream_read;
 108   stream_class->skip = g_local_file_input_stream_skip;
 109   stream_class->close_fn = g_local_file_input_stream_close;
 110   file_stream_class->tell = g_local_file_input_stream_tell;
 111   file_stream_class->can_seek = g_local_file_input_stream_can_seek;
 112   file_stream_class->seek = g_local_file_input_stream_seek;
 113   file_stream_class->query_info = g_local_file_input_stream_query_info;
 114 }
 115
 116 static void
 117 g_local_file_input_stream_init (GLocalFileInputStream *info)
 118 {
 119   info->priv = G_TYPE_INSTANCE_GET_PRIVATE (info,
 120                                             G_TYPE_LOCAL_FILE_INPUT_STREAM,
 121                                             GLocalFileInputStreamPrivate);
 122   info->priv->do_close = TRUE;
 123 }
 124
 125 /**
 126  * g_local_file_input_stream_new:
 127  * @fd: File Descriptor.
 128  *
 129  * Returns: #GFileInputStream for the given file descriptor.
 130  **/
 131 GFileInputStream *
 132 _g_local_file_input_stream_new (int fd)
 133 {
 134   GLocalFileInputStream *stream;
 135
 136   stream = g_object_new (G_TYPE_LOCAL_FILE_INPUT_STREAM, NULL);
 137   stream->priv->fd = fd;
 138
 139   return G_FILE_INPUT_STREAM (stream);
 140 }
 141
 142 static gssize
 143 g_local_file_input_stream_read (GInputStream  *stream,
 144                                 void          *buffer,
 145                                 gsize          count,
 146                                 GCancellable  *cancellable,
 147                                 GError       **error)
 148 {
 149   GLocalFileInputStream *file;
 150   gssize res;
 151
 152   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 153
 154   res = -1;
 155   while (1)
 156     {
 157       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 158         break;
 159       res = read (file->priv->fd, buffer, count);
 160       if (res == -1)
 161         {
 162           int errsv = errno;
 163
 164           if (errsv == EINTR)
 165             continue;
 166
 167           g_set_error (error, G_IO_ERROR,
 168                        g_io_error_from_errno (errsv),
 169                        _("Error reading from file: %s"),
 170                        g_strerror (errsv));
 171         }
 172
 173       break;
 174     }
 175
 176   return res;
 177 }
 178
 179 static gssize
 180 g_local_file_input_stream_skip (GInputStream  *stream,
 181                                 gsize          count,
 182                                 GCancellable  *cancellable,
 183                                 GError       **error)
 184 {
 185   off_t res, start;
 186   GLocalFileInputStream *file;
 187
 188   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 189
 190   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 191     return -1;
 192
 193   start = lseek (file->priv->fd, 0, SEEK_CUR);
 194   if (start == -1)
 195     {
 196       int errsv = errno;
 197
 198       g_set_error (error, G_IO_ERROR,
 199                    g_io_error_from_errno (errsv),
 200                    _("Error seeking in file: %s"),
 201                    g_strerror (errsv));
 202       return -1;
 203     }
 204
 205   res = lseek (file->priv->fd, count, SEEK_CUR);
 206   if (res == -1)
 207     {
 208       int errsv = errno;
 209
 210       g_set_error (error, G_IO_ERROR,
 211                    g_io_error_from_errno (errsv),
 212                    _("Error seeking in file: %s"),
 213                    g_strerror (errsv));
 214       return -1;
 215     }
 216
 217   return res - start;
 218 }
 219
 220 static gboolean
 221 g_local_file_input_stream_close (GInputStream  *stream,
 222                                  GCancellable  *cancellable,
 223                                  GError       **error)
 224 {
 225   GLocalFileInputStream *file;
 226   int res;
 227
 228   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 229
 230   if (!file->priv->do_close)
 231     return TRUE;
 232
 233   if (file->priv->fd == -1)
 234     return TRUE;
 235
 236   while (1)
 237     {
 238       res = close (file->priv->fd);
 239       if (res == -1)
 240         {
 241           int errsv = errno;
 242
 243           g_set_error (error, G_IO_ERROR,
 244                        g_io_error_from_errno (errsv),
 245                        _("Error closing file: %s"),
 246                        g_strerror (errsv));
 247         }
 248       break;
 249     }
 250
 251   return res != -1;
 252 }
 253
 254
 255 static goffset
 256 g_local_file_input_stream_tell (GFileInputStream *stream)
 257 {
 258   GLocalFileInputStream *file;
 259   off_t pos;
 260
 261   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 262
 263   pos = lseek (file->priv->fd, 0, SEEK_CUR);
 264
 265   if (pos == (off_t)-1)
 266     return 0;
 267
 268   return pos;
 269 }
 270
 271 static gboolean
 272 g_local_file_input_stream_can_seek (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 && errno == ESPIPE)
 282     return FALSE;
 283
 284   return TRUE;
 285 }
 286
 287 static int
 288 seek_type_to_lseek (GSeekType type)
 289 {
 290   switch (type)
 291     {
 292     default:
 293     case G_SEEK_CUR:
 294       return SEEK_CUR;
 295
 296     case G_SEEK_SET:
 297       return SEEK_SET;
 298
 299     case G_SEEK_END:
 300       return SEEK_END;
 301     }
 302 }
 303
 304 static gboolean
 305 g_local_file_input_stream_seek (GFileInputStream  *stream,
 306                                 goffset            offset,
 307                                 GSeekType          type,
 308                                 GCancellable      *cancellable,
 309                                 GError           **error)
 310 {
 311   GLocalFileInputStream *file;
 312   off_t pos;
 313
 314   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 315
 316   pos = lseek (file->priv->fd, offset, seek_type_to_lseek (type));
 317
 318   if (pos == (off_t)-1)
 319     {
 320       int errsv = errno;
 321
 322       g_set_error (error, G_IO_ERROR,
 323                    g_io_error_from_errno (errsv),
 324                    _("Error seeking in file: %s"),
 325                    g_strerror (errsv));
 326       return FALSE;
 327     }
 328
 329   return TRUE;
 330 }
 331
 332 static GFileInfo *
 333 g_local_file_input_stream_query_info (GFileInputStream  *stream,
 334                                       const char        *attributes,
 335                                       GCancellable      *cancellable,
 336                                       GError           **error)
 337 {
 338   GLocalFileInputStream *file;
 339
 340   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 341
 342   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 343     return NULL;
 344
 345   return _g_local_file_info_get_from_fd (file->priv->fd,
 346                                          attributes,
 347                                          error);
 348 }