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 #include <unistd.h>
  29 #include <errno.h>
  30
  31 #include <glib.h>
  32 #include <glib/gstdio.h>
  33 #include "gioerror.h"
  34 #include "glocalfileinputstream.h"
  35 #include "glocalfileinfo.h"
  36 #include "glibintl.h"
  37
  38 #include "gioalias.h"
  39
  40 #define g_local_file_input_stream_get_type _g_local_file_input_stream_get_type
  41 G_DEFINE_TYPE (GLocalFileInputStream, g_local_file_input_stream, G_TYPE_FILE_INPUT_STREAM);
  42
  43 struct _GLocalFileInputStreamPrivate {
  44   int fd;
  45 };
  46
  47 static gssize     g_local_file_input_stream_read       (GInputStream      *stream,
  48                                                         void              *buffer,
  49                                                         gsize              count,
  50                                                         GCancellable      *cancellable,
  51                                                         GError           **error);
  52 static gssize     g_local_file_input_stream_skip       (GInputStream      *stream,
  53                                                         gsize              count,
  54                                                         GCancellable      *cancellable,
  55                                                         GError           **error);
  56 static gboolean   g_local_file_input_stream_close      (GInputStream      *stream,
  57                                                         GCancellable      *cancellable,
  58                                                         GError           **error);
  59 static goffset    g_local_file_input_stream_tell       (GFileInputStream  *stream);
  60 static gboolean   g_local_file_input_stream_can_seek   (GFileInputStream  *stream);
  61 static gboolean   g_local_file_input_stream_seek       (GFileInputStream  *stream,
  62                                                         goffset            offset,
  63                                                         GSeekType          type,
  64                                                         GCancellable      *cancellable,
  65                                                         GError           **error);
  66 static GFileInfo *g_local_file_input_stream_query_info (GFileInputStream  *stream,
  67                                                         char              *attributes,
  68                                                         GCancellable      *cancellable,
  69                                                         GError           **error);
  70
  71 static void
  72 g_local_file_input_stream_finalize (GObject *object)
  73 {
  74   GLocalFileInputStream *file;
  75
  76   file = G_LOCAL_FILE_INPUT_STREAM (object);
  77
  78   if (G_OBJECT_CLASS (g_local_file_input_stream_parent_class)->finalize)
  79     (*G_OBJECT_CLASS (g_local_file_input_stream_parent_class)->finalize) (object);
  80 }
  81
  82 static void
  83 g_local_file_input_stream_class_init (GLocalFileInputStreamClass *klass)
  84 {
  85   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
  86   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
  87   GFileInputStreamClass *file_stream_class = G_FILE_INPUT_STREAM_CLASS (klass);
  88
  89   g_type_class_add_private (klass, sizeof (GLocalFileInputStreamPrivate));
  90
  91   gobject_class->finalize = g_local_file_input_stream_finalize;
  92
  93   stream_class->read = g_local_file_input_stream_read;
  94   stream_class->skip = g_local_file_input_stream_skip;
  95   stream_class->close = g_local_file_input_stream_close;
  96   file_stream_class->tell = g_local_file_input_stream_tell;
  97   file_stream_class->can_seek = g_local_file_input_stream_can_seek;
  98   file_stream_class->seek = g_local_file_input_stream_seek;
  99   file_stream_class->query_info = g_local_file_input_stream_query_info;
 100 }
 101
 102 static void
 103 g_local_file_input_stream_init (GLocalFileInputStream *info)
 104 {
 105   info->priv = G_TYPE_INSTANCE_GET_PRIVATE (info,
 106                                             G_TYPE_LOCAL_FILE_INPUT_STREAM,
 107                                             GLocalFileInputStreamPrivate);
 108 }
 109
 110 /**
 111  * g_local_file_input_stream_new:
 112  * @fd: File Descriptor.
 113  *
 114  * Returns: #GFileInputStream for the given file descriptor.
 115  **/
 116 GFileInputStream *
 117 _g_local_file_input_stream_new (int fd)
 118 {
 119   GLocalFileInputStream *stream;
 120
 121   stream = g_object_new (G_TYPE_LOCAL_FILE_INPUT_STREAM, NULL);
 122   stream->priv->fd = fd;
 123
 124   return G_FILE_INPUT_STREAM (stream);
 125 }
 126
 127 static gssize
 128 g_local_file_input_stream_read (GInputStream *stream,
 129                                 void         *buffer,
 130                                 gsize         count,
 131                                 GCancellable *cancellable,
 132                                 GError      **error)
 133 {
 134   GLocalFileInputStream *file;
 135   gssize res;
 136
 137   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 138
 139   res = -1;
 140   while (1)
 141     {
 142       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 143         break;
 144       res = read (file->priv->fd, buffer, count);
 145       if (res == -1)
 146         {
 147           if (errno == EINTR)
 148             continue;
 149
 150           g_set_error (error, G_IO_ERROR,
 151                        g_io_error_from_errno (errno),
 152                        _("Error reading from file: %s"),
 153                        g_strerror (errno));
 154         }
 155
 156       break;
 157     }
 158
 159   return res;
 160 }
 161
 162 static gssize
 163 g_local_file_input_stream_skip (GInputStream *stream,
 164                                 gsize         count,
 165                                 GCancellable *cancellable,
 166                                 GError      **error)
 167 {
 168   off_t res, start;
 169   GLocalFileInputStream *file;
 170
 171   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 172
 173   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 174     return -1;
 175
 176   start = lseek (file->priv->fd, 0, SEEK_CUR);
 177   if (start == -1)
 178     {
 179       g_set_error (error, G_IO_ERROR,
 180                    g_io_error_from_errno (errno),
 181                    _("Error seeking in file: %s"),
 182                    g_strerror (errno));
 183       return -1;
 184     }
 185
 186   res = lseek (file->priv->fd, count, SEEK_CUR);
 187   if (res == -1)
 188     {
 189       g_set_error (error, G_IO_ERROR,
 190                    g_io_error_from_errno (errno),
 191                    _("Error seeking in file: %s"),
 192                    g_strerror (errno));
 193       return -1;
 194     }
 195
 196   return res - start;
 197 }
 198
 199 static gboolean
 200 g_local_file_input_stream_close (GInputStream *stream,
 201                                  GCancellable *cancellable,
 202                                  GError      **error)
 203 {
 204   GLocalFileInputStream *file;
 205   int res;
 206
 207   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 208
 209   if (file->priv->fd == -1)
 210     return TRUE;
 211
 212   while (1)
 213     {
 214       res = close (file->priv->fd);
 215       if (res == -1)
 216         {
 217           g_set_error (error, G_IO_ERROR,
 218                        g_io_error_from_errno (errno),
 219                        _("Error closing file: %s"),
 220                        g_strerror (errno));
 221         }
 222       break;
 223     }
 224
 225   return res != -1;
 226 }
 227
 228
 229 static goffset
 230 g_local_file_input_stream_tell (GFileInputStream *stream)
 231 {
 232   GLocalFileInputStream *file;
 233   off_t pos;
 234
 235   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 236
 237   pos = lseek (file->priv->fd, 0, SEEK_CUR);
 238
 239   if (pos == (off_t)-1)
 240     return 0;
 241
 242   return pos;
 243 }
 244
 245 static gboolean
 246 g_local_file_input_stream_can_seek (GFileInputStream *stream)
 247 {
 248   GLocalFileInputStream *file;
 249   off_t pos;
 250
 251   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 252
 253   pos = lseek (file->priv->fd, 0, SEEK_CUR);
 254
 255   if (pos == (off_t)-1 &&
 256       errno == ESPIPE)
 257     return FALSE;
 258
 259   return TRUE;
 260 }
 261
 262 static int
 263 seek_type_to_lseek (GSeekType type)
 264 {
 265   switch (type)
 266     {
 267     default:
 268     case G_SEEK_CUR:
 269       return SEEK_CUR;
 270
 271     case G_SEEK_SET:
 272       return SEEK_SET;
 273
 274     case G_SEEK_END:
 275       return SEEK_END;
 276     }
 277 }
 278
 279 static gboolean
 280 g_local_file_input_stream_seek (GFileInputStream     *stream,
 281                                 goffset               offset,
 282                                 GSeekType             type,
 283                                 GCancellable         *cancellable,
 284                                 GError              **error)
 285 {
 286   GLocalFileInputStream *file;
 287   off_t pos;
 288
 289   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 290
 291   pos = lseek (file->priv->fd, offset, seek_type_to_lseek (type));
 292
 293   if (pos == (off_t)-1)
 294     {
 295       g_set_error (error, G_IO_ERROR,
 296                    g_io_error_from_errno (errno),
 297                    _("Error seeking in file: %s"),
 298                    g_strerror (errno));
 299       return FALSE;
 300     }
 301
 302   return TRUE;
 303 }
 304
 305 static GFileInfo *
 306 g_local_file_input_stream_query_info (GFileInputStream     *stream,
 307                                       char                 *attributes,
 308                                       GCancellable         *cancellable,
 309                                       GError              **error)
 310 {
 311   GLocalFileInputStream *file;
 312
 313   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 314
 315   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 316     return NULL;
 317
 318   return _g_local_file_info_get_from_fd (file->priv->fd,
 319                                          attributes,
 320                                          error);
 321 }