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 };
  53
  54 static gssize     g_local_file_input_stream_read       (GInputStream      *stream,
  55                                                         void              *buffer,
  56                                                         gsize              count,
  57                                                         GCancellable      *cancellable,
  58                                                         GError           **error);
  59 static gssize     g_local_file_input_stream_skip       (GInputStream      *stream,
  60                                                         gsize              count,
  61                                                         GCancellable      *cancellable,
  62                                                         GError           **error);
  63 static gboolean   g_local_file_input_stream_close      (GInputStream      *stream,
  64                                                         GCancellable      *cancellable,
  65                                                         GError           **error);
  66 static goffset    g_local_file_input_stream_tell       (GFileInputStream  *stream);
  67 static gboolean   g_local_file_input_stream_can_seek   (GFileInputStream  *stream);
  68 static gboolean   g_local_file_input_stream_seek       (GFileInputStream  *stream,
  69                                                         goffset            offset,
  70                                                         GSeekType          type,
  71                                                         GCancellable      *cancellable,
  72                                                         GError           **error);
  73 static GFileInfo *g_local_file_input_stream_query_info (GFileInputStream  *stream,
  74                                                         char              *attributes,
  75                                                         GCancellable      *cancellable,
  76                                                         GError           **error);
  77
  78 static void
  79 g_local_file_input_stream_finalize (GObject *object)
  80 {
  81   GLocalFileInputStream *file;
  82
  83   file = G_LOCAL_FILE_INPUT_STREAM (object);
  84
  85   G_OBJECT_CLASS (g_local_file_input_stream_parent_class)->finalize (object);
  86 }
  87
  88 static void
  89 g_local_file_input_stream_class_init (GLocalFileInputStreamClass *klass)
  90 {
  91   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
  92   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
  93   GFileInputStreamClass *file_stream_class = G_FILE_INPUT_STREAM_CLASS (klass);
  94
  95   g_type_class_add_private (klass, sizeof (GLocalFileInputStreamPrivate));
  96
  97   gobject_class->finalize = g_local_file_input_stream_finalize;
  98
  99   stream_class->read_fn = g_local_file_input_stream_read;
 100   stream_class->skip = g_local_file_input_stream_skip;
 101   stream_class->close_fn = g_local_file_input_stream_close;
 102   file_stream_class->tell = g_local_file_input_stream_tell;
 103   file_stream_class->can_seek = g_local_file_input_stream_can_seek;
 104   file_stream_class->seek = g_local_file_input_stream_seek;
 105   file_stream_class->query_info = g_local_file_input_stream_query_info;
 106 }
 107
 108 static void
 109 g_local_file_input_stream_init (GLocalFileInputStream *info)
 110 {
 111   info->priv = G_TYPE_INSTANCE_GET_PRIVATE (info,
 112                                             G_TYPE_LOCAL_FILE_INPUT_STREAM,
 113                                             GLocalFileInputStreamPrivate);
 114 }
 115
 116 /**
 117  * g_local_file_input_stream_new:
 118  * @fd: File Descriptor.
 119  *
 120  * Returns: #GFileInputStream for the given file descriptor.
 121  **/
 122 GFileInputStream *
 123 _g_local_file_input_stream_new (int fd)
 124 {
 125   GLocalFileInputStream *stream;
 126
 127   stream = g_object_new (G_TYPE_LOCAL_FILE_INPUT_STREAM, NULL);
 128   stream->priv->fd = fd;
 129
 130   return G_FILE_INPUT_STREAM (stream);
 131 }
 132
 133 static gssize
 134 g_local_file_input_stream_read (GInputStream  *stream,
 135                                 void          *buffer,
 136                                 gsize          count,
 137                                 GCancellable  *cancellable,
 138                                 GError       **error)
 139 {
 140   GLocalFileInputStream *file;
 141   gssize res;
 142
 143   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 144
 145   res = -1;
 146   while (1)
 147     {
 148       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 149         break;
 150       res = read (file->priv->fd, buffer, count);
 151       if (res == -1)
 152         {
 153           int errsv = errno;
 154
 155           if (errsv == EINTR)
 156             continue;
 157
 158           g_set_error (error, G_IO_ERROR,
 159                        g_io_error_from_errno (errsv),
 160                        _("Error reading from file: %s"),
 161                        g_strerror (errsv));
 162         }
 163
 164       break;
 165     }
 166
 167   return res;
 168 }
 169
 170 static gssize
 171 g_local_file_input_stream_skip (GInputStream  *stream,
 172                                 gsize          count,
 173                                 GCancellable  *cancellable,
 174                                 GError       **error)
 175 {
 176   off_t res, start;
 177   GLocalFileInputStream *file;
 178
 179   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 180
 181   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 182     return -1;
 183
 184   start = lseek (file->priv->fd, 0, SEEK_CUR);
 185   if (start == -1)
 186     {
 187       int errsv = errno;
 188
 189       g_set_error (error, G_IO_ERROR,
 190                    g_io_error_from_errno (errsv),
 191                    _("Error seeking in file: %s"),
 192                    g_strerror (errsv));
 193       return -1;
 194     }
 195
 196   res = lseek (file->priv->fd, count, SEEK_CUR);
 197   if (res == -1)
 198     {
 199       int errsv = errno;
 200
 201       g_set_error (error, G_IO_ERROR,
 202                    g_io_error_from_errno (errsv),
 203                    _("Error seeking in file: %s"),
 204                    g_strerror (errsv));
 205       return -1;
 206     }
 207
 208   return res - start;
 209 }
 210
 211 static gboolean
 212 g_local_file_input_stream_close (GInputStream  *stream,
 213                                  GCancellable  *cancellable,
 214                                  GError       **error)
 215 {
 216   GLocalFileInputStream *file;
 217   int res;
 218
 219   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 220
 221   if (file->priv->fd == -1)
 222     return TRUE;
 223
 224   while (1)
 225     {
 226       res = close (file->priv->fd);
 227       if (res == -1)
 228         {
 229           int errsv = errno;
 230
 231           g_set_error (error, G_IO_ERROR,
 232                        g_io_error_from_errno (errsv),
 233                        _("Error closing file: %s"),
 234                        g_strerror (errsv));
 235         }
 236       break;
 237     }
 238
 239   return res != -1;
 240 }
 241
 242
 243 static goffset
 244 g_local_file_input_stream_tell (GFileInputStream *stream)
 245 {
 246   GLocalFileInputStream *file;
 247   off_t pos;
 248
 249   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 250
 251   pos = lseek (file->priv->fd, 0, SEEK_CUR);
 252
 253   if (pos == (off_t)-1)
 254     return 0;
 255
 256   return pos;
 257 }
 258
 259 static gboolean
 260 g_local_file_input_stream_can_seek (GFileInputStream *stream)
 261 {
 262   GLocalFileInputStream *file;
 263   off_t pos;
 264
 265   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 266
 267   pos = lseek (file->priv->fd, 0, SEEK_CUR);
 268
 269   if (pos == (off_t)-1 && errno == ESPIPE)
 270     return FALSE;
 271
 272   return TRUE;
 273 }
 274
 275 static int
 276 seek_type_to_lseek (GSeekType type)
 277 {
 278   switch (type)
 279     {
 280     default:
 281     case G_SEEK_CUR:
 282       return SEEK_CUR;
 283
 284     case G_SEEK_SET:
 285       return SEEK_SET;
 286
 287     case G_SEEK_END:
 288       return SEEK_END;
 289     }
 290 }
 291
 292 static gboolean
 293 g_local_file_input_stream_seek (GFileInputStream  *stream,
 294                                 goffset            offset,
 295                                 GSeekType          type,
 296                                 GCancellable      *cancellable,
 297                                 GError           **error)
 298 {
 299   GLocalFileInputStream *file;
 300   off_t pos;
 301
 302   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 303
 304   pos = lseek (file->priv->fd, offset, seek_type_to_lseek (type));
 305
 306   if (pos == (off_t)-1)
 307     {
 308       int errsv = errno;
 309
 310       g_set_error (error, G_IO_ERROR,
 311                    g_io_error_from_errno (errsv),
 312                    _("Error seeking in file: %s"),
 313                    g_strerror (errsv));
 314       return FALSE;
 315     }
 316
 317   return TRUE;
 318 }
 319
 320 static GFileInfo *
 321 g_local_file_input_stream_query_info (GFileInputStream  *stream,
 322                                       char              *attributes,
 323                                       GCancellable      *cancellable,
 324                                       GError           **error)
 325 {
 326   GLocalFileInputStream *file;
 327
 328   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 329
 330   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 331     return NULL;
 332
 333   return _g_local_file_info_get_from_fd (file->priv->fd,
 334                                          attributes,
 335                                          error);
 336 }