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