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 "gioerror.h"
  36 #include "glocalfileinputstream.h"
  37 #include "glocalfileinfo.h"
  38 #include "glibintl.h"
  39
  40 #include "gioalias.h"
  41
  42 #define g_local_file_input_stream_get_type _g_local_file_input_stream_get_type
  43 G_DEFINE_TYPE (GLocalFileInputStream, g_local_file_input_stream, G_TYPE_FILE_INPUT_STREAM);
  44
  45 struct _GLocalFileInputStreamPrivate {
  46   int fd;
  47 };
  48
  49 static gssize     g_local_file_input_stream_read       (GInputStream      *stream,
  50                                                         void              *buffer,
  51                                                         gsize              count,
  52                                                         GCancellable      *cancellable,
  53                                                         GError           **error);
  54 static gssize     g_local_file_input_stream_skip       (GInputStream      *stream,
  55                                                         gsize              count,
  56                                                         GCancellable      *cancellable,
  57                                                         GError           **error);
  58 static gboolean   g_local_file_input_stream_close      (GInputStream      *stream,
  59                                                         GCancellable      *cancellable,
  60                                                         GError           **error);
  61 static goffset    g_local_file_input_stream_tell       (GFileInputStream  *stream);
  62 static gboolean   g_local_file_input_stream_can_seek   (GFileInputStream  *stream);
  63 static gboolean   g_local_file_input_stream_seek       (GFileInputStream  *stream,
  64                                                         goffset            offset,
  65                                                         GSeekType          type,
  66                                                         GCancellable      *cancellable,
  67                                                         GError           **error);
  68 static GFileInfo *g_local_file_input_stream_query_info (GFileInputStream  *stream,
  69                                                         char              *attributes,
  70                                                         GCancellable      *cancellable,
  71                                                         GError           **error);
  72
  73 static void
  74 g_local_file_input_stream_finalize (GObject *object)
  75 {
  76   GLocalFileInputStream *file;
  77
  78   file = G_LOCAL_FILE_INPUT_STREAM (object);
  79
  80   if (G_OBJECT_CLASS (g_local_file_input_stream_parent_class)->finalize)
  81     (*G_OBJECT_CLASS (g_local_file_input_stream_parent_class)->finalize) (object);
  82 }
  83
  84 static void
  85 g_local_file_input_stream_class_init (GLocalFileInputStreamClass *klass)
  86 {
  87   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
  88   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
  89   GFileInputStreamClass *file_stream_class = G_FILE_INPUT_STREAM_CLASS (klass);
  90
  91   g_type_class_add_private (klass, sizeof (GLocalFileInputStreamPrivate));
  92
  93   gobject_class->finalize = g_local_file_input_stream_finalize;
  94
  95   stream_class->read_fn = g_local_file_input_stream_read;
  96   stream_class->skip = g_local_file_input_stream_skip;
  97   stream_class->close_fn = g_local_file_input_stream_close;
  98   file_stream_class->tell = g_local_file_input_stream_tell;
  99   file_stream_class->can_seek = g_local_file_input_stream_can_seek;
 100   file_stream_class->seek = g_local_file_input_stream_seek;
 101   file_stream_class->query_info = g_local_file_input_stream_query_info;
 102 }
 103
 104 static void
 105 g_local_file_input_stream_init (GLocalFileInputStream *info)
 106 {
 107   info->priv = G_TYPE_INSTANCE_GET_PRIVATE (info,
 108                                             G_TYPE_LOCAL_FILE_INPUT_STREAM,
 109                                             GLocalFileInputStreamPrivate);
 110 }
 111
 112 /**
 113  * g_local_file_input_stream_new:
 114  * @fd: File Descriptor.
 115  *
 116  * Returns: #GFileInputStream for the given file descriptor.
 117  **/
 118 GFileInputStream *
 119 _g_local_file_input_stream_new (int fd)
 120 {
 121   GLocalFileInputStream *stream;
 122
 123   stream = g_object_new (G_TYPE_LOCAL_FILE_INPUT_STREAM, NULL);
 124   stream->priv->fd = fd;
 125
 126   return G_FILE_INPUT_STREAM (stream);
 127 }
 128
 129 static gssize
 130 g_local_file_input_stream_read (GInputStream  *stream,
 131                                 void          *buffer,
 132                                 gsize          count,
 133                                 GCancellable  *cancellable,
 134                                 GError       **error)
 135 {
 136   GLocalFileInputStream *file;
 137   gssize res;
 138
 139   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 140
 141   res = -1;
 142   while (1)
 143     {
 144       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 145         break;
 146       res = read (file->priv->fd, buffer, count);
 147       if (res == -1)
 148         {
 149           if (errno == EINTR)
 150             continue;
 151
 152           g_set_error (error, G_IO_ERROR,
 153                        g_io_error_from_errno (errno),
 154                        _("Error reading from file: %s"),
 155                        g_strerror (errno));
 156         }
 157
 158       break;
 159     }
 160
 161   return res;
 162 }
 163
 164 static gssize
 165 g_local_file_input_stream_skip (GInputStream  *stream,
 166                                 gsize          count,
 167                                 GCancellable  *cancellable,
 168                                 GError       **error)
 169 {
 170   off_t res, start;
 171   GLocalFileInputStream *file;
 172
 173   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 174
 175   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 176     return -1;
 177
 178   start = lseek (file->priv->fd, 0, SEEK_CUR);
 179   if (start == -1)
 180     {
 181       g_set_error (error, G_IO_ERROR,
 182                    g_io_error_from_errno (errno),
 183                    _("Error seeking in file: %s"),
 184                    g_strerror (errno));
 185       return -1;
 186     }
 187
 188   res = lseek (file->priv->fd, count, SEEK_CUR);
 189   if (res == -1)
 190     {
 191       g_set_error (error, G_IO_ERROR,
 192                    g_io_error_from_errno (errno),
 193                    _("Error seeking in file: %s"),
 194                    g_strerror (errno));
 195       return -1;
 196     }
 197
 198   return res - start;
 199 }
 200
 201 static gboolean
 202 g_local_file_input_stream_close (GInputStream  *stream,
 203                                  GCancellable  *cancellable,
 204                                  GError       **error)
 205 {
 206   GLocalFileInputStream *file;
 207   int res;
 208
 209   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 210
 211   if (file->priv->fd == -1)
 212     return TRUE;
 213
 214   while (1)
 215     {
 216       res = close (file->priv->fd);
 217       if (res == -1)
 218         g_set_error (error, G_IO_ERROR,
 219                      g_io_error_from_errno (errno),
 220                      _("Error closing file: %s"),
 221                      g_strerror (errno));
 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 }