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   G_OBJECT_CLASS (g_local_file_input_stream_parent_class)->finalize (object);
  83 }
  84
  85 void
  86 _g_local_file_input_stream_set_do_close (GLocalFileInputStream *in,
  87                                           gboolean do_close)
  88 {
  89   in->priv->do_close = do_close;
  90 }
  91
  92 static void
  93 g_local_file_input_stream_class_init (GLocalFileInputStreamClass *klass)
  94 {
  95   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
  96   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
  97   GFileInputStreamClass *file_stream_class = G_FILE_INPUT_STREAM_CLASS (klass);
  98
  99   g_type_class_add_private (klass, sizeof (GLocalFileInputStreamPrivate));
 100
 101   gobject_class->finalize = g_local_file_input_stream_finalize;
 102
 103   stream_class->read_fn = g_local_file_input_stream_read;
 104   stream_class->skip = g_local_file_input_stream_skip;
 105   stream_class->close_fn = g_local_file_input_stream_close;
 106   file_stream_class->tell = g_local_file_input_stream_tell;
 107   file_stream_class->can_seek = g_local_file_input_stream_can_seek;
 108   file_stream_class->seek = g_local_file_input_stream_seek;
 109   file_stream_class->query_info = g_local_file_input_stream_query_info;
 110 }
 111
 112 static void
 113 g_local_file_input_stream_init (GLocalFileInputStream *info)
 114 {
 115   info->priv = G_TYPE_INSTANCE_GET_PRIVATE (info,
 116                                             G_TYPE_LOCAL_FILE_INPUT_STREAM,
 117                                             GLocalFileInputStreamPrivate);
 118   info->priv->do_close = TRUE;
 119 }
 120
 121 /**
 122  * g_local_file_input_stream_new:
 123  * @fd: File Descriptor.
 124  *
 125  * Returns: #GFileInputStream for the given file descriptor.
 126  **/
 127 GFileInputStream *
 128 _g_local_file_input_stream_new (int fd)
 129 {
 130   GLocalFileInputStream *stream;
 131
 132   stream = g_object_new (G_TYPE_LOCAL_FILE_INPUT_STREAM, NULL);
 133   stream->priv->fd = fd;
 134
 135   return G_FILE_INPUT_STREAM (stream);
 136 }
 137
 138 static gssize
 139 g_local_file_input_stream_read (GInputStream  *stream,
 140                                 void          *buffer,
 141                                 gsize          count,
 142                                 GCancellable  *cancellable,
 143                                 GError       **error)
 144 {
 145   GLocalFileInputStream *file;
 146   gssize res;
 147
 148   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 149
 150   res = -1;
 151   while (1)
 152     {
 153       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 154         break;
 155       res = read (file->priv->fd, buffer, count);
 156       if (res == -1)
 157         {
 158           int errsv = errno;
 159
 160           if (errsv == EINTR)
 161             continue;
 162
 163           g_set_error (error, G_IO_ERROR,
 164                        g_io_error_from_errno (errsv),
 165                        _("Error reading from file: %s"),
 166                        g_strerror (errsv));
 167         }
 168
 169       break;
 170     }
 171
 172   return res;
 173 }
 174
 175 static gssize
 176 g_local_file_input_stream_skip (GInputStream  *stream,
 177                                 gsize          count,
 178                                 GCancellable  *cancellable,
 179                                 GError       **error)
 180 {
 181   off_t res, start;
 182   GLocalFileInputStream *file;
 183
 184   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 185
 186   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 187     return -1;
 188
 189   start = lseek (file->priv->fd, 0, SEEK_CUR);
 190   if (start == -1)
 191     {
 192       int errsv = errno;
 193
 194       g_set_error (error, G_IO_ERROR,
 195                    g_io_error_from_errno (errsv),
 196                    _("Error seeking in file: %s"),
 197                    g_strerror (errsv));
 198       return -1;
 199     }
 200
 201   res = lseek (file->priv->fd, count, SEEK_CUR);
 202   if (res == -1)
 203     {
 204       int errsv = errno;
 205
 206       g_set_error (error, G_IO_ERROR,
 207                    g_io_error_from_errno (errsv),
 208                    _("Error seeking in file: %s"),
 209                    g_strerror (errsv));
 210       return -1;
 211     }
 212
 213   return res - start;
 214 }
 215
 216 static gboolean
 217 g_local_file_input_stream_close (GInputStream  *stream,
 218                                  GCancellable  *cancellable,
 219                                  GError       **error)
 220 {
 221   GLocalFileInputStream *file;
 222   int res;
 223
 224   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 225
 226   if (!file->priv->do_close)
 227     return TRUE;
 228
 229   if (file->priv->fd == -1)
 230     return TRUE;
 231
 232   while (1)
 233     {
 234       res = close (file->priv->fd);
 235       if (res == -1)
 236         {
 237           int errsv = errno;
 238
 239           g_set_error (error, G_IO_ERROR,
 240                        g_io_error_from_errno (errsv),
 241                        _("Error closing file: %s"),
 242                        g_strerror (errsv));
 243         }
 244       break;
 245     }
 246
 247   return res != -1;
 248 }
 249
 250
 251 static goffset
 252 g_local_file_input_stream_tell (GFileInputStream *stream)
 253 {
 254   GLocalFileInputStream *file;
 255   off_t pos;
 256
 257   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 258
 259   pos = lseek (file->priv->fd, 0, SEEK_CUR);
 260
 261   if (pos == (off_t)-1)
 262     return 0;
 263
 264   return pos;
 265 }
 266
 267 static gboolean
 268 g_local_file_input_stream_can_seek (GFileInputStream *stream)
 269 {
 270   GLocalFileInputStream *file;
 271   off_t pos;
 272
 273   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 274
 275   pos = lseek (file->priv->fd, 0, SEEK_CUR);
 276
 277   if (pos == (off_t)-1 && errno == ESPIPE)
 278     return FALSE;
 279
 280   return TRUE;
 281 }
 282
 283 static int
 284 seek_type_to_lseek (GSeekType type)
 285 {
 286   switch (type)
 287     {
 288     default:
 289     case G_SEEK_CUR:
 290       return SEEK_CUR;
 291
 292     case G_SEEK_SET:
 293       return SEEK_SET;
 294
 295     case G_SEEK_END:
 296       return SEEK_END;
 297     }
 298 }
 299
 300 static gboolean
 301 g_local_file_input_stream_seek (GFileInputStream  *stream,
 302                                 goffset            offset,
 303                                 GSeekType          type,
 304                                 GCancellable      *cancellable,
 305                                 GError           **error)
 306 {
 307   GLocalFileInputStream *file;
 308   off_t pos;
 309
 310   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 311
 312   pos = lseek (file->priv->fd, offset, seek_type_to_lseek (type));
 313
 314   if (pos == (off_t)-1)
 315     {
 316       int errsv = errno;
 317
 318       g_set_error (error, G_IO_ERROR,
 319                    g_io_error_from_errno (errsv),
 320                    _("Error seeking in file: %s"),
 321                    g_strerror (errsv));
 322       return FALSE;
 323     }
 324
 325   return TRUE;
 326 }
 327
 328 static GFileInfo *
 329 g_local_file_input_stream_query_info (GFileInputStream  *stream,
 330                                       const char        *attributes,
 331                                       GCancellable      *cancellable,
 332                                       GError           **error)
 333 {
 334   GLocalFileInputStream *file;
 335
 336   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 337
 338   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 339     return NULL;
 340
 341   return _g_local_file_info_get_from_fd (file->priv->fd,
 342                                          attributes,
 343                                          error);
 344 }