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_UNIX
  42 #include "gfiledescriptorbased.h"
  43 #endif
  44
  45 #ifdef G_OS_WIN32
  46 #include <io.h>
  47 #endif
  48
  49 #include "gioalias.h"
  50
  51
  52 #ifdef G_OS_UNIX
  53 static void       g_file_descriptor_based_iface_init   (GFileDescriptorBasedIface *iface);
  54 #endif
  55
  56 #define g_local_file_input_stream_get_type _g_local_file_input_stream_get_type
  57 G_DEFINE_TYPE_WITH_CODE (GLocalFileInputStream, g_local_file_input_stream, G_TYPE_FILE_INPUT_STREAM,
  58 #ifdef G_OS_UNIX
  59                          G_IMPLEMENT_INTERFACE (G_TYPE_FILE_DESCRIPTOR_BASED,
  60                                                 g_file_descriptor_based_iface_init)
  61 #endif
  62 );
  63
  64 struct _GLocalFileInputStreamPrivate {
  65   int fd;
  66   guint do_close : 1;
  67 };
  68
  69 static gssize     g_local_file_input_stream_read       (GInputStream      *stream,
  70                                                         void              *buffer,
  71                                                         gsize              count,
  72                                                         GCancellable      *cancellable,
  73                                                         GError           **error);
  74 static gssize     g_local_file_input_stream_skip       (GInputStream      *stream,
  75                                                         gsize              count,
  76                                                         GCancellable      *cancellable,
  77                                                         GError           **error);
  78 static gboolean   g_local_file_input_stream_close      (GInputStream      *stream,
  79                                                         GCancellable      *cancellable,
  80                                                         GError           **error);
  81 static goffset    g_local_file_input_stream_tell       (GFileInputStream  *stream);
  82 static gboolean   g_local_file_input_stream_can_seek   (GFileInputStream  *stream);
  83 static gboolean   g_local_file_input_stream_seek       (GFileInputStream  *stream,
  84                                                         goffset            offset,
  85                                                         GSeekType          type,
  86                                                         GCancellable      *cancellable,
  87                                                         GError           **error);
  88 static GFileInfo *g_local_file_input_stream_query_info (GFileInputStream  *stream,
  89                                                         const char        *attributes,
  90                                                         GCancellable      *cancellable,
  91                                                         GError           **error);
  92 #ifdef G_OS_UNIX
  93 static int        g_local_file_input_stream_get_fd     (GFileDescriptorBased *stream);
  94 #endif
  95
  96 static void
  97 g_local_file_input_stream_finalize (GObject *object)
  98 {
  99   G_OBJECT_CLASS (g_local_file_input_stream_parent_class)->finalize (object);
 100 }
 101
 102 void
 103 _g_local_file_input_stream_set_do_close (GLocalFileInputStream *in,
 104                                           gboolean do_close)
 105 {
 106   in->priv->do_close = do_close;
 107 }
 108
 109 static void
 110 g_local_file_input_stream_class_init (GLocalFileInputStreamClass *klass)
 111 {
 112   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
 113   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
 114   GFileInputStreamClass *file_stream_class = G_FILE_INPUT_STREAM_CLASS (klass);
 115
 116   g_type_class_add_private (klass, sizeof (GLocalFileInputStreamPrivate));
 117
 118   gobject_class->finalize = g_local_file_input_stream_finalize;
 119
 120   stream_class->read_fn = g_local_file_input_stream_read;
 121   stream_class->skip = g_local_file_input_stream_skip;
 122   stream_class->close_fn = g_local_file_input_stream_close;
 123   file_stream_class->tell = g_local_file_input_stream_tell;
 124   file_stream_class->can_seek = g_local_file_input_stream_can_seek;
 125   file_stream_class->seek = g_local_file_input_stream_seek;
 126   file_stream_class->query_info = g_local_file_input_stream_query_info;
 127 }
 128
 129 #ifdef G_OS_UNIX
 130 static void
 131 g_file_descriptor_based_iface_init (GFileDescriptorBasedIface *iface)
 132 {
 133   iface->get_fd = g_local_file_input_stream_get_fd;
 134 }
 135 #endif
 136
 137 static void
 138 g_local_file_input_stream_init (GLocalFileInputStream *info)
 139 {
 140   info->priv = G_TYPE_INSTANCE_GET_PRIVATE (info,
 141                                             G_TYPE_LOCAL_FILE_INPUT_STREAM,
 142                                             GLocalFileInputStreamPrivate);
 143   info->priv->do_close = TRUE;
 144 }
 145
 146 GFileInputStream *
 147 _g_local_file_input_stream_new (int fd)
 148 {
 149   GLocalFileInputStream *stream;
 150
 151   stream = g_object_new (G_TYPE_LOCAL_FILE_INPUT_STREAM, NULL);
 152   stream->priv->fd = fd;
 153
 154   return G_FILE_INPUT_STREAM (stream);
 155 }
 156
 157 static gssize
 158 g_local_file_input_stream_read (GInputStream  *stream,
 159                                 void          *buffer,
 160                                 gsize          count,
 161                                 GCancellable  *cancellable,
 162                                 GError       **error)
 163 {
 164   GLocalFileInputStream *file;
 165   gssize res;
 166
 167   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 168
 169   res = -1;
 170   while (1)
 171     {
 172       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 173         break;
 174       res = read (file->priv->fd, buffer, count);
 175       if (res == -1)
 176         {
 177           int errsv = errno;
 178
 179           if (errsv == EINTR)
 180             continue;
 181
 182           g_set_error (error, G_IO_ERROR,
 183                        g_io_error_from_errno (errsv),
 184                        _("Error reading from file: %s"),
 185                        g_strerror (errsv));
 186         }
 187
 188       break;
 189     }
 190
 191   return res;
 192 }
 193
 194 static gssize
 195 g_local_file_input_stream_skip (GInputStream  *stream,
 196                                 gsize          count,
 197                                 GCancellable  *cancellable,
 198                                 GError       **error)
 199 {
 200   off_t res, start;
 201   GLocalFileInputStream *file;
 202
 203   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 204
 205   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 206     return -1;
 207
 208   start = lseek (file->priv->fd, 0, SEEK_CUR);
 209   if (start == -1)
 210     {
 211       int errsv = errno;
 212
 213       g_set_error (error, G_IO_ERROR,
 214                    g_io_error_from_errno (errsv),
 215                    _("Error seeking in file: %s"),
 216                    g_strerror (errsv));
 217       return -1;
 218     }
 219
 220   res = lseek (file->priv->fd, count, SEEK_CUR);
 221   if (res == -1)
 222     {
 223       int errsv = errno;
 224
 225       g_set_error (error, G_IO_ERROR,
 226                    g_io_error_from_errno (errsv),
 227                    _("Error seeking in file: %s"),
 228                    g_strerror (errsv));
 229       return -1;
 230     }
 231
 232   return res - start;
 233 }
 234
 235 static gboolean
 236 g_local_file_input_stream_close (GInputStream  *stream,
 237                                  GCancellable  *cancellable,
 238                                  GError       **error)
 239 {
 240   GLocalFileInputStream *file;
 241   int res;
 242
 243   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 244
 245   if (!file->priv->do_close)
 246     return TRUE;
 247
 248   if (file->priv->fd == -1)
 249     return TRUE;
 250
 251   while (1)
 252     {
 253       res = close (file->priv->fd);
 254       if (res == -1)
 255         {
 256           int errsv = errno;
 257
 258           g_set_error (error, G_IO_ERROR,
 259                        g_io_error_from_errno (errsv),
 260                        _("Error closing file: %s"),
 261                        g_strerror (errsv));
 262         }
 263       break;
 264     }
 265
 266   return res != -1;
 267 }
 268
 269
 270 static goffset
 271 g_local_file_input_stream_tell (GFileInputStream *stream)
 272 {
 273   GLocalFileInputStream *file;
 274   off_t pos;
 275
 276   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 277
 278   pos = lseek (file->priv->fd, 0, SEEK_CUR);
 279
 280   if (pos == (off_t)-1)
 281     return 0;
 282
 283   return pos;
 284 }
 285
 286 static gboolean
 287 g_local_file_input_stream_can_seek (GFileInputStream *stream)
 288 {
 289   GLocalFileInputStream *file;
 290   off_t pos;
 291
 292   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 293
 294   pos = lseek (file->priv->fd, 0, SEEK_CUR);
 295
 296   if (pos == (off_t)-1 && errno == ESPIPE)
 297     return FALSE;
 298
 299   return TRUE;
 300 }
 301
 302 static int
 303 seek_type_to_lseek (GSeekType type)
 304 {
 305   switch (type)
 306     {
 307     default:
 308     case G_SEEK_CUR:
 309       return SEEK_CUR;
 310
 311     case G_SEEK_SET:
 312       return SEEK_SET;
 313
 314     case G_SEEK_END:
 315       return SEEK_END;
 316     }
 317 }
 318
 319 static gboolean
 320 g_local_file_input_stream_seek (GFileInputStream  *stream,
 321                                 goffset            offset,
 322                                 GSeekType          type,
 323                                 GCancellable      *cancellable,
 324                                 GError           **error)
 325 {
 326   GLocalFileInputStream *file;
 327   off_t pos;
 328
 329   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 330
 331   pos = lseek (file->priv->fd, offset, seek_type_to_lseek (type));
 332
 333   if (pos == (off_t)-1)
 334     {
 335       int errsv = errno;
 336
 337       g_set_error (error, G_IO_ERROR,
 338                    g_io_error_from_errno (errsv),
 339                    _("Error seeking in file: %s"),
 340                    g_strerror (errsv));
 341       return FALSE;
 342     }
 343
 344   return TRUE;
 345 }
 346
 347 static GFileInfo *
 348 g_local_file_input_stream_query_info (GFileInputStream  *stream,
 349                                       const char        *attributes,
 350                                       GCancellable      *cancellable,
 351                                       GError           **error)
 352 {
 353   GLocalFileInputStream *file;
 354
 355   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 356
 357   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 358     return NULL;
 359
 360   return _g_local_file_info_get_from_fd (file->priv->fd,
 361                                          attributes,
 362                                          error);
 363 }
 364
 365 #ifdef G_OS_UNIX
 366 static int
 367 g_local_file_input_stream_get_fd (GFileDescriptorBased *fd_based)
 368 {
 369   GLocalFileInputStream *stream = G_LOCAL_FILE_INPUT_STREAM (fd_based);
 370   return stream->priv->fd;
 371 }
 372 #endif