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