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