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 2.1 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, see <http://www.gnu.org/licenses/>.
  17  *
  18  * Author: Alexander Larsson <alexl@redhat.com>
  19  */
  20
  21 #include "config.h"
  22
  23 #include <sys/types.h>
  24 #include <sys/stat.h>
  25 #include <fcntl.h>
  26 #include <errno.h>
  27
  28 #include <glib.h>
  29 #include <glib/gstdio.h>
  30 #include "gcancellable.h"
  31 #include "gioerror.h"
  32 #include "glocalfileinputstream.h"
  33 #include "glocalfileinfo.h"
  34 #include "glibintl.h"
  35
  36 #ifdef G_OS_UNIX
  37 #include <unistd.h>
  38 #include "glib-unix.h"
  39 #include "gfiledescriptorbased.h"
  40 #endif
  41
  42 #ifdef G_OS_WIN32
  43 #include <io.h>
  44 #endif
  45
  46 struct _GLocalFileInputStreamPrivate {
  47   int fd;
  48   guint do_close : 1;
  49 };
  50
  51 #ifdef G_OS_UNIX
  52 static void       g_file_descriptor_based_iface_init   (GFileDescriptorBasedIface *iface);
  53 #endif
  54
  55 #define g_local_file_input_stream_get_type _g_local_file_input_stream_get_type
  56 #ifdef G_OS_UNIX
  57 G_DEFINE_TYPE_WITH_CODE (GLocalFileInputStream, g_local_file_input_stream, G_TYPE_FILE_INPUT_STREAM,
  58                          G_ADD_PRIVATE (GLocalFileInputStream)
  59                          G_IMPLEMENT_INTERFACE (G_TYPE_FILE_DESCRIPTOR_BASED,
  60                                                 g_file_descriptor_based_iface_init))
  61 #else
  62 G_DEFINE_TYPE_WITH_CODE (GLocalFileInputStream, g_local_file_input_stream, G_TYPE_FILE_INPUT_STREAM,
  63                          G_ADD_PRIVATE (GLocalFileInputStream))
  64 #endif
  65
  66 static gssize     g_local_file_input_stream_read       (GInputStream      *stream,
  67                                                         void              *buffer,
  68                                                         gsize              count,
  69                                                         GCancellable      *cancellable,
  70                                                         GError           **error);
  71 static gssize     g_local_file_input_stream_skip       (GInputStream      *stream,
  72                                                         gsize              count,
  73                                                         GCancellable      *cancellable,
  74                                                         GError           **error);
  75 static gboolean   g_local_file_input_stream_close      (GInputStream      *stream,
  76                                                         GCancellable      *cancellable,
  77                                                         GError           **error);
  78 static goffset    g_local_file_input_stream_tell       (GFileInputStream  *stream);
  79 static gboolean   g_local_file_input_stream_can_seek   (GFileInputStream  *stream);
  80 static gboolean   g_local_file_input_stream_seek       (GFileInputStream  *stream,
  81                                                         goffset            offset,
  82                                                         GSeekType          type,
  83                                                         GCancellable      *cancellable,
  84                                                         GError           **error);
  85 static GFileInfo *g_local_file_input_stream_query_info (GFileInputStream  *stream,
  86                                                         const char        *attributes,
  87                                                         GCancellable      *cancellable,
  88                                                         GError           **error);
  89 #ifdef G_OS_UNIX
  90 static int        g_local_file_input_stream_get_fd     (GFileDescriptorBased *stream);
  91 #endif
  92
  93 void
  94 _g_local_file_input_stream_set_do_close (GLocalFileInputStream *in,
  95                                           gboolean do_close)
  96 {
  97   in->priv->do_close = do_close;
  98 }
  99
 100 static void
 101 g_local_file_input_stream_class_init (GLocalFileInputStreamClass *klass)
 102 {
 103   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
 104   GFileInputStreamClass *file_stream_class = G_FILE_INPUT_STREAM_CLASS (klass);
 105
 106   stream_class->read_fn = g_local_file_input_stream_read;
 107   stream_class->skip = g_local_file_input_stream_skip;
 108   stream_class->close_fn = g_local_file_input_stream_close;
 109   file_stream_class->tell = g_local_file_input_stream_tell;
 110   file_stream_class->can_seek = g_local_file_input_stream_can_seek;
 111   file_stream_class->seek = g_local_file_input_stream_seek;
 112   file_stream_class->query_info = g_local_file_input_stream_query_info;
 113 }
 114
 115 #ifdef G_OS_UNIX
 116 static void
 117 g_file_descriptor_based_iface_init (GFileDescriptorBasedIface *iface)
 118 {
 119   iface->get_fd = g_local_file_input_stream_get_fd;
 120 }
 121 #endif
 122
 123 static void
 124 g_local_file_input_stream_init (GLocalFileInputStream *info)
 125 {
 126   info->priv = g_local_file_input_stream_get_instance_private (info);
 127   info->priv->do_close = TRUE;
 128 }
 129
 130 GFileInputStream *
 131 _g_local_file_input_stream_new (int fd)
 132 {
 133   GLocalFileInputStream *stream;
 134
 135   stream = g_object_new (G_TYPE_LOCAL_FILE_INPUT_STREAM, NULL);
 136   stream->priv->fd = fd;
 137
 138   return G_FILE_INPUT_STREAM (stream);
 139 }
 140
 141 static gssize
 142 g_local_file_input_stream_read (GInputStream  *stream,
 143                                 void          *buffer,
 144                                 gsize          count,
 145                                 GCancellable  *cancellable,
 146                                 GError       **error)
 147 {
 148   GLocalFileInputStream *file;
 149   gssize res;
 150
 151   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 152
 153   res = -1;
 154   while (1)
 155     {
 156       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 157         break;
 158       res = read (file->priv->fd, buffer, count);
 159       if (res == -1)
 160         {
 161           int errsv = errno;
 162
 163           if (errsv == EINTR)
 164             continue;
 165
 166           g_set_error (error, G_IO_ERROR,
 167                        g_io_error_from_errno (errsv),
 168                        _("Error reading from file: %s"),
 169                        g_strerror (errsv));
 170         }
 171
 172       break;
 173     }
 174
 175   return res;
 176 }
 177
 178 static gssize
 179 g_local_file_input_stream_skip (GInputStream  *stream,
 180                                 gsize          count,
 181                                 GCancellable  *cancellable,
 182                                 GError       **error)
 183 {
 184   off_t start, end;
 185   GLocalFileInputStream *file;
 186
 187   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 188
 189   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 190     return -1;
 191
 192   start = lseek (file->priv->fd, 0, SEEK_CUR);
 193   if (start == -1)
 194     {
 195       int errsv = errno;
 196
 197       g_set_error (error, G_IO_ERROR,
 198                    g_io_error_from_errno (errsv),
 199                    _("Error seeking in file: %s"),
 200                    g_strerror (errsv));
 201       return -1;
 202     }
 203
 204   end = lseek (file->priv->fd, 0, SEEK_END);
 205   if (end == -1)
 206     {
 207       int errsv = errno;
 208
 209       g_set_error (error, G_IO_ERROR,
 210                    g_io_error_from_errno (errsv),
 211                    _("Error seeking in file: %s"),
 212                    g_strerror (errsv));
 213       return -1;
 214     }
 215
 216   if (end - start > count)
 217     {
 218       end = lseek (file->priv->fd, count - (end - start), SEEK_CUR);
 219       if (end == -1)
 220         {
 221           int errsv = errno;
 222
 223           g_set_error (error, G_IO_ERROR,
 224                        g_io_error_from_errno (errsv),
 225                        _("Error seeking in file: %s"),
 226                        g_strerror (errsv));
 227           return -1;
 228         }
 229     }
 230
 231   return end - start;
 232 }
 233
 234 static gboolean
 235 g_local_file_input_stream_close (GInputStream  *stream,
 236                                  GCancellable  *cancellable,
 237                                  GError       **error)
 238 {
 239   GLocalFileInputStream *file;
 240
 241   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 242
 243   if (!file->priv->do_close)
 244     return TRUE;
 245
 246   if (file->priv->fd == -1)
 247     return TRUE;
 248
 249   if (!g_close (file->priv->fd, NULL))
 250     {
 251       int errsv = errno;
 252
 253       g_set_error (error, G_IO_ERROR,
 254                    g_io_error_from_errno (errsv),
 255                    _("Error closing file: %s"),
 256                    g_strerror (errsv));
 257       return FALSE;
 258     }
 259
 260   return TRUE;
 261 }
 262
 263
 264 static goffset
 265 g_local_file_input_stream_tell (GFileInputStream *stream)
 266 {
 267   GLocalFileInputStream *file;
 268   off_t pos;
 269
 270   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 271
 272   pos = lseek (file->priv->fd, 0, SEEK_CUR);
 273
 274   if (pos == (off_t)-1)
 275     return 0;
 276
 277   return pos;
 278 }
 279
 280 static gboolean
 281 g_local_file_input_stream_can_seek (GFileInputStream *stream)
 282 {
 283   GLocalFileInputStream *file;
 284   off_t pos;
 285
 286   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 287
 288   pos = lseek (file->priv->fd, 0, SEEK_CUR);
 289
 290   if (pos == (off_t)-1 && errno == ESPIPE)
 291     return FALSE;
 292
 293   return TRUE;
 294 }
 295
 296 static int
 297 seek_type_to_lseek (GSeekType type)
 298 {
 299   switch (type)
 300     {
 301     default:
 302     case G_SEEK_CUR:
 303       return SEEK_CUR;
 304
 305     case G_SEEK_SET:
 306       return SEEK_SET;
 307
 308     case G_SEEK_END:
 309       return SEEK_END;
 310     }
 311 }
 312
 313 static gboolean
 314 g_local_file_input_stream_seek (GFileInputStream  *stream,
 315                                 goffset            offset,
 316                                 GSeekType          type,
 317                                 GCancellable      *cancellable,
 318                                 GError           **error)
 319 {
 320   GLocalFileInputStream *file;
 321   off_t pos;
 322
 323   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 324
 325   pos = lseek (file->priv->fd, offset, seek_type_to_lseek (type));
 326
 327   if (pos == (off_t)-1)
 328     {
 329       int errsv = errno;
 330
 331       g_set_error (error, G_IO_ERROR,
 332                    g_io_error_from_errno (errsv),
 333                    _("Error seeking in file: %s"),
 334                    g_strerror (errsv));
 335       return FALSE;
 336     }
 337
 338   return TRUE;
 339 }
 340
 341 static GFileInfo *
 342 g_local_file_input_stream_query_info (GFileInputStream  *stream,
 343                                       const char        *attributes,
 344                                       GCancellable      *cancellable,
 345                                       GError           **error)
 346 {
 347   GLocalFileInputStream *file;
 348
 349   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 350
 351   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 352     return NULL;
 353
 354   return _g_local_file_info_get_from_fd (file->priv->fd,
 355                                          attributes,
 356                                          error);
 357 }
 358
 359 #ifdef G_OS_UNIX
 360 static int
 361 g_local_file_input_stream_get_fd (GFileDescriptorBased *fd_based)
 362 {
 363   GLocalFileInputStream *stream = G_LOCAL_FILE_INPUT_STREAM (fd_based);
 364   return stream->priv->fd;
 365 }
 366 #endif