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 #include <errno.h>
  29
  30 #include <glib.h>
  31 #include <glib/gstdio.h>
  32 #include "gcancellable.h"
  33 #include "gioerror.h"
  34 #include "glocalfileinputstream.h"
  35 #include "glocalfileinfo.h"
  36 #include "glibintl.h"
  37
  38 #ifdef G_OS_UNIX
  39 #include <unistd.h>
  40 #include "glib-unix.h"
  41 #include "gfiledescriptorbased.h"
  42 #endif
  43
  44 #ifdef G_OS_WIN32
  45 #include <io.h>
  46 #endif
  47
  48 struct _GLocalFileInputStreamPrivate {
  49   int fd;
  50   guint do_close : 1;
  51 };
  52
  53 #ifdef G_OS_UNIX
  54 static void       g_file_descriptor_based_iface_init   (GFileDescriptorBasedIface *iface);
  55 #endif
  56
  57 #define g_local_file_input_stream_get_type _g_local_file_input_stream_get_type
  58 #ifdef G_OS_UNIX
  59 G_DEFINE_TYPE_WITH_CODE (GLocalFileInputStream, g_local_file_input_stream, G_TYPE_FILE_INPUT_STREAM,
  60                          G_ADD_PRIVATE (GLocalFileInputStream)
  61                          G_IMPLEMENT_INTERFACE (G_TYPE_FILE_DESCRIPTOR_BASED,
  62                                                 g_file_descriptor_based_iface_init))
  63 #else
  64 G_DEFINE_TYPE_WITH_CODE (GLocalFileInputStream, g_local_file_input_stream, G_TYPE_FILE_INPUT_STREAM,
  65                          G_ADD_PRIVATE (GLocalFileInputStream))
  66 #endif
  67
  68 static gssize     g_local_file_input_stream_read       (GInputStream      *stream,
  69                                                         void              *buffer,
  70                                                         gsize              count,
  71                                                         GCancellable      *cancellable,
  72                                                         GError           **error);
  73 static gssize     g_local_file_input_stream_skip       (GInputStream      *stream,
  74                                                         gsize              count,
  75                                                         GCancellable      *cancellable,
  76                                                         GError           **error);
  77 static gboolean   g_local_file_input_stream_close      (GInputStream      *stream,
  78                                                         GCancellable      *cancellable,
  79                                                         GError           **error);
  80 static goffset    g_local_file_input_stream_tell       (GFileInputStream  *stream);
  81 static gboolean   g_local_file_input_stream_can_seek   (GFileInputStream  *stream);
  82 static gboolean   g_local_file_input_stream_seek       (GFileInputStream  *stream,
  83                                                         goffset            offset,
  84                                                         GSeekType          type,
  85                                                         GCancellable      *cancellable,
  86                                                         GError           **error);
  87 static GFileInfo *g_local_file_input_stream_query_info (GFileInputStream  *stream,
  88                                                         const char        *attributes,
  89                                                         GCancellable      *cancellable,
  90                                                         GError           **error);
  91 #ifdef G_OS_UNIX
  92 static int        g_local_file_input_stream_get_fd     (GFileDescriptorBased *stream);
  93 #endif
  94
  95 void
  96 _g_local_file_input_stream_set_do_close (GLocalFileInputStream *in,
  97                                           gboolean do_close)
  98 {
  99   in->priv->do_close = do_close;
 100 }
 101
 102 static void
 103 g_local_file_input_stream_class_init (GLocalFileInputStreamClass *klass)
 104 {
 105   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
 106   GFileInputStreamClass *file_stream_class = G_FILE_INPUT_STREAM_CLASS (klass);
 107
 108   stream_class->read_fn = g_local_file_input_stream_read;
 109   stream_class->skip = g_local_file_input_stream_skip;
 110   stream_class->close_fn = g_local_file_input_stream_close;
 111   file_stream_class->tell = g_local_file_input_stream_tell;
 112   file_stream_class->can_seek = g_local_file_input_stream_can_seek;
 113   file_stream_class->seek = g_local_file_input_stream_seek;
 114   file_stream_class->query_info = g_local_file_input_stream_query_info;
 115 }
 116
 117 #ifdef G_OS_UNIX
 118 static void
 119 g_file_descriptor_based_iface_init (GFileDescriptorBasedIface *iface)
 120 {
 121   iface->get_fd = g_local_file_input_stream_get_fd;
 122 }
 123 #endif
 124
 125 static void
 126 g_local_file_input_stream_init (GLocalFileInputStream *info)
 127 {
 128   info->priv = g_local_file_input_stream_get_instance_private (info);
 129   info->priv->do_close = TRUE;
 130 }
 131
 132 GFileInputStream *
 133 _g_local_file_input_stream_new (int fd)
 134 {
 135   GLocalFileInputStream *stream;
 136
 137   stream = g_object_new (G_TYPE_LOCAL_FILE_INPUT_STREAM, NULL);
 138   stream->priv->fd = fd;
 139
 140   return G_FILE_INPUT_STREAM (stream);
 141 }
 142
 143 static gssize
 144 g_local_file_input_stream_read (GInputStream  *stream,
 145                                 void          *buffer,
 146                                 gsize          count,
 147                                 GCancellable  *cancellable,
 148                                 GError       **error)
 149 {
 150   GLocalFileInputStream *file;
 151   gssize res;
 152
 153   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 154
 155   res = -1;
 156   while (1)
 157     {
 158       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 159         break;
 160       res = read (file->priv->fd, buffer, count);
 161       if (res == -1)
 162         {
 163           int errsv = errno;
 164
 165           if (errsv == EINTR)
 166             continue;
 167
 168           g_set_error (error, G_IO_ERROR,
 169                        g_io_error_from_errno (errsv),
 170                        _("Error reading from file: %s"),
 171                        g_strerror (errsv));
 172         }
 173
 174       break;
 175     }
 176
 177   return res;
 178 }
 179
 180 static gssize
 181 g_local_file_input_stream_skip (GInputStream  *stream,
 182                                 gsize          count,
 183                                 GCancellable  *cancellable,
 184                                 GError       **error)
 185 {
 186   off_t start, end;
 187   GLocalFileInputStream *file;
 188
 189   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 190
 191   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 192     return -1;
 193
 194   start = lseek (file->priv->fd, 0, SEEK_CUR);
 195   if (start == -1)
 196     {
 197       int errsv = errno;
 198
 199       g_set_error (error, G_IO_ERROR,
 200                    g_io_error_from_errno (errsv),
 201                    _("Error seeking in file: %s"),
 202                    g_strerror (errsv));
 203       return -1;
 204     }
 205
 206   end = lseek (file->priv->fd, 0, SEEK_END);
 207   if (end == -1)
 208     {
 209       int errsv = errno;
 210
 211       g_set_error (error, G_IO_ERROR,
 212                    g_io_error_from_errno (errsv),
 213                    _("Error seeking in file: %s"),
 214                    g_strerror (errsv));
 215       return -1;
 216     }
 217
 218   if (end - start > count)
 219     {
 220       end = lseek (file->priv->fd, count - (end - start), SEEK_CUR);
 221       if (end == -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
 233   return end - start;
 234 }
 235
 236 static gboolean
 237 g_local_file_input_stream_close (GInputStream  *stream,
 238                                  GCancellable  *cancellable,
 239                                  GError       **error)
 240 {
 241   GLocalFileInputStream *file;
 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   if (!g_close (file->priv->fd, NULL))
 252     {
 253       int errsv = errno;
 254
 255       g_set_error (error, G_IO_ERROR,
 256                    g_io_error_from_errno (errsv),
 257                    _("Error closing file: %s"),
 258                    g_strerror (errsv));
 259       return FALSE;
 260     }
 261
 262   return TRUE;
 263 }
 264
 265
 266 static goffset
 267 g_local_file_input_stream_tell (GFileInputStream *stream)
 268 {
 269   GLocalFileInputStream *file;
 270   off_t pos;
 271
 272   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 273
 274   pos = lseek (file->priv->fd, 0, SEEK_CUR);
 275
 276   if (pos == (off_t)-1)
 277     return 0;
 278
 279   return pos;
 280 }
 281
 282 static gboolean
 283 g_local_file_input_stream_can_seek (GFileInputStream *stream)
 284 {
 285   GLocalFileInputStream *file;
 286   off_t pos;
 287
 288   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 289
 290   pos = lseek (file->priv->fd, 0, SEEK_CUR);
 291
 292   if (pos == (off_t)-1 && errno == ESPIPE)
 293     return FALSE;
 294
 295   return TRUE;
 296 }
 297
 298 static int
 299 seek_type_to_lseek (GSeekType type)
 300 {
 301   switch (type)
 302     {
 303     default:
 304     case G_SEEK_CUR:
 305       return SEEK_CUR;
 306
 307     case G_SEEK_SET:
 308       return SEEK_SET;
 309
 310     case G_SEEK_END:
 311       return SEEK_END;
 312     }
 313 }
 314
 315 static gboolean
 316 g_local_file_input_stream_seek (GFileInputStream  *stream,
 317                                 goffset            offset,
 318                                 GSeekType          type,
 319                                 GCancellable      *cancellable,
 320                                 GError           **error)
 321 {
 322   GLocalFileInputStream *file;
 323   off_t pos;
 324
 325   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 326
 327   pos = lseek (file->priv->fd, offset, seek_type_to_lseek (type));
 328
 329   if (pos == (off_t)-1)
 330     {
 331       int errsv = errno;
 332
 333       g_set_error (error, G_IO_ERROR,
 334                    g_io_error_from_errno (errsv),
 335                    _("Error seeking in file: %s"),
 336                    g_strerror (errsv));
 337       return FALSE;
 338     }
 339
 340   return TRUE;
 341 }
 342
 343 static GFileInfo *
 344 g_local_file_input_stream_query_info (GFileInputStream  *stream,
 345                                       const char        *attributes,
 346                                       GCancellable      *cancellable,
 347                                       GError           **error)
 348 {
 349   GLocalFileInputStream *file;
 350
 351   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 352
 353   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 354     return NULL;
 355
 356   return _g_local_file_info_get_from_fd (file->priv->fd,
 357                                          attributes,
 358                                          error);
 359 }
 360
 361 #ifdef G_OS_UNIX
 362 static int
 363 g_local_file_input_stream_get_fd (GFileDescriptorBased *fd_based)
 364 {
 365   GLocalFileInputStream *stream = G_LOCAL_FILE_INPUT_STREAM (fd_based);
 366   return stream->priv->fd;
 367 }
 368 #endif