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 <unistd.h>
  29 #include <errno.h>
  30
  31 #include <glib.h>
  32 #include <glib/gstdio.h>
  33 #include "gioerror.h"
  34 #include "glocalfileinputstream.h"
  35 #include "glocalfileinfo.h"
  36 #include "glibintl.h"
  37
  38 #include "gioalias.h"
  39
  40 G_DEFINE_TYPE (GLocalFileInputStream, g_local_file_input_stream, G_TYPE_FILE_INPUT_STREAM);
  41
  42 struct _GLocalFileInputStreamPrivate {
  43   int fd;
  44 };
  45
  46 static gssize     g_local_file_input_stream_read       (GInputStream      *stream,
  47                                                         void              *buffer,
  48                                                         gsize              count,
  49                                                         GCancellable      *cancellable,
  50                                                         GError           **error);
  51 static gssize     g_local_file_input_stream_skip       (GInputStream      *stream,
  52                                                         gsize              count,
  53                                                         GCancellable      *cancellable,
  54                                                         GError           **error);
  55 static gboolean   g_local_file_input_stream_close      (GInputStream      *stream,
  56                                                         GCancellable      *cancellable,
  57                                                         GError           **error);
  58 static goffset    g_local_file_input_stream_tell       (GFileInputStream  *stream);
  59 static gboolean   g_local_file_input_stream_can_seek   (GFileInputStream  *stream);
  60 static gboolean   g_local_file_input_stream_seek       (GFileInputStream  *stream,
  61                                                         goffset            offset,
  62                                                         GSeekType          type,
  63                                                         GCancellable      *cancellable,
  64                                                         GError           **error);
  65 static GFileInfo *g_local_file_input_stream_query_info (GFileInputStream  *stream,
  66                                                         char              *attributes,
  67                                                         GCancellable      *cancellable,
  68                                                         GError           **error);
  69
  70 static void
  71 g_local_file_input_stream_finalize (GObject *object)
  72 {
  73   GLocalFileInputStream *file;
  74
  75   file = G_LOCAL_FILE_INPUT_STREAM (object);
  76
  77   if (G_OBJECT_CLASS (g_local_file_input_stream_parent_class)->finalize)
  78     (*G_OBJECT_CLASS (g_local_file_input_stream_parent_class)->finalize) (object);
  79 }
  80
  81 static void
  82 g_local_file_input_stream_class_init (GLocalFileInputStreamClass *klass)
  83 {
  84   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
  85   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
  86   GFileInputStreamClass *file_stream_class = G_FILE_INPUT_STREAM_CLASS (klass);
  87
  88   g_type_class_add_private (klass, sizeof (GLocalFileInputStreamPrivate));
  89
  90   gobject_class->finalize = g_local_file_input_stream_finalize;
  91
  92   stream_class->read = g_local_file_input_stream_read;
  93   stream_class->skip = g_local_file_input_stream_skip;
  94   stream_class->close = g_local_file_input_stream_close;
  95   file_stream_class->tell = g_local_file_input_stream_tell;
  96   file_stream_class->can_seek = g_local_file_input_stream_can_seek;
  97   file_stream_class->seek = g_local_file_input_stream_seek;
  98   file_stream_class->query_info = g_local_file_input_stream_query_info;
  99 }
 100
 101 static void
 102 g_local_file_input_stream_init (GLocalFileInputStream *info)
 103 {
 104   info->priv = G_TYPE_INSTANCE_GET_PRIVATE (info,
 105                                             G_TYPE_LOCAL_FILE_INPUT_STREAM,
 106                                             GLocalFileInputStreamPrivate);
 107 }
 108
 109 /**
 110  * g_local_file_input_stream_new:
 111  * @fd: File Descriptor.
 112  *
 113  * Returns: #GFileInputStream for the given file descriptor.
 114  **/
 115 GFileInputStream *
 116 g_local_file_input_stream_new (int fd)
 117 {
 118   GLocalFileInputStream *stream;
 119
 120   stream = g_object_new (G_TYPE_LOCAL_FILE_INPUT_STREAM, NULL);
 121   stream->priv->fd = fd;
 122
 123   return G_FILE_INPUT_STREAM (stream);
 124 }
 125
 126 static gssize
 127 g_local_file_input_stream_read (GInputStream *stream,
 128                                 void         *buffer,
 129                                 gsize         count,
 130                                 GCancellable *cancellable,
 131                                 GError      **error)
 132 {
 133   GLocalFileInputStream *file;
 134   gssize res;
 135
 136   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 137
 138   res = -1;
 139   while (1)
 140     {
 141       if (g_cancellable_set_error_if_cancelled (cancellable, error))
 142         break;
 143       res = read (file->priv->fd, buffer, count);
 144       if (res == -1)
 145         {
 146           if (errno == EINTR)
 147             continue;
 148
 149           g_set_error (error, G_IO_ERROR,
 150                        g_io_error_from_errno (errno),
 151                        _("Error reading from file: %s"),
 152                        g_strerror (errno));
 153         }
 154
 155       break;
 156     }
 157
 158   return res;
 159 }
 160
 161 static gssize
 162 g_local_file_input_stream_skip (GInputStream *stream,
 163                                 gsize         count,
 164                                 GCancellable *cancellable,
 165                                 GError      **error)
 166 {
 167   off_t res, start;
 168   GLocalFileInputStream *file;
 169
 170   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 171
 172   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 173     return -1;
 174
 175   start = lseek (file->priv->fd, 0, SEEK_CUR);
 176   if (start == -1)
 177     {
 178       g_set_error (error, G_IO_ERROR,
 179                    g_io_error_from_errno (errno),
 180                    _("Error seeking in file: %s"),
 181                    g_strerror (errno));
 182       return -1;
 183     }
 184
 185   res = lseek (file->priv->fd, count, SEEK_CUR);
 186   if (res == -1)
 187     {
 188       g_set_error (error, G_IO_ERROR,
 189                    g_io_error_from_errno (errno),
 190                    _("Error seeking in file: %s"),
 191                    g_strerror (errno));
 192       return -1;
 193     }
 194
 195   return res - start;
 196 }
 197
 198 static gboolean
 199 g_local_file_input_stream_close (GInputStream *stream,
 200                                  GCancellable *cancellable,
 201                                  GError      **error)
 202 {
 203   GLocalFileInputStream *file;
 204   int res;
 205
 206   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 207
 208   if (file->priv->fd == -1)
 209     return TRUE;
 210
 211   while (1)
 212     {
 213       res = close (file->priv->fd);
 214       if (res == -1)
 215         {
 216           g_set_error (error, G_IO_ERROR,
 217                        g_io_error_from_errno (errno),
 218                        _("Error closing file: %s"),
 219                        g_strerror (errno));
 220         }
 221       break;
 222     }
 223
 224   return res != -1;
 225 }
 226
 227
 228 static goffset
 229 g_local_file_input_stream_tell (GFileInputStream *stream)
 230 {
 231   GLocalFileInputStream *file;
 232   off_t pos;
 233
 234   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 235
 236   pos = lseek (file->priv->fd, 0, SEEK_CUR);
 237
 238   if (pos == (off_t)-1)
 239     return 0;
 240
 241   return pos;
 242 }
 243
 244 static gboolean
 245 g_local_file_input_stream_can_seek (GFileInputStream *stream)
 246 {
 247   GLocalFileInputStream *file;
 248   off_t pos;
 249
 250   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 251
 252   pos = lseek (file->priv->fd, 0, SEEK_CUR);
 253
 254   if (pos == (off_t)-1 &&
 255       errno == ESPIPE)
 256     return FALSE;
 257
 258   return TRUE;
 259 }
 260
 261 static int
 262 seek_type_to_lseek (GSeekType type)
 263 {
 264   switch (type)
 265     {
 266     default:
 267     case G_SEEK_CUR:
 268       return SEEK_CUR;
 269
 270     case G_SEEK_SET:
 271       return SEEK_SET;
 272
 273     case G_SEEK_END:
 274       return SEEK_END;
 275     }
 276 }
 277
 278 static gboolean
 279 g_local_file_input_stream_seek (GFileInputStream     *stream,
 280                                 goffset               offset,
 281                                 GSeekType             type,
 282                                 GCancellable         *cancellable,
 283                                 GError              **error)
 284 {
 285   GLocalFileInputStream *file;
 286   off_t pos;
 287
 288   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 289
 290   pos = lseek (file->priv->fd, offset, seek_type_to_lseek (type));
 291
 292   if (pos == (off_t)-1)
 293     {
 294       g_set_error (error, G_IO_ERROR,
 295                    g_io_error_from_errno (errno),
 296                    _("Error seeking in file: %s"),
 297                    g_strerror (errno));
 298       return FALSE;
 299     }
 300
 301   return TRUE;
 302 }
 303
 304 static GFileInfo *
 305 g_local_file_input_stream_query_info (GFileInputStream     *stream,
 306                                       char                 *attributes,
 307                                       GCancellable         *cancellable,
 308                                       GError              **error)
 309 {
 310   GLocalFileInputStream *file;
 311
 312   file = G_LOCAL_FILE_INPUT_STREAM (stream);
 313
 314   if (g_cancellable_set_error_if_cancelled (cancellable, error))
 315     return NULL;
 316
 317   return _g_local_file_info_get_from_fd (file->priv->fd,
 318                                          attributes,
 319                                          error);
 320 }