1 /* GIO - GLib Input, Output and Streaming Library
3 * Copyright (C) 2006-2007 Red Hat, Inc.
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.
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.
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.
20 * Author: Alexander Larsson <alexl@redhat.com>
25 #include <sys/types.h>
35 #include <glib/gstdio.h>
38 #include "gcancellable.h"
39 #include "glocalfileoutputstream.h"
40 #include "glocalfileinfo.h"
45 #define S_ISDIR(m) (((m) & _S_IFMT) == _S_IFDIR)
48 #define S_ISREG(m) (((m) & _S_IFMT) == _S_IFREG)
58 #define g_local_file_output_stream_get_type _g_local_file_output_stream_get_type
59 G_DEFINE_TYPE (GLocalFileOutputStream
, g_local_file_output_stream
, G_TYPE_FILE_OUTPUT_STREAM
);
61 /* Some of the file replacement code was based on the code from gedit,
62 * relicenced to LGPL with permissions from the authors.
65 #define BACKUP_EXTENSION "~"
67 struct _GLocalFileOutputStreamPrivate
{
69 char *original_filename
;
70 char *backup_filename
;
75 static gssize
g_local_file_output_stream_write (GOutputStream
*stream
,
78 GCancellable
*cancellable
,
80 static gboolean
g_local_file_output_stream_close (GOutputStream
*stream
,
81 GCancellable
*cancellable
,
83 static GFileInfo
*g_local_file_output_stream_query_info (GFileOutputStream
*stream
,
85 GCancellable
*cancellable
,
87 static char * g_local_file_output_stream_get_etag (GFileOutputStream
*stream
);
88 static goffset
g_local_file_output_stream_tell (GFileOutputStream
*stream
);
89 static gboolean
g_local_file_output_stream_can_seek (GFileOutputStream
*stream
);
90 static gboolean
g_local_file_output_stream_seek (GFileOutputStream
*stream
,
93 GCancellable
*cancellable
,
95 static gboolean
g_local_file_output_stream_can_truncate (GFileOutputStream
*stream
);
96 static gboolean
g_local_file_output_stream_truncate (GFileOutputStream
*stream
,
98 GCancellable
*cancellable
,
102 g_local_file_output_stream_finalize (GObject
*object
)
104 GLocalFileOutputStream
*file
;
106 file
= G_LOCAL_FILE_OUTPUT_STREAM (object
);
108 g_free (file
->priv
->tmp_filename
);
109 g_free (file
->priv
->original_filename
);
110 g_free (file
->priv
->backup_filename
);
111 g_free (file
->priv
->etag
);
113 G_OBJECT_CLASS (g_local_file_output_stream_parent_class
)->finalize (object
);
117 g_local_file_output_stream_class_init (GLocalFileOutputStreamClass
*klass
)
119 GObjectClass
*gobject_class
= G_OBJECT_CLASS (klass
);
120 GOutputStreamClass
*stream_class
= G_OUTPUT_STREAM_CLASS (klass
);
121 GFileOutputStreamClass
*file_stream_class
= G_FILE_OUTPUT_STREAM_CLASS (klass
);
123 g_type_class_add_private (klass
, sizeof (GLocalFileOutputStreamPrivate
));
125 gobject_class
->finalize
= g_local_file_output_stream_finalize
;
127 stream_class
->write_fn
= g_local_file_output_stream_write
;
128 stream_class
->close_fn
= g_local_file_output_stream_close
;
129 file_stream_class
->query_info
= g_local_file_output_stream_query_info
;
130 file_stream_class
->get_etag
= g_local_file_output_stream_get_etag
;
131 file_stream_class
->tell
= g_local_file_output_stream_tell
;
132 file_stream_class
->can_seek
= g_local_file_output_stream_can_seek
;
133 file_stream_class
->seek
= g_local_file_output_stream_seek
;
134 file_stream_class
->can_truncate
= g_local_file_output_stream_can_truncate
;
135 file_stream_class
->truncate_fn
= g_local_file_output_stream_truncate
;
139 g_local_file_output_stream_init (GLocalFileOutputStream
*stream
)
141 stream
->priv
= G_TYPE_INSTANCE_GET_PRIVATE (stream
,
142 G_TYPE_LOCAL_FILE_OUTPUT_STREAM
,
143 GLocalFileOutputStreamPrivate
);
147 g_local_file_output_stream_write (GOutputStream
*stream
,
150 GCancellable
*cancellable
,
153 GLocalFileOutputStream
*file
;
156 file
= G_LOCAL_FILE_OUTPUT_STREAM (stream
);
160 if (g_cancellable_set_error_if_cancelled (cancellable
, error
))
162 res
= write (file
->priv
->fd
, buffer
, count
);
170 g_set_error (error
, G_IO_ERROR
,
171 g_io_error_from_errno (errsv
),
172 _("Error writing to file: %s"),
183 g_local_file_output_stream_close (GOutputStream
*stream
,
184 GCancellable
*cancellable
,
187 GLocalFileOutputStream
*file
;
188 struct stat final_stat
;
191 file
= G_LOCAL_FILE_OUTPUT_STREAM (stream
);
193 if (file
->priv
->tmp_filename
)
195 /* We need to move the temp file to its final place,
196 * and possibly create the backup file
199 if (file
->priv
->backup_filename
)
201 if (g_cancellable_set_error_if_cancelled (cancellable
, error
))
205 /* create original -> backup link, the original is then renamed over */
206 if (g_unlink (file
->priv
->backup_filename
) != 0 &&
211 g_set_error (error
, G_IO_ERROR
,
212 G_IO_ERROR_CANT_CREATE_BACKUP
,
213 _("Error removing old backup link: %s"),
218 if (link (file
->priv
->original_filename
, file
->priv
->backup_filename
) != 0)
220 /* link failed or is not supported, try rename */
221 if (g_rename (file
->priv
->original_filename
, file
->priv
->backup_filename
) != 0)
225 g_set_error (error
, G_IO_ERROR
,
226 G_IO_ERROR_CANT_CREATE_BACKUP
,
227 _("Error creating backup copy: %s"),
233 /* If link not supported, just rename... */
234 if (g_rename (file
->priv
->original_filename
, file
->priv
->backup_filename
) != 0)
238 g_set_error (error
, G_IO_ERROR
,
239 G_IO_ERROR_CANT_CREATE_BACKUP
,
240 _("Error creating backup copy: %s"),
248 if (g_cancellable_set_error_if_cancelled (cancellable
, error
))
251 /* tmp -> original */
252 if (g_rename (file
->priv
->tmp_filename
, file
->priv
->original_filename
) != 0)
256 g_set_error (error
, G_IO_ERROR
,
257 g_io_error_from_errno (errno
),
258 _("Error renaming temporary file: %s"),
264 if (g_cancellable_set_error_if_cancelled (cancellable
, error
))
267 if (fstat (file
->priv
->fd
, &final_stat
) == 0)
268 file
->priv
->etag
= _g_local_file_info_create_etag (&final_stat
);
272 res
= close (file
->priv
->fd
);
277 g_set_error (error
, G_IO_ERROR
,
278 g_io_error_from_errno (errsv
),
279 _("Error closing file: %s"),
288 /* A simple try to close the fd in case we fail before the actual close */
289 close (file
->priv
->fd
);
294 g_local_file_output_stream_get_etag (GFileOutputStream
*stream
)
296 GLocalFileOutputStream
*file
;
298 file
= G_LOCAL_FILE_OUTPUT_STREAM (stream
);
300 return g_strdup (file
->priv
->etag
);
304 g_local_file_output_stream_tell (GFileOutputStream
*stream
)
306 GLocalFileOutputStream
*file
;
309 file
= G_LOCAL_FILE_OUTPUT_STREAM (stream
);
311 pos
= lseek (file
->priv
->fd
, 0, SEEK_CUR
);
313 if (pos
== (off_t
)-1)
320 g_local_file_output_stream_can_seek (GFileOutputStream
*stream
)
322 GLocalFileOutputStream
*file
;
325 file
= G_LOCAL_FILE_OUTPUT_STREAM (stream
);
327 pos
= lseek (file
->priv
->fd
, 0, SEEK_CUR
);
329 if (pos
== (off_t
)-1 && errno
== ESPIPE
)
336 seek_type_to_lseek (GSeekType type
)
353 g_local_file_output_stream_seek (GFileOutputStream
*stream
,
356 GCancellable
*cancellable
,
359 GLocalFileOutputStream
*file
;
362 file
= G_LOCAL_FILE_OUTPUT_STREAM (stream
);
364 pos
= lseek (file
->priv
->fd
, offset
, seek_type_to_lseek (type
));
366 if (pos
== (off_t
)-1)
370 g_set_error (error
, G_IO_ERROR
,
371 g_io_error_from_errno (errsv
),
372 _("Error seeking in file: %s"),
381 g_local_file_output_stream_can_truncate (GFileOutputStream
*stream
)
383 /* We can't truncate pipes and stuff where we can't seek */
384 return g_local_file_output_stream_can_seek (stream
);
388 g_local_file_output_stream_truncate (GFileOutputStream
*stream
,
390 GCancellable
*cancellable
,
393 GLocalFileOutputStream
*file
;
396 file
= G_LOCAL_FILE_OUTPUT_STREAM (stream
);
400 res
= g_win32_ftruncate (file
->priv
->fd
, size
);
402 res
= ftruncate (file
->priv
->fd
, size
);
411 if (g_cancellable_set_error_if_cancelled (cancellable
, error
))
416 g_set_error (error
, G_IO_ERROR
,
417 g_io_error_from_errno (errsv
),
418 _("Error truncating file: %s"),
428 g_local_file_output_stream_query_info (GFileOutputStream
*stream
,
430 GCancellable
*cancellable
,
433 GLocalFileOutputStream
*file
;
435 file
= G_LOCAL_FILE_OUTPUT_STREAM (stream
);
437 if (g_cancellable_set_error_if_cancelled (cancellable
, error
))
440 return _g_local_file_info_get_from_fd (file
->priv
->fd
,
446 _g_local_file_output_stream_create (const char *filename
,
447 GFileCreateFlags flags
,
448 GCancellable
*cancellable
,
451 GLocalFileOutputStream
*stream
;
455 if (g_cancellable_set_error_if_cancelled (cancellable
, error
))
458 if (flags
& G_FILE_CREATE_PRIVATE
)
463 fd
= g_open (filename
, O_CREAT
| O_EXCL
| O_WRONLY
| O_BINARY
, mode
);
469 /* This must be an invalid filename, on e.g. FAT */
470 g_set_error_literal (error
, G_IO_ERROR
,
471 G_IO_ERROR_INVALID_FILENAME
,
472 _("Invalid filename"));
475 char *display_name
= g_filename_display_name (filename
);
476 g_set_error (error
, G_IO_ERROR
,
477 g_io_error_from_errno (errsv
),
478 _("Error opening file '%s': %s"),
479 display_name
, g_strerror (errsv
));
480 g_free (display_name
);
485 stream
= g_object_new (G_TYPE_LOCAL_FILE_OUTPUT_STREAM
, NULL
);
486 stream
->priv
->fd
= fd
;
487 return G_FILE_OUTPUT_STREAM (stream
);
491 _g_local_file_output_stream_append (const char *filename
,
492 GFileCreateFlags flags
,
493 GCancellable
*cancellable
,
496 GLocalFileOutputStream
*stream
;
500 if (g_cancellable_set_error_if_cancelled (cancellable
, error
))
503 if (flags
& G_FILE_CREATE_PRIVATE
)
508 fd
= g_open (filename
, O_CREAT
| O_APPEND
| O_WRONLY
| O_BINARY
, mode
);
514 /* This must be an invalid filename, on e.g. FAT */
515 g_set_error_literal (error
, G_IO_ERROR
,
516 G_IO_ERROR_INVALID_FILENAME
,
517 _("Invalid filename"));
520 char *display_name
= g_filename_display_name (filename
);
521 g_set_error (error
, G_IO_ERROR
,
522 g_io_error_from_errno (errsv
),
523 _("Error opening file '%s': %s"),
524 display_name
, g_strerror (errsv
));
525 g_free (display_name
);
530 stream
= g_object_new (G_TYPE_LOCAL_FILE_OUTPUT_STREAM
, NULL
);
531 stream
->priv
->fd
= fd
;
533 return G_FILE_OUTPUT_STREAM (stream
);
537 create_backup_filename (const char *filename
)
539 return g_strconcat (filename
, BACKUP_EXTENSION
, NULL
);
542 #define BUFSIZE 8192 /* size of normal write buffer */
545 copy_file_data (gint sfd
,
551 const gchar
*write_buffer
;
553 gssize bytes_to_write
;
554 gssize bytes_written
;
556 buffer
= g_malloc (BUFSIZE
);
560 bytes_read
= read (sfd
, buffer
, BUFSIZE
);
561 if (bytes_read
== -1)
568 g_set_error (error
, G_IO_ERROR
,
569 g_io_error_from_errno (errsv
),
570 _("Error reading from file: %s"),
576 bytes_to_write
= bytes_read
;
577 write_buffer
= buffer
;
581 bytes_written
= write (dfd
, write_buffer
, bytes_to_write
);
582 if (bytes_written
== -1)
589 g_set_error (error
, G_IO_ERROR
,
590 g_io_error_from_errno (errsv
),
591 _("Error writing to file: %s"),
597 bytes_to_write
-= bytes_written
;
598 write_buffer
+= bytes_written
;
600 while (bytes_to_write
> 0);
602 } while ((bytes_read
!= 0) && (ret
== TRUE
));
610 handle_overwrite_open (const char *filename
,
612 gboolean create_backup
,
613 char **temp_filename
,
614 GCancellable
*cancellable
,
618 struct stat original_stat
;
623 /* We only need read access to the original file if we are creating a backup.
624 * We also add O_CREATE to avoid a race if the file was just removed */
626 open_flags
= O_RDWR
| O_CREAT
| O_BINARY
;
628 open_flags
= O_WRONLY
| O_CREAT
| O_BINARY
;
630 /* Some systems have O_NOFOLLOW, which lets us avoid some races
631 * when finding out if the file we opened was a symlink */
634 fd
= g_open (filename
, open_flags
| O_NOFOLLOW
, 0666);
635 if (fd
== -1 && errno
== ELOOP
)
637 /* Could be a symlink, or it could be a regular ELOOP error,
638 * but then the next open will fail too. */
640 fd
= g_open (filename
, open_flags
, 0666);
643 fd
= g_open (filename
, open_flags
, 0666);
644 /* This is racy, but we do it as soon as possible to minimize the race */
645 is_symlink
= g_file_test (filename
, G_FILE_TEST_IS_SYMLINK
);
651 char *display_name
= g_filename_display_name (filename
);
652 g_set_error (error
, G_IO_ERROR
,
653 g_io_error_from_errno (errsv
),
654 _("Error opening file '%s': %s"),
655 display_name
, g_strerror (errsv
));
656 g_free (display_name
);
660 if (fstat (fd
, &original_stat
) != 0)
663 char *display_name
= g_filename_display_name (filename
);
664 g_set_error (error
, G_IO_ERROR
,
665 g_io_error_from_errno (errsv
),
666 _("Error stating file '%s': %s"),
667 display_name
, g_strerror (errsv
));
668 g_free (display_name
);
672 /* not a regular file */
673 if (!S_ISREG (original_stat
.st_mode
))
675 if (S_ISDIR (original_stat
.st_mode
))
676 g_set_error_literal (error
,
678 G_IO_ERROR_IS_DIRECTORY
,
679 _("Target file is a directory"));
681 g_set_error_literal (error
,
683 G_IO_ERROR_NOT_REGULAR_FILE
,
684 _("Target file is not a regular file"));
690 current_etag
= _g_local_file_info_create_etag (&original_stat
);
691 if (strcmp (etag
, current_etag
) != 0)
693 g_set_error_literal (error
,
695 G_IO_ERROR_WRONG_ETAG
,
696 _("The file was externally modified"));
697 g_free (current_etag
);
700 g_free (current_etag
);
703 /* We use two backup strategies.
704 * The first one (which is faster) consist in saving to a
705 * tmp file then rename the original file to the backup and the
706 * tmp file to the original name. This is fast but doesn't work
707 * when the file is a link (hard or symbolic) or when we can't
708 * write to the current dir or can't set the permissions on the
710 * The second strategy consist simply in copying the old file
711 * to a backup file and rewrite the contents of the file.
714 if (!(original_stat
.st_nlink
> 1) && !is_symlink
)
716 char *dirname
, *tmp_filename
;
719 dirname
= g_path_get_dirname (filename
);
720 tmp_filename
= g_build_filename (dirname
, ".goutputstream-XXXXXX", NULL
);
723 tmpfd
= g_mkstemp (tmp_filename
);
726 g_free (tmp_filename
);
727 goto fallback_strategy
;
730 /* try to keep permissions */
734 fchown (tmpfd
, original_stat
.st_uid
, original_stat
.st_gid
) == -1 ||
737 fchmod (tmpfd
, original_stat
.st_mode
) == -1 ||
742 struct stat tmp_statbuf
;
744 /* Check that we really needed to change something */
745 if (fstat (tmpfd
, &tmp_statbuf
) != 0 ||
746 original_stat
.st_uid
!= tmp_statbuf
.st_uid
||
747 original_stat
.st_gid
!= tmp_statbuf
.st_gid
||
748 original_stat
.st_mode
!= tmp_statbuf
.st_mode
)
751 g_unlink (tmp_filename
);
752 g_free (tmp_filename
);
753 goto fallback_strategy
;
758 *temp_filename
= tmp_filename
;
766 struct stat tmp_statbuf
;
767 char *backup_filename
;
770 backup_filename
= create_backup_filename (filename
);
772 if (g_unlink (backup_filename
) == -1 && errno
!= ENOENT
)
774 g_set_error_literal (error
,
776 G_IO_ERROR_CANT_CREATE_BACKUP
,
777 _("Backup file creation failed"));
778 g_free (backup_filename
);
782 bfd
= g_open (backup_filename
,
783 O_WRONLY
| O_CREAT
| O_EXCL
| O_BINARY
,
784 original_stat
.st_mode
& 0777);
788 g_set_error_literal (error
,
790 G_IO_ERROR_CANT_CREATE_BACKUP
,
791 _("Backup file creation failed"));
792 g_free (backup_filename
);
796 /* If needed, Try to set the group of the backup same as the
797 * original file. If this fails, set the protection
798 * bits for the group same as the protection bits for
800 #if defined(HAVE_FCHOWN) && defined(HAVE_FCHMOD)
801 if (fstat (bfd
, &tmp_statbuf
) != 0)
803 g_set_error_literal (error
,
805 G_IO_ERROR_CANT_CREATE_BACKUP
,
806 _("Backup file creation failed"));
807 g_unlink (backup_filename
);
808 g_free (backup_filename
);
812 if ((original_stat
.st_gid
!= tmp_statbuf
.st_gid
) &&
813 fchown (bfd
, (uid_t
) -1, original_stat
.st_gid
) != 0)
816 (original_stat
.st_mode
& 0707) |
817 ((original_stat
.st_mode
& 07) << 3)) != 0)
819 g_set_error_literal (error
,
821 G_IO_ERROR_CANT_CREATE_BACKUP
,
822 _("Backup file creation failed"));
823 g_unlink (backup_filename
);
825 g_free (backup_filename
);
831 if (!copy_file_data (fd
, bfd
, NULL
))
833 g_set_error_literal (error
,
835 G_IO_ERROR_CANT_CREATE_BACKUP
,
836 _("Backup file creation failed"));
837 g_unlink (backup_filename
);
839 g_free (backup_filename
);
845 g_free (backup_filename
);
847 /* Seek back to the start of the file after the backup copy */
848 if (lseek (fd
, 0, SEEK_SET
) == -1)
852 g_set_error (error
, G_IO_ERROR
,
853 g_io_error_from_errno (errsv
),
854 _("Error seeking in file: %s"),
860 /* Truncate the file at the start */
862 if (g_win32_ftruncate (fd
, 0) == -1)
864 if (ftruncate (fd
, 0) == -1)
869 g_set_error (error
, G_IO_ERROR
,
870 g_io_error_from_errno (errsv
),
871 _("Error truncating file: %s"),
884 _g_local_file_output_stream_replace (const char *filename
,
886 gboolean create_backup
,
887 GFileCreateFlags flags
,
888 GCancellable
*cancellable
,
891 GLocalFileOutputStream
*stream
;
896 if (g_cancellable_set_error_if_cancelled (cancellable
, error
))
901 if (flags
& G_FILE_CREATE_PRIVATE
)
906 /* If the file doesn't exist, create it */
907 fd
= g_open (filename
, O_CREAT
| O_EXCL
| O_WRONLY
| O_BINARY
, mode
);
909 if (fd
== -1 && errno
== EEXIST
)
911 /* The file already exists */
912 fd
= handle_overwrite_open (filename
, etag
, create_backup
, &temp_file
,
922 /* This must be an invalid filename, on e.g. FAT */
923 g_set_error_literal (error
, G_IO_ERROR
,
924 G_IO_ERROR_INVALID_FILENAME
,
925 _("Invalid filename"));
928 char *display_name
= g_filename_display_name (filename
);
929 g_set_error (error
, G_IO_ERROR
,
930 g_io_error_from_errno (errsv
),
931 _("Error opening file '%s': %s"),
932 display_name
, g_strerror (errsv
));
933 g_free (display_name
);
939 stream
= g_object_new (G_TYPE_LOCAL_FILE_OUTPUT_STREAM
, NULL
);
940 stream
->priv
->fd
= fd
;
941 stream
->priv
->tmp_filename
= temp_file
;
943 stream
->priv
->backup_filename
= create_backup_filename (filename
);
944 stream
->priv
->original_filename
= g_strdup (filename
);
946 return G_FILE_OUTPUT_STREAM (stream
);