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 GLocalFileStat final_stat;
191 file = G_LOCAL_FILE_OUTPUT_STREAM (stream);
195 /* Must close before renaming on Windows, so just do the close first
196 * in all cases for now.
198 if (_fstati64 (file->priv->fd, &final_stat) == 0)
199 file->priv->etag = _g_local_file_info_create_etag (&final_stat);
201 res = close (file->priv->fd);
206 g_set_error (error, G_IO_ERROR,
207 g_io_error_from_errno (errsv),
208 _("Error closing file: %s"),
215 if (file->priv->tmp_filename)
217 /* We need to move the temp file to its final place,
218 * and possibly create the backup file
221 if (file->priv->backup_filename)
223 if (g_cancellable_set_error_if_cancelled (cancellable, error))
227 /* create original -> backup link, the original is then renamed over */
228 if (g_unlink (file->priv->backup_filename) != 0 &&
233 g_set_error (error, G_IO_ERROR,
234 G_IO_ERROR_CANT_CREATE_BACKUP,
235 _("Error removing old backup link: %s"),
240 if (link (file->priv->original_filename, file->priv->backup_filename) != 0)
242 /* link failed or is not supported, try rename */
243 if (g_rename (file->priv->original_filename, file->priv->backup_filename) != 0)
247 g_set_error (error, G_IO_ERROR,
248 G_IO_ERROR_CANT_CREATE_BACKUP,
249 _("Error creating backup copy: %s"),
255 /* If link not supported, just rename... */
256 if (g_rename (file->priv->original_filename, file->priv->backup_filename) != 0)
260 g_set_error (error, G_IO_ERROR,
261 G_IO_ERROR_CANT_CREATE_BACKUP,
262 _("Error creating backup copy: %s"),
270 if (g_cancellable_set_error_if_cancelled (cancellable, error))
273 /* tmp -> original */
274 if (g_rename (file->priv->tmp_filename, file->priv->original_filename) != 0)
278 g_set_error (error, G_IO_ERROR,
279 g_io_error_from_errno (errno),
280 _("Error renaming temporary file: %s"),
286 if (g_cancellable_set_error_if_cancelled (cancellable, error))
289 #ifndef G_OS_WIN32 /* Already did the fstat() and close() above on Win32 */
291 if (fstat (file->priv->fd, &final_stat) == 0)
292 file->priv->etag = _g_local_file_info_create_etag (&final_stat);
296 res = close (file->priv->fd);
301 g_set_error (error, G_IO_ERROR,
302 g_io_error_from_errno (errsv),
303 _("Error closing file: %s"),
320 /* A simple try to close the fd in case we fail before the actual close */
321 close (file->priv->fd);
327 g_local_file_output_stream_get_etag (GFileOutputStream *stream)
329 GLocalFileOutputStream *file;
331 file = G_LOCAL_FILE_OUTPUT_STREAM (stream);
333 return g_strdup (file->priv->etag);
337 g_local_file_output_stream_tell (GFileOutputStream *stream)
339 GLocalFileOutputStream *file;
342 file = G_LOCAL_FILE_OUTPUT_STREAM (stream);
344 pos = lseek (file->priv->fd, 0, SEEK_CUR);
346 if (pos == (off_t)-1)
353 g_local_file_output_stream_can_seek (GFileOutputStream *stream)
355 GLocalFileOutputStream *file;
358 file = G_LOCAL_FILE_OUTPUT_STREAM (stream);
360 pos = lseek (file->priv->fd, 0, SEEK_CUR);
362 if (pos == (off_t)-1 && errno == ESPIPE)
369 seek_type_to_lseek (GSeekType type)
386 g_local_file_output_stream_seek (GFileOutputStream *stream,
389 GCancellable *cancellable,
392 GLocalFileOutputStream *file;
395 file = G_LOCAL_FILE_OUTPUT_STREAM (stream);
397 pos = lseek (file->priv->fd, offset, seek_type_to_lseek (type));
399 if (pos == (off_t)-1)
403 g_set_error (error, G_IO_ERROR,
404 g_io_error_from_errno (errsv),
405 _("Error seeking in file: %s"),
414 g_local_file_output_stream_can_truncate (GFileOutputStream *stream)
416 /* We can't truncate pipes and stuff where we can't seek */
417 return g_local_file_output_stream_can_seek (stream);
421 g_local_file_output_stream_truncate (GFileOutputStream *stream,
423 GCancellable *cancellable,
426 GLocalFileOutputStream *file;
429 file = G_LOCAL_FILE_OUTPUT_STREAM (stream);
433 res = g_win32_ftruncate (file->priv->fd, size);
435 res = ftruncate (file->priv->fd, size);
444 if (g_cancellable_set_error_if_cancelled (cancellable, error))
449 g_set_error (error, G_IO_ERROR,
450 g_io_error_from_errno (errsv),
451 _("Error truncating file: %s"),
461 g_local_file_output_stream_query_info (GFileOutputStream *stream,
463 GCancellable *cancellable,
466 GLocalFileOutputStream *file;
468 file = G_LOCAL_FILE_OUTPUT_STREAM (stream);
470 if (g_cancellable_set_error_if_cancelled (cancellable, error))
473 return _g_local_file_info_get_from_fd (file->priv->fd,
479 _g_local_file_output_stream_create (const char *filename,
480 GFileCreateFlags flags,
481 GCancellable *cancellable,
484 GLocalFileOutputStream *stream;
488 if (g_cancellable_set_error_if_cancelled (cancellable, error))
491 if (flags & G_FILE_CREATE_PRIVATE)
496 fd = g_open (filename, O_CREAT | O_EXCL | O_WRONLY | O_BINARY, mode);
502 /* This must be an invalid filename, on e.g. FAT */
503 g_set_error_literal (error, G_IO_ERROR,
504 G_IO_ERROR_INVALID_FILENAME,
505 _("Invalid filename"));
508 char *display_name = g_filename_display_name (filename);
509 g_set_error (error, G_IO_ERROR,
510 g_io_error_from_errno (errsv),
511 _("Error opening file '%s': %s"),
512 display_name, g_strerror (errsv));
513 g_free (display_name);
518 stream = g_object_new (G_TYPE_LOCAL_FILE_OUTPUT_STREAM, NULL);
519 stream->priv->fd = fd;
520 return G_FILE_OUTPUT_STREAM (stream);
524 _g_local_file_output_stream_append (const char *filename,
525 GFileCreateFlags flags,
526 GCancellable *cancellable,
529 GLocalFileOutputStream *stream;
533 if (g_cancellable_set_error_if_cancelled (cancellable, error))
536 if (flags & G_FILE_CREATE_PRIVATE)
541 fd = g_open (filename, O_CREAT | O_APPEND | O_WRONLY | O_BINARY, mode);
547 /* This must be an invalid filename, on e.g. FAT */
548 g_set_error_literal (error, G_IO_ERROR,
549 G_IO_ERROR_INVALID_FILENAME,
550 _("Invalid filename"));
553 char *display_name = g_filename_display_name (filename);
554 g_set_error (error, G_IO_ERROR,
555 g_io_error_from_errno (errsv),
556 _("Error opening file '%s': %s"),
557 display_name, g_strerror (errsv));
558 g_free (display_name);
563 stream = g_object_new (G_TYPE_LOCAL_FILE_OUTPUT_STREAM, NULL);
564 stream->priv->fd = fd;
566 return G_FILE_OUTPUT_STREAM (stream);
570 create_backup_filename (const char *filename)
572 return g_strconcat (filename, BACKUP_EXTENSION, NULL);
575 #define BUFSIZE 8192 /* size of normal write buffer */
578 copy_file_data (gint sfd,
584 const gchar *write_buffer;
586 gssize bytes_to_write;
587 gssize bytes_written;
589 buffer = g_malloc (BUFSIZE);
593 bytes_read = read (sfd, buffer, BUFSIZE);
594 if (bytes_read == -1)
601 g_set_error (error, G_IO_ERROR,
602 g_io_error_from_errno (errsv),
603 _("Error reading from file: %s"),
609 bytes_to_write = bytes_read;
610 write_buffer = buffer;
614 bytes_written = write (dfd, write_buffer, bytes_to_write);
615 if (bytes_written == -1)
622 g_set_error (error, G_IO_ERROR,
623 g_io_error_from_errno (errsv),
624 _("Error writing to file: %s"),
630 bytes_to_write -= bytes_written;
631 write_buffer += bytes_written;
633 while (bytes_to_write > 0);
635 } while ((bytes_read != 0) && (ret == TRUE));
643 handle_overwrite_open (const char *filename,
645 gboolean create_backup,
646 char **temp_filename,
647 GFileCreateFlags flags,
648 GCancellable *cancellable,
652 GLocalFileStat original_stat;
659 if (flags & G_FILE_CREATE_PRIVATE)
664 /* We only need read access to the original file if we are creating a backup.
665 * We also add O_CREATE to avoid a race if the file was just removed */
667 open_flags = O_RDWR | O_CREAT | O_BINARY;
669 open_flags = O_WRONLY | O_CREAT | O_BINARY;
671 /* Some systems have O_NOFOLLOW, which lets us avoid some races
672 * when finding out if the file we opened was a symlink */
675 fd = g_open (filename, open_flags | O_NOFOLLOW, mode);
676 if (fd == -1 && errno == ELOOP)
678 /* Could be a symlink, or it could be a regular ELOOP error,
679 * but then the next open will fail too. */
681 fd = g_open (filename, open_flags, mode);
684 fd = g_open (filename, open_flags, mode);
685 /* This is racy, but we do it as soon as possible to minimize the race */
686 is_symlink = g_file_test (filename, G_FILE_TEST_IS_SYMLINK);
692 char *display_name = g_filename_display_name (filename);
693 g_set_error (error, G_IO_ERROR,
694 g_io_error_from_errno (errsv),
695 _("Error opening file '%s': %s"),
696 display_name, g_strerror (errsv));
697 g_free (display_name);
702 res = _fstati64 (fd, &original_stat);
704 res = fstat (fd, &original_stat);
710 char *display_name = g_filename_display_name (filename);
711 g_set_error (error, G_IO_ERROR,
712 g_io_error_from_errno (errsv),
713 _("Error stating file '%s': %s"),
714 display_name, g_strerror (errsv));
715 g_free (display_name);
719 /* not a regular file */
720 if (!S_ISREG (original_stat.st_mode))
722 if (S_ISDIR (original_stat.st_mode))
723 g_set_error_literal (error,
725 G_IO_ERROR_IS_DIRECTORY,
726 _("Target file is a directory"));
728 g_set_error_literal (error,
730 G_IO_ERROR_NOT_REGULAR_FILE,
731 _("Target file is not a regular file"));
737 current_etag = _g_local_file_info_create_etag (&original_stat);
738 if (strcmp (etag, current_etag) != 0)
740 g_set_error_literal (error,
742 G_IO_ERROR_WRONG_ETAG,
743 _("The file was externally modified"));
744 g_free (current_etag);
747 g_free (current_etag);
750 /* We use two backup strategies.
751 * The first one (which is faster) consist in saving to a
752 * tmp file then rename the original file to the backup and the
753 * tmp file to the original name. This is fast but doesn't work
754 * when the file is a link (hard or symbolic) or when we can't
755 * write to the current dir or can't set the permissions on the
757 * The second strategy consist simply in copying the old file
758 * to a backup file and rewrite the contents of the file.
761 if ((flags & G_FILE_CREATE_REPLACE_DESTINATION) ||
762 (!(original_stat.st_nlink > 1) && !is_symlink))
764 char *dirname, *tmp_filename;
767 dirname = g_path_get_dirname (filename);
768 tmp_filename = g_build_filename (dirname, ".goutputstream-XXXXXX", NULL);
771 tmpfd = g_mkstemp (tmp_filename);
774 g_free (tmp_filename);
775 goto fallback_strategy;
778 /* try to keep permissions (unless replacing) */
780 if ( ! (flags & G_FILE_CREATE_REPLACE_DESTINATION) &&
783 fchown (tmpfd, original_stat.st_uid, original_stat.st_gid) == -1 ||
786 fchmod (tmpfd, original_stat.st_mode) == -1 ||
792 struct stat tmp_statbuf;
794 /* Check that we really needed to change something */
795 if (fstat (tmpfd, &tmp_statbuf) != 0 ||
796 original_stat.st_uid != tmp_statbuf.st_uid ||
797 original_stat.st_gid != tmp_statbuf.st_gid ||
798 original_stat.st_mode != tmp_statbuf.st_mode)
801 g_unlink (tmp_filename);
802 g_free (tmp_filename);
803 goto fallback_strategy;
808 *temp_filename = tmp_filename;
816 #if defined(HAVE_FCHOWN) && defined(HAVE_FCHMOD)
817 struct stat tmp_statbuf;
819 char *backup_filename;
822 backup_filename = create_backup_filename (filename);
824 if (g_unlink (backup_filename) == -1 && errno != ENOENT)
826 g_set_error_literal (error,
828 G_IO_ERROR_CANT_CREATE_BACKUP,
829 _("Backup file creation failed"));
830 g_free (backup_filename);
834 bfd = g_open (backup_filename,
835 O_WRONLY | O_CREAT | O_EXCL | O_BINARY,
836 original_stat.st_mode & 0777);
840 g_set_error_literal (error,
842 G_IO_ERROR_CANT_CREATE_BACKUP,
843 _("Backup file creation failed"));
844 g_free (backup_filename);
848 /* If needed, Try to set the group of the backup same as the
849 * original file. If this fails, set the protection
850 * bits for the group same as the protection bits for
852 #if defined(HAVE_FCHOWN) && defined(HAVE_FCHMOD)
853 if (fstat (bfd, &tmp_statbuf) != 0)
855 g_set_error_literal (error,
857 G_IO_ERROR_CANT_CREATE_BACKUP,
858 _("Backup file creation failed"));
859 g_unlink (backup_filename);
860 g_free (backup_filename);
864 if ((original_stat.st_gid != tmp_statbuf.st_gid) &&
865 fchown (bfd, (uid_t) -1, original_stat.st_gid) != 0)
868 (original_stat.st_mode & 0707) |
869 ((original_stat.st_mode & 07) << 3)) != 0)
871 g_set_error_literal (error,
873 G_IO_ERROR_CANT_CREATE_BACKUP,
874 _("Backup file creation failed"));
875 g_unlink (backup_filename);
877 g_free (backup_filename);
883 if (!copy_file_data (fd, bfd, NULL))
885 g_set_error_literal (error,
887 G_IO_ERROR_CANT_CREATE_BACKUP,
888 _("Backup file creation failed"));
889 g_unlink (backup_filename);
891 g_free (backup_filename);
897 g_free (backup_filename);
899 /* Seek back to the start of the file after the backup copy */
900 if (lseek (fd, 0, SEEK_SET) == -1)
904 g_set_error (error, G_IO_ERROR,
905 g_io_error_from_errno (errsv),
906 _("Error seeking in file: %s"),
912 if (flags & G_FILE_CREATE_REPLACE_DESTINATION)
916 if (g_unlink (filename) != 0)
920 g_set_error (error, G_IO_ERROR,
921 g_io_error_from_errno (errsv),
922 _("Error removing old file: %s"),
927 fd = g_open (filename, O_WRONLY | O_CREAT | O_BINARY, mode);
931 char *display_name = g_filename_display_name (filename);
932 g_set_error (error, G_IO_ERROR,
933 g_io_error_from_errno (errsv),
934 _("Error opening file '%s': %s"),
935 display_name, g_strerror (errsv));
936 g_free (display_name);
942 /* Truncate the file at the start */
944 if (g_win32_ftruncate (fd, 0) == -1)
946 if (ftruncate (fd, 0) == -1)
951 g_set_error (error, G_IO_ERROR,
952 g_io_error_from_errno (errsv),
953 _("Error truncating file: %s"),
968 _g_local_file_output_stream_replace (const char *filename,
970 gboolean create_backup,
971 GFileCreateFlags flags,
972 GCancellable *cancellable,
975 GLocalFileOutputStream *stream;
980 if (g_cancellable_set_error_if_cancelled (cancellable, error))
985 if (flags & G_FILE_CREATE_PRIVATE)
990 /* If the file doesn't exist, create it */
991 fd = g_open (filename, O_CREAT | O_EXCL | O_WRONLY | O_BINARY, mode);
993 if (fd == -1 && errno == EEXIST)
995 /* The file already exists */
996 fd = handle_overwrite_open (filename, etag, create_backup, &temp_file,
997 flags, cancellable, error);
1005 if (errsv == EINVAL)
1006 /* This must be an invalid filename, on e.g. FAT */
1007 g_set_error_literal (error, G_IO_ERROR,
1008 G_IO_ERROR_INVALID_FILENAME,
1009 _("Invalid filename"));
1012 char *display_name = g_filename_display_name (filename);
1013 g_set_error (error, G_IO_ERROR,
1014 g_io_error_from_errno (errsv),
1015 _("Error opening file '%s': %s"),
1016 display_name, g_strerror (errsv));
1017 g_free (display_name);
1023 stream = g_object_new (G_TYPE_LOCAL_FILE_OUTPUT_STREAM, NULL);
1024 stream->priv->fd = fd;
1025 stream->priv->tmp_filename = temp_file;
1027 stream->priv->backup_filename = create_backup_filename (filename);
1028 stream->priv->original_filename = g_strdup (filename);
1030 return G_FILE_OUTPUT_STREAM (stream);