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 GCancellable *cancellable,
651 GLocalFileStat original_stat;
657 /* We only need read access to the original file if we are creating a backup.
658 * We also add O_CREATE to avoid a race if the file was just removed */
660 open_flags = O_RDWR | O_CREAT | O_BINARY;
662 open_flags = O_WRONLY | O_CREAT | O_BINARY;
664 /* Some systems have O_NOFOLLOW, which lets us avoid some races
665 * when finding out if the file we opened was a symlink */
668 fd = g_open (filename, open_flags | O_NOFOLLOW, 0666);
669 if (fd == -1 && errno == ELOOP)
671 /* Could be a symlink, or it could be a regular ELOOP error,
672 * but then the next open will fail too. */
674 fd = g_open (filename, open_flags, 0666);
677 fd = g_open (filename, open_flags, 0666);
678 /* This is racy, but we do it as soon as possible to minimize the race */
679 is_symlink = g_file_test (filename, G_FILE_TEST_IS_SYMLINK);
685 char *display_name = g_filename_display_name (filename);
686 g_set_error (error, G_IO_ERROR,
687 g_io_error_from_errno (errsv),
688 _("Error opening file '%s': %s"),
689 display_name, g_strerror (errsv));
690 g_free (display_name);
695 res = _fstati64 (fd, &original_stat);
697 res = fstat (fd, &original_stat);
703 char *display_name = g_filename_display_name (filename);
704 g_set_error (error, G_IO_ERROR,
705 g_io_error_from_errno (errsv),
706 _("Error stating file '%s': %s"),
707 display_name, g_strerror (errsv));
708 g_free (display_name);
712 /* not a regular file */
713 if (!S_ISREG (original_stat.st_mode))
715 if (S_ISDIR (original_stat.st_mode))
716 g_set_error_literal (error,
718 G_IO_ERROR_IS_DIRECTORY,
719 _("Target file is a directory"));
721 g_set_error_literal (error,
723 G_IO_ERROR_NOT_REGULAR_FILE,
724 _("Target file is not a regular file"));
730 current_etag = _g_local_file_info_create_etag (&original_stat);
731 if (strcmp (etag, current_etag) != 0)
733 g_set_error_literal (error,
735 G_IO_ERROR_WRONG_ETAG,
736 _("The file was externally modified"));
737 g_free (current_etag);
740 g_free (current_etag);
743 /* We use two backup strategies.
744 * The first one (which is faster) consist in saving to a
745 * tmp file then rename the original file to the backup and the
746 * tmp file to the original name. This is fast but doesn't work
747 * when the file is a link (hard or symbolic) or when we can't
748 * write to the current dir or can't set the permissions on the
750 * The second strategy consist simply in copying the old file
751 * to a backup file and rewrite the contents of the file.
754 if (!(original_stat.st_nlink > 1) && !is_symlink)
756 char *dirname, *tmp_filename;
759 dirname = g_path_get_dirname (filename);
760 tmp_filename = g_build_filename (dirname, ".goutputstream-XXXXXX", NULL);
763 tmpfd = g_mkstemp (tmp_filename);
766 g_free (tmp_filename);
767 goto fallback_strategy;
770 /* try to keep permissions */
774 fchown (tmpfd, original_stat.st_uid, original_stat.st_gid) == -1 ||
777 fchmod (tmpfd, original_stat.st_mode) == -1 ||
782 struct stat tmp_statbuf;
784 /* Check that we really needed to change something */
785 if (fstat (tmpfd, &tmp_statbuf) != 0 ||
786 original_stat.st_uid != tmp_statbuf.st_uid ||
787 original_stat.st_gid != tmp_statbuf.st_gid ||
788 original_stat.st_mode != tmp_statbuf.st_mode)
791 g_unlink (tmp_filename);
792 g_free (tmp_filename);
793 goto fallback_strategy;
798 *temp_filename = tmp_filename;
806 #if defined(HAVE_FCHOWN) && defined(HAVE_FCHMOD)
807 struct stat tmp_statbuf;
809 char *backup_filename;
812 backup_filename = create_backup_filename (filename);
814 if (g_unlink (backup_filename) == -1 && errno != ENOENT)
816 g_set_error_literal (error,
818 G_IO_ERROR_CANT_CREATE_BACKUP,
819 _("Backup file creation failed"));
820 g_free (backup_filename);
824 bfd = g_open (backup_filename,
825 O_WRONLY | O_CREAT | O_EXCL | O_BINARY,
826 original_stat.st_mode & 0777);
830 g_set_error_literal (error,
832 G_IO_ERROR_CANT_CREATE_BACKUP,
833 _("Backup file creation failed"));
834 g_free (backup_filename);
838 /* If needed, Try to set the group of the backup same as the
839 * original file. If this fails, set the protection
840 * bits for the group same as the protection bits for
842 #if defined(HAVE_FCHOWN) && defined(HAVE_FCHMOD)
843 if (fstat (bfd, &tmp_statbuf) != 0)
845 g_set_error_literal (error,
847 G_IO_ERROR_CANT_CREATE_BACKUP,
848 _("Backup file creation failed"));
849 g_unlink (backup_filename);
850 g_free (backup_filename);
854 if ((original_stat.st_gid != tmp_statbuf.st_gid) &&
855 fchown (bfd, (uid_t) -1, original_stat.st_gid) != 0)
858 (original_stat.st_mode & 0707) |
859 ((original_stat.st_mode & 07) << 3)) != 0)
861 g_set_error_literal (error,
863 G_IO_ERROR_CANT_CREATE_BACKUP,
864 _("Backup file creation failed"));
865 g_unlink (backup_filename);
867 g_free (backup_filename);
873 if (!copy_file_data (fd, bfd, NULL))
875 g_set_error_literal (error,
877 G_IO_ERROR_CANT_CREATE_BACKUP,
878 _("Backup file creation failed"));
879 g_unlink (backup_filename);
881 g_free (backup_filename);
887 g_free (backup_filename);
889 /* Seek back to the start of the file after the backup copy */
890 if (lseek (fd, 0, SEEK_SET) == -1)
894 g_set_error (error, G_IO_ERROR,
895 g_io_error_from_errno (errsv),
896 _("Error seeking in file: %s"),
902 /* Truncate the file at the start */
904 if (g_win32_ftruncate (fd, 0) == -1)
906 if (ftruncate (fd, 0) == -1)
911 g_set_error (error, G_IO_ERROR,
912 g_io_error_from_errno (errsv),
913 _("Error truncating file: %s"),
926 _g_local_file_output_stream_replace (const char *filename,
928 gboolean create_backup,
929 GFileCreateFlags flags,
930 GCancellable *cancellable,
933 GLocalFileOutputStream *stream;
938 if (g_cancellable_set_error_if_cancelled (cancellable, error))
943 if (flags & G_FILE_CREATE_PRIVATE)
948 /* If the file doesn't exist, create it */
949 fd = g_open (filename, O_CREAT | O_EXCL | O_WRONLY | O_BINARY, mode);
951 if (fd == -1 && errno == EEXIST)
953 /* The file already exists */
954 fd = handle_overwrite_open (filename, etag, create_backup, &temp_file,
964 /* This must be an invalid filename, on e.g. FAT */
965 g_set_error_literal (error, G_IO_ERROR,
966 G_IO_ERROR_INVALID_FILENAME,
967 _("Invalid filename"));
970 char *display_name = g_filename_display_name (filename);
971 g_set_error (error, G_IO_ERROR,
972 g_io_error_from_errno (errsv),
973 _("Error opening file '%s': %s"),
974 display_name, g_strerror (errsv));
975 g_free (display_name);
981 stream = g_object_new (G_TYPE_LOCAL_FILE_OUTPUT_STREAM, NULL);
982 stream->priv->fd = fd;
983 stream->priv->tmp_filename = temp_file;
985 stream->priv->backup_filename = create_backup_filename (filename);
986 stream->priv->original_filename = g_strdup (filename);
988 return G_FILE_OUTPUT_STREAM (stream);