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/*
* Copyright © 2010 Codethink Limited
* Copyright © 2012 Canonical Limited
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the licence, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
* Author: Ryan Lortie <desrt@desrt.ca>
*/
#include "config.h"
#include "dconf-gvdb-utils.h"
#include "../common/dconf-paths.h"
#include "../gvdb/gvdb-builder.h"
#include "../gvdb/gvdb-reader.h"
#include <errno.h>
#include <glib.h>
#include <glib/gstdio.h>
#include <string.h>
DConfChangeset *
dconf_gvdb_utils_read_and_back_up_file (const gchar *filename,
gboolean *file_missing,
GError **error)
{
DConfChangeset *database;
GError *my_error = NULL;
GvdbTable *table = NULL;
gchar *contents;
gsize size;
if (g_file_get_contents (filename, &contents, &size, &my_error))
{
GBytes *bytes;
bytes = g_bytes_new_take (contents, size);
table = gvdb_table_new_from_bytes (bytes, FALSE, &my_error);
g_bytes_unref (bytes);
}
/* It is perfectly fine if the file does not exist -- then it's
* just empty.
*/
if (g_error_matches (my_error, G_FILE_ERROR, G_FILE_ERROR_NOENT))
g_clear_error (&my_error);
/* Otherwise, we should report errors to prevent ourselves from
* overwriting the database in other situations...
*/
if (g_error_matches (my_error, G_FILE_ERROR, G_FILE_ERROR_INVAL))
{
/* Move the database to a backup file, warn and continue with a new
* database. The alternative is erroring out and exiting the daemon,
* which leaves the user’s session essentially unusable.
*
* The code to find an unused backup filename is racy, but this is an
* error handling path. Who cares. */
g_autofree gchar *backup_filename = NULL;
guint i;
for (i = 0;
i < G_MAXUINT &&
(backup_filename == NULL || g_file_test (backup_filename, G_FILE_TEST_EXISTS));
i++)
{
g_free (backup_filename);
backup_filename = g_strdup_printf ("%s~%u", filename, i);
}
if (g_rename (filename, backup_filename) != 0)
g_warning ("Error renaming corrupt database from ‘%s’ to ‘%s’: %s",
filename, backup_filename, g_strerror (errno));
else
g_warning ("Database ‘%s’ was corrupt: moved it to ‘%s’ and created an empty replacement",
filename, backup_filename);
g_clear_error (&my_error);
}
else if (my_error)
{
g_propagate_prefixed_error (error, my_error, "Cannot open dconf database: ");
return NULL;
}
/* Only allocate once we know we are in a non-error situation */
database = dconf_changeset_new_database (NULL);
/* Fill the table up with the initial state */
if (table != NULL)
{
gchar **names;
gsize n_names;
gsize i;
names = gvdb_table_get_names (table, &n_names);
for (i = 0; i < n_names; i++)
{
if (dconf_is_key (names[i], NULL))
{
GVariant *value;
value = gvdb_table_get_value (table, names[i]);
if (value != NULL)
{
dconf_changeset_set (database, names[i], value);
g_variant_unref (value);
}
}
g_free (names[i]);
}
gvdb_table_free (table);
g_free (names);
}
if (file_missing)
*file_missing = (table == NULL);
return database;
}
static GvdbItem *
dconf_gvdb_utils_get_parent (GHashTable *table,
const gchar *key)
{
GvdbItem *grandparent, *parent;
gchar *parent_name;
gint len;
if (g_str_equal (key, "/"))
return NULL;
len = strlen (key);
if (key[len - 1] == '/')
len--;
while (key[len - 1] != '/')
len--;
parent_name = g_strndup (key, len);
parent = g_hash_table_lookup (table, parent_name);
if (parent == NULL)
{
parent = gvdb_hash_table_insert (table, parent_name);
grandparent = dconf_gvdb_utils_get_parent (table, parent_name);
if (grandparent != NULL)
gvdb_item_set_parent (parent, grandparent);
}
g_free (parent_name);
return parent;
}
static gboolean
dconf_gvdb_utils_add_key (const gchar *path,
GVariant *value,
gpointer user_data)
{
GHashTable *gvdb = user_data;
GvdbItem *item;
g_assert (g_hash_table_lookup (gvdb, path) == NULL);
item = gvdb_hash_table_insert (gvdb, path);
gvdb_item_set_parent (item, dconf_gvdb_utils_get_parent (gvdb, path));
gvdb_item_set_value (item, value);
return TRUE;
}
gboolean
dconf_gvdb_utils_write_file (const gchar *filename,
DConfChangeset *database,
GError **error)
{
GHashTable *gvdb;
gboolean success;
gvdb = gvdb_hash_table_new (NULL, NULL);
dconf_changeset_all (database, dconf_gvdb_utils_add_key, gvdb);
success = gvdb_table_write_contents (gvdb, filename, FALSE, error);
if (!success)
{
gchar *dirname;
/* Maybe it failed because the directory doesn't exist. Try
* again, after mkdir().
*/
dirname = g_path_get_dirname (filename);
g_mkdir_with_parents (dirname, 0700);
g_free (dirname);
g_clear_error (error);
success = gvdb_table_write_contents (gvdb, filename, FALSE, error);
}
g_hash_table_unref (gvdb);
return success;
}
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