service/dconf-gvdb-utils.c

   1 /*
   2  * Copyright © 2010 Codethink Limited
   3  * Copyright © 2012 Canonical Limited
   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 licence, 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 Public
  16  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  17  *
  18  * Author: Ryan Lortie <desrt@desrt.ca>
  19  */
  20
  21 #include "config.h"
  22
  23 #include "dconf-gvdb-utils.h"
  24
  25 #include "../common/dconf-paths.h"
  26 #include "../gvdb/gvdb-builder.h"
  27 #include "../gvdb/gvdb-reader.h"
  28
  29 #include <string.h>
  30
  31 DConfChangeset *
  32 dconf_gvdb_utils_read_file (const gchar  *filename,
  33                             gboolean     *file_missing,
  34                             GError      **error)
  35 {
  36   DConfChangeset *database;
  37   GError *my_error = NULL;
  38   GvdbTable *table = NULL;
  39   gchar *contents;
  40   gsize size;
  41
  42   if (g_file_get_contents (filename, &contents, &size, &my_error))
  43     {
  44       GBytes *bytes;
  45
  46       bytes = g_bytes_new_take (contents, size);
  47       table = gvdb_table_new_from_bytes (bytes, FALSE, &my_error);
  48       g_bytes_unref (bytes);
  49     }
  50
  51   /* It is perfectly fine if the file does not exist -- then it's
  52    * just empty.
  53    */
  54   if (g_error_matches (my_error, G_FILE_ERROR, G_FILE_ERROR_NOENT))
  55     g_clear_error (&my_error);
  56
  57   /* Otherwise, we should report errors to prevent ourselves from
  58    * overwriting the database in other situations...
  59    */
  60   if (my_error)
  61     {
  62       g_propagate_prefixed_error (error, my_error, "Cannot open dconf database: ");
  63       return NULL;
  64     }
  65
  66   /* Only allocate once we know we are in a non-error situation */
  67   database = dconf_changeset_new_database (NULL);
  68
  69   /* Fill the table up with the initial state */
  70   if (table != NULL)
  71     {
  72       gchar **names;
  73       gint n_names;
  74       gint i;
  75
  76       names = gvdb_table_get_names (table, &n_names);
  77       for (i = 0; i < n_names; i++)
  78         {
  79           if (dconf_is_key (names[i], NULL))
  80             {
  81               GVariant *value;
  82
  83               value = gvdb_table_get_value (table, names[i]);
  84
  85               if (value != NULL)
  86                 {
  87                   dconf_changeset_set (database, names[i], value);
  88                   g_variant_unref (value);
  89                 }
  90             }
  91
  92           g_free (names[i]);
  93         }
  94
  95       gvdb_table_free (table);
  96       g_free (names);
  97     }
  98
  99   if (file_missing)
 100     *file_missing = (table == NULL);
 101
 102   return database;
 103 }
 104
 105 static GvdbItem *
 106 dconf_gvdb_utils_get_parent (GHashTable  *table,
 107                              const gchar *key)
 108 {
 109   GvdbItem *grandparent, *parent;
 110   gchar *parent_name;
 111   gint len;
 112
 113   if (g_str_equal (key, "/"))
 114     return NULL;
 115
 116   len = strlen (key);
 117   if (key[len - 1] == '/')
 118     len--;
 119
 120   while (key[len - 1] != '/')
 121     len--;
 122
 123   parent_name = g_strndup (key, len);
 124   parent = g_hash_table_lookup (table, parent_name);
 125
 126   if (parent == NULL)
 127     {
 128       parent = gvdb_hash_table_insert (table, parent_name);
 129
 130       grandparent = dconf_gvdb_utils_get_parent (table, parent_name);
 131
 132       if (grandparent != NULL)
 133         gvdb_item_set_parent (parent, grandparent);
 134     }
 135
 136   g_free (parent_name);
 137
 138   return parent;
 139 }
 140
 141 static gboolean
 142 dconf_gvdb_utils_add_key (const gchar *path,
 143                           GVariant    *value,
 144                           gpointer     user_data)
 145 {
 146   GHashTable *gvdb = user_data;
 147   GvdbItem *item;
 148
 149   g_assert (g_hash_table_lookup (gvdb, path) == NULL);
 150   item = gvdb_hash_table_insert (gvdb, path);
 151   gvdb_item_set_parent (item, dconf_gvdb_utils_get_parent (gvdb, path));
 152   gvdb_item_set_value (item, value);
 153
 154   return TRUE;
 155 }
 156
 157 gboolean
 158 dconf_gvdb_utils_write_file (const gchar     *filename,
 159                              DConfChangeset  *database,
 160                              GError         **error)
 161 {
 162   GHashTable *gvdb;
 163   gboolean success;
 164
 165   gvdb = gvdb_hash_table_new (NULL, NULL);
 166   dconf_changeset_all (database, dconf_gvdb_utils_add_key, gvdb);
 167   success = gvdb_table_write_contents (gvdb, filename, FALSE, error);
 168
 169   if (!success)
 170     {
 171       gchar *dirname;
 172
 173       /* Maybe it failed because the directory doesn't exist.  Try
 174        * again, after mkdir().
 175        */
 176       dirname = g_path_get_dirname (filename);
 177       g_mkdir_with_parents (dirname, 0700);
 178       g_free (dirname);
 179
 180       g_clear_error (error);
 181       success = gvdb_table_write_contents (gvdb, filename, FALSE, error);
 182     }
 183
 184   g_hash_table_unref (gvdb);
 185
 186   return success;
 187 }