gio/gmemorysettingsbackend.c

   1 /*
   2  * Copyright © 2010 Codethink Limited
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the licence, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  *
  19  * Author: Ryan Lortie <desrt@desrt.ca>
  20  */
  21
  22 #include "config.h"
  23
  24 #include "gmemorysettingsbackend.h"
  25 #include "gsimplepermission.h"
  26 #include "gsettingsbackend.h"
  27 #include "giomodule.h"
  28
  29 #include "gioalias.h"
  30
  31 #define G_TYPE_MEMORY_SETTINGS_BACKEND  (g_memory_settings_backend_get_type())
  32 #define G_MEMORY_SETTINGS_BACKEND(inst) (G_TYPE_CHECK_INSTANCE_CAST ((inst), \
  33                                          G_TYPE_MEMORY_SETTINGS_BACKEND,     \
  34                                          GMemorySettingsBackend))
  35
  36 typedef GSettingsBackendClass GMemorySettingsBackendClass;
  37 typedef struct
  38 {
  39   GSettingsBackend parent_instance;
  40   GHashTable *table;
  41 } GMemorySettingsBackend;
  42
  43 G_DEFINE_TYPE_WITH_CODE (GMemorySettingsBackend,
  44                          g_memory_settings_backend,
  45                          G_TYPE_SETTINGS_BACKEND,
  46                          g_io_extension_point_implement (G_SETTINGS_BACKEND_EXTENSION_POINT_NAME,
  47                                                          g_define_type_id, "memory", 10))
  48
  49 static GVariant *
  50 g_memory_settings_backend_read (GSettingsBackend   *backend,
  51                                 const gchar        *key,
  52                                 const GVariantType *expected_type,
  53                                 gboolean            default_value)
  54 {
  55   GMemorySettingsBackend *memory = G_MEMORY_SETTINGS_BACKEND (backend);
  56   GVariant *value;
  57
  58   if (default_value)
  59     return NULL;
  60
  61   value = g_hash_table_lookup (memory->table, key);
  62
  63   if (value != NULL)
  64     g_variant_ref (value);
  65
  66   return value;
  67 }
  68
  69 static gboolean
  70 g_memory_settings_backend_write (GSettingsBackend *backend,
  71                                  const gchar      *key,
  72                                  GVariant         *value,
  73                                  gpointer          origin_tag)
  74 {
  75   GMemorySettingsBackend *memory = G_MEMORY_SETTINGS_BACKEND (backend);
  76   GVariant *old_value;
  77
  78   old_value = g_hash_table_lookup (memory->table, key);
  79   g_variant_ref_sink (value);
  80
  81   if (old_value == NULL || !g_variant_equal (value, old_value))
  82     {
  83       g_hash_table_insert (memory->table, g_strdup (key), value);
  84       g_settings_backend_changed (backend, key, origin_tag);
  85     }
  86   else
  87     g_variant_unref (value);
  88
  89   return TRUE;
  90 }
  91
  92 static gboolean
  93 g_memory_settings_backend_write_one (gpointer key,
  94                                      gpointer value,
  95                                      gpointer data)
  96 {
  97   GMemorySettingsBackend *memory = data;
  98
  99   g_hash_table_insert (memory->table, g_strdup (key), g_variant_ref (value));
 100
 101   return FALSE;
 102 }
 103
 104 static gboolean
 105 g_memory_settings_backend_write_keys (GSettingsBackend *backend,
 106                                       GTree            *tree,
 107                                       gpointer          origin_tag)
 108 {
 109   g_tree_foreach (tree, g_memory_settings_backend_write_one, backend);
 110   g_settings_backend_changed_tree (backend, tree, origin_tag);
 111
 112   return TRUE;
 113 }
 114
 115 static gboolean
 116 g_memory_settings_backend_get_writable (GSettingsBackend *backend,
 117                                         const gchar      *name)
 118 {
 119   return TRUE;
 120 }
 121
 122 static GPermission *
 123 g_memory_settings_backend_get_permission (GSettingsBackend *backend,
 124                                           const gchar      *path)
 125 {
 126   return g_simple_permission_new (TRUE);
 127 }
 128
 129 static void
 130 g_memory_settings_backend_finalize (GObject *object)
 131 {
 132   GMemorySettingsBackend *memory = G_MEMORY_SETTINGS_BACKEND (object);
 133
 134   g_hash_table_unref (memory->table);
 135
 136   G_OBJECT_CLASS (g_memory_settings_backend_parent_class)
 137     ->finalize (object);
 138 }
 139
 140 static void
 141 g_memory_settings_backend_init (GMemorySettingsBackend *memory)
 142 {
 143   memory->table = g_hash_table_new_full (g_str_hash, g_str_equal, g_free,
 144                                          (GDestroyNotify) g_variant_unref);
 145 }
 146
 147 static void
 148 g_memory_settings_backend_class_init (GMemorySettingsBackendClass *class)
 149 {
 150   GSettingsBackendClass *backend_class = G_SETTINGS_BACKEND_CLASS (class);
 151   GObjectClass *object_class = G_OBJECT_CLASS (class);
 152
 153   backend_class->read = g_memory_settings_backend_read;
 154   backend_class->write = g_memory_settings_backend_write;
 155   backend_class->write_keys = g_memory_settings_backend_write_keys;
 156   backend_class->get_writable = g_memory_settings_backend_get_writable;
 157   backend_class->get_permission = g_memory_settings_backend_get_permission;
 158   object_class->finalize = g_memory_settings_backend_finalize;
 159 }