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
  30 #define G_TYPE_MEMORY_SETTINGS_BACKEND  (g_memory_settings_backend_get_type())
  31 #define G_MEMORY_SETTINGS_BACKEND(inst) (G_TYPE_CHECK_INSTANCE_CAST ((inst), \
  32                                          G_TYPE_MEMORY_SETTINGS_BACKEND,     \
  33                                          GMemorySettingsBackend))
  34
  35 typedef GSettingsBackendClass GMemorySettingsBackendClass;
  36 typedef struct
  37 {
  38   GSettingsBackend parent_instance;
  39   GHashTable *table;
  40 } GMemorySettingsBackend;
  41
  42 G_DEFINE_TYPE_WITH_CODE (GMemorySettingsBackend,
  43                          g_memory_settings_backend,
  44                          G_TYPE_SETTINGS_BACKEND,
  45                          g_io_extension_point_implement (G_SETTINGS_BACKEND_EXTENSION_POINT_NAME,
  46                                                          g_define_type_id, "memory", 10))
  47
  48 static GVariant *
  49 g_memory_settings_backend_read (GSettingsBackend   *backend,
  50                                 const gchar        *key,
  51                                 const GVariantType *expected_type,
  52                                 gboolean            default_value)
  53 {
  54   GMemorySettingsBackend *memory = G_MEMORY_SETTINGS_BACKEND (backend);
  55   GVariant *value;
  56
  57   if (default_value)
  58     return NULL;
  59
  60   value = g_hash_table_lookup (memory->table, key);
  61
  62   if (value != NULL)
  63     g_variant_ref (value);
  64
  65   return value;
  66 }
  67
  68 static gboolean
  69 g_memory_settings_backend_write (GSettingsBackend *backend,
  70                                  const gchar      *key,
  71                                  GVariant         *value,
  72                                  gpointer          origin_tag)
  73 {
  74   GMemorySettingsBackend *memory = G_MEMORY_SETTINGS_BACKEND (backend);
  75   GVariant *old_value;
  76
  77   old_value = g_hash_table_lookup (memory->table, key);
  78   g_variant_ref_sink (value);
  79
  80   if (old_value == NULL || !g_variant_equal (value, old_value))
  81     {
  82       g_hash_table_insert (memory->table, g_strdup (key), value);
  83       g_settings_backend_changed (backend, key, origin_tag);
  84     }
  85   else
  86     g_variant_unref (value);
  87
  88   return TRUE;
  89 }
  90
  91 static gboolean
  92 g_memory_settings_backend_write_one (gpointer key,
  93                                      gpointer value,
  94                                      gpointer data)
  95 {
  96   GMemorySettingsBackend *memory = data;
  97
  98   g_hash_table_insert (memory->table, g_strdup (key), g_variant_ref (value));
  99
 100   return FALSE;
 101 }
 102
 103 static gboolean
 104 g_memory_settings_backend_write_keys (GSettingsBackend *backend,
 105                                       GTree            *tree,
 106                                       gpointer          origin_tag)
 107 {
 108   g_tree_foreach (tree, g_memory_settings_backend_write_one, backend);
 109   g_settings_backend_changed_tree (backend, tree, origin_tag);
 110
 111   return TRUE;
 112 }
 113
 114 static gboolean
 115 g_memory_settings_backend_get_writable (GSettingsBackend *backend,
 116                                         const gchar      *name)
 117 {
 118   return TRUE;
 119 }
 120
 121 static GPermission *
 122 g_memory_settings_backend_get_permission (GSettingsBackend *backend,
 123                                           const gchar      *path)
 124 {
 125   return g_simple_permission_new (TRUE);
 126 }
 127
 128 static void
 129 g_memory_settings_backend_finalize (GObject *object)
 130 {
 131   GMemorySettingsBackend *memory = G_MEMORY_SETTINGS_BACKEND (object);
 132
 133   g_hash_table_unref (memory->table);
 134
 135   G_OBJECT_CLASS (g_memory_settings_backend_parent_class)
 136     ->finalize (object);
 137 }
 138
 139 static void
 140 g_memory_settings_backend_init (GMemorySettingsBackend *memory)
 141 {
 142   memory->table = g_hash_table_new_full (g_str_hash, g_str_equal, g_free,
 143                                          (GDestroyNotify) g_variant_unref);
 144 }
 145
 146 static void
 147 g_memory_settings_backend_class_init (GMemorySettingsBackendClass *class)
 148 {
 149   GSettingsBackendClass *backend_class = G_SETTINGS_BACKEND_CLASS (class);
 150   GObjectClass *object_class = G_OBJECT_CLASS (class);
 151
 152   backend_class->read = g_memory_settings_backend_read;
 153   backend_class->write = g_memory_settings_backend_write;
 154   backend_class->write_keys = g_memory_settings_backend_write_keys;
 155   backend_class->get_writable = g_memory_settings_backend_get_writable;
 156   backend_class->get_permission = g_memory_settings_backend_get_permission;
 157   object_class->finalize = g_memory_settings_backend_finalize;
 158 }