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 "gsettingsbackend.h"
  26 #include "giomodule.h"
  27
  28 #include "gioalias.h"
  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 {
  53   GVariant *value;
  54
  55   GMemorySettingsBackend *memory = G_MEMORY_SETTINGS_BACKEND (backend);
  56
  57   value = g_hash_table_lookup (memory->table, key);
  58
  59   if (value != NULL)
  60     g_variant_ref (value);
  61
  62   return value;
  63 }
  64
  65 static gboolean
  66 g_memory_settings_backend_write (GSettingsBackend *backend,
  67                                  const gchar      *key,
  68                                  GVariant         *value,
  69                                  gpointer          origin_tag)
  70 {
  71   GMemorySettingsBackend *memory = G_MEMORY_SETTINGS_BACKEND (backend);
  72   GVariant *old_value;
  73
  74   old_value = g_hash_table_lookup (memory->table, key);
  75   g_variant_ref_sink (value);
  76
  77   if (old_value == NULL || !g_variant_equal (value, old_value))
  78     {
  79       g_hash_table_insert (memory->table, g_strdup (key), value);
  80       g_settings_backend_changed (backend, key, origin_tag);
  81     }
  82   else
  83     g_variant_unref (value);
  84
  85   return TRUE;
  86 }
  87
  88 static gboolean
  89 g_memory_settings_backend_write_one (gpointer key,
  90                                      gpointer value,
  91                                      gpointer data)
  92 {
  93   GMemorySettingsBackend *memory = data;
  94
  95   g_hash_table_insert (memory->table, g_strdup (key), g_variant_ref (value));
  96
  97   return FALSE;
  98 }
  99
 100 static gboolean
 101 g_memory_settings_backend_write_keys (GSettingsBackend *backend,
 102                                       GTree            *tree,
 103                                       gpointer          origin_tag)
 104 {
 105   g_tree_foreach (tree, g_memory_settings_backend_write_one, backend);
 106   g_settings_backend_changed_tree (backend, tree, origin_tag);
 107
 108   return TRUE;
 109 }
 110
 111 static gboolean
 112 g_memory_settings_backend_get_writable (GSettingsBackend *backend,
 113                                         const gchar      *name)
 114 {
 115   return TRUE;
 116 }
 117
 118 static void
 119 g_memory_settings_backend_finalize (GObject *object)
 120 {
 121   GMemorySettingsBackend *memory = G_MEMORY_SETTINGS_BACKEND (object);
 122
 123   g_hash_table_unref (memory->table);
 124
 125   G_OBJECT_CLASS (g_memory_settings_backend_parent_class)
 126     ->finalize (object);
 127 }
 128
 129 static void
 130 g_memory_settings_backend_init (GMemorySettingsBackend *memory)
 131 {
 132   memory->table = g_hash_table_new_full (g_str_hash, g_str_equal, g_free,
 133                                          (GDestroyNotify) g_variant_unref);
 134 }
 135
 136 static void
 137 g_memory_settings_backend_class_init (GMemorySettingsBackendClass *class)
 138 {
 139   GSettingsBackendClass *backend_class = G_SETTINGS_BACKEND_CLASS (class);
 140   GObjectClass *object_class = G_OBJECT_CLASS (class);
 141
 142   backend_class->read = g_memory_settings_backend_read;
 143   backend_class->write = g_memory_settings_backend_write;
 144   backend_class->write_keys = g_memory_settings_backend_write_keys;
 145   backend_class->get_writable = g_memory_settings_backend_get_writable;
 146   object_class->finalize = g_memory_settings_backend_finalize;
 147 }