1 /*
2 * Copyright © 2010 Codethink Limited
3 *
4 * SPDX-License-Identifier: LGPL-2.1-or-later
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18 *
19 * Author: Ryan Lortie <desrt@desrt.ca>
20 */
21
22 #include "config.h"
23
24 #include "gsimplepermission.h"
25 #include "gsettingsbackendinternal.h"
26 #include "giomodule-priv.h"
27
28
29 #define G_TYPE_MEMORY_SETTINGS_BACKEND (g_memory_settings_backend_get_type())
30 #define G_MEMORY_SETTINGS_BACKEND(inst) (G_TYPE_CHECK_INSTANCE_CAST ((inst), \
31 G_TYPE_MEMORY_SETTINGS_BACKEND, \
32 GMemorySettingsBackend))
33
34 typedef GSettingsBackendClass GMemorySettingsBackendClass;
35 typedef struct
36 {
37 GSettingsBackend parent_instance;
38 GHashTable *table;
39 } GMemorySettingsBackend;
40
41 G_DEFINE_TYPE_WITH_CODE (GMemorySettingsBackend,
42 g_memory_settings_backend,
43 G_TYPE_SETTINGS_BACKEND,
44 _g_io_modules_ensure_extension_points_registered ();
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 if (value != NULL)
99 g_hash_table_insert (memory->table, g_strdup (key), g_variant_ref (value));
100 else
101 g_hash_table_remove (memory->table, key);
102
103 return FALSE;
104 }
105
106 static gboolean
107 g_memory_settings_backend_write_tree (GSettingsBackend *backend,
108 GTree *tree,
109 gpointer origin_tag)
110 {
111 g_tree_foreach (tree, g_memory_settings_backend_write_one, backend);
112 g_settings_backend_changed_tree (backend, tree, origin_tag);
113
114 return TRUE;
115 }
116
117 static void
118 g_memory_settings_backend_reset (GSettingsBackend *backend,
119 const gchar *key,
120 gpointer origin_tag)
121 {
122 GMemorySettingsBackend *memory = G_MEMORY_SETTINGS_BACKEND (backend);
123
124 if (g_hash_table_lookup (memory->table, key))
125 {
126 g_hash_table_remove (memory->table, key);
127 g_settings_backend_changed (backend, key, origin_tag);
128 }
129 }
130
131 static gboolean
132 g_memory_settings_backend_get_writable (GSettingsBackend *backend,
133 const gchar *name)
134 {
135 return TRUE;
136 }
137
138 static GPermission *
139 g_memory_settings_backend_get_permission (GSettingsBackend *backend,
140 const gchar *path)
141 {
142 return g_simple_permission_new (TRUE);
143 }
144
145 static void
146 g_memory_settings_backend_finalize (GObject *object)
147 {
148 GMemorySettingsBackend *memory = G_MEMORY_SETTINGS_BACKEND (object);
149
150 g_hash_table_unref (memory->table);
151
152 G_OBJECT_CLASS (g_memory_settings_backend_parent_class)
153 ->finalize (object);
154 }
155
156 static void
157 g_memory_settings_backend_init (GMemorySettingsBackend *memory)
158 {
159 memory->table = g_hash_table_new_full (g_str_hash, g_str_equal, g_free,
160 (GDestroyNotify) g_variant_unref);
161 }
162
163 static void
164 g_memory_settings_backend_class_init (GMemorySettingsBackendClass *class)
165 {
166 GSettingsBackendClass *backend_class = G_SETTINGS_BACKEND_CLASS (class);
167 GObjectClass *object_class = G_OBJECT_CLASS (class);
168
169 backend_class->read = g_memory_settings_backend_read;
170 backend_class->write = g_memory_settings_backend_write;
171 backend_class->write_tree = g_memory_settings_backend_write_tree;
172 backend_class->reset = g_memory_settings_backend_reset;
173 backend_class->get_writable = g_memory_settings_backend_get_writable;
174 backend_class->get_permission = g_memory_settings_backend_get_permission;
175 object_class->finalize = g_memory_settings_backend_finalize;
176 }
177
178 /**
179 * g_memory_settings_backend_new:
180 *
181 * Creates a memory-backed #GSettingsBackend.
182 *
183 * This backend allows changes to settings, but does not write them
184 * to any backing storage, so the next time you run your application,
185 * the memory backend will start out with the default values again.
186 *
187 * Returns: (transfer full): a newly created #GSettingsBackend
188 *
189 * Since: 2.28
190 */
191 GSettingsBackend *
192 g_memory_settings_backend_new (void)
193 {
194 return g_object_new (G_TYPE_MEMORY_SETTINGS_BACKEND, NULL);
195 }