[glib] add GMemorySettingsBackend

[Ryan Lortie <ryanl src gnome org>]

commit c8e264b6d0e258241420800978745ca6dcd95137
Author: Ryan Lortie <desrt desrt ca>
Date:   Sat Apr 17 01:02:57 2010 -0400

    add GMemorySettingsBackend

 gio/Makefile.am              |    2 +
 gio/giomodule.c              |    2 +
 gio/gmemorysettingsbackend.c |  147 ++++++++++++++++++++++++++++++++++++++++++
 gio/gmemorysettingsbackend.h |   30 +++++++++
 4 files changed, 181 insertions(+), 0 deletions(-)
---
diff --git a/gio/Makefile.am b/gio/Makefile.am
index 1f3ff10..9749b3e 100644
--- a/gio/Makefile.am
+++ b/gio/Makefile.am
@@ -91,6 +91,8 @@ settings_sources = \
 	gdelayedsettingsbackend.c	\
 	gkeyfilesettingsbackend.h	\
 	gkeyfilesettingsbackend.c	\
+	gmemorysettingsbackend.h	\
+	gmemorysettingsbackend.c	\
 	gnullsettingsbackend.h		\
 	gnullsettingsbackend.c		\
 	gsettingsbackendinternal.h	\
diff --git a/gio/giomodule.c b/gio/giomodule.c
index 3f92038..587cc81 100644
--- a/gio/giomodule.c
+++ b/gio/giomodule.c
@@ -26,6 +26,7 @@
 
 #include "giomodule.h"
 #include "giomodule-priv.h"
+#include "gmemorysettingsbackend.h"
 #include "glocalfilemonitor.h"
 #include "glocaldirectorymonitor.h"
 #include "gnativevolumemonitor.h"
@@ -565,6 +566,7 @@ _g_io_modules_ensure_loaded (void)
 	}
 
       /* Initialize types from built-in "modules" */
+      g_memory_settings_backend_get_type ();
 #if defined(HAVE_SYS_INOTIFY_H) || defined(HAVE_LINUX_INOTIFY_H)
       _g_inotify_directory_monitor_get_type ();
       _g_inotify_file_monitor_get_type ();
diff --git a/gio/gmemorysettingsbackend.c b/gio/gmemorysettingsbackend.c
new file mode 100644
index 0000000..902bce1
--- /dev/null
+++ b/gio/gmemorysettingsbackend.c
@@ -0,0 +1,147 @@
+/*
+ * Copyright © 2010 Codethink Limited
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the licence, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Author: Ryan Lortie <desrt desrt ca>
+ */
+
+#include "config.h"
+
+#include "gmemorysettingsbackend.h"
+#include "gsettingsbackend.h"
+#include "giomodule.h"
+
+#include "gioalias.h"
+
+#define G_TYPE_MEMORY_SETTINGS_BACKEND  (g_memory_settings_backend_get_type())
+#define G_MEMORY_SETTINGS_BACKEND(inst) (G_TYPE_CHECK_INSTANCE_CAST ((inst), \
+                                         G_TYPE_MEMORY_SETTINGS_BACKEND,     \
+                                         GMemorySettingsBackend))
+
+typedef GSettingsBackendClass GMemorySettingsBackendClass;
+typedef struct
+{
+  GSettingsBackend parent_instance;
+  GHashTable *table;
+} GMemorySettingsBackend;
+
+G_DEFINE_TYPE_WITH_CODE (GMemorySettingsBackend,
+                         g_memory_settings_backend,
+                         G_TYPE_SETTINGS_BACKEND,
+                         g_io_extension_point_implement (G_SETTINGS_BACKEND_EXTENSION_POINT_NAME,
+                                                         g_define_type_id, "memory", 10))
+
+static GVariant *
+g_memory_settings_backend_read (GSettingsBackend   *backend,
+                                const gchar        *key,
+                                const GVariantType *expected_type)
+{
+  GVariant *value;
+
+  GMemorySettingsBackend *memory = G_MEMORY_SETTINGS_BACKEND (backend);
+
+  value = g_hash_table_lookup (memory->table, key);
+
+  if (value != NULL)
+    g_variant_ref (value);
+
+  return value;
+}
+
+static gboolean
+g_memory_settings_backend_write (GSettingsBackend *backend,
+                                 const gchar      *key,
+                                 GVariant         *value,
+                                 gpointer          origin_tag)
+{
+  GMemorySettingsBackend *memory = G_MEMORY_SETTINGS_BACKEND (backend);
+  GVariant *old_value;
+
+  old_value = g_hash_table_lookup (memory->table, key);
+  g_variant_ref_sink (value);
+
+  if (old_value == NULL || !g_variant_equal (value, old_value))
+    {
+      g_hash_table_insert (memory->table, g_strdup (key), value);
+      g_settings_backend_changed (backend, key, origin_tag);
+    }
+  else
+    g_variant_unref (value);
+
+  return TRUE;
+}
+
+static gboolean
+g_memory_settings_backend_write_one (gpointer key,
+                                     gpointer value,
+                                     gpointer data)
+{
+  GMemorySettingsBackend *memory = data;
+
+  g_hash_table_insert (memory->table, g_strdup (key), g_variant_ref (value));
+
+  return FALSE;
+}
+
+static gboolean
+g_memory_settings_backend_write_keys (GSettingsBackend *backend,
+                                      GTree            *tree,
+                                      gpointer          origin_tag)
+{
+  g_tree_foreach (tree, g_memory_settings_backend_write_one, backend);
+  g_settings_backend_changed_tree (backend, tree, origin_tag);
+
+  return TRUE;
+}
+
+static gboolean
+g_memory_settings_backend_get_writable (GSettingsBackend *backend,
+                                        const gchar      *name)
+{
+  return TRUE;
+}
+
+static void
+g_memory_settings_backend_finalize (GObject *object)
+{
+  GMemorySettingsBackend *memory = G_MEMORY_SETTINGS_BACKEND (object);
+
+  g_hash_table_unref (memory->table);
+
+  G_OBJECT_CLASS (g_memory_settings_backend_parent_class)
+    ->finalize (object);
+}
+
+static void
+g_memory_settings_backend_init (GMemorySettingsBackend *memory)
+{
+  memory->table = g_hash_table_new_full (g_str_hash, g_str_equal, g_free,
+                                         (GDestroyNotify) g_variant_unref);
+}
+
+static void
+g_memory_settings_backend_class_init (GMemorySettingsBackendClass *class)
+{
+  GSettingsBackendClass *backend_class = G_SETTINGS_BACKEND_CLASS (class);
+  GObjectClass *object_class = G_OBJECT_CLASS (class);
+
+  backend_class->read = g_memory_settings_backend_read;
+  backend_class->write = g_memory_settings_backend_write;
+  backend_class->write_keys = g_memory_settings_backend_write_keys;
+  backend_class->get_writable = g_memory_settings_backend_get_writable;
+  object_class->finalize = g_memory_settings_backend_finalize;
+}
diff --git a/gio/gmemorysettingsbackend.h b/gio/gmemorysettingsbackend.h
new file mode 100644
index 0000000..9b7756c
--- /dev/null
+++ b/gio/gmemorysettingsbackend.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright © 2010 Codethink Limited
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the licence, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ *
+ * Author: Ryan Lortie <desrt desrt ca>
+ */
+
+#ifndef __GMEMORY_SETTINGS_BACKEND_H__
+#define __GMEMORY_SETTINGS_BACKEND_H__
+
+#include <glib-object.h>
+
+G_GNUC_INTERNAL
+GType g_memory_settings_backend_get_type (void);
+
+#endif /* __G_MEMORY_SETTINGS_BACKEND_H__ */