[gnome-software] Only load the PackageKit history proxy when required

[Richard Hughes <rhughes src gnome org>]

commit 8e9d135f21445c3f659b4270cf914f59efd589b1
Author: Richard Hughes <richard hughsie com>
Date:   Mon Oct 14 17:49:03 2013 +0100

    Only load the PackageKit history proxy when required
    
    This saves 55ms at cold start as it means we can parallelize it with other start-up tasks.

 src/plugins/gs-plugin-packagekit-history.c |   65 +++++++++++++++++-----------
 1 files changed, 39 insertions(+), 26 deletions(-)
---
diff --git a/src/plugins/gs-plugin-packagekit-history.c b/src/plugins/gs-plugin-packagekit-history.c
index d4eb14f..b5e831b 100644
--- a/src/plugins/gs-plugin-packagekit-history.c
+++ b/src/plugins/gs-plugin-packagekit-history.c
@@ -27,7 +27,8 @@
 #include <gs-plugin.h>
 
 struct GsPluginPrivate {
-       GDBusProxy              *proxy;
+       gsize                    loaded;
+       GDBusConnection         *connection;
 };
 
 /**
@@ -45,23 +46,7 @@ gs_plugin_get_name (void)
 void
 gs_plugin_initialize (GsPlugin *plugin)
 {
-       GError *error = NULL;
-
-       /* create private area */
        plugin->priv = GS_PLUGIN_GET_PRIVATE (GsPluginPrivate);
-       plugin->priv->proxy = g_dbus_proxy_new_for_bus_sync (G_BUS_TYPE_SYSTEM,
-                                                            G_DBUS_PROXY_FLAGS_DO_NOT_LOAD_PROPERTIES |
-                                                            G_DBUS_PROXY_FLAGS_DO_NOT_CONNECT_SIGNALS,
-                                                            NULL,
-                                                            "org.freedesktop.PackageKit",
-                                                            "/org/freedesktop/PackageKit",
-                                                            "org.freedesktop.PackageKit",
-                                                            NULL,
-                                                            &error);
-       if (plugin->priv->proxy == NULL) {
-               g_warning ("Failed to create proxy for PackageKit: %s", error->message);
-               g_error_free (error);
-       }
 }
 
 /**
@@ -79,7 +64,8 @@ gs_plugin_get_priority (GsPlugin *plugin)
 void
 gs_plugin_destroy (GsPlugin *plugin)
 {
-       g_object_unref (plugin->priv->proxy);
+       if (plugin->priv->connection != NULL)
+               g_object_unref (plugin->priv->connection);
 }
 
 /**
@@ -143,13 +129,28 @@ out:
        g_object_unref (history);
 }
 
+/**
+ * gs_plugin_load:
+ */
+static gboolean
+gs_plugin_load (GsPlugin *plugin, GCancellable *cancellable, GError **error)
+{
+       gboolean ret = TRUE;
+       plugin->priv->connection = g_bus_get_sync (G_BUS_TYPE_SYSTEM,
+                                                  cancellable,
+                                                  error);
+       if (plugin->priv->connection == NULL)
+               ret = FALSE;
+       return ret;
+}
+
 static gboolean
 gs_plugin_packagekit_refine (GsPlugin *plugin,
                             GList *list,
                             GCancellable *cancellable,
                             GError **error)
 {
-       const gchar **package_names;
+       const gchar **package_names = NULL;
        gboolean ret = TRUE;
        GError *error_local = NULL;
        GList *l;
@@ -161,6 +162,14 @@ gs_plugin_packagekit_refine (GsPlugin *plugin,
        GVariant *tuple = NULL;
        GVariant *value;
 
+       /* already loaded */
+       if (g_once_init_enter (&plugin->priv->loaded)) {
+               ret = gs_plugin_load (plugin, cancellable, error);
+               g_once_init_leave (&plugin->priv->loaded, TRUE);
+               if (!ret)
+                       goto out;
+       }
+
        /* get an array of package names */
        package_names = g_new0 (const gchar *, g_list_length (list) + 1);
        for (l = list; l != NULL; l = l->next) {
@@ -169,13 +178,17 @@ gs_plugin_packagekit_refine (GsPlugin *plugin,
        }
 
        g_debug ("getting history for %i packages", g_list_length (list));
-       result = g_dbus_proxy_call_sync (plugin->priv->proxy,
-                                        "GetPackageHistory",
-                                        g_variant_new ("(^asu)", package_names, 0),
-                                        G_DBUS_CALL_FLAGS_NONE,
-                                        200, /* 200ms should be more than enough... */
-                                        cancellable,
-                                        &error_local);
+       result = g_dbus_connection_call_sync (plugin->priv->connection,
+                                             "org.freedesktop.PackageKit",
+                                             "/org/freedesktop/PackageKit",
+                                             "org.freedesktop.PackageKit",
+                                             "GetPackageHistory",
+                                             g_variant_new ("(^asu)", package_names, 0),
+                                             NULL,
+                                             G_DBUS_CALL_FLAGS_NONE,
+                                             200, /* 200ms should be more than enough... */
+                                             cancellable,
+                                             &error_local);
        if (result == NULL) {
                if (g_error_matches (error_local,
                                     G_DBUS_ERROR,