[glib] rework GMenuProxy links

[Ryan Lortie <ryanl src gnome org>]

commit 7a0faf66fe41649def3753eda09149883991da60
Author: Ryan Lortie <desrt desrt ca>
Date:   Mon Nov 28 11:45:20 2011 -0500

    rework GMenuProxy links
    
    Only resolve the link at the point that we pull it through the API
    rather than at the point that we first are told about it.  This reduces
    the lifespan of subscriptions and, more importantly, avoids a tricky
    reference cycle issue.

 gio/gmenuproxy.c |   72 ++++++++++++++++++++++++++++++-----------------------
 1 files changed, 41 insertions(+), 31 deletions(-)
---
diff --git a/gio/gmenuproxy.c b/gio/gmenuproxy.c
index 4eb0dbb..add5d86 100644
--- a/gio/gmenuproxy.c
+++ b/gio/gmenuproxy.c
@@ -128,9 +128,10 @@
  * proxy is inactive, the change signal is ignored.
  *
  * GMenuProxyItem is just a pair of hashtables, one for the attributes
- * and one for the links of the item (mapping strings to
- * other GMenuProxy instances). XXX reconsider this since it means the
- * submenu proxies stay around forever.....
+ * and one for the links of the item.  Both map strings to GVariant
+ * instances.  In the case of links, the GVariant has type '(uu)' and is
+ * turned into a GMenuProxy at the point that the user pulls it through
+ * the API.
  *
  * Following the "empty is the same as non-existent" rule, the hashtable
  * of GSequence of GMenuProxyItem holds NULL for empty menus.
@@ -393,8 +394,7 @@ g_menu_proxy_item_free (gpointer data)
 }
 
 static GMenuProxyItem *
-g_menu_proxy_group_create_item (GMenuProxyGroup *context,
-                                GVariant        *description)
+g_menu_proxy_group_create_item (GVariant *description)
 {
   GMenuProxyItem *item;
   GVariantIter iter;
@@ -403,34 +403,13 @@ g_menu_proxy_group_create_item (GMenuProxyGroup *context,
 
   item = g_slice_new (GMenuProxyItem);
   item->attributes = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, (GDestroyNotify) g_variant_unref);
-  item->links = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, (GDestroyNotify) g_object_unref);
+  item->links = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, (GDestroyNotify) g_variant_unref);
 
   g_variant_iter_init (&iter, description);
   while (g_variant_iter_loop (&iter, "{&sv}", &key, &value))
     if (key[0] == ':')
-      {
-        if (g_variant_is_of_type (value, G_VARIANT_TYPE ("(uu)")))
-          {
-            guint group_id, menu_id;
-            GMenuProxyGroup *group;
-            GMenuProxy *proxy;
-
-            g_variant_get (value, "(uu)", &group_id, &menu_id);
-
-            /* save the hash lookup in a relatively common case */
-            if (context->id != group_id)
-              group = g_menu_proxy_group_get_from_path (context->path, group_id);
-            else
-              group = g_menu_proxy_group_ref (context);
-
-            proxy = g_menu_proxy_get_from_group (group, menu_id);
-
-            /* key + 1 to skip the ':' */
-            g_hash_table_insert (item->links, g_strdup (key + 1), proxy);
-
-            g_menu_proxy_group_unref (group);
-          }
-      }
+      /* key + 1 to skip the ':' */
+      g_hash_table_insert (item->links, g_strdup (key + 1), g_variant_ref (value));
     else
       g_hash_table_insert (item->attributes, g_strdup (key), g_variant_ref (value));
 
@@ -629,7 +608,7 @@ g_menu_proxy_group_changed (GMenuProxyGroup *group,
 
   n_added = g_variant_iter_init (&iter, added);
   while (g_variant_iter_loop (&iter, "@a{sv}", &item))
-    g_sequence_insert_before (point, g_menu_proxy_group_create_item (group, item));
+    g_sequence_insert_before (point, g_menu_proxy_group_create_item (item));
 
   if (g_sequence_get_length (items) == 0)
     {
@@ -757,7 +736,38 @@ g_menu_proxy_get_item_links (GMenuModel  *model,
   item = g_sequence_get (iter);
   g_return_if_fail (item);
 
-  *table = g_hash_table_ref (item->links);
+  *table = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_object_unref);
+
+  {
+    GHashTableIter tmp;
+    gpointer key;
+    gpointer value;
+
+    g_hash_table_iter_init (&tmp, item->links);
+    while (g_hash_table_iter_next (&tmp, &key, &value))
+      {
+        if (g_variant_is_of_type (value, G_VARIANT_TYPE ("(uu)")))
+          {
+            guint group_id, menu_id;
+            GMenuProxyGroup *group;
+            GMenuProxy *link;
+
+            g_variant_get (value, "(uu)", &group_id, &menu_id);
+
+            /* save the hash lookup in a relatively common case */
+            if (proxy->group->id != group_id)
+              group = g_menu_proxy_group_get_from_path (proxy->group->path, group_id);
+            else
+              group = g_menu_proxy_group_ref (proxy->group);
+
+            link = g_menu_proxy_get_from_group (group, menu_id);
+
+            g_hash_table_insert (*table, g_strdup (key), link);
+
+            g_menu_proxy_group_unref (group);
+          }
+      }
+  }
 }
 
 static void