[json-glib] object: Use a GQueue for members_ordered

[Garrett Regier <gregier src gnome org>]

commit 7b3c405df41c0b6f6fe58fdb05c922614f08c4c4
Author: Garrett Regier <garrettregier gmail com>
Date:   Thu Oct 20 19:42:56 2016 -0700

    object: Use a GQueue for members_ordered
    
    This makes the list always ordered
    and removes the g_list_reverse()
    in json_object_get_members().
    
    https://bugzilla.gnome.org/show_bug.cgi?id=773504

 json-glib/json-object.c        |   27 ++++++++++-----------------
 json-glib/json-types-private.h |    3 +--
 2 files changed, 11 insertions(+), 19 deletions(-)
---
diff --git a/json-glib/json-object.c b/json-glib/json-object.c
index be458ed..b6c08a5 100644
--- a/json-glib/json-object.c
+++ b/json-glib/json-object.c
@@ -67,7 +67,7 @@ json_object_new (void)
   object->members = g_hash_table_new_full (g_str_hash, g_str_equal,
                                            g_free,
                                            (GDestroyNotify) json_node_unref);
-  object->members_ordered = NULL;
+  g_queue_init (&object->members_ordered);
 
   return object;
 }
@@ -108,9 +108,8 @@ json_object_unref (JsonObject *object)
 
   if (--object->ref_count == 0)
     {
-      g_list_free (object->members_ordered);
+      g_queue_clear (&object->members_ordered);
       g_hash_table_destroy (object->members);
-      object->members_ordered = NULL;
       object->members = NULL;
 
       g_slice_free (JsonObject, object);
@@ -177,7 +176,7 @@ object_set_member_internal (JsonObject  *object,
   gchar *name = g_strdup (member_name);
 
   if (g_hash_table_lookup (object->members, name) == NULL)
-    object->members_ordered = g_list_prepend (object->members_ordered, name);
+    g_queue_push_tail (&object->members_ordered, name);
   else
     {
       GList *l;
@@ -186,7 +185,7 @@ object_set_member_internal (JsonObject  *object,
        * pointer to its name, to avoid keeping invalid pointers
        * once we replace the key in the hash table
        */
-      l = g_list_find_custom (object->members_ordered, name, (GCompareFunc) strcmp);
+      l = g_queue_find_custom (&object->members_ordered, name, (GCompareFunc) strcmp);
       if (l != NULL)
         l->data = name;
     }
@@ -483,13 +482,9 @@ json_object_set_object_member (JsonObject  *object,
 GList *
 json_object_get_members (JsonObject *object)
 {
-  GList *copy;
-
   g_return_val_if_fail (object != NULL, NULL);
 
-  copy = g_list_copy (object->members_ordered);
-
-  return g_list_reverse (copy);
+  return g_list_copy (object->members_ordered.head);
 }
 
 /**
@@ -512,7 +507,7 @@ json_object_get_values (JsonObject *object)
   g_return_val_if_fail (object != NULL, NULL);
 
   values = NULL;
-  for (l = object->members_ordered; l != NULL; l = l->next)
+  for (l = object->members_ordered.tail; l != NULL; l = l->prev)
     values = g_list_prepend (values, g_hash_table_lookup (object->members, l->data));
 
   return values;
@@ -855,13 +850,13 @@ json_object_remove_member (JsonObject  *object,
   g_return_if_fail (object != NULL);
   g_return_if_fail (member_name != NULL);
 
-  for (l = object->members_ordered; l != NULL; l = l->next)
+  for (l = object->members_ordered.head; l != NULL; l = l->next)
     {
       const gchar *name = l->data;
 
       if (g_strcmp0 (name, member_name) == 0)
         {
-          object->members_ordered = g_list_delete_link (object->members_ordered, l);
+          g_queue_delete_link (&object->members_ordered, l);
           break;
         }
     }
@@ -889,14 +884,12 @@ json_object_foreach_member (JsonObject        *object,
                             JsonObjectForeach  func,
                             gpointer           data)
 {
-  GList *members, *l;
+  GList *l;
 
   g_return_if_fail (object != NULL);
   g_return_if_fail (func != NULL);
 
-  /* the list is stored in reverse order to have constant time additions */
-  members = g_list_last (object->members_ordered);
-  for (l = members; l != NULL; l = l->prev)
+  for (l = object->members_ordered.head; l != NULL; l = l->next)
     {
       const gchar *member_name = l->data;
       JsonNode *member_node = g_hash_table_lookup (object->members, member_name);
diff --git a/json-glib/json-types-private.h b/json-glib/json-types-private.h
index db5dea6..fc7646b 100644
--- a/json-glib/json-types-private.h
+++ b/json-glib/json-types-private.h
@@ -102,8 +102,7 @@ struct _JsonObject
 {
   GHashTable *members;
 
-  /* the members of the object, ordered in reverse */
-  GList *members_ordered;
+  GQueue members_ordered;
 
   guint immutable_hash;  /* valid iff immutable */
   volatile gint ref_count;