Iterate user table in a sorted way, fix tests with latest glib

This is primarily to help test cases which assume that the adopted algorithm
prioritizes the users in the exact reverse order they appear in the test
cases (and get inserted into the session in reverse order). With older glib
version, the five users being inserted happened to return the order expected by
the tests. With latest glib, due to a minor tweak in hashing strategy, the
insertion leads to unsorted list leading to failed tests.

In addition, GHashTable makes no guarantees about the stability of items when
iterating multiple times. Since the algorithm is sensitive to order of users, it
is best to return users in an order that is consistent over multiple calls and
stable over insert/remove operations.

This patch maintains a sorted list of user ids and uses it for iteration.

Closes: #22.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>

libinfinity/common/inf-user-table.c

@@ -36,15 +36,11 @@
  * users within the session.
  */
 
-typedef struct _InfUserTableForeachUserData InfUserTableForeachUserData;
-struct _InfUserTableForeachUserData {
-  InfUserTableForeachUserFunc func;
-  gpointer user_data;
-};
-
 typedef struct _InfUserTablePrivate InfUserTablePrivate;
 struct _InfUserTablePrivate {
   GHashTable* table;
+  /* To be able to iterate users in sorted order */
+  GSList* user_ids;
   /* TODO: It would be smarter to map the hash table to a helper struct
    * which stores the user availability, locality and the InfUser object */
   GSList* availables;
@@ -179,15 +175,11 @@ inf_user_table_lookup_user_by_name_func(gpointer key,
   return FALSE;
 }
 
-static void
-inf_user_table_foreach_user_func(gpointer key,
-                                 gpointer value,
-                                 gpointer user_data)
+static gint
+inf_user_ids_list_sort_compare_func(gconstpointer a,
+                                    gconstpointer b)
 {
-  InfUserTableForeachUserData* data;
-  data = (InfUserTableForeachUserData*)user_data;
-
-  data->func(INF_USER(value), data->user_data);
+  return GPOINTER_TO_UINT(a) - GPOINTER_TO_UINT(b);
 }
 
 static void
@@ -197,6 +189,7 @@ inf_user_table_init(InfUserTable* user_table)
   priv = INF_USER_TABLE_PRIVATE(user_table);
 
   priv->table = g_hash_table_new_full(NULL, NULL, NULL, NULL);
+  priv->user_ids = NULL;
   priv->availables = NULL;
   priv->locals = NULL;
 }
@@ -216,6 +209,9 @@ inf_user_table_dispose(GObject* object)
   g_slist_free(priv->availables);
   priv->availables = NULL;
 
+  g_slist_free(priv->user_ids);
+  priv->user_ids = NULL;
+
   g_hash_table_foreach(
     priv->table,
     inf_user_table_dispose_foreach_func,
@@ -256,6 +252,12 @@ inf_user_table_add_user_handler(InfUserTable* user_table,
   g_hash_table_insert(priv->table, GUINT_TO_POINTER(id), user);
   g_object_ref(user);
 
+  priv->user_ids = g_slist_insert_sorted(
+    priv->user_ids,
+    GUINT_TO_POINTER(id),
+    inf_user_ids_list_sort_compare_func
+  );
+
   g_signal_connect(
     G_OBJECT(user),
     "notify::status",
@@ -314,6 +316,8 @@ inf_user_table_remove_user_handler(InfUserTable* user_table,
     );
   }
 
+  priv->user_ids = g_slist_remove(priv->user_ids, GUINT_TO_POINTER(id));
+
   inf_user_table_unref_user(user_table, user);
   g_assert(g_hash_table_lookup(priv->table, GUINT_TO_POINTER(id)) == user);
   g_hash_table_remove(priv->table, GUINT_TO_POINTER(id));
@@ -646,21 +650,22 @@ inf_user_table_foreach_user(InfUserTable* user_table,
                             gpointer user_data)
 {
   InfUserTablePrivate* priv;
-  InfUserTableForeachUserData data;
+  InfUser* user;
+  GSList* item;
+
+  guint user_id;
 
   g_return_if_fail(INF_IS_USER_TABLE(user_table));
   g_return_if_fail(func != NULL);
 
   priv = INF_USER_TABLE_PRIVATE(user_table);
 
-  data.func = func;
-  data.user_data = user_data;
-
-  g_hash_table_foreach(
-    priv->table,
-    inf_user_table_foreach_user_func,
-    &data
-  );
+  for(item = priv->user_ids; item != NULL; item = g_slist_next(item))
+  {
+    user_id = GPOINTER_TO_UINT(item->data);
+    user = inf_user_table_lookup_user_by_id(user_table, user_id);
+    func(user, user_data);
+  }
 }
 
 /**