[gnome-software] gs-plugin-loader: Iterate over hash tables directly

[Richard Hughes <rhughes src gnome org>]

commit cfc3766ab770fe98be47128e6d31936310eb6854
Author: Philip Withnall <withnall endlessm com>
Date:   Thu Apr 2 10:32:26 2020 +0100

    gs-plugin-loader: Iterate over hash tables directly
    
    `g_hash_table_get_{keys,values}()` are quite inefficient: they have to
    iterate over the hash table and copy the keys/values into a newly
    allocated linked list, return that, and then the calling code has to
    iterate over that again.
    
    Instead, use `GHashTableIter`, which does zero allocations and iterates
    directly in the calling code.
    
    This introduces no functional changes.
    
    Signed-off-by: Philip Withnall <withnall endlessm com>

 lib/gs-plugin-loader.c | 35 +++++++++++++++++++----------------
 1 file changed, 19 insertions(+), 16 deletions(-)
---
diff --git a/lib/gs-plugin-loader.c b/lib/gs-plugin-loader.c
index f0e124cb..59c3d3e6 100644
--- a/lib/gs-plugin-loader.c
+++ b/lib/gs-plugin-loader.c
@@ -1823,16 +1823,17 @@ gboolean
 gs_plugin_loader_get_allow_updates (GsPluginLoader *plugin_loader)
 {
        GsPluginLoaderPrivate *priv = gs_plugin_loader_get_instance_private (plugin_loader);
-       g_autoptr(GList) list = NULL;
+       GHashTableIter iter;
+       gpointer value;
 
        /* nothing */
        if (g_hash_table_size (priv->disallow_updates) == 0)
                return TRUE;
 
        /* list */
-       list = g_hash_table_get_values (priv->disallow_updates);
-       for (GList *l = list; l != NULL; l = l->next) {
-               const gchar *reason = l->data;
+       g_hash_table_iter_init (&iter, priv->disallow_updates);
+       while (g_hash_table_iter_next (&iter, NULL, &value)) {
+               const gchar *reason = value;
                g_debug ("managed updates inhibited by %s", reason);
        }
        return FALSE;
@@ -1880,16 +1881,17 @@ gs_plugin_loader_get_events (GsPluginLoader *plugin_loader)
 {
        GsPluginLoaderPrivate *priv = gs_plugin_loader_get_instance_private (plugin_loader);
        GPtrArray *events = g_ptr_array_new_with_free_func ((GDestroyNotify) g_object_unref);
-       g_autoptr(GList) keys = NULL;
        g_autoptr(GMutexLocker) locker = g_mutex_locker_new (&priv->events_by_id_mutex);
+       GHashTableIter iter;
+       gpointer key, value;
 
        /* just add everything */
-       keys = g_hash_table_get_keys (priv->events_by_id);
-       for (GList *l = keys; l != NULL; l = l->next) {
-               const gchar *key = l->data;
-               GsPluginEvent *event = g_hash_table_lookup (priv->events_by_id, key);
+       g_hash_table_iter_init (&iter, priv->events_by_id);
+       while (g_hash_table_iter_next (&iter, &key, &value)) {
+               const gchar *id = key;
+               GsPluginEvent *event = value;
                if (event == NULL) {
-                       g_warning ("failed to get event for '%s'", key);
+                       g_warning ("failed to get event for '%s'", id);
                        continue;
                }
                g_ptr_array_add (events, g_object_ref (event));
@@ -1910,16 +1912,17 @@ GsPluginEvent *
 gs_plugin_loader_get_event_default (GsPluginLoader *plugin_loader)
 {
        GsPluginLoaderPrivate *priv = gs_plugin_loader_get_instance_private (plugin_loader);
-       g_autoptr(GList) keys = NULL;
        g_autoptr(GMutexLocker) locker = g_mutex_locker_new (&priv->events_by_id_mutex);
+       GHashTableIter iter;
+       gpointer key, value;
 
        /* just add everything */
-       keys = g_hash_table_get_keys (priv->events_by_id);
-       for (GList *l = keys; l != NULL; l = l->next) {
-               const gchar *key = l->data;
-               GsPluginEvent *event = g_hash_table_lookup (priv->events_by_id, key);
+       g_hash_table_iter_init (&iter, priv->events_by_id);
+       while (g_hash_table_iter_next (&iter, &key, &value)) {
+               const gchar *id = key;
+               GsPluginEvent *event = value;
                if (event == NULL) {
-                       g_warning ("failed to get event for '%s'", key);
+                       g_warning ("failed to get event for '%s'", id);
                        continue;
                }
                if (!gs_plugin_event_has_flag (event, GS_PLUGIN_EVENT_FLAG_INVALID))