[gnome-software] Call gs_plugin_reload() if more than 10 apps change

[Richard Hughes <rhughes src gnome org>]

commit 359b296c3ab152d021887e188ebe3c00ccf219c2
Author: Richard Hughes <richard hughsie com>
Date:   Sat Jun 11 23:17:34 2016 +0100

    Call gs_plugin_reload() if more than 10 apps change
    
    We maintain a hash of applications to work out what was added and/or removed.
    This means we don't need to do an explicit reload every time the flatpak repos
    change in any way. We still need to update any GsApp's in the cache in future
    patches.

 src/plugins/gs-flatpak.c          |    2 -
 src/plugins/gs-plugin-appstream.c |   73 +++++++++++++++++++++++++++++++++++++
 2 files changed, 73 insertions(+), 2 deletions(-)
---
diff --git a/src/plugins/gs-flatpak.c b/src/plugins/gs-flatpak.c
index 269cf2c..d6bbc3d 100644
--- a/src/plugins/gs-flatpak.c
+++ b/src/plugins/gs-flatpak.c
@@ -205,8 +205,6 @@ gs_flatpak_refresh_appstream (GsFlatpak *self, guint cache_age,
                                                  cancellable,
                                                  error))
                        return FALSE;
-               /* FIXME: we don't want to do this; rely on AppStream */
-               gs_plugin_reload (self->plugin);
        }
 
        return TRUE;
diff --git a/src/plugins/gs-plugin-appstream.c b/src/plugins/gs-plugin-appstream.c
index e226a9b..be50e1a 100644
--- a/src/plugins/gs-plugin-appstream.c
+++ b/src/plugins/gs-plugin-appstream.c
@@ -38,13 +38,82 @@
 
 struct GsPluginData {
        AsStore                 *store;
+       GHashTable              *app_hash_old;
 };
 
+#define GS_PLUGIN_NUMBER_CHANGED_RELOAD        10
+
+static GHashTable *
+gs_plugin_appstream_create_app_hash (AsStore *store)
+{
+       GHashTable *hash;
+       GPtrArray *apps;
+       guint i;
+
+       hash = g_hash_table_new_full (g_str_hash, g_str_equal,
+                                     g_free, (GDestroyNotify) g_object_unref);
+       apps = as_store_get_apps (store);
+       for (i = 0; i < apps->len; i++) {
+               AsApp *app = g_ptr_array_index (apps, i);
+               gchar *key = g_strdup (as_app_get_id (app));
+               g_hash_table_insert (hash, key, g_object_ref (app));
+       }
+       return hash;
+}
+
+static void
+gs_plugin_detect_reload_apps (GsPlugin *plugin)
+{
+       GsPluginData *priv = gs_plugin_get_data (plugin);
+       AsApp *item;
+       GList *l;
+       guint cnt = 0;
+       g_autoptr(GHashTable) app_hash = NULL;
+       g_autoptr(GList) keys = NULL;
+       g_autoptr(GList) keys_old = NULL;
+
+       /* find packages that have been added */
+       app_hash = gs_plugin_appstream_create_app_hash (priv->store);
+       keys = g_hash_table_get_keys (app_hash);
+       for (l = keys; l != NULL; l = l->next) {
+               const gchar *key = l->data;
+               item = g_hash_table_lookup (priv->app_hash_old, key);
+               if (item == NULL)
+                       cnt++;
+       }
+
+       /* find packages that have been removed */
+       keys_old = g_hash_table_get_keys (priv->app_hash_old);
+       for (l = keys_old; l != NULL; l = l->next) {
+               const gchar *key = l->data;
+               item = g_hash_table_lookup (app_hash, key);
+               if (item == NULL)
+                       cnt++;
+       }
+
+       /* replace if any changes */
+       if (cnt > 0) {
+               if (priv->app_hash_old != NULL)
+                       g_hash_table_unref (priv->app_hash_old);
+               priv->app_hash_old = g_hash_table_ref (app_hash);
+       }
+
+       /* invalidate all if a large number of apps changed */
+       if (cnt > GS_PLUGIN_NUMBER_CHANGED_RELOAD) {
+               g_debug ("%i is more than %i AsApps changed",
+                        cnt, GS_PLUGIN_NUMBER_CHANGED_RELOAD);
+               gs_plugin_reload (plugin);
+       }
+}
+
 static void
 gs_plugin_appstream_store_changed_cb (AsStore *store, GsPlugin *plugin)
 {
        g_debug ("AppStream metadata changed");
 
+       /* send ::reload-apps */
+       gs_plugin_detect_reload_apps (plugin);
+
        /* all the UI is reloaded as something external has happened */
        if (!gs_plugin_has_flags (plugin, GS_PLUGIN_FLAGS_RUNNING_OTHER))
                gs_plugin_reload (plugin);
@@ -67,6 +136,7 @@ void
 gs_plugin_destroy (GsPlugin *plugin)
 {
        GsPluginData *priv = gs_plugin_get_data (plugin);
+       g_hash_table_unref (priv->app_hash_old);
        g_object_unref (priv->store);
 }
 
@@ -168,6 +238,9 @@ gs_plugin_setup (GsPlugin *plugin, GCancellable *cancellable, GError **error)
                return FALSE;
        }
 
+       /* prime the cache */
+       priv->app_hash_old = gs_plugin_appstream_create_app_hash (priv->store);
+
        /* watch for changes */
        g_signal_connect (priv->store, "changed",
                          G_CALLBACK (gs_plugin_appstream_store_changed_cb),