[gnome-software] plugins: Add a cache to desktopdb to speed up each refine by 231ms per run

[Richard Hughes <rhughes src gnome org>]

commit 53f1097e50591420b144e273c3e9d07b7f980154
Author: Richard Hughes <richard hughsie com>
Date:   Thu Mar 7 11:21:22 2013 +0000

    plugins: Add a cache to desktopdb to speed up each refine by 231ms per run

 src/plugins/gs-plugin-desktopdb.c |   48 ++++++++++++++++++++++++------------
 1 files changed, 32 insertions(+), 16 deletions(-)
---
diff --git a/src/plugins/gs-plugin-desktopdb.c b/src/plugins/gs-plugin-desktopdb.c
index 662dd74..0431678 100644
--- a/src/plugins/gs-plugin-desktopdb.c
+++ b/src/plugins/gs-plugin-desktopdb.c
@@ -29,6 +29,7 @@
 struct GsPluginPrivate {
        PkDesktop               *desktop;
        gboolean                 loaded;
+       GHashTable              *cache;
 };
 
 /**
@@ -49,6 +50,10 @@ gs_plugin_initialize (GsPlugin *plugin)
        /* create private area */
        plugin->priv = GS_PLUGIN_GET_PRIVATE (GsPluginPrivate);
        plugin->priv->desktop = pk_desktop_new ();
+       plugin->priv->cache = g_hash_table_new_full (g_str_hash,
+                                                    g_str_equal,
+                                                    g_free,
+                                                    g_free);
 }
 
 /**
@@ -67,6 +72,7 @@ void
 gs_plugin_destroy (GsPlugin *plugin)
 {
        g_object_unref (plugin->priv->desktop);
+       g_hash_table_unref (plugin->priv->cache);
 }
 
 /**
@@ -81,23 +87,33 @@ gs_plugin_desktopdb_set_metadata (GsPlugin *plugin,
        GError *error = NULL;
        GPtrArray *files = NULL;
 
-       /* try to get the list of desktop files for this package */
-       files = pk_desktop_get_shown_for_package (plugin->priv->desktop,
-                                                 pkg_name,
-                                                 &error);
-       if (files == NULL) {
-               g_warning ("failed to get files for %s: %s",
-                          pkg_name, error->message);
-               g_error_free (error);
-               goto out;
-       }
-       if (files->len == 0) {
-               g_debug ("not an application %s", pkg_name);
-               goto out;
-       }
+       /* is in cache */
+       desktop_file = g_hash_table_lookup (plugin->priv->cache, pkg_name);
+       if (desktop_file == NULL) {
 
-       /* add just the first desktop file */
-       desktop_file = g_ptr_array_index (files, 0);
+               /* try to get the list of desktop files for this package */
+               files = pk_desktop_get_shown_for_package (plugin->priv->desktop,
+                                                         pkg_name,
+                                                         &error);
+               if (files == NULL) {
+                       g_warning ("failed to get files for %s: %s",
+                                  pkg_name, error->message);
+                       g_error_free (error);
+                       goto out;
+               }
+               if (files->len == 0) {
+                       g_debug ("not an application %s", pkg_name);
+                       goto out;
+               }
+
+               /* add just the first desktop file */
+               desktop_file = g_ptr_array_index (files, 0);
+
+               /* add to the cache */
+               g_hash_table_insert (plugin->priv->cache,
+                                    g_strdup (pkg_name),
+                                    g_strdup (desktop_file));
+       }
        gs_app_set_metadata (app,
                             "datadir-desktop-filename",
                             desktop_file);