[gnome-software] plugins: Add a GKeyFile cache to datadir-apps to speed up each refine by 308ms per run

[Richard Hughes <rhughes src gnome org>]

commit d95d7da8c0baf49590b0994c7dd0e56d40d1b56d
Author: Richard Hughes <richard hughsie com>
Date:   Thu Mar 7 11:30:44 2013 +0000

    plugins: Add a GKeyFile cache to datadir-apps to speed up each refine by 308ms per run

 src/plugins/gs-plugin-datadir-apps.c |   60 ++++++++++++++++++++++++++++-----
 1 files changed, 51 insertions(+), 9 deletions(-)
---
diff --git a/src/plugins/gs-plugin-datadir-apps.c b/src/plugins/gs-plugin-datadir-apps.c
index 8d1fdc0..2af6c85 100644
--- a/src/plugins/gs-plugin-datadir-apps.c
+++ b/src/plugins/gs-plugin-datadir-apps.c
@@ -23,6 +23,10 @@
 
 #include <gs-plugin.h>
 
+struct GsPluginPrivate {
+       GHashTable              *cache;
+};
+
 /**
  * gs_plugin_get_name:
  */
@@ -33,6 +37,20 @@ gs_plugin_get_name (void)
 }
 
 /**
+ * gs_plugin_initialize:
+ */
+void
+gs_plugin_initialize (GsPlugin *plugin)
+{
+       /* create private area */
+       plugin->priv = GS_PLUGIN_GET_PRIVATE (GsPluginPrivate);
+       plugin->priv->cache = g_hash_table_new_full (g_str_hash,
+                                                    g_str_equal,
+                                                    g_free,
+                                                    (GDestroyNotify) g_key_file_unref);
+}
+
+/**
  * gs_plugin_get_priority:
  */
 gdouble
@@ -42,6 +60,15 @@ gs_plugin_get_priority (GsPlugin *plugin)
 }
 
 /**
+ * gs_plugin_destroy:
+ */
+void
+gs_plugin_destroy (GsPlugin *plugin)
+{
+       g_hash_table_unref (plugin->priv->cache);
+}
+
+/**
  * gs_plugin_datadir_apps_extract_desktop_data:
  */
 static gboolean
@@ -51,7 +78,8 @@ gs_plugin_datadir_apps_extract_desktop_data (GsPlugin *plugin,
                                             GError **error)
 {
        const gchar *basename_tmp = NULL;
-       gboolean ret;
+       gboolean ret = TRUE;
+       gboolean in_cache = FALSE;
        gchar *basename = NULL;
        gchar *comment = NULL;
        gchar *name = NULL;
@@ -59,14 +87,21 @@ gs_plugin_datadir_apps_extract_desktop_data (GsPlugin *plugin,
        GKeyFile *key_file;
        GdkPixbuf *pixbuf = NULL;
 
-       /* load desktop file */
-       key_file = g_key_file_new ();
-       ret = g_key_file_load_from_file (key_file,
-                                        desktop_file,
-                                        G_KEY_FILE_NONE,
-                                        error);
-       if (!ret)
-               goto out;
+       /* is in cache */
+       key_file = g_hash_table_lookup (plugin->priv->cache, desktop_file);
+       if (key_file != NULL) {
+               g_key_file_ref (key_file);
+               in_cache = TRUE;
+       } else {
+               /* load desktop file */
+               key_file = g_key_file_new ();
+               ret = g_key_file_load_from_file (key_file,
+                                                desktop_file,
+                                                G_KEY_FILE_NONE,
+                                                error);
+               if (!ret)
+                       goto out;
+       }
 
        /* get desktop name */
        name = g_key_file_get_string (key_file,
@@ -121,6 +156,13 @@ gs_plugin_datadir_apps_extract_desktop_data (GsPlugin *plugin,
 
        /* mark as an application */
        gs_app_set_kind (app, GS_APP_KIND_NORMAL);
+
+       /* add to cache */
+       if (!in_cache) {
+               g_hash_table_insert (plugin->priv->cache,
+                                    g_strdup (desktop_file),
+                                    g_key_file_ref (key_file));
+       }
 out:
        g_key_file_unref (key_file);
        if (pixbuf != NULL)