[gnome-software] Only download the fwupd metadata signature once per day

[Richard Hughes <rhughes src gnome org>]

commit 31c8e81eb568220d703297a2e550c19e4c73afda
Author: Richard Hughes <richard hughsie com>
Date:   Mon Sep 28 13:44:06 2015 +0100

    Only download the fwupd metadata signature once per day
    
    With the new refresh code we could be downloading (albeit a very small file)
    up to 24 times per client per day.

 src/plugins/gs-plugin-fwupd.c |   37 +++++++++++++++++++++++++++++++++++++
 1 files changed, 37 insertions(+), 0 deletions(-)
---
diff --git a/src/plugins/gs-plugin-fwupd.c b/src/plugins/gs-plugin-fwupd.c
index e871ef6..d4629ac 100644
--- a/src/plugins/gs-plugin-fwupd.c
+++ b/src/plugins/gs-plugin-fwupd.c
@@ -615,6 +615,32 @@ gs_plugin_fwupd_update_lvfs_metadata (const gchar *data_fn, const gchar *sig_fn,
 }
 
 /**
+ * gs_plugin_fwupd_get_file_cache_age:
+ */
+static guint
+gs_plugin_fwupd_get_file_cache_age (const gchar *fn)
+{
+       guint64 now;
+       guint64 mtime;
+       g_autoptr(GFile) file = NULL;
+       g_autoptr(GFileInfo) info = NULL;
+
+       file = g_file_new_for_path (fn);
+       info = g_file_query_info (file,
+                                 G_FILE_ATTRIBUTE_TIME_MODIFIED,
+                                 G_FILE_QUERY_INFO_NONE,
+                                 NULL,
+                                 NULL);
+       if (info == NULL)
+               return G_MAXUINT;
+       mtime = g_file_info_get_attribute_uint64 (info, G_FILE_ATTRIBUTE_TIME_MODIFIED);
+       now = (guint64) g_get_real_time () / G_USEC_PER_SEC;
+       if (mtime > now)
+               return G_MAXUINT;
+       return now - mtime;
+}
+
+/**
  * gs_plugin_fwupd_check_lvfs_metadata:
  */
 static gboolean
@@ -645,6 +671,17 @@ gs_plugin_fwupd_check_lvfs_metadata (GsPlugin *plugin,
        if (!g_key_file_load_from_file (config, config_fn, G_KEY_FILE_NONE, error))
                return FALSE;
 
+       /* check cache age */
+       if (cache_age > 0) {
+               guint tmp;
+               tmp = gs_plugin_fwupd_get_file_cache_age (plugin->priv->lvfs_sig_fn);
+               if (tmp < cache_age) {
+                       g_debug ("%s is only %i seconds old, so ignoring refresh",
+                                plugin->priv->lvfs_sig_fn, tmp);
+                       return TRUE;
+               }
+       }
+
        /* download the signature */
        url_data = g_key_file_get_string (config, "fwupd", "DownloadURI", error);
        if (url_data == NULL)