[gnome-software] Allow AppStream to be downloaded out-of-band per-user

[Richard Hughes <rhughes src gnome org>]

commit 95742e774ec2285b3e2755a0aff46c5929480833
Author: Richard Hughes <richard hughsie com>
Date:   Tue May 2 09:51:13 2017 +0100

    Allow AppStream to be downloaded out-of-band per-user

 data/org.gnome.software.gschema.xml                |    4 +
 plugins/core/gs-plugin-appstream.c                 |   81 ++++++++++++++++++++
 .../gs-plugin-external-appstream.c                 |    7 ++
 3 files changed, 92 insertions(+), 0 deletions(-)
---
diff --git a/data/org.gnome.software.gschema.xml b/data/org.gnome.software.gschema.xml
index bf57f99..81808b0 100644
--- a/data/org.gnome.software.gschema.xml
+++ b/data/org.gnome.software.gschema.xml
@@ -138,5 +138,9 @@
       <default>[]</default>
       <summary>A list of URLs pointing to appstream files that will be downloaded into an app-info 
folder</summary>
     </key>
+    <key name="external-appstream-system-wide" type="b">
+      <default>false</default>
+      <summary>Install the AppStream files to a system-wide location for all users</summary>
+    </key>
   </schema>
 </schemalist>
diff --git a/plugins/core/gs-plugin-appstream.c b/plugins/core/gs-plugin-appstream.c
index 40afaea..14f2865 100644
--- a/plugins/core/gs-plugin-appstream.c
+++ b/plugins/core/gs-plugin-appstream.c
@@ -40,6 +40,7 @@ struct GsPluginData {
        AsStore                 *store;
        GHashTable              *app_hash_old;
        guint                    store_changed_id;
+       GSettings               *settings;
 };
 
 #define GS_PLUGIN_NUMBER_CHANGED_RELOAD        10
@@ -181,6 +182,9 @@ gs_plugin_initialize (GsPlugin *plugin)
 
        /* need package name */
        gs_plugin_add_rule (plugin, GS_PLUGIN_RULE_RUN_AFTER, "dpkg");
+
+       /* require settings */
+       priv->settings = g_settings_new ("org.gnome.software");
 }
 
 void
@@ -192,6 +196,7 @@ gs_plugin_destroy (GsPlugin *plugin)
        if (priv->app_hash_old != NULL)
                g_hash_table_unref (priv->app_hash_old);
        g_object_unref (priv->store);
+       g_object_unref (priv->settings);
 }
 
 /*
@@ -640,3 +645,79 @@ gs_plugin_add_featured (GsPlugin *plugin,
        return gs_appstream_add_featured (plugin, priv->store, list, cancellable,
                                          error);
 }
+
+static gboolean
+gs_plugin_appstream_refresh_url (GsPlugin *plugin,
+                                const gchar *url,
+                                guint cache_age,
+                                GCancellable *cancellable,
+                                GError **error)
+{
+       guint file_age;
+       g_autofree gchar *basename = NULL;
+       g_autofree gchar *fullpath = NULL;
+       g_autoptr(GFile) file = NULL;
+
+       /* check age */
+       basename = g_path_get_basename (url);
+       fullpath = g_build_filename (g_get_user_data_dir (),
+                                    "app-info",
+                                    "xmls",
+                                    basename,
+                                    NULL);
+       file = g_file_new_for_path (fullpath);
+       file_age = gs_utils_get_file_age (file);
+       if (file_age < cache_age) {
+               g_debug ("skipping %s: cache age is older than file", fullpath);
+               return TRUE;
+       }
+
+       /* download file */
+       return gs_plugin_download_file (plugin,
+                                       NULL, /* GsApp */
+                                       url,
+                                       fullpath,
+                                       cancellable,
+                                       error);
+}
+
+gboolean
+gs_plugin_refresh (GsPlugin *plugin,
+                  guint cache_age,
+                  GsPluginRefreshFlags flags,
+                  GCancellable *cancellable,
+                  GError **error)
+{
+       GsPluginData *priv = gs_plugin_get_data (plugin);
+       g_auto(GStrv) appstream_urls = NULL;
+
+       if ((flags & GS_PLUGIN_REFRESH_FLAGS_METADATA) == 0)
+               return TRUE;
+
+       /* check we want per-user */
+       if (g_settings_get_boolean (priv->settings,
+                                   "external-appstream-system-wide")) {
+               g_debug ("not per-user for external appstream");
+               return TRUE;
+       }
+       appstream_urls = g_settings_get_strv (priv->settings,
+                                             "external-appstream-urls");
+       for (guint i = 0; appstream_urls[i] != NULL; ++i) {
+               g_autoptr(GError) local_error = NULL;
+               if (!g_str_has_prefix (appstream_urls[i], "https")) {
+                       g_warning ("cannot use AppStream source %s: use https://";,
+                                  appstream_urls[i]);
+                       continue;
+               }
+               if (!gs_plugin_appstream_refresh_url (plugin,
+                                                     appstream_urls[i],
+                                                     cache_age,
+                                                     cancellable,
+                                                     &local_error)) {
+                       g_warning ("failed to update external AppStream file: %s",
+                                  local_error->message);
+               }
+       }
+
+       return TRUE;
+}
diff --git a/plugins/external-appstream/gs-plugin-external-appstream.c 
b/plugins/external-appstream/gs-plugin-external-appstream.c
index 658ea1a..55b2ebe 100644
--- a/plugins/external-appstream/gs-plugin-external-appstream.c
+++ b/plugins/external-appstream/gs-plugin-external-appstream.c
@@ -225,6 +225,13 @@ gs_plugin_refresh (GsPlugin *plugin,
        if ((flags & GS_PLUGIN_REFRESH_FLAGS_METADATA) == 0)
                return TRUE;
 
+       /* check we want system-wide */
+       if (!g_settings_get_boolean (priv->settings,
+                                    "external-appstream-system-wide")) {
+               g_debug ("not system-wide for external appstream");
+               return TRUE;
+       }
+
        appstream_urls = g_settings_get_strv (priv->settings,
                                              "external-appstream-urls");
        for (i = 0; appstream_urls[i] != NULL; ++i) {