[gnome-software/gnome-3-22] snap: Cancel snapd transaction when install/remove cancelled

[Robert Ancell <rancell src gnome org>]

commit 403099f8133e861cbed76c46c53b7c352925889c
Author: Robert Ancell <robert ancell canonical com>
Date:   Fri Oct 27 14:29:29 2017 +1300

    snap: Cancel snapd transaction when install/remove cancelled

 src/plugins/gs-snapd.c |  110 ++++++++++++++++++++++++++++++++++++------------
 1 files changed, 83 insertions(+), 27 deletions(-)
---
diff --git a/src/plugins/gs-snapd.c b/src/plugins/gs-snapd.c
index 85ce282..6fa8235 100644
--- a/src/plugins/gs-snapd.c
+++ b/src/plugins/gs-snapd.c
@@ -570,9 +570,9 @@ gs_snapd_get_interfaces (const gchar *macaroon, gchar **discharges, GCancellable
 }
 
 static JsonObject *
-get_changes (const gchar *macaroon, gchar **discharges,
-            const gchar *change_id,
-            GCancellable *cancellable, GError **error)
+get_change (const gchar *macaroon, gchar **discharges,
+           const gchar *change_id,
+           GCancellable *cancellable, GError **error)
 {
        g_autofree gchar *path = NULL;
        guint status_code;
@@ -615,6 +615,52 @@ get_changes (const gchar *macaroon, gchar **discharges,
        return json_object_ref (result);
 }
 
+static JsonObject *
+abort_change (const gchar *macaroon, gchar **discharges,
+             const gchar *change_id,
+             GCancellable *cancellable, GError **error)
+{
+       g_autofree gchar *path = NULL;
+       guint status_code;
+       g_autofree gchar *reason_phrase = NULL;
+       g_autofree gchar *response_type = NULL;
+       g_autofree gchar *response = NULL;
+       g_autoptr(JsonParser) parser = NULL;
+       JsonObject *root, *result;
+
+       path = g_strdup_printf ("/v2/changes/%s", change_id);
+       if (!send_request ("POST", path, "{\"action\": \"abort\"}",
+                          macaroon, discharges,
+                          &status_code, &reason_phrase,
+                          &response_type, &response, NULL,
+                          cancellable, error))
+               return NULL;
+
+       if (status_code != SOUP_STATUS_OK) {
+               g_set_error (error,
+                            GS_PLUGIN_ERROR,
+                            GS_PLUGIN_ERROR_FAILED,
+                            "snapd returned status code %u: %s",
+                            status_code, reason_phrase);
+               return NULL;
+       }
+
+       parser = parse_result (response, response_type, error);
+       if (parser == NULL)
+               return NULL;
+       root = json_node_get_object (json_parser_get_root (parser));
+       result = json_object_get_object_member (root, "result");
+       if (result == NULL) {
+               g_set_error (error,
+                            GS_PLUGIN_ERROR,
+                            GS_PLUGIN_ERROR_FAILED,
+                            "snapd returned no result");
+               return NULL;
+       }
+
+       return json_object_ref (result);
+}
+
 static gboolean
 send_package_action (const gchar *macaroon,
                     gchar **discharges,
@@ -632,8 +678,10 @@ send_package_action (const gchar *macaroon,
        g_autofree gchar *response = NULL;
        g_autofree gchar *status = NULL;
        g_autoptr(JsonParser) parser = NULL;
-       JsonObject *root, *result;
+       JsonObject *root;
        const gchar *type;
+       const gchar *change_id;
+       gboolean aborted = FALSE;
 
        content = g_strdup_printf ("{\"action\": \"%s\"}", action);
        path = g_strdup_printf ("/v2/snaps/%s", name);
@@ -641,7 +689,7 @@ send_package_action (const gchar *macaroon,
                           macaroon, discharges,
                           &status_code, &reason_phrase,
                           &response_type, &response, NULL,
-                          cancellable, error))
+                          NULL, error))
                return FALSE;
 
        if (status_code == SOUP_STATUS_UNAUTHORIZED) {
@@ -667,38 +715,46 @@ send_package_action (const gchar *macaroon,
 
        root = json_node_get_object (json_parser_get_root (parser));
        type = json_object_get_string_member (root, "type");
+       if (g_strcmp0 (type, "async") != 0) {
+               g_set_error (error,
+                            GS_PLUGIN_ERROR,
+                            GS_PLUGIN_ERROR_NOT_SUPPORTED,
+                            "snapd operation returned unexpected type '%s'", type);
+               return FALSE;
+       }
+       change_id = json_object_get_string_member (root, "change");
 
-       if (g_strcmp0 (type, "async") == 0) {
-               const gchar *change_id;
-
-               change_id = json_object_get_string_member (root, "change");
+       while (TRUE) {
+               g_autoptr(JsonObject) result = NULL;
 
-               while (TRUE) {
+               if (g_cancellable_is_cancelled (cancellable) && !aborted) {
+                       result = abort_change (macaroon, discharges, change_id, NULL, error);
+                       aborted = TRUE;
+               }
+               else {
                        /* Wait for a little bit before polling */
                        g_usleep (100 * 1000);
+                       result = get_change (macaroon, discharges, change_id, NULL, error);
+               }
+               if (result == NULL)
+                       return FALSE;
 
-                       result = get_changes (macaroon, discharges, change_id, cancellable, error);
-                       if (result == NULL)
-                               return FALSE;
-
-                       status = g_strdup (json_object_get_string_member (result, "status"));
+               callback (result, user_data);
 
-                       if (g_strcmp0 (status, "Done") == 0)
-                               break;
+               if (!json_object_get_boolean_member (result, "ready"))
+                       continue;
 
-                       callback (result, user_data);
+               if (json_object_has_member (result, "err")) {
+                       g_set_error (error,
+                                    GS_PLUGIN_ERROR,
+                                    GS_PLUGIN_ERROR_NOT_SUPPORTED,
+                                    "snapd operation finished with error: %s",
+                                    json_object_get_string_member (result, "err"));
+                       return FALSE;
                }
-       }
 
-       if (g_strcmp0 (status, "Done") != 0) {
-               g_set_error (error,
-                            GS_PLUGIN_ERROR,
-                            GS_PLUGIN_ERROR_NOT_SUPPORTED,
-                            "snapd operation finished with status %s", status);
-               return FALSE;
+               return TRUE;
        }
-
-       return TRUE;
 }
 
 gboolean