[gnome-online-accounts/wip/rishi/kerberos-task-data-2: 2/2] kerberos: Use GTask's task data slot to leverage the compiler

[Debarshi Ray <debarshir src gnome org>]

commit cbb08f411d9b6e0fafc1d19ebc83ee7efe6fd912
Author: Debarshi Ray <debarshir gnome org>
Date:   Tue Aug 13 21:38:42 2019 +0200

    kerberos: Use GTask's task data slot to leverage the compiler
    
    GObject's arbitrary named key to data mapping is prone to programmer
    errors that cannot be caught by the compiler while building. eg., a
    typo in the name of a key will only be detected at run-time.

 src/goabackend/goakerberosprovider.c | 65 +++++++++++++++++++++++++-----------
 1 file changed, 46 insertions(+), 19 deletions(-)
---
diff --git a/src/goabackend/goakerberosprovider.c b/src/goabackend/goakerberosprovider.c
index 4f572f5a..53f8311f 100644
--- a/src/goabackend/goakerberosprovider.c
+++ b/src/goabackend/goakerberosprovider.c
@@ -146,6 +146,38 @@ translate_error (GError **error)
   g_dbus_error_strip_remote_error (*error);
 }
 
+/* ---------------------------------------------------------------------------------------------------- */
+
+typedef struct
+{
+  gchar *identifier;
+  gchar *password;
+  gchar *preauth_source;
+} SignInIdentityData;
+
+static SignInIdentityData *
+sign_in_identity_data_new (const gchar *identifier, const gchar *password, const gchar *preauth_source)
+{
+  SignInIdentityData *data;
+
+  data = g_slice_new0 (SignInIdentityData);
+  data->identifier = g_strdup (identifier);
+  data->password = g_strdup (password);
+  data->preauth_source = g_strdup (preauth_source);
+
+  return data;
+}
+
+static void
+sign_in_identity_data_free (SignInIdentityData *data)
+{
+  g_free (data->identifier);
+  g_free (data->password);
+  g_free (data->preauth_source);
+
+  g_slice_free (SignInIdentityData, data);
+}
+
 static void
 sign_in_identity (GoaKerberosProvider  *self,
                   const char           *identifier,
@@ -156,18 +188,12 @@ sign_in_identity (GoaKerberosProvider  *self,
                   gpointer              user_data)
 {
   GTask *task;
+  SignInIdentityData *data = NULL;
+
+  data = sign_in_identity_data_new (identifier, password, preauth_source);
 
   task = g_task_new (self, cancellable, callback, user_data);
-  g_task_set_source_tag (task, (gpointer) identifier);
-
-  g_object_set_data (G_OBJECT (task),
-                     "password",
-                     (gpointer)
-                     password);
-  g_object_set_data_full (G_OBJECT (task),
-                          "preauthentication-source",
-                          g_strdup (preauth_source),
-                          g_free);
+  g_task_set_task_data (task, data, (GDestroyNotify) sign_in_identity_data_free);
   g_task_run_in_thread (task, (GTaskThreadFunc) sign_in_thread);
 
   g_object_unref (task);
@@ -189,6 +215,8 @@ sign_in_identity_finish (GoaKerberosProvider  *self,
   return g_task_propagate_pointer (task, error);
 }
 
+/* ---------------------------------------------------------------------------------------------------- */
+
 static gboolean
 get_ticket_sync (GoaKerberosProvider *self,
                  GoaObject           *object,
@@ -1383,21 +1411,20 @@ sign_in_identity_sync (GoaKerberosProvider  *self,
 static void
 sign_in_thread (GTask               *task,
                 GoaKerberosProvider *self,
-                gpointer             task_data G_GNUC_UNUSED,
+                gpointer             task_data,
                 GCancellable        *cancellable)
 {
-  const char *identifier;
-  const char *password;
-  const char *preauth_source;
+  SignInIdentityData *data = (SignInIdentityData *) task_data;
   char *object_path;
   GError *error;
 
-  identifier = g_task_get_source_tag (task);
-  password = g_object_get_data (G_OBJECT (task), "password");
-  preauth_source = g_object_get_data (G_OBJECT (task), "preauth-source");
-
   error = NULL;
-  object_path = sign_in_identity_sync (self, identifier, password, preauth_source, cancellable, &error);
+  object_path = sign_in_identity_sync (self,
+                                       data->identifier,
+                                       data->password,
+                                       data->preauth_source,
+                                       cancellable,
+                                       &error);
   if (object_path == NULL)
     g_task_return_error (task, error);
   else