[libsecret/wip/dueno/local-file: 6/8] storage: Add function to retrieve a singleton instance

[Daiki Ueno <dueno src gnome org>]

commit 4f6a4f7a367430558cf160f0e6c72777a647f0ae
Author: Daiki Ueno <dueno src gnome org>
Date:   Sun Sep 23 08:33:34 2018 +0200

    storage: Add function to retrieve a singleton instance

 libsecret/secret-storage.c | 109 +++++++++++++++++++++++++++++++++++++++++++++
 libsecret/secret-storage.h |   9 ++++
 2 files changed, 118 insertions(+)
---
diff --git a/libsecret/secret-storage.c b/libsecret/secret-storage.c
index 1cbf00b..9f66e88 100644
--- a/libsecret/secret-storage.c
+++ b/libsecret/secret-storage.c
@@ -262,6 +262,115 @@ secret_storage_async_initable_iface_init (GAsyncInitableIface *iface)
        iface->init_finish = secret_storage_init_finish;
 }
 
+G_LOCK_DEFINE (storage_instance);
+static gpointer storage_instance = NULL;
+
+static void
+on_new_async (GObject      *source_object,
+              GAsyncResult *result,
+              gpointer      user_data)
+{
+       GAsyncInitable *initable = G_ASYNC_INITABLE (source_object);
+       GTask *task = G_TASK (user_data);
+       GObject *instance;
+       GError *error = NULL;
+
+       instance = g_async_initable_new_finish (initable, result, &error);
+       if (!instance) {
+               g_task_return_error (task, error);
+               g_object_unref (task);
+               return;
+       }
+
+       G_LOCK (storage_instance);
+       storage_instance = instance;
+       G_UNLOCK (storage_instance);
+
+       g_task_return_pointer (task, instance, NULL);
+       g_object_unref (task);
+}
+
+void
+secret_storage_get_default (int                  io_priority,
+                           GCancellable        *cancellable,
+                           GAsyncReadyCallback  callback,
+                           gpointer             user_data)
+{
+       SecretStorage *instance = NULL;
+       const gchar *envvar;
+       const gchar *password;
+       GFile *file;
+       GFile *dir;
+       GTask *task;
+       GError *error;
+
+       task = g_task_new (NULL, cancellable, callback, user_data);
+
+       G_LOCK (storage_instance);
+       if (storage_instance != NULL)
+               instance = g_object_ref (storage_instance);
+       G_UNLOCK (storage_instance);
+
+       if (instance != NULL) {
+               g_task_return_pointer (task, instance, g_object_unref);
+               g_object_unref (task);
+               return;
+       }
+
+       envvar = g_getenv ("SECRET_STORAGE_PASSWORD");
+       if (!envvar || *envvar == '\0') {
+               g_task_return_new_error (task,
+                                        G_IO_ERROR,
+                                        G_IO_ERROR_INVALID_ARGUMENT,
+                                        "storage password is not set");
+               g_object_unref (task);
+               return;
+       }
+       password = envvar;
+
+       envvar = g_getenv ("SECRET_STORAGE_PATH");
+       if (!envvar || *envvar == '\0') {
+               gchar *path;
+
+               path = g_build_filename (g_get_user_data_dir (), "keyrings",
+                                        "default.jwe", NULL);
+               file = g_file_new_for_path (path);
+               g_free (path);
+       } else {
+               file = g_file_new_for_path (envvar);
+       }
+
+       dir = g_file_get_parent (file);
+       if (!g_file_query_exists (file, cancellable)) {
+               error = NULL;
+               if (!g_file_make_directory_with_parents (dir, cancellable, &error)) {
+                       g_object_unref (file);
+                       g_object_unref (dir);
+                       g_task_return_error (task, error);
+                       g_object_unref (task);
+                       return;
+               }
+       }
+       
+       g_async_initable_new_async (SECRET_TYPE_STORAGE,
+                                   io_priority,
+                                   cancellable,
+                                   on_new_async,
+                                   task,
+                                   "password", password,
+                                   "file", file,
+                                   NULL);
+}
+
+SecretStorage *
+secret_storage_get_default_finish (GAsyncResult  *result,
+                                   GError       **error)
+{
+       g_return_val_if_fail (g_task_is_valid (result, NULL), NULL);
+
+       return g_task_propagate_pointer (G_TASK (result), error);
+}
+
 static void
 on_replace_contents (GObject *source_object,
                     GAsyncResult *result,
diff --git a/libsecret/secret-storage.h b/libsecret/secret-storage.h
index f692538..5b039e3 100644
--- a/libsecret/secret-storage.h
+++ b/libsecret/secret-storage.h
@@ -36,6 +36,15 @@ typedef struct _SecretStorageClass   SecretStorageClass;
 
 GType        secret_storage_get_type      (void) G_GNUC_CONST;
 
+void         secret_storage_get_default   (int                  io_priority,
+                                           GCancellable        *cancellable,
+                                           GAsyncReadyCallback  callback,
+                                           gpointer             user_data);
+
+SecretStorage *secret_storage_get_default_finish
+                                          (GAsyncResult        *result,
+                                           GError             **error);
+
 void         secret_storage_store         (SecretStorage       *self,
                                            const SecretSchema  *schema,
                                            GHashTable          *attributes,