libygg

libygg is a GObject-based library providing an API for applications to interact with yggdrasil.

Requirements

• pkgconfig(dbus-1) >= 1.14.0
• pkgconfig(gio-2.0) >= 2.56.0
• pkgconfig(gobject-introspection-1.0)

Installation

Source

libygg is compiled with meson. Use typical meson setup, meson compile, meson install approach to compile and install libygg.

meson setup builddir
meson compile -C builddir
meson install -C builddir

It is also possible to compile libygg into an RPM suitable for installation on Fedora-based distributions. See the README in dist/srpm for details.

Features

• Worker Developer API

Worker Developer API

YggWorker is a GObject subclass that provides an API for developing workers in C (or any other language that supports gobject-introspection). To create a worker using this library, you must supply the worker with a callback function that is invoked when the worker receives data. The library handles all the D-Bus connection logic.

Directly

The API is available directly via the C library.

static void handle_rx (gchar *addr,
                       gchar *id,
                       gchar *response_to,
                       GHashTable *metadata,
                       GBytes *data,
                       gpointer user_data)
{
    g_debug ("%s", (guint8 *) g_bytes_get_data (data, NULL));
}

gint main (gint argc, gchar *argv[])
{
    YggWorker *worker = ygg_worker_new ("echo", FALSE, NULL, handle_rx, NULL);
    GError *error = NULL;
    if (!ygg_worker_connect (worker, &error)) {
        g_error ("%s", error->message);
    }

    GMainLoop *loop = g_main_loop_new (NULL, FALSE);
    g_main_loop_run (loop);

    return 0;
}

Indirectly

Additionally, the API can be used through gobject-introspection, as in the Python example below.

def handle_rx(worker, addr, id, response_to, meta_data, data):
    # data is an instance of GLib.Bytes (GBytes), so the raw bytes array must be
    # accessed via the GLib API (g_bytes_*).
    logging.debug(data.get_bytes())

if __name__ == "__main__":
    worker = Ygg.Worker(directive="echo", remote_content=False, features=None)
    worker.set_rx_func(handle_rx)
    worker.connect()

    loop = GLib.MainLoop()
    loop.run()

See examples for details on how to use the library in different programming languages.

Running

Under normal conditions, the worker will get started by systemd or D-Bus service activation. When running a worker manually, make sure to set the value of the DBUS_STARTER_BUS_TYPE environment variable to "session" or "system" accordingly. ygg_worker_connect relies on the value of this variable to determine which bus to connect to. If this value is missing, the worker will not connect to a bus at all.

Contact

Chat on Matrix: #yggd:matrix.org.