Gio.DBusMessage.bytes_needed

function bytes_needed(blob: ByteArray): Number(gssize) {
    // Gjs wrapper for g_dbus_message_bytes_needed()
}

Utility function to calculate how many bytes are needed to completely deserialize the D-Bus message stored at blob.

Since 2.26

blob

A blob represent a binary D-Bus message.

Returns

Number of bytes needed or -1 if @error is set (e.g. if blob contains invalid data or not enough data is available to determine the size).