def get_signals_dict_from_db(dbc_db):
    """
    Get dictionary of signals from db where keys are signal names.

    Parameters
    ----------
    dbc_db : cantools.db.Database
        The dbc database which contains the messages and signals.

    Returns
    -------
    signals : :obj:`dict` of cantools.database.can.signal.Signal
        Dictionary of the signals where keys are signal names.

    """
    signals = {}
    for message in dbc_db.messages:
        for signal in message.signals:
            signals[signal.name] = signal
    return signals