/// <summary>
/// The amount of time a Topic should stay in memory after its last subscriber is removed.
/// </summary>
/// <param name="options"></param>
/// <returns></returns>
public static TimeSpan TopicTtl(this TransportOptions options)
{
// If the deep-alive is disabled, don't take it into account when calculating the topic TTL.
var keepAliveTimeout = options.KeepAliveTimeout() ?? TimeSpan.Zero;
// Keep topics alive for twice as long as we let connections to reconnect. (The DisconnectTimeout)
// Also add twice the keep-alive timeout since clients might take a while to notice they are disconnected.
// This should be a very conservative estimate for how long we must wait before considering a topic dead.
return(TimeSpan.FromTicks((options.DisconnectTimeout.Ticks + keepAliveTimeout.Ticks) * 2));
}
