/// <summary>
/// TBD
/// </summary>
public override void HeartBeat()
{
var timestamp = _clock();
var oldState = state;
HeartbeatHistory newHistory = null;
if (!oldState.TimeStamp.HasValue)
{
//this is a heartbeat for a new resource
//add starter records for this new resource
newHistory = FirstHeartBeat;
}
else
{
//this is a known connection
var interval = timestamp - oldState.TimeStamp.Value;
//don't use the first heartbeat after failure for the history, since a long pause will skew the stats
if (IsTimeStampAvailable(timestamp))
{
newHistory = (oldState.History + interval);
}
else
{
newHistory = oldState.History;
}
}
var newState = new State(newHistory, timestamp);
//if we won the race then update else try again
if (!_state.CompareAndSet(oldState, newState))
{
HeartBeat();
}
}
private static HeartbeatHistory DropOldest(HeartbeatHistory history)
{
return(new HeartbeatHistory(history._maxSampleSize, history._intervals.Skip(1).ToList(), history._intervalSum - history._intervals.First(), history._squaredIntervalSum - Pow2(history._intervals.First())));
}
private static HeartbeatHistory DropOldest(HeartbeatHistory history)
{
return new HeartbeatHistory(history._maxSampleSize, history._intervals.Skip(1).ToList(), history._intervalSum - history._intervals.First(), history._squaredIntervalSum - Pow2(history._intervals.First()));
}
/// <summary>
/// TBD
/// </summary>
/// <param name="history">TBD</param>
/// <param name="timeStamp">TBD</param>
public State(HeartbeatHistory history, long?timeStamp)
{
TimeStamp = timeStamp;
History = history;
}
public State(HeartbeatHistory history, long? timeStamp)
{
TimeStamp = timeStamp;
History = history;
}