/// <summary>
/// Gets permission to attempt a send of a message.
/// </summary>
/// <param name="ipAddress">The IP Address we wan't to send from.</param>
/// <param name="mxRecord">The MX Record of the destination.</param>
/// <returns>TRUE if we can send FALSE if we should throttle.</returns>
public bool TryGetSendAuth(VirtualMTA ipAddress, MXRecord mxRecord)
{
int mxPatternID = -1;
int maxMessagesHour = OutboundRuleManager.GetMaxMessagesDestinationHour(ipAddress, mxRecord, out mxPatternID);
// If the Max messages is -1 then unlimited so can just return true here.
// No need for any logging or calculating.
if (maxMessagesHour == -1)
{
return(true);
}
// Create or get this outbound IP/mx pattern send history.
ThrottleManager.MxPatternThrottlingSendHistory mxSndHist = null;
if (!this._sendHistory.TryGetValue(ipAddress.IPAddress.ToString(), out mxSndHist))
{
mxSndHist = new ThrottleManager.MxPatternThrottlingSendHistory();
this._sendHistory.AddOrUpdate(ipAddress.IPAddress.ToString(), mxSndHist, (string s, ThrottleManager.MxPatternThrottlingSendHistory sh) => mxSndHist);
}
//this._sendHistory.GetOrAdd(ipAddress.IPAddress.ToString(), new ThrottleManager.MxPatternThrottlingSendHistory());
List <DateTime> sndHistory = mxSndHist.GetOrAdd(mxPatternID, new List <DateTime>());
// Only calculate if needed.
if (mxSndHist.IntervalValuesNeedRecalcTimestamp <= DateTime.UtcNow)
{
int maxMessages = 0;
int maxMessagesIntervalMinute = 0;
while (maxMessages < 1 && maxMessagesIntervalMinute <= 60)
{
maxMessagesIntervalMinute++;
maxMessages = (int)Math.Floor((double)maxMessagesHour / 60d * (double)maxMessagesIntervalMinute);
}
mxSndHist.IntervalMaxMessages = maxMessages;
mxSndHist.IntervalMinutes = maxMessagesIntervalMinute;
mxSndHist.IntervalValuesNeedRecalcTimestamp = DateTime.UtcNow.AddMinutes(MtaParameters.MTA_CACHE_MINUTES);
}
lock (sndHistory)
{
// Remove sends that happened over "Interval" minute(s) ago.
DateTime sendsAfterTimestamp = DateTime.UtcNow.AddMinutes((double)(mxSndHist.IntervalMinutes * -1));
sndHistory.RemoveAll((DateTime d) => d <= sendsAfterTimestamp);
// Check for throttling
if (sndHistory.Count < mxSndHist.IntervalMaxMessages)
{
// Not hit throttle limit yet.
// Log send and return true.
sndHistory.Add(DateTime.UtcNow);
return(true);
}
else
{
// THROTTLED!
return(false);
}
}
}
/// <summary>
/// Keeps the send history clean by removing old values.
/// This should only be called on background thread as it will run forever.
/// </summary>
private void DoSendHistoryCleaning()
{
while (true)
{
// Stopwatch is used to time the cleaning process.
Stopwatch timer = new Stopwatch();
timer.Start();
// Loop through all outbound IPs send history
foreach (KeyValuePair <string, ThrottleManager.MxPatternThrottlingSendHistory> ipHistory in this._sendHistory)
{
ThrottleManager.MxPatternThrottlingSendHistory ipMxPtnHistory = ipHistory.Value;
// Loop through each MX Pattern within each outbound IP
foreach (KeyValuePair <int, List <DateTime> > mxPatternHistory in ipMxPtnHistory)
{
// Lock the ArrayList that contains the send history.
lock (mxPatternHistory.Value)
{
// ArrayList will hold the position of elements to remove from mxPatternHistory.Value
ArrayList toRemove = new ArrayList();
// Go through every log send and check that it hasn't expired.
for (int i = 0; i < mxPatternHistory.Value.Count; i++)
{
if (mxPatternHistory.Value[i].AddMinutes((double)ipMxPtnHistory.IntervalMinutes) < DateTime.UtcNow)
{
toRemove.Add(i);
}
}
// Remove send history that is no longer required.
for (int z = toRemove.Count - 1; z >= 0; z--)
{
mxPatternHistory.Value.RemoveAt((int)toRemove[z]);
}
}
}
}
// We don't wan't to have the cleaner thread running indefinitely if there isn't anything
// to do. Sleep thread so it only runs once every 15 seconds. Unless it's taking longer than
// 15 seconds to clean in which case go again instantly.
timer.Stop();
TimeSpan ts = (TimeSpan.FromSeconds(15) - timer.Elapsed);
if (ts > TimeSpan.FromSeconds(0))
{
Thread.Sleep(ts);
}
}
}