/// <summary>
/// ThrottleBehavior constructor
/// </summary>
/// <param name="maxRequestPerSecond">Maximum number of operations per second</param>
/// <param name="measurePeriodMs">Measure period to estimate current number of operations</param>
public ThrottleBehavior(double maxRequestPerSecond, int measurePeriodMs)
{
if (maxRequestPerSecond <= 0)
{
throw new ArgumentOutOfRangeException(nameof(maxRequestPerSecond), nameof(maxRequestPerSecond) + " should be positive");
}
if (measurePeriodMs <= 50)
{
throw new ArgumentOutOfRangeException(nameof(measurePeriodMs), nameof(measurePeriodMs) + " should be grater than 50");
}
_measurePeriod = measurePeriodMs;
_maxRequestPerSecond = maxRequestPerSecond;
_lastTimeMeasure = GetTimeMeasureInMs();
_hitCount = 0;
_syncObj = new object();
var tmpHit = Math.Ceiling(measurePeriodMs * maxRequestPerSecond / 1000.0);
if (tmpHit < int.MaxValue)
{
_maxHitPerMeasure = (int)tmpHit;
}
else
{
_maxHitPerMeasure = int.MaxValue;
}
TurboContract.Assert(_maxHitPerMeasure > 0, conditionString: "_maxHitPerMeasure > 0");
}
/// <summary>
/// Add subscription to the current delegate
/// </summary>
/// <param name="reference">New subscriber</param>
public void Add(T reference)
{
if (reference == null)
{
return;
}
TurboContract.Assert(reference is Delegate, conditionString: "reference is Delegate");
if (reference is MulticastDelegate)
{
var invList = (reference as MulticastDelegate).GetInvocationList();
lock (_locker)
{
for (int i = 0; i < invList.Length; i++)
{
var weakEventReference = new WeakDelegate(invList[i]);
_handlers.Add(weakEventReference);
}
}
}
else
{
lock (_locker)
{
var weakEventReference = new WeakDelegate(reference as Delegate);
_handlers.Add(weakEventReference);
}
}
}
/// <summary>
/// Builds the strongly referenced delegate from the current weak delegate
/// </summary>
/// <returns>Constructed delegate</returns>
public T GetDelegate()
{
Delegate result = null;
lock (_locker)
{
for (int i = 0; i < _handlers.Count; i++)
{
TurboContract.Assert(_handlers[i] != null, conditionString: "_handlers[i] != null");
var newDeleg = _handlers[i].GetDelegate();
if (newDeleg != null)
{
result = Delegate.Combine(result, newDeleg);
}
else
{
_handlers.RemoveAt(i);
i--;
}
}
}
return(result as T);
}
/// <summary>
/// Remove subscription from the current delegate
/// </summary>
/// <param name="reference">Subscriber that will be removed</param>
public void Remove(T reference)
{
if (reference == null)
{
return;
}
TurboContract.Assert(reference is Delegate, conditionString: "reference is Delegate");
if (reference is MulticastDelegate)
{
var invList = (reference as MulticastDelegate).GetInvocationList();
lock (_locker)
{
int index = _handlers.FindIndex(x => Array.IndexOf(invList, x.GetDelegate()) >= 0);
if (index >= 0)
{
_handlers.RemoveAt(index);
}
_handlers.RemoveAll(x => !x.IsActive);
}
}
else
{
lock (_locker)
{
int index = _handlers.FindIndex(x => reference.Equals(x.GetDelegate()));
if (index >= 0)
{
_handlers.RemoveAt(index);
}
_handlers.RemoveAll(x => !x.IsActive);
}
}
}
private void Invariant()
{
TurboContract.Invariant(_valueStorage != null || _staticDelegateStorage != null);
TurboContract.Invariant(_delegateType != null);
TurboContract.Invariant(_methodInfo != null);
}
/// <summary>
/// Creates unlimited ThrottleBehavior (allow all operations)
/// </summary>
/// <returns>Created ThrottleBehavior</returns>
public static ThrottleBehavior CreateNotLimited()
{
TurboContract.Ensures(TurboContract.Result <ThrottleBehavior>() != null);
return(new ThrottleBehavior(int.MaxValue, 1000));
}
/// <summary>
/// Calls when operation should be skipped (op/s exeeded)
/// </summary>
/// <param name="restTimeMs">Time in milliseconds till the end of the current measure period</param>
protected virtual void OnThrottle(int restTimeMs)
{
TurboContract.Requires(restTimeMs >= 0, conditionString: "restTimeMs >= 0");
}
