/// <summary>
/// Routes the call using the ResolverFrx
/// </summary>
/// <param name="sAddress">Address which the call was sent to</param>
/// <param name="Context">Dictionary of context variables used for routing and/or processing</param>
/// <param name="Body">Message Body/Call Body</param>
/// <param name="overrideDefaultExecutionStrategy">overrides the router's default execution strategy</param>
/// <returns>Routing Result</returns>
public virtual async Task <RER> RouteAsync(string sAddress,
IDictionary <string, object> Context,
Stream Body,
ContextExecuteStrategyBase overrideDefaultExecutionStrategy)
{
// context management
var chs = overrideDefaultExecutionStrategy == null ? mDefaultContextExecuteStrategy : overrideDefaultExecutionStrategy;
RoutingContextBase re;
RER rer;
Context = null != Context ? Context : new Dictionary <string, object>();
// can be used by various sub system involved to reach the router, unique call instance id, or the trace log
Context.Add(Context_Router_Call_InstanceId_Key, Guid.NewGuid().ToString()); // instance id
#region Resolve
try
{
re = await ResolveAsync(sAddress, Context, Body);
}
// caller can handle this ae, or RouterResolveException
catch (AggregateException ae)
{
throw new RouterResolveException(ae);
}
catch (Exception e)
{
// this is either a telemetry error, and shouldn't happen in runtime
// (unless you are doing something funny with the telemetry sub system)
// or you have a sub class that is doing something funny.
throw new RouterResolveException(e);
}
#endregion
// if no resolver is matching then we need return null
if (null == re)
{
return(null);
}
#region Execute
try
{
rer = await ExecuteContextAsync(re, chs);
}
catch
{
throw;
}
finally
{
// context maintenance
// just in case the caller intersted in reusing the dictionary
Context.Remove(Context_Router_Call_InstanceId_Key);
}
return(rer);
#endregion
}
public static ContextExecuteStrategyBase ThenTryAgain(this ContextExecuteStrategyBase strategy,
int times,
int DelayMs)
{
var current = strategy;
for (var i = 1; i <= times; i++)
{
current.Next = new RetryAfterStrategy(DelayMs);
current = current.Next;
}
return(current);
}
/// <summary>
/// chains multiple retries with different backoffs
/// </summary>
/// <param name="strategy"></param>
/// <param name="times"></param>
/// <param name="DelayMs"></param>
/// <param name="delayFactor"></param>
/// <returns></returns>
public static ContextExecuteStrategyBase ThenTryAgainWithBackOff(this ContextExecuteStrategyBase strategy,
int times,
int DelayMs,
float delayFactor)
{
var current = strategy;
for (var i = 1; i <= times; i++)
{
var actualDelay = 1 == i ? DelayMs : i * delayFactor * DelayMs;
current.Next = new RetryAfterStrategy((int)actualDelay);
current = current.Next;
}
return(current);
}
protected virtual async Task <RER> ExecuteContextAsync(RoutingContextBase re, ContextExecuteStrategyBase chs)
{
RER rer = null;
Stopwatch sw = new Stopwatch();
var currentChs = chs;
ContextExecuteModeBase ExecuteMode = new DoNotRetryMode();
var TryCount = 1;
var bSucess = false;
while (true)
{
try
{
sw.Start();
rer = (RER)await re.ExecuteAsync(ExecuteMode);
sw.Stop();
bSucess = true;
}
catch (Exception e)
{
if (null == currentChs)
{
throw;
}
TryCount++;
// circut breaker
if (TryCount > mMaxRetryCount)
{
throw new RouterMaxedRetryException(new AggregateException(e))
{
RetryCount = (TryCount - 1), RoutingContext = re
}
}
;
try
{
// execute current strategy;
ExecuteMode = await currentChs.ExecuteStrategyAsync(TryCount, re, new AggregateException(e));
}
catch (Exception StrategyExecuteFail)
{
// if we failed to execute strategy we just wrap the exception
// along with the orginal execution one.
throw new FailedToExecuteStrategyException(StrategyExecuteFail, e)
{
TryCount = TryCount, RoutingContext = re
};
}
// move to next strategy
currentChs = currentChs.Next;
if (!ExecuteMode.ShouldRouterTryAgain)
{
throw new AggregateException(e);
}
}
finally
{
OnTelemetryExecute(re, rer, sw.Elapsed.TotalMilliseconds);
Trace.WriteLine(string.Format("Execute in {0} Call Count {1} Routing Type:{2}",
sw.Elapsed.TotalMilliseconds, TryCount, re.RouteExecuteType), "Verbose");
sw.Reset(); // reset the clock
}
if (bSucess)
{
break; // exit the loop
}
}
return(rer);
}
public static ContextExecuteStrategyBase ThrowIfExceptionIsIn(this ContextExecuteStrategyBase strategy, params Exception[] exceptions)
{
return(strategy.Then(new ThrowIfInnerExceptionNotIn(exceptions)));
}
public virtual ContextExecuteStrategyBase Then(ContextExecuteStrategyBase next)
{
this.Next = next;
return(this.Next);
}
