public Task Observe <TRequest, TResponse>(RequestHandlerExperiment <TRequest, TResponse> experiment)
where TRequest : IRequest <TResponse>
{
Console.WriteLine($"baseline result: {experiment.BaselineExecution.Task.Result}");
var experimentExecution = experiment.ExperimentalExecutions.Single();
var message = experimentExecution.Task.IsCompletedSuccessfully
? $"experiment response: {experimentExecution.Task.Result}"
: $"experiment error: {experimentExecution.Task.Exception.Message}";
Console.WriteLine(message);
return(Task.CompletedTask);
}
public async Task <TResponse> Execute <TRequest, TResponse>(List <IRequestHandler <TRequest, TResponse> > handlers, RequestPipelineContext <TRequest> context)
where TRequest : IRequest <TResponse>
{
if (handlers.Count <= 1)
{
return(await DefaultRequestHandlerExecutionStrategy.Instance.Execute(handlers, context).ConfigureAwait());
}
var baselineHandler = GetBaselineHandler(handlers);
var toggle = context.ServiceProvider.GetRequiredService <IRequestHandlerExperimentToggle>();
var request = context.Request;
var cancellationToken = context.CancellationToken;
if (!await toggle.IsEnabled <TRequest, TResponse>(_experimentInfo, context).ConfigureAwait())
{
return(await baselineHandler.Handle(request, cancellationToken).ConfigureAwait());
}
var observer = context.ServiceProvider.GetRequiredService <IRequestHandlerExperimentObserver>();
var tasks = handlers.Select(handler => Execute(handler, request, cancellationToken)).ToListOptimized();
var executions = await Task.WhenAll(tasks).ConfigureAwait();
var baselineExecution = executions.Single(x => x.Handler == baselineHandler);
var experimentExecutions = executions.Where(x => x != baselineExecution).ToList();
var experiment = new RequestHandlerExperiment <TRequest, TResponse>
{
BaselineExecution = baselineExecution,
CancellationToken = cancellationToken,
ExperimentalExecutions = experimentExecutions,
Request = request
};
await observer.Observe(experiment).ConfigureAwait();
return(await baselineExecution.Task.ConfigureAwait());
}