// ReSharper disable once UnusedMember.Global
public Task Invoke(HttpContext httpContext, IServerTiming serverTiming, IEnumerable <IServerTimingCallback> callbacks)
{
var callbackServices = callbacks as IServerTimingCallback[] ?? callbacks.ToArray();
var invokeCallbacks = _options.InvokeCallbackServices && callbackServices.Length > 0;
var requestOptions = new RequestTimingOptions();
_options.ConfigureRequestTimingOptions(httpContext, requestOptions);
if (!requestOptions.WriteHeader && !invokeCallbacks)
{
return(_next(httpContext));
}
var totalMetric = serverTiming.Manual(
_options.TotalMetricName,
_options.TotalMetricDescription);
totalMetric.Start();
httpContext.Response.OnStarting(() => OnResponseStarting(httpContext, totalMetric, serverTiming, requestOptions));
if (invokeCallbacks)
{
httpContext.Response.OnCompleted(() => OnResponseCompleted(httpContext, serverTiming, callbackServices));
}
return(_next(httpContext));
}
internal Task OnResponseStarting(HttpContext httpContext, IManualMetric totalMetric, IServerTiming serverTiming, RequestTimingOptions requestOptions)
{
totalMetric.Stop();
var metrics = serverTiming.GetMetrics();
if (_options.ValidateMetrics && httpContext.Response.StatusCode != 500)
{
// ReSharper disable once ForCanBeConvertedToForeach
for (var i = 0; i < metrics.Count; i++)
{
if (metrics[i] is IValidatableMetric validatableMetric)
{
if (!validatableMetric.Validate(out var message))
{
_logger.LogWarning(message);
}
}
}
}
if (!requestOptions.WriteHeader)
{
return(Task.CompletedTask);
}
if (!requestOptions.IncludeCustomMetrics)
{
metrics = new[] { (IMetric)totalMetric }
}
;
_headerWriter.WriteHeaders(httpContext.Response.Headers, requestOptions.IncludeDescriptions, metrics);
return(Task.CompletedTask);
}