/// <summary>
/// Observes request state, updated aggregate metrics.
/// </summary>
/// <param name="requestState"></param>
internal void ObserveRequestState(WebMetricsRequestState requestState)
{
lock (_lock)
{
_requestHandlerMillisecondsComposite.Increment(requestState.RequestHandlerMilliseconds);
_requestMillisecondsComposite.Increment(requestState.RequestMilliseconds);
_responseBodyLengthComposite.Increment(requestState.ResponseBodyLength);
TotalObservedRequests.Increment();
}
}
/// <summary>
/// We observe the `BeginRequest` event to allocate request state and
/// capture the request start time.
/// </summary>
private void OnBeginRequest(object sender, EventArgs e)
{
// NOTE: we remove Accept-Encoding and replace with "identity" to
// avoid opportunity for response filter to receive
// compressed content
if (AppDomain.CurrentDomain.FriendlyName.Contains("/W3SVC/"))
{
HttpContext.Current.Request.Headers.Remove("Accept-Encoding");
HttpContext.Current.Request.Headers.Add("Accept-Encoding", "identity");
}
var requestState = new WebMetricsRequestState(HttpContext.Current.Request.RawUrl);
HttpContext.Current.Items[HTTPCONTEXT_WEBMETRICS_REQUESTSTATE_KEY] = requestState;
HttpContext.Current.Response.BufferOutput = true;
HttpContext.Current.Response.Filter = new IO.HtmlRewriteFilterStream(
HttpContext.Current.Response,
requestState,
s_aggregateState);
requestState.ObserveBeginRequest();
}