public static Task <HttpResponseMessage> SendAsync(
this HttpClient httpClient,
CorrelationVector correlationVector,
HttpRequestMessage requestMessage)
{
requestMessage.AddCorrelationVector(correlationVector);
return(httpClient.SendAsync(requestMessage));
}
public void OnNext(KeyValuePair <string, object> value)
{
if (value.Key == "Microsoft.AspNetCore.Hosting.HttpRequestIn.Start")
{
// This happens on incoming requests to ASP.NET. Grab the MS-CV header and store
// it on the HttpContext.
//
HttpContext httpContext =
value.Value.GetType().GetProperty("HttpContext")?.GetValue(value.Value, null)
as HttpContext;
CorrelationVector correlationVector;
if (httpContext == null)
{
return;
}
if (httpContext.Request.Headers.ContainsKey("MS-CV"))
{
correlationVector = CorrelationVector.Extend(httpContext.Request.Headers["MS-CV"][0]);
}
else
{
correlationVector = new CorrelationVector();
}
CorrelationVector.Current = correlationVector;
}
else if (value.Key == "System.Net.Http.HttpRequestOut.Start")
{
// This happens on outgoing Http requests via Http Client. See if a Correlation
// Vector has been stored on the Request Message's properties and use it to
// stamp an MS-CV header (after incrementing the CV).
//
HttpRequestMessage requestMessage =
value.Value.GetType().GetProperty("Request")?.GetValue(value.Value, null)
as HttpRequestMessage;
if (requestMessage == null)
{
return;
}
CorrelationVector correlationVector = requestMessage.GetCorrelationVector() ?? CorrelationVector.Current;
if (correlationVector != null)
{
requestMessage.Headers.Add("MS-CV", correlationVector.Increment());
}
}
}
public static void AddCorrelationVector(this HttpRequestMessage requestMessage, CorrelationVector correlationVector )
{
requestMessage.Properties.Add( nameof( CorrelationVector ), correlationVector );
}
