public void ActivityImportExport()
{
using (DiagnosticListener listener = new DiagnosticListener("TestingBasicIsEnabled"))
{
DiagnosticSource source = listener;
var result = new List <KeyValuePair <string, object> >();
bool seenPredicate = false;
Func <string, object, object, bool> predicate = delegate(string name, object obj1, object obj2)
{
seenPredicate = true;
return(true);
};
Activity importerActivity = new Activity("activityImporter");
object importer = "MyImporterObject";
bool seenActivityImport = false;
Action <Activity, object> activityImport = delegate(Activity activity, object payload)
{
Assert.Equal(activity.GetHashCode(), importerActivity.GetHashCode());
Assert.Equal(importer, payload);
seenActivityImport = true;
};
Activity exporterActivity = new Activity("activityExporter");
object exporter = "MyExporterObject";
bool seenActivityExport = false;
Action <Activity, object> activityExport = delegate(Activity activity, object payload)
{
Assert.Equal(activity.GetHashCode(), exporterActivity.GetHashCode());
Assert.Equal(exporter, payload);
seenActivityExport = true;
};
// Use the Subscribe that allows you to hook the OnActivityImport and OnActivityExport calls.
using (listener.Subscribe(new ObserverToList <TelemData>(result), predicate, activityImport, activityExport))
{
if (listener.IsEnabled("IntPayload"))
{
listener.Write("IntPayload", 5);
}
Assert.True(seenPredicate);
Assert.Equal(1, result.Count);
Assert.Equal("IntPayload", result[0].Key);
Assert.Equal(5, result[0].Value);
listener.OnActivityImport(importerActivity, importer);
Assert.True(seenActivityImport);
listener.OnActivityExport(exporterActivity, exporter);
Assert.True(seenActivityExport);
}
}
}
private Activity StartActivity(HttpContext httpContext, out bool hasDiagnosticListener)
{
var activity = new Activity(ActivityName);
hasDiagnosticListener = false;
var headers = httpContext.Request.Headers;
if (!headers.TryGetValue(HeaderNames.TraceParent, out var requestId))
{
headers.TryGetValue(HeaderNames.RequestId, out requestId);
}
if (!StringValues.IsNullOrEmpty(requestId))
{
activity.SetParentId(requestId);
if (headers.TryGetValue(HeaderNames.TraceState, out var traceState))
{
activity.TraceStateString = traceState;
}
// We expect baggage to be empty by default
// Only very advanced users will be using it in near future, we encourage them to keep baggage small (few items)
var baggage = headers.GetCommaSeparatedValues(HeaderNames.Baggage);
if (baggage.Length == 0)
{
baggage = headers.GetCommaSeparatedValues(HeaderNames.CorrelationContext);
}
// AddBaggage adds items at the beginning of the list, so we need to add them in reverse to keep the same order as the client
// An order could be important if baggage has two items with the same key (that is allowed by the contract)
for (var i = baggage.Length - 1; i >= 0; i--)
{
if (NameValueHeaderValue.TryParse(baggage[i], out var baggageItem))
{
activity.AddBaggage(baggageItem.Name.ToString(), HttpUtility.UrlDecode(baggageItem.Value.ToString()));
}
}
}
_diagnosticListener.OnActivityImport(activity, httpContext);
if (_diagnosticListener.IsEnabled(ActivityStartKey))
{
hasDiagnosticListener = true;
StartActivity(activity, httpContext);
}
else
{
activity.Start();
}
return(activity);
}
private Activity StartActivity(HttpContext httpContext, out bool hasDiagnosticListener)
{
var activity = new Activity(ActivityName);
hasDiagnosticListener = false;
var headers = httpContext.Request.Headers;
if (!headers.TryGetValue(HeaderNames.TraceParent, out var requestId))
{
headers.TryGetValue(HeaderNames.RequestId, out requestId);
}
if (!StringValues.IsNullOrEmpty(requestId))
{
activity.SetParentId(requestId);
if (headers.TryGetValue(HeaderNames.TraceState, out var traceState))
{
activity.TraceStateString = traceState;
}
// We expect baggage to be empty by default
// Only very advanced users will be using it in near future, we encourage them to keep baggage small (few items)
string[] baggage = headers.GetCommaSeparatedValues(HeaderNames.CorrelationContext);
if (baggage.Length > 0)
{
foreach (var item in baggage)
{
if (NameValueHeaderValue.TryParse(item, out var baggageItem))
{
activity.AddBaggage(baggageItem.Name.ToString(), HttpUtility.UrlDecode(baggageItem.Value.ToString()));
}
}
}
}
_diagnosticListener.OnActivityImport(activity, httpContext);
if (_diagnosticListener.IsEnabled(ActivityStartKey))
{
hasDiagnosticListener = true;
StartActivity(activity, httpContext);
}
else
{
activity.Start();
}
return(activity);
}
private Activity StartActivity(HttpContext httpContext)
{
var activity = new Activity(ActivityName);
if (!httpContext.Request.Headers.TryGetValue(TraceParentHeaderName, out var requestId))
{
httpContext.Request.Headers.TryGetValue(RequestIdHeaderName, out requestId);
}
if (!StringValues.IsNullOrEmpty(requestId))
{
activity.SetParentId(requestId);
if (httpContext.Request.Headers.TryGetValue(TraceStateHeaderName, out var traceState))
{
activity.TraceStateString = traceState;
}
// We expect baggage to be empty by default
// Only very advanced users will be using it in near future, we encourage them to keep baggage small (few items)
string[] baggage = httpContext.Request.Headers.GetCommaSeparatedValues(CorrelationContextHeaderName);
if (baggage != StringValues.Empty)
{
foreach (var item in baggage)
{
if (NameValueHeaderValue.TryParse(item, out var baggageItem))
{
activity.AddBaggage(baggageItem.Name.ToString(), baggageItem.Value.ToString());
}
}
}
}
_diagnosticListener.OnActivityImport(activity, httpContext);
if (_diagnosticListener.IsEnabled(ActivityStartKey))
{
_diagnosticListener.StartActivity(activity, new { HttpContext = httpContext });
}
else
{
activity.Start();
}
return(activity);
}
/// <summary>
/// Creates root (first level) activity that describes incoming request.
/// </summary>
/// <param name="context">Current HttpContext.</param>
/// <param name="parseHeaders">Determines if headers should be parsed get correlation ids.</param>
/// <returns>New root activity.</returns>
public static Activity CreateRootActivity(HttpContext context, bool parseHeaders)
{
if (AspNetListener.IsEnabled() && AspNetListener.IsEnabled(AspNetActivityName))
{
var rootActivity = new Activity(AspNetActivityName);
if (parseHeaders)
{
rootActivity.Extract(context.Request.Unvalidated.Headers);
}
AspNetListener.OnActivityImport(rootActivity, null);
if (StartAspNetActivity(rootActivity))
{
context.Items[ActivityKey] = rootActivity;
AspNetTelemetryCorrelationEventSource.Log.ActivityStarted(rootActivity.Id);
return(rootActivity);
}
}
return(null);
}