public void OnNext()

in NETCORE/src/Microsoft.ApplicationInsights.AspNetCore/DiagnosticListeners/Implementation/HostingDiagnosticListener.cs [333:424]
82 lines of code
22 McCabe index (conditional complexity)

        public void OnNext(KeyValuePair<string, object> value)
        {
            HttpContext httpContext = null;
            Exception exception = null;

            try
            {
                //// Top messages in if-else are the most often used messages.
                //// Switch is compiled into GetHashCode() and binary search, if-else without GetHashCode()
                //// is faster if 2.0 or higher events are used.
                if (value.Key == "Microsoft.AspNetCore.Hosting.HttpRequestIn.Start")
                {
                    httpContext = this.httpContextFetcherStart.Fetch(value.Value) as HttpContext;
                    if (httpContext != null)
                    {
                        this.OnHttpRequestInStart(httpContext);
                    }
                }
                else if (value.Key == "Microsoft.AspNetCore.Hosting.HttpRequestIn.Stop")
                {
                    httpContext = this.httpContextFetcherStop.Fetch(value.Value) as HttpContext;
                    if (httpContext != null)
                    {
                        this.OnHttpRequestInStop(httpContext);
                    }
                }
                else if (value.Key == "Microsoft.AspNetCore.Mvc.BeforeAction")
                {
                    HttpContext context = null;
                    object routeData = null;

                    // Asp.Net Core 3.0 changed the field name to "RouteData" from "routeData and "HttpContext" from "httpContext"
                    if (this.aspNetCoreMajorVersion == AspNetCoreMajorVersion.Three)
                    {
                        context = this.httpContextFetcherOnBeforeAction30.Fetch(value.Value) as HttpContext;
                        if (context == null)
                        {
                            context = this.httpContextFetcherOnBeforeAction.Fetch(value.Value) as HttpContext;
                        }

                        routeData = this.routeDataFetcher30.Fetch(value.Value);
                        if (routeData == null)
                        {
                            routeData = this.routeDataFetcher.Fetch(value.Value);
                        }
                    }
                    else
                    {
                        context = this.httpContextFetcherOnBeforeAction.Fetch(value.Value) as HttpContext;
                        if (context == null)
                        {
                            context = this.httpContextFetcherOnBeforeAction30.Fetch(value.Value) as HttpContext;
                        }

                        routeData = this.routeDataFetcher.Fetch(value.Value);
                        if (routeData == null)
                        {
                            routeData = this.routeDataFetcher30.Fetch(value.Value);
                        }
                    }

                    var routeValues = this.routeValuesFetcher.Fetch(routeData) as IDictionary<string, object>;

                    if (context != null && routeValues != null)
                    {
                        OnBeforeAction(context, routeValues);
                    }
                }
                else if (this.trackExceptions && value.Key == "Microsoft.AspNetCore.Diagnostics.UnhandledException")
                {
                    httpContext = this.httpContextFetcherDiagExceptionUnhandled.Fetch(value.Value) as HttpContext;
                    exception = this.exceptionFetcherDiagExceptionUnhandled.Fetch(value.Value) as Exception;
                    if (httpContext != null && exception != null)
                    {
                        this.OnDiagnosticsUnhandledException(httpContext, exception);
                    }
                }
                else if (this.trackExceptions && value.Key == "Microsoft.AspNetCore.Diagnostics.HandledException")
                {
                    httpContext = this.httpContextFetcherDiagExceptionHandled.Fetch(value.Value) as HttpContext;
                    exception = this.exceptionFetcherDiagExceptionHandled.Fetch(value.Value) as Exception;
                    if (httpContext != null && exception != null)
                    {
                        this.OnDiagnosticsHandledException(httpContext, exception);
                    }
                }
            }
            catch (Exception ex)
            {
                AspNetCoreEventSource.Instance.DiagnosticListenerWarning(value.Key, ex.ToInvariantString());
            }
        }