I am trying to following this web blog on uploading large files using the Web Api class via Asp.Net Web Forms. If you look through the post you will notice that in order to avoid an out of memory because of buffering of larges files, they recommend overriding the IHostBufferPolicySelector interface. Where do I implement the interface? Do I do it in the Web Api class, in the Global.asax or am I completely off track and need to do the implementation somewhere else?
You don't need to implement this interface, I only listed it as a reference - that code is already part of Web API source (under System.Web.Http/Hosting/IHostBufferPolicySelector.cs)
What you need to do is override the base class System.Web.Http.WebHost.WebHostBufferPolicySelector
This is enough:
public class NoBufferPolicySelector : WebHostBufferPolicySelector
{
public override bool UseBufferedInputStream(object hostContext)
{
var context = hostContext as HttpContextBase;
if (context != null)
{
if (string.Equals(context.Request.RequestContext.RouteData.Values["controller"].ToString(), "uploading", StringComparison.InvariantCultureIgnoreCase))
return false;
}
return true;
}
public override bool UseBufferedOutputStream(HttpResponseMessage response)
{
return base.UseBufferedOutputStream(response);
}
}
and then registering your new class in either Global.asax or WebApiConfig.cs (whichever you prefer):
GlobalConfiguration.Configuration.Services.Replace(typeof(IHostBufferPolicySelector), new NoBufferPolicySelector());
Related
I am toying with Swashbuckle.Examples package (3.10.0) in an ASP.NET MVC project. However, I cannot make request examples appear within the UI.
Configuration (SwaggerConfig.cs)
public static void Register()
{
var thisAssembly = typeof(SwaggerConfig).Assembly;
GlobalConfiguration.Configuration
.EnableSwagger(c => {
c.SingleApiVersion("v1", "TestApp.Web");
c.IncludeXmlComments(string.Format(#"{0}\bin\TestApp.Web.xml", System.AppDomain.CurrentDomain.BaseDirectory));
c.OperationFilter<ExamplesOperationFilter>();
c.OperationFilter<DescriptionOperationFilter>();
c.OperationFilter<AppendAuthorizeToSummaryOperationFilter>();
})
.EnableSwaggerUi(c => { });
}
Request example classes
public class EchoRequestExample : IExamplesProvider
{
public object GetExamples()
{
return new EchoInput { Value = 7 } ;
}
}
public class EchoInput
{
public int Value { get; set; }
}
Action
[HttpGet]
[Route("Echo")]
[CustomApiAuthorize]
[SwaggerRequestExample(typeof(EchoInput), typeof(EchoRequestExample))]
[ResponseType(typeof(EchoServiceModel))]
public HttpResponseMessage Echo([FromUri] EchoInput model)
{
var ret = new EchoServiceModel
{
Username = RequestContext.Principal.Identity.Name,
Value = value
};
return Request.CreateResponse(HttpStatusCode.OK, ret);
}
Swagger UI shows xml comments and output metadata (model and an example containing default values), but shows no request example. I attached to process and EchoRequestExample.GetExamples is not hit.
Question: How to make SwaggerRequestExample attribute work in ASP.NET MVC 5?
Note: Windows identity is used for authorization.
I received an answer from library owner here:
Swagger request examples can only set on [HttpPost] actions
It is not clear if this is a design choice or just a limitation, as I find [HttpGet] examples also relevant.
I know the feeling, lot's of overhead just for an example, I struggle with this for a while, so I created my own fork of swashbuckle, and after unsuccessful attempts to merge my ideas I ended up detaching and renaming my project and pushed to nuget, here it is: Swagger-Net
An example like that will be:
[SwaggerExample("id", "123456")]
public IHttpActionResult GetById(int id)
{
Here the full code for that: Swagger_Test/Controllers/IHttpActionResultController.cs#L26
Wondering how that looks like on the Swagger-UI, here it is:
http://swagger-net-test.azurewebsites.net/swagger/ui/index?filter=IHttpActionResult#/IHttpActionResult/IHttpActionResult_GetById
We have an Azure web role deployed that has been using Application Insights (ver. 1.0.0.4220), however, we're going over our data quota. Is it possible to configure Application Insights ignore a specific URL?
We have a status web service that gets a huge amount of traffic but never throws any errors. If I could exclude this one service URL I could cut my data usage in half.
Out of the box it is not supported. Sampling feature is coming but that would not be configurable by specific url. You can implement your own channel that would have your custom filtering. Basically your channel will get event to be sent, you check if you want to send it or not and then if yes pass to standard AI channel. Here you can read more about custom channels.
There are two things that changed since this blog post has been written:
channel should implement only ITelemetryChannel interface (ISupportConfiguration was removed)
and instead of PersistenceChannel you should use Microsoft.ApplicationInsights.Extensibility.Web.TelemetryChannel
UPDATE: Latest version has filtering support: https://azure.microsoft.com/en-us/blog/request-filtering-in-application-insights-with-telemetry-processor/
My team had a similiar situation where we needed to filter out urls that were successful image requests (we had a lot of these which made us hit the 30k datapoints/min limit).
We ended up using a modified version of the class in Sergey Kanzhelevs blog post to filter these out.
We created a RequestFilterChannel class which is an instance of ServerTelemetryChannel and extended the Send method. In this method we test each telemetry item to be sent to see if it is an image request and if so, we prevent it from being sent.
public class RequestFilterChannel : ITelemetryChannel, ITelemetryModule
{
private ServerTelemetryChannel channel;
public RequestFilterChannel()
{
this.channel = new ServerTelemetryChannel();
}
public void Initialize(TelemetryConfiguration configuration)
{
this.channel.Initialize(configuration);
}
public void Send(ITelemetry item)
{
if (item is RequestTelemetry)
{
var requestTelemetry = (RequestTelemetry) item;
if (requestTelemetry.Success && isImageRequest((RequestTelemetry) item))
{
// do nothing
}
else
{
this.channel.Send(item);
}
}
else
{
this.channel.Send(item);
}
}
public bool? DeveloperMode
{
get { return this.channel.DeveloperMode; }
set { this.channel.DeveloperMode = value; }
}
public string EndpointAddress
{
get { return this.channel.EndpointAddress; }
set { this.channel.EndpointAddress = value; }
}
public void Flush()
{
this.channel.Flush();
}
public void Dispose()
{
this.channel.Dispose();
}
private bool IsImageRequest(RequestTelemetry request)
{
if (request.Url.AbsolutePath.StartsWith("/image.axd"))
{
return true;
}
return false;
}
}
Once the class has been created you need to add it to your ApplicationInsights.config file.
Replace this line:
<TelemetryChannel Type="Microsoft.ApplicationInsights.WindowsServer.TelemetryChannel.ServerTelemetryChannel, Microsoft.AI.ServerTelemetryChannel"/>
with a link to your class:
<TelemetryChannel Type="XXX.RequestFilterChannel, XXX" />
Alternatively, you can disable the automated request collection and keep only exception auto-collection, just remove the RequestTrackingModule line from applicationinsights.config.
If you still need to collect some of the requests, not just filter all out, you can then call TrackRequest() (in the object of TelemetryClient class) from your code in the appropriate place after you know that you certainly need to log this request to AI.
Update: Filtering feature has been released some time ago and allows for exclusion of certain telemetry items way easier.
I've installed MVC Site Map Provider for MVC5 and just used everything out of the the box. It works fine. Now I want to implement roles based menu trimming so assuming my controller:
public class Home: Controller
{
[Authorize(Roles="Admin")]
public ActionResult Index()
{
return View();
}
}
Now basically only Admin role users can see the menu. Perfect works fine.
Also to implement this I added to my web.config this line:
<add key="MvcSiteMapProvider_SecurityTrimmingEnabled" value="true" />
The problem is that it works but it's slow. It takes about 7 seconds for the page to load. If I remove the web.config line, basically removing menu trimming based on roles it takes ~300ms for the page to load. Something is wrong in here.
Any ideas why my menu trimming based on roles is slow? I haven't done any customizations.
The security trimming feature relies on creating a controller instance for every node in order to determine if the current user context has access.
The most likely cause of this slowness is that your controllers (or their base class) have too much heavy processing happening in the constructor.
public class HomeController
{
public HomeController() {
// Lots of heavy processing
System.Threading.Thread.Sleep(300);
};
}
The above example will add 300 ms to the page load time for every node that represents an action method in the HomeController. If your other controllers also have heavy processing during instantiation, they will also add additional time to each page load.
When following DI best practices, this is not an issue because heavy processing takes place in external services after the controller instance is created.
public interface IHeavyProcessingService
{
IProcessingResult DoSomethingExpensive();
}
public class HeavyProcessingService : IHeavyProcessingService
{
public HeavyProcessingService() {
}
public IProcessingResult DoSomethingExpensive() {
// Lots of heavy processing
System.Threading.Thread.Sleep(300);
}
}
public class HomeController
{
private readonly IHeavyProcessingService heavyProcessingService;
// The constructor does no heavy processing. It is deferred until after
// the instance is created by HeavyProcessingService.
// The only thing happening here is assignment of dependencies.
public HomeController(IHeavyProcessingService heavyProcessingService) {
if (heavyProcessingService == null)
throw new ArgumentNullException("heavyProcessingService");
this.heavyProcessingService = heavyProcessingService;
};
public ActionResult Index()
{
var result = this.heavyProcessingService.DoSomethingExpensive();
// Do something with the result of the heavy processing
return View();
}
public ActionResult About()
{
return View();
}
public ActionResult Contact()
{
return View();
}
}
Notice in the above example that no heavy processing happens in the constructor? This means that creating an instance of HomeController is very cheap. It also means that action methods that don't require the heavy processing to happen (as in About() and Contact() in the example) won't take the hit of heavy processing required by Index().
If not using DI, MVC still requires that a new controller instance be created for each request (controller instances are never shared between users or action methods). Although, in that case it is not as noticeable on a per user basis because only 1 instance is created per user. Basically, MvcSiteMapProvider is slowing down because of a pre-existing issue with your application (which you can now fix).
Even if you are not using DI, it is still a best practice to defer heavy processing until after the controller instance is created.
public class HomeController
{
private readonly IHeavyProcessingService heavyProcessingService;
public HomeController() {
this.heavyProcessingService = new HeavyProcessingService();
};
public ActionResult Index()
{
var result = this.heavyProcessingService.DoSomethingExpensive();
// Do something with the result of the heavy processing
return View();
}
}
But if moving heavy processing into external services in your application is not an option, you can still defer processing until its needed by moving the processing into another method so it is not too expensive to create controller instances.
public class HomeController
{
public HomeController() {
};
private IProcessingResult DoSomethingExpensive() {
// Lots of heavy processing
System.Threading.Thread.Sleep(300);
}
public ActionResult Index()
{
var result = this.DoSomethingExpensive();
// Do something with the result of the heavy processing
return View();
}
}
Although there is a bug posted for Route values not preserved correctly in v4?
But looks like it was fixed in version 4 next release.
Another Workaround to fix this problem is cache here is a related article.
MVC siteMap provider cache
I want to use a third party view controller that already inherits from UIViewController (https://bitbucket.org/thedillonb/monotouch.slideoutnavigation/src/f4e51488598b/MonoTouch.SlideoutNavigation?at=master), how would I integrate that with MVVMCross?
I could just take the source and change it to inherit from MvxViewController, but guessing I will run into this with other libraries.
Do I need to implement all the interfaces MvxViewController does? IMvxTouchView? IMvxEventSourceViewController?
For this particular case, where you don't actually want to do any data-binding so you can just use a custom presenter - e.g. see #Blounty's answer, or see this project demo - https://github.com/fcaico/MvxSlidingPanels.Touch
If you ever do need to convert third party ViewController base classes so that they support data-binding, then the easiest way is exactly what you guessed:
inherit from them to provide an EventSource-ViewController
inherit from the EventSource-ViewController to add the Mvx BindingContext
This technique is exactly how MvvmCross itself extends each of UIViewController, UITableViewController, UITabBarController, etc in order to provide data-binding.
For example, see:
extending UIViewController to provide an eventsource - MvxEventSourceViewController.cs
extending the event source ViewController to provide a binding context - MvxViewController.cs
Note that because C# doesn't have any Multiple-Inhertiance or any true Mixin support, this adaption of ViewControllers does involve a little cut-and-paste, but we have tried to minimise this through the use of event hooks and extension methods.
If it helps, this iOS technique for a previous MvvmCross version was discussed in Integrating Google Mobile Analytics with MVVMCross (obviously this is out of date now - but the general principles kind of remain the same - we adapt an existing viewcontroller via inheritance)
In Android, a similar process is also followed for Activity base classes - see ActionBarSherlock with latest MVVMCross
You can use a custom view presenter like below, This is pretty much straight out of my app using the SlideOutNavigation.
public class Presenter
: IMvxTouchViewPresenter
{
private readonly MvxApplicationDelegate applicationDelegate;
private readonly UIWindow window;
private SlideoutNavigationController slideNavigationController;
private IMvxTouchViewCreator viewCreator;
public Presenter(MvxApplicationDelegate applicationDelegate, UIWindow window)
{
this.applicationDelegate = applicationDelegate;
this.window = window;
this.slideNavigationController = new SlideoutNavigationController();
this.slideNavigationController.SlideWidth = 200f;
this.window.RootViewController = this.slideNavigationController;
}
public async void Show(MvxViewModelRequest request)
{
var creator = Mvx.Resolve<IMvxTouchViewCreator>();
if (this.slideNavigationController.MenuView == null)
{
// TODO: MAke this not be sucky
this.slideNavigationController.MenuView = (MenuView)creator.CreateView(new MenuViewModel());
((MenuView) this.slideNavigationController.MenuView).MenuItemSelectedAction = this.MenuItemSelected;
}
var view = creator.CreateView(request);
this.slideNavigationController.TopView = (UIViewController)view;
}
public void ChangePresentation(MvxPresentationHint hint)
{
Console.WriteLine("Change Presentation Requested");
}
public bool PresentModalViewController(UIViewController controller, bool animated)
{
Console.WriteLine("Present View Controller Requested");
return true;
}
public void NativeModalViewControllerDisappearedOnItsOwn()
{
Console.WriteLine("NativeModalViewControllerDisappearedOnItsOwn");
}
private void MenuItemSelected(string targetType, string objectId)
{
var type = Type.GetType(string.Format("App.Core.ViewModels.{0}ViewModel, AppCore", targetType));
var parameters = new Dictionary<string, string>();
parameters.Add("objectId", objectId);
this.Show(new MvxViewModelRequest { ViewModelType = type, ParameterValues = parameters });
}
}
I'm using ServiceStack (version 3.9.44.0) as a Windows Service (so I'm not using IIS) and I use both its abilities both as an API and for serving web pages.
However, I haven't been able to find how exactly I should enable compression when the client supports it.
I imagined that ServiceStack would transparently compress data if the client's request included the Accept-Encoding:gzip,deflate header, but I'm not seeing any corresponding Content-Encoding:gzip in the returned responses.
So I have a couple of related questions:
In the context of using ServiceStack as a standalone service (without IIS), how do I enable compression for the responses when the browser accepts it.
In the context of a C# client, how do similarly I ensure that communication between the client/server is compressed.
If I'm missing something, any help would be welcome.
Thank you.
If you want to enable compression globally across your API, another option is to do this:
Add this override to your AppHost:
public override IServiceRunner<TRequest> CreateServiceRunner<TRequest>(ActionContext actionContext)
{
return new MyServiceRunner<TRequest>(this, actionContext);
}
Then implement that class like this:
public class MyServiceRunner<TRequest> : ServiceRunner<TRequest>
{
public MyServiceRunner(IAppHost appHost, ActionContext actionContext) : base(appHost, actionContext)
{
}
public override void OnBeforeExecute(IRequestContext requestContext, TRequest request)
{
base.OnBeforeExecute(requestContext, request);
}
public override object OnAfterExecute(IRequestContext requestContext, object response)
{
if ((response != null) && !(response is CompressedResult))
response = requestContext.ToOptimizedResult(response);
return base.OnAfterExecute(requestContext, response);
}
public override object HandleException(IRequestContext requestContext, TRequest request, Exception ex)
{
return base.HandleException(requestContext, request, ex);
}
}
OnAfterExecute will be called and give you the chance to change the response. Here, I am compressing anything that is not null and not already compressed (in case I'm using ToOptimizedResultUsingCache somewhere). You can be more selective if you need to but in my case, I'm all POCO objects with json.
References
ServiceStack New Api
For those interested, a partial answer to my own question, you can use the extension method ToOptimizedResult() or, if you are using caching ToOptimizedResultUsingCache().
For instance, returning a compressed result:
public class ArticleService : Service
{
public object Get(Articles request) {
return base.RequestContext.ToOptimizedResult(
new List<Articles> {
new Article {Ref = "SILVER01", Description = "Silver watch"},
new Article {Ref = "GOLD1547", Description = "Gold Bracelet"}
});
}
}
References
CachedServices.cs example
CompressedResult.cs
Google Group question on Compression in ServiceStack