Earliest moment to abandon POST request in webservice?

Question

One of the 'security measures' in my webservice is blocking large file uploads.
I want to cancel a file upload request ASAP when too large files are sent.

Since the requests with the file uploads are going to be the largest ones anyway, I currently have this code in the BeforeDispatch handler of the TWebModule:

procedure TWebModuleWebServices.WebModuleBeforeDispatch(Sender: TObject; Request: TWebRequest; Response: TWebResponse; var Handled: Boolean);
begin
   // Request that are too large are going to be dropped silently:
   if Request.ContentLength > cMaxContentSize then
   begin
      Handled := true;
      Exit;
   end;

Is the BeforeDispatch handler the earliest possible stage for this test, or is there a better place?

The web service is built around a TIdHTTPWebBrokerBridge (= class(TIdCustomHTTPServer), see IdHTTPWebBrokerBridge.pas)

Answer 1

With Indy, TCustomWebDispatcher.BeforeDispatch event is too late as the post data stream has already been retrieved in TIdCustomHttpServer.DoExecute. You can use TIdCustomHTTPServer.OnHeadersAvailable event - which is triggered earlier - to avoid it by setting VContinueProcessing to False.