I know there is a couple answered questions on here regarding “request scoped” globals, but I want to nit-pick on something specifically and maybe squeeze some extra enlightenment out of one or two of you.
I have an ASP.NET C# Website and a static Dictionary of objects (loaded from DB once on Application start). Each page request will need to do a lookup in the Dictionary (based on a key derived from the request url/etc) and get the appropriate object.
The issue is I’m trying to maximize efficiency by reducing the lookups to the Dictionary per Request. Doing just a single lookup within a Page itself is easy enough and I can pass the object to sub controls, etc too.. but global.asax is separate from the Page and it also needs to use the object (in Application_BeginRequest and Session_Start).
So is doing a Dictionary lookup once in Application_BeginRequest, once (when necessary) in Session_Start and once in the Page negligible speed wise, even if there are many requests coming in every second?
I would like it if I could just have a Request scoped global variable that I can easily call upon.. the only one I see available though is HttpContext.Current.Items and that is a Dictionary itself.
Am I being ridiculously nit-picky with my concern over efficiency? or will these milliseconds (nanoseconds?) get me in the long run when more and more requests are being made?
Thanks.
PS. I currently only have around 100 objects in the Dictionary although this may increase in the future.
A dictionary lookup is (roughly) a constant-time operation, so, yes, I do believe that you are trying to over-optimize here.
As always, when performance is an issue, try to do profiling (there are tools available for this) before doing micro-optimization. Otherwise, you might end up wasting time on optimizing the wrong parts of your application.