缓存和ASP.NET

Question

I have a question that is more related to how ASP.NET works and will try my best to explain so here goes.

I have a four tiered architecture in my app

1. Web (ASP.NET Web Application)
2. Business (Class Library)
3. Generic CRUD layer ** (Class Library)
4. Data (Class Library)

This generic CRUD layer of mine uses reflection to set and read properties of an object, however I have read that using PropertyInfo is fairly expensive and thus want to cache these items.

Here is the scenario:

Two people access the site, lets call them Fred and Jim. Fred creates a Customer which in turn called the Generic CRUD layer and caches the property info of the Customer class within System.RuntimeCache. Jim, then seconds later also creates a Customer.

My question is will the two requests from both Fred and Jim cause the obtaining of propery info to be triggered twice? Or will ASP.NET retrieve it from cache the second time, ie Jim's request is quicker as property info is obtained via the cache?

My thinking is that because my CRUD is a class library and not having access to System.Web.Cache, the property info won't be cached across all sessions / users?

Answer 1

No, it will issue new queries for each request (unless you've coded otherwise).

There are multiple layers of caching that could happen in ASP.Net application (browser, proxies, server side response caching, intermediate objects caching, DA layer caching) which all can be configured/used. But nothing is ever cached in ASP.Net (or in any application) unless one specifically wrote code/rules/configuration to do so.

Answer 2

As Alexei Levenkov points out, you have to configure caching to happen explicitly: you're not going to get automatic caching of specific property values.

But let me point out that while using PropertyInfo is expensive compared to writing code to directly access properties, it pales in comparison to the cost of a database round-trip or the latency between your server and your end user. Tools like Entity Framework, WebForms, and MVC all make extensive use of reflection because the performance cost it incurs is totally worth the reduced maintenance costs.

Avoid premature optimization.