Question

I’m using .NET C# for a project.

I have a list of products which I want to cache as they’re used company wide. If the products drop out of cache I already know how to lock the cache and rebuild it ok as per the patterns on various authority/blog sites.

In my pages/user controls etc, I might grab a reference to the cache, like this:

var myCacheInstance = cachedProducts

However, I might also want to do something like this:

myCacheInstance.Add(new product(...));

Which will also update the cache as it’s the same object.

I have 2 queries.

1. If I have a reference to the cached object is it guaranteed to remain in cache for the lifetime of my variable?
2. In the scanario outlined above, how do I go about ensuring integrity? I’m only planning on adding in this instance, but suppose, I was updating and deleting objects as well?

Answer 1

1) If I have a reference to the cached object is it guaranteed to
remain in cache for the lifetime of my variable?

If I right interpret this question: responce is no.

cache.Add("key", new object()); // ADD KEY
var obj = cache["key"];         // GET REFERENCE TO CACHED OBJECT
cache.Remove("key");            // REMOVE OBJECT FROM CACHE

obj.DoSomething(..);            //PERFECTLY VALID, STILL WORK ..

2) In the scanario outlined above, how do I go about ensuring
integrity? I’m only planning on adding in this instance, but suppose,
I was updating and deleting objects as well?

Can add bool property like, for example:

public bool IsValid
{
    get; private set;
}

when object removed this property is set from the class to false. Just example, iff it really fits your need can tell us only you.