We\'ve started implementing some caching code in our MVC project. We\'ve derived

Question

We've started implementing some caching code in our MVC project. We've derived from .Net's ObjectCache to store it in a SQL database.

What we do right now is in each method we want to cache we have code like this:

public StatusCounts GetCounts()
{
   var cache = new SqlCache<StatusCounts>("mykey");
   if(cache.HasCachedData())
      return cache.GetCachedData();

   var data = StatusRepository.GetCounts();

   cache.SetData(data, DateTime.Now.AddHours(2));
}
As far as caching goes, it works. But my concern is it seems like now GetCounts has multiple responsibilities. It's no longer just calculating counts, it's getting them from a cache (if they exist) and saving them to a cache before returning.

Is there a cleaner way to do this?

Explanation / Answer

You can separate the cache initialization from returning the value, and implement the cache initialization in a generic way:

public StatusCounts GetCounts()
{
var cache = GetInitializedCache<StatusCounts>("mykey",StatusRepository.GetCounts,2);
return cache.GetCachedData();
}

private SqlCache<T> GetInitializedCache<T>(string key,Function<T> getData,double hours)
{
var cache = new SqlCache<T>(key);
if(!cache.HasCachedData())
{
T data = getData();
cache.SetData(data, DateTime.Now.AddHours(hours));
}
return cache;
}
That will separate the concerns of caching and calculating the values as well as giving you a reusable function. Of course, the method body of GetCounts is still aware of the caching mechanics, and if you want to avoid that too, @Peri's answer maybe the right approach (for the price of having to introduce a non-trivial third-party component).

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.