Caching Data in Web API

Question

I have the need to cache a collection of objects that is mostly static (might have changes 1x per day) that is avaliable in my ASP.NET Web API OData service. This result set

Answer 1

The solution I ended up using involved MemoryCache in the System.Runtime.Caching namespace. Here is the code that ended up working for caching my collection:

//If the data exists in cache, pull it from there, otherwise make a call to database to get the data
ObjectCache cache = MemoryCache.Default;

var peopleData = cache.Get("PeopleData") as List;
if (peopleData != null)
   return peopleData ;

peopleData = GetAllPeople();
CacheItemPolicy policy = new CacheItemPolicy {AbsoluteExpiration = DateTimeOffset.Now.AddMinutes(30)};
cache.Add("PeopleData", peopleData, policy);
return peopleData;

Here is another way I found using Lazy to take into account locking and concurrency. Total credit goes to this post: How to deal with costly building operations using MemoryCache?

private IEnumerable GetFromCache(string key, Func> valueFactory) where TEntity : class 
{
    ObjectCache cache = MemoryCache.Default;
    var newValue = new Lazy>(valueFactory);            
    CacheItemPolicy policy = new CacheItemPolicy { AbsoluteExpiration = DateTimeOffset.Now.AddMinutes(30) };
    //The line below returns existing item or adds the new value if it doesn't exist
    var value = cache.AddOrGetExisting(key, newValue, policy) as Lazy>;
    return (value ?? newValue).Value; // Lazy handles the locking itself
}