How can I cache objects in ASP.NET MVC?

Question

I\'d like to cache objects in ASP.NET MVC. I have a BaseController that I want all Controllers to inherit from. In the BaseController there is a User

Answer 1

Implementation with a minimal cache locking. The value stored in the cache is wrapped in a container. If the value is not in the cache, then the value container is locked. The cache is locked only during the creation of the container.

public static class CacheExtensions
{
    private static object sync = new object();

    private class Container
    {
        public T Value;
    }

    public static TValue GetOrStore(this Cache cache, string key, Func create, TimeSpan slidingExpiration)
    {
        return cache.GetOrStore(key, create, Cache.NoAbsoluteExpiration, slidingExpiration);
    }

    public static TValue GetOrStore(this Cache cache, string key, Func create, DateTime absoluteExpiration)
    {
        return cache.GetOrStore(key, create, absoluteExpiration, Cache.NoSlidingExpiration);
    }

    public static TValue GetOrStore(this Cache cache, string key, Func create, DateTime absoluteExpiration, TimeSpan slidingExpiration)
    {
        return cache.GetOrCreate(key, x => create());
    }

    public static TValue GetOrStore(this Cache cache, string key, Func create, DateTime absoluteExpiration, TimeSpan slidingExpiration)
    {
        var instance = cache.GetOrStoreContainer(key, absoluteExpiration, slidingExpiration);
        if (instance.Value == null)
            lock (instance)
                if (instance.Value == null)
                    instance.Value = create(key);

        return instance.Value;
    }

    private static Container GetOrStoreContainer(this Cache cache, string key, DateTime absoluteExpiration, TimeSpan slidingExpiration)
    {
        var instance = cache[key];
        if (instance == null)
            lock (cache)
            {
                instance = cache[key];
                if (instance == null)
                {
                    instance = new Container();

                    cache.Add(key, instance, null, absoluteExpiration, slidingExpiration, CacheItemPriority.Default, null);
                }
            }

        return (Container)instance;
    }
}