Cache Eval

CacheEval.cs

// Implementation
private const int DEFAULT_RETENTION = 60;

public static T Eval<T>(this IMemoryCache cache, string key, Func<T> expression)
    => Eval(cache, key, DEFAULT_RETENTION, expression);

public static T Eval<T>(this IMemoryCache cache, string key, int retentionMinutes, Func<T> expression)
{
    T val;
    if (!cache.TryGetValue<T>(key, out val))
    {
        val = expression();
        cache.Set(key, val, new TimeSpan(retentionMinutes / 60, retentionMinutes % 60, 0));
    }
    return val;
}

// Usage
public IActionResult GetMyModel(int Id)
{
    var vm = _cache.Eval<MyModel>("myModelCacheKey", () => {
        return _db.Query<MyModel>("SELECT * FROM dbo.MyModel WHERE Id = @Id", new { Id });
    });
    return Json(vm);
}