ASP.NET

public static bool IsValid(ActionTypeEnum actionType)
{
    HttpContext context = HttpContext.Current;
    if(context.Request.Browser.Crawler)return false;

    string key = actionType.ToString() + context.Request.UserHostAddress;
    var hit = (HitInfo)(context.Cache[key]?? new HitInfo());

    if(hit.Hits == 1)
    {
        context.Cache.Add(key, hit, null, DateTime.Now.AddMinutes(DURATION), System.Web.Caching.Cache.NoSlidingExpiration, System.Web.Caching.CacheItemPriority.Normal, null);
    }

    return true;
}