CacheExtensions

CacheExtensions.cs

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

        /// <summary>
        /// Executes a method and stores the result in cache using the given cache key.  If the data already exists in cache, it returns the data
        /// and doesn't execute the method.  Thread safe, although the method parametersn't guaranteed to be thread safe.
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="cache"></param>
        /// <param name="cacheKey">Each method has it's own isolated set of cache items,so cacheKeys won't overlap accross methods.</param>
        /// <param name="method"></param>
        /// <param name="expirationSeconds">Lifetime of cache items, in seconds</param>
        /// <returns></returns>
        public static T Data<T>(this Cache cache, string cacheKey, int expirationSeconds, Func<T> method)
        {
            //var hash = method.GetHashCode().ToString();
            //var data = (T)cache[hash + cacheKey];
            cacheKey = cacheKey.ToLower();

            var data = (T)cache[cacheKey];

            if (data == null)
            {
                data = method();

                if (expirationSeconds > 0 && data != null)
                    lock (sync)
                    {
                        //cache.Insert(hash + cacheKey, data, null, DateTime.Now.AddSeconds(expirationSeconds), Cache.NoSlidingExpiration);
                        cache.Insert(cacheKey, data, null, DateTime.Now.AddSeconds(expirationSeconds), Cache.NoSlidingExpiration);
                    }
            }
            return data;
        }

        public static void Clear(this Cache cache)
        {
            List<string> keys = new List<string>();
            // retrieve application Cache enumerator
            IDictionaryEnumerator enumerator = cache.GetEnumerator();
            // copy all keys that currently exist in Cache
            while (enumerator.MoveNext())
            {
                keys.Add(enumerator.Key.ToString());
            }
            // delete every key from cache
            for (int i = 0; i < keys.Count; i++)
            {
                cache.Remove(keys[i]);
            }
        }
    }