[更新]缓存管理的帮助类（MemoryCache版，需要.net 4以上）

转载

mob604756fda125 2012-07-10 16:08:00

本来想发布下新版Luke.Net，正好刚刚再次重构了缓存的帮助类这里发布下：

测试代码

        [Fact]
        public void SimpleTest()
        {
            ICache<int, string> cacheMenager = MemoryCache<int, string>.Instance;
            var value = cacheMenager.Get(1, () => 1, TimeSpan.FromSeconds(10));
            Assert.Equal(value, 1);
            value = cacheMenager.Get(1, () => 2, TimeSpan.FromSeconds(10));
            Assert.Equal(value, 1);
            System.Threading.Thread.Sleep(10 * 1000);
            value = cacheMenager.Get(1, () => 3, TimeSpan.FromSeconds(10));
            Assert.Equal(value, 3);
        }

接口

    public interface ICache<TK,TV> 
    {
        TV Get<TV>(TK cacheKey, Func<TV> getUncachedValue, DateTimeOffset dateTimeOffset);

        TV Get<TV>(TK cacheKey, Func<TV> getUncachedValue, TimeSpan timeSpan);

        void Remove(TK cacheKey);
    }

用到的单例类

    public class SingletonProvider<T> where T : new()
    {
        SingletonProvider() { }

        public static T Instance
        {
            get { return SingletonCreator.instance; }
        }

        class SingletonCreator
        {
            static SingletonCreator() { }
            internal static readonly T instance = new T();
        }
    }

最后是更新后的缓存类，

    public class MemoryCache<TK, TV> : ICache<TK, TV>
    {
        private ObjectCache _memoryCache;
        public static MemoryCache<TK, TV> Instance
        {
            get { return SingletonProvider<MemoryCache<TK, TV>>.Instance; }
        }

        public MemoryCache() : this(null) { }
        public MemoryCache(string name)
        {
            _memoryCache = new MemoryCache(string.Format("{0}-{1}-{2}", typeof(TK).Name, typeof(TV).Name, name));
        }

        public TV Get<TV>(TK cacheKey, Func<TV> getUncachedValue, DateTimeOffset dateTimeOffset)
        {
            if (_memoryCache.Contains(ParseKey(cacheKey)))
            {
                return (TV)_memoryCache[ParseKey(cacheKey)];
            }
            else
            {
                var v = getUncachedValue();
                object o = v;
                _memoryCache.Set(ParseKey(cacheKey), o, dateTimeOffset);
                return v;
            }
        }

        public TV Get<TV>(TK cacheKey, Func<TV> getUncachedValue, TimeSpan timeSpan)
        {
            return Get(cacheKey, getUncachedValue, new DateTimeOffset(DateTime.UtcNow + timeSpan));
        }

        public void Remove(TK cacheKey)
        {
            _memoryCache.Remove(ParseKey(cacheKey));
        }

        private string ParseKey(TK key)
        {
            return key.GetHashCode().ToString();
        }
    }