[更新]缓存管理的帮助类（MemoryCache版，需要.net 4以上）

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();
    }
}