如何在c#中实现通用缓存管理器

Question

我正在尝试实现通用缓存管理器,但是我不确定如何进行锁定.

到目前为止我有以下内容,但是如果我有两个具有相同返回类型的缓存条目,那么我猜测将使用相同的锁对象!

public class CacheManager : ICacheManager
{
    static class TypeLock<T>
    {
        public static readonly object SyncLock = new object();
    }
    private readonly ICache _cache;
    public CacheManager(ICache cache)
    {
        if (cache == null)
            throw new ArgumentNullException("cache");

        _cache = cache;
    }

    public TResult AddCache<TResult>(string cacheKey, Func<TResult> acquire, int cacheDurationInMinutes) where TResult : class
    {
        return AddCache(cacheKey, null, acquire, cacheDurationInMinutes);
    }

    public TResult AddCache<TResult>(string cacheKey, CacheDependency dependency, Func<TResult> acquire, int cacheDurationInMinutes) where TResult : class
    {
        var entry = acquire.Invoke();
        if (entry != null)
        {
            if (dependency != null)
                _cache.InsertWithDependency(cacheKey, entry, dependency, DateTime.Now.AddMinutes(cacheDurationInMinutes));
            else
                _cache.Insert(cacheKey, entry, DateTime.Now.AddMinutes(cacheDurationInMinutes));
        }
        return entry;
    }

    public TResult GetOrAddCache<TResult>(string cacheKey, Func<TResult> acquire, int cacheDurationInMinutes) where TResult : class
    {
        return GetOrAddCache(cacheKey, null, acquire, cacheDurationInMinutes);
    }

    public TResult GetOrAddCache<TResult>(string cacheKey, CacheDependency dependency, Func<TResult> acquire, int cacheDurationInMinutes) where TResult : class
    {
        var entry = _cache.GetItem(cacheKey) as TResult;

        if (entry == null)
        {
            lock (TypeLock<TResult>.SyncLock)
            {
                entry = _cache.GetItem(cacheKey) as TResult;
                if (entry == null)
                {
                    entry = acquire.Invoke();
                    if (entry != null)
                    {
                        if (dependency != null)
                            _cache.InsertWithDependency(cacheKey, entry, dependency,
                                                        DateTime.Now.AddMinutes(cacheDurationInMinutes));
                        else
                            _cache.Insert(cacheKey, entry, DateTime.Now.AddMinutes(cacheDurationInMinutes));
                    }
                }
            }
        }

        return entry;
    }
}

任何帮助将非常感激!

Answer 1

你是对的，这将为同一类型的所有缓存条目使用相同的锁。为了使您的实际缓存方法（内存、文件、数据库...）独立于该缓存管理器，我建议为每个缓存条目存储一个额外的同步对象，这样您的缓存条目将看起来像而不是Tuple<object, TResult>仅仅TResult，其中object将是new object()每个条目的 a 并将用于锁定。