/// <summary>
/// 根据现有缓存策略创建 MemoryCache 的缓存策略
/// </summary>
/// <param name="cachePolicy">缓存策略</param>
/// <returns>MemoryCache 的缓存策略</returns>
private CacheItemPolicy CreateCacheItemPolicy(CachePolicyItem cachePolicy)
{
return(new CacheItemPolicy
{
AbsoluteExpiration = cachePolicy.Expires,
Priority = cachePolicy.Priority.IsHighPriority ? CacheItemPriority.NotRemovable : CacheItemPriority.Default,
});
}
/// <summary>
/// 设置一个缓存
/// </summary>
/// <param name="cacheKey">缓存键</param>
/// <param name="value">缓存值</param>
/// <param name="cachePolicy">缓存策略</param>
public async Task Set(string cacheKey, object value, CachePolicyItem cachePolicy)
{
_manager.SetCachePolicy(cacheKey, cachePolicy);
var stream = new MemoryStream();
_serializer.Serialize(stream, value);
await _manager.WriteStream(cacheKey, stream);
}
/// <summary>
/// 设置缓存策略对象
/// </summary>
/// <param name="cacheKey"></param>
/// <param name="cachePolicy"></param>
public void SetCachePolicy(string cacheKey, CachePolicyItem cachePolicy)
{
var filepath = Path.Combine(CurrentDirectory, cacheKey + ".policy");
using (var writer = new StreamWriter(new FileStream(filepath, FileMode.Create, FileAccess.Write, FileShare.Delete), Encoding.UTF8))
{
writer.Write(cachePolicy.ToString());
}
}
/// <summary>
/// 创建一个缓存项
/// </summary>
/// <param name="value">缓存值</param>
/// <param name="policy">缓存策略</param>
public CacheEntry(T value, CachePolicyItem policy)
{
_value = value;
_policy = policy;
if (_policy == null)
{
throw new ArgumentNullException("policy");
}
}
public virtual async Task Set(string key, object value, CachePolicyItem cachePolicy)
{
//清除一级缓存，写入二级缓存
await L1Cache.Remove(key);
await L2Cache.Set(key, value, cachePolicy);
//后台写入一级缓存。
Background(L1Cache.Set(key, value, cachePolicy));
}
/// <summary>
/// 获取缓存策略对象
/// </summary>
/// <param name="cacheKey">缓存键</param>
/// <returns>缓存策略对象</returns>
public CachePolicyItem GetCachePolicy(string cacheKey)
{
var filepath = Path.Combine(CurrentDirectory, cacheKey + ".policy");
if (File.Exists(filepath) == false)
{
return(CachePolicyItem.InvalidCachePolicy);
}
try
{
string data;
using (var reader = new StreamReader(new FileStream(filepath, FileMode.Open, FileAccess.Read, FileShare.Delete | FileShare.ReadWrite), Encoding.UTF8))
{
data = reader.ReadToEnd();
}
return(CachePolicyItem.Parse(data));
}
catch (IOException)
{
return(CachePolicyItem.InvalidCachePolicy);
}
}
/// <summary>
/// 设置缓存值
/// </summary>
/// <param name="key">缓存键</param>
/// <param name="value">缓存值</param>
/// <param name="cachePolicy">缓存策略</param>
public void Set(string key, object value, CachePolicyItem cachePolicy)
{
_host.Set(new System.Runtime.Caching.CacheItem(key, value), CreateCacheItemPolicy(cachePolicy));
}
async Task IAsyncCacheProvider.Set(string cacheKey, object value, CachePolicyItem cachePolicy)
{
var provider = await GetCacheProvider(cacheKey);
await provider.Set(cacheKey, value, cachePolicy);
}
public Task Set(string key, object value, CachePolicyItem cachePolicy)
{
provider.Set(key, value, cachePolicy);
return(Task.FromResult((object)null));
}
public SpecifyCachePolicy(CachePolicyItem item)
{
_item = item;
}
void ICacheProvider.Set(string cacheKey, object value, CachePolicyItem cachePolicy)
{
}