using System;
using System.Collections.Generic;
using System.Runtime.Caching;
namespace Infrastructure.Cache
{
 public class RuntimeMemoryCache : ICache
 {
 private readonly MemoryCache memoryCache = MemoryCache.Default;
 /// <summary>
 /// 加入缓存项(绝对过期时间)
 /// </summary>
 /// <param name="key">缓存项标识</param>
 /// <param name="value">缓存项</param>
 /// <param name="timeSpan">缓存失效时间</param>
 public void Add(string key, object value, TimeSpan timeSpan)
 {
 if (!string.IsNullOrEmpty(key) && (value != null))
 {
 CacheItemPolicy cip = new CacheItemPolicy()
 {
 AbsoluteExpiration = DateTime.Now.Add(timeSpan)
 };
 this.memoryCache.Add(key, value, cip, null);
 }
 }
 /// <summary>
 /// 加入依赖物理文件的缓存项
 /// </summary>
 /// <param name="key">缓存项标识</param>
 /// <param name="value">缓存项</param>
 /// <param name="fullFileNameOfFileDependency">依赖的文件全路径</param>
 public void AddWithFileDependency(string key, object value, string fullFileNameOfFileDependency)
 {
 if (!string.IsNullOrEmpty(key) && (value != null))
 {
 CacheItemPolicy policy = new CacheItemPolicy
 {
 AbsoluteExpiration = DateTimeOffset.Now.AddMonths(1)
 };
 policy.ChangeMonitors.Add(new HostFileChangeMonitor(new List<string> { fullFileNameOfFileDependency }));
 this.memoryCache.Add(key, value, policy, null);
 }
 }

 public object Get(string cacheKey)
 {
 return this.memoryCache[cacheKey];
 }

 public T Get<T>(string cacheKey) where T : class
 {
 object obj = this.Get(cacheKey);
 if (obj != null)
 {
 return (obj as T);
 }
 return default(T);
 }

 public void Remove(string cacheKey)
 {
 this.memoryCache.Remove(cacheKey, null);
 }
 /// <summary>
 /// 如果不存在缓存项则添加,否则更新(相对过期)
 /// </summary>
 /// <param name="key">缓存项标识</param>
 /// <param name="value">缓存项</param>
 /// <param name="timeSpan">缓存失效时间</param>
 public void Set(string key, object value, TimeSpan timeSpan)
 {
 CacheItemPolicy cip = new CacheItemPolicy()
 {
 SlidingExpiration = timeSpan,
 };
 this.memoryCache.Set(key, value, cip, null);
 }
 /// <summary>
 /// 设置绝对过期时间
 /// </summary>
 /// <param name="key">缓存项标识</param>
 /// <param name="value">缓存项</param>
 /// <param name="timeSpan">缓存失效时间</param>
 public void SetAbsoluteExpiration(string key, object value, TimeSpan timeSpan)
 {
 CacheItemPolicy cip = new CacheItemPolicy()
 {
 AbsoluteExpiration = DateTime.Now.Add(timeSpan),
 };
 this.memoryCache.Set(key, value, cip, null);
 }
 }
}