/// <summary>
/// 创建一个标准缓存策略
/// </summary>
/// <param name="context">请求上下文</param>
/// <param name="token">缓存标示</param>
/// <param name="provider">缓存策略提供程序</param>
/// <param name="duration">缓存持续时间</param>
/// <param name="enableClientCache">是否启用客户端缓存</param>
/// <param name="localcacheVirtualPath">静态文件缓存虚拟路径</param>
/// <param name="enableMemoryCache">是否启用内存缓存</param>
public StandardCachePolicy( HttpContextBase context, CacheToken token, ICachePolicyProvider provider, TimeSpan duration, bool enableClientCache, string localcacheVirtualPath, bool enableMemoryCache )
: base( context, token, provider )
{
if ( context == null )
throw new ArgumentNullException( "context" );
if ( provider == null )
throw new ArgumentNullException( "provider" );
Duration = duration;
EnableClientCache = enableClientCache;
if ( localcacheVirtualPath != null )
{
var physicalPath = context.Server.MapPath( localcacheVirtualPath );
CacheStorageProvider = new StaticFileCacheStorageProvider( physicalPath, enableMemoryCache );
}
else
{
CacheStorageProvider = new WebCacheStorageProvider( HttpRuntime.Cache );
}
}
/// <summary>
/// 创建一个标准缓存策略
/// </summary>
/// <param name="context">请求上下文</param>
/// <param name="token">缓存标示</param>
/// <param name="provider">缓存策略提供程序</param>
/// <param name="duration">缓存持续时间</param>
/// <param name="enableClientCache">是否启用客户端缓存</param>
/// <param name="localcacheVirtualPath">静态文件缓存虚拟路径</param>
/// <param name="enableMemoryCache">是否启用内存缓存</param>
public StandardCachePolicy(HttpContextBase context, CacheToken token, ICachePolicyProvider provider, TimeSpan duration, bool enableClientCache, string localcacheVirtualPath, bool enableMemoryCache)
: base(context, token, provider)
{
if (context == null)
{
throw new ArgumentNullException("context");
}
if (provider == null)
{
throw new ArgumentNullException("provider");
}
Duration = duration;
EnableClientCache = enableClientCache;
if (localcacheVirtualPath != null)
{
var physicalPath = context.Server.MapPath(localcacheVirtualPath);
CacheStorageProvider = new StaticFileCacheStorageProvider(physicalPath, enableMemoryCache);
}
else
{
CacheStorageProvider = new WebCacheStorageProvider(HttpRuntime.Cache);
}
}
/// <summary>
/// 创建持久化输出流
/// </summary>
/// <param name="token"></param>
/// <returns></returns>
protected override Stream CreateSaveStream(CacheToken token)
{
Directory.CreateDirectory(PhysicalPath);
var path = Path.Combine(PhysicalPath, CreateFilename(token));
return(File.OpenWrite(path));
}
/// <summary>
/// 缓存项是否还有效
/// </summary>
/// <param name="token">缓存标识，检查检查缓存项的标识是否与提供的一致，否则也认为缓存项无效</param>
/// <returns>是否有效</returns>
public bool IsValid(CacheToken token)
{
if (IsValid())
{
return(CacheToken == token);
}
return(false);
}
/// <summary>
/// 获取缓存项
/// </summary>
/// <param name="token"></param>
/// <returns></returns>
public virtual CacheItem GetCacheItem(CacheToken token)
{
var cacheItem = LoadCacheItem(token);
if (cacheItem != null && cacheItem.IsValid(token))//检查缓存是否已过期
{
return(cacheItem);
}
return(null);
}
/// <summary>
/// 获取缓存项
/// </summary>
/// <param name="token"></param>
/// <returns></returns>
public virtual CacheItem GetCacheItem( CacheToken token )
{
var cacheItem = LoadCacheItem( token );
if ( cacheItem != null && cacheItem.IsValid( token ) )//检查缓存是否已过期
return cacheItem;
return null;
}
/// <summary>
/// 创建一个缓存项
/// </summary>
/// <param name="token">缓存项的缓存依据</param>
/// <param name="cached">缓存的数据</param>
/// <param name="duration">最大缓存时间</param>
public CacheItem( CacheToken token, ICachedResponse cached, TimeSpan duration )
{
CacheToken = token;
CachedResponse = cached;
var shake = Math.Min( DurationWhenCreated.TotalMilliseconds / 50, maxShake.TotalMilliseconds );
var random = new Random( DateTime.Now.Millisecond );
var offset = TimeSpan.FromMilliseconds( random.NextDouble() * shake );
Expiration = DateTime.UtcNow + duration + offset;
DurationWhenCreated = duration;
}
/// <summary>
/// 创建持久化输入流
/// </summary>
/// <param name="token"></param>
/// <returns></returns>
protected override Stream CreateLoadStream(CacheToken token)
{
var path = Path.Combine(PhysicalPath, CreateFilename(token));
if (File.Exists(path))
{
return(File.OpenRead(path));
}
else
{
return(null);
}
}
/// <summary>
/// 创建一个缓存项
/// </summary>
/// <param name="token">缓存项的缓存依据</param>
/// <param name="cached">缓存的数据</param>
/// <param name="duration">最大缓存时间</param>
public CacheItem(CacheToken token, ICachedResponse cached, TimeSpan duration)
{
CacheToken = token;
CachedResponse = cached;
var shake = Math.Min(DurationWhenCreated.TotalMilliseconds / 50, maxShake.TotalMilliseconds);
var random = new Random(DateTime.Now.Millisecond);
var offset = TimeSpan.FromMilliseconds(random.NextDouble() * shake);
Expiration = DateTime.UtcNow + duration + offset;
DurationWhenCreated = duration;
}
/// <summary>
/// 根据缓存标识创建静态缓存的文件名
/// </summary>
/// <param name="token">缓存标识</param>
/// <returns></returns>
protected virtual string CreateFilename(CacheToken token)
{
var cacheKey = token.CacheKey();
var name = invalidPathCharactor.Replace(token.CacheKey(), "");
if (name.Length > 20)
{
name = name.Substring(0, 20);
}
var hash = FormsAuthentication.HashPasswordForStoringInConfigFile(cacheKey, "SHA1");
return(name + "_" + hash + ".cache");
}
/// <summary>
/// 从 WebCache 获取缓存的响应
/// </summary>
/// <param name="cache"></param>
/// <param name="token"></param>
/// <returns></returns>
public static ICachedResponse GetCachedResponse(this Cache cache, CacheToken token)
{
var cacheItem = cache.GetCacheItem(token);
if (cacheItem == null)
{
return(null);
}
else
{
return(cacheItem.CachedResponse);
}
}
/// <summary>
/// 创建一个标准缓存策略
/// </summary>
/// <param name="context">请求上下文</param>
/// <param name="token">缓存标示</param>
/// <param name="provider">缓存策略提供程序</param>
/// <param name="duration">缓存持续时间</param>
/// <param name="enableClientCache">是否启用客户端缓存</param>
/// <param name="storageProvider">缓存储存提供程序</param>
public StandardCachePolicy( HttpContextBase context, CacheToken token, ICachePolicyProvider provider, TimeSpan duration, bool enableClientCache, ICacheStorageProvider storageProvider )
: base(context, token, provider)
{
if ( context == null )
throw new ArgumentNullException( "context" );
if ( provider == null )
throw new ArgumentNullException( "provider" );
Duration = duration;
EnableClientCache = enableClientCache;
CacheStorageProvider = storageProvider;
}
/// <summary>
/// 从持久化设备中加载缓存项
/// </summary>
/// <param name="token"></param>
/// <returns></returns>
protected virtual CacheItem LoadCacheItem( CacheToken token )
{
using ( var stream = CreateLoadStream( token ) )
{
if ( stream == null )
return null;
var cacheItem = Deserialize( stream );
if ( cacheItem != null && cacheItem.IsValid( token ) )
return cacheItem;
else
return null;
}
}
/// <summary>
/// 创建一个标准缓存策略
/// </summary>
/// <param name="context">请求上下文</param>
/// <param name="token">缓存标示</param>
/// <param name="provider">缓存策略提供程序</param>
/// <param name="duration">缓存持续时间</param>
/// <param name="enableClientCache">是否启用客户端缓存</param>
/// <param name="storageProvider">缓存储存提供程序</param>
public StandardCachePolicy(HttpContextBase context, CacheToken token, ICachePolicyProvider provider, TimeSpan duration, bool enableClientCache, ICacheStorageProvider storageProvider)
: base(context, token, provider)
{
if (context == null)
{
throw new ArgumentNullException("context");
}
if (provider == null)
{
throw new ArgumentNullException("provider");
}
Duration = duration;
EnableClientCache = enableClientCache;
CacheStorageProvider = storageProvider;
}
/// <summary>
/// 获取缓存项
/// </summary>
/// <param name="token">缓存标识</param>
/// <returns></returns>
public override CacheItem GetCacheItem(CacheToken token)
{
if (EnableMemoryCache)
{
var cacheItem = HttpRuntime.Cache.GetCacheItem(token);
if (cacheItem != null)
{
if (!cacheItem.IsValid())//缓存已过期
{
return(null);
}
return(cacheItem);
}
}
return(base.GetCacheItem(token));
}
/// <summary>
/// 从持久化设备中加载缓存项
/// </summary>
/// <param name="token"></param>
/// <returns></returns>
protected virtual CacheItem LoadCacheItem(CacheToken token)
{
using (var stream = CreateLoadStream(token))
{
if (stream == null)
{
return(null);
}
var cacheItem = Deserialize(stream);
if (cacheItem != null && cacheItem.IsValid(token))
{
return(cacheItem);
}
else
{
return(null);
}
}
}
/// <summary> /// 创建持久化输入流 /// </summary> /// <param name="token"></param> /// <returns></returns> protected abstract Stream CreateLoadStream( CacheToken token );
public MyCachePolicy( HttpContextBase context, CacheToken cacheToken, ICachePolicyProvider provider )
: base(context, cacheToken, provider, TimeSpan.FromDays( 1 ), true, "~/StaticCaches", true)
{
}
/// <summary>
/// 创建一个标准缓存策略
/// </summary>
/// <param name="context">请求上下文</param>
/// <param name="token">缓存标示</param>
/// <param name="provider">缓存策略提供程序</param>
/// <param name="duration">缓存持续时间</param>
/// <param name="enableClientCache">是否启用客户端缓存</param>
public StandardCachePolicy(HttpContextBase context, CacheToken token, ICachePolicyProvider provider, TimeSpan duration, bool enableClientCache)
: this(context, token, provider, duration, enableClientCache, new WebCacheStorageProvider())
{
}
/// <summary>
/// 从 WebCache 获取一个缓存项
/// </summary>
/// <param name="cache"></param>
/// <param name="token"></param>
/// <returns></returns>
public static CacheItem GetCacheItem(this Cache cache, CacheToken token)
{
return(cache.Get(token.CacheKey()) as CacheItem);
}
/// <summary> /// 创建持久化输入流 /// </summary> /// <param name="token"></param> /// <returns></returns> protected abstract Stream CreateLoadStream(CacheToken token);
/// <summary> /// 创建持久化输出流 /// </summary> /// <param name="token"></param> /// <returns></returns> protected abstract Stream CreateSaveStream(CacheToken token);
/// <summary>
/// 创建 CachePolicy 实例
/// </summary>
/// <param name="context">HTTP 上下文</param>
/// <param name="token">缓存标识</param>
/// <param name="provider">缓存策略提供程序</param>
public CachePolicy( HttpContextBase context, CacheToken token, ICachePolicyProvider provider )
{
HttpContext = context;
CacheToken = token;
Provider = provider;
}
/// <summary>
/// 根据缓存标识创建静态缓存的文件名
/// </summary>
/// <param name="token">缓存标识</param>
/// <returns></returns>
protected virtual string CreateFilename( CacheToken token )
{
var cacheKey = token.CacheKey();
var name = invalidPathCharactor.Replace( token.CacheKey(), "" );
if ( name.Length > 20 )
name = name.Substring( 0, 20 );
var hash = FormsAuthentication.HashPasswordForStoringInConfigFile( cacheKey, "SHA1" );
return name + "_" + hash + ".cache";
}
/// <summary>
/// 创建持久化输出流
/// </summary>
/// <param name="token"></param>
/// <returns></returns>
protected override Stream CreateSaveStream( CacheToken token )
{
Directory.CreateDirectory( PhysicalPath );
var path = Path.Combine( PhysicalPath, CreateFilename( token ) );
return File.OpenWrite( path );
}
/// <summary>
/// 缓存项是否还有效
/// </summary>
/// <param name="token">缓存标识，检查检查缓存项的标识是否与提供的一致，否则也认为缓存项无效</param>
/// <returns>是否有效</returns>
public bool IsValid( CacheToken token )
{
if ( IsValid() )
return CacheToken == token;
return false;
}
/// <summary>
/// 创建 CachePolicy 实例
/// </summary>
/// <param name="context">HTTP 上下文</param>
/// <param name="token">缓存标识</param>
/// <param name="provider">缓存策略提供程序</param>
public CachePolicy(HttpContextBase context, CacheToken token, ICachePolicyProvider provider)
{
HttpContext = context;
CacheToken = token;
Provider = provider;
}
/// <summary>
/// 从 WebCache 获取一个缓存项
/// </summary>
/// <param name="cache"></param>
/// <param name="token"></param>
/// <returns></returns>
public static CacheItem GetCacheItem( this Cache cache, CacheToken token )
{
return cache.Get( token.CacheKey() ) as CacheItem;
}
/// <summary>
/// 从 WebCache 获取缓存的响应
/// </summary>
/// <param name="cache"></param>
/// <param name="token"></param>
/// <returns></returns>
public static ICachedResponse GetCachedResponse( this Cache cache, CacheToken token )
{
var cacheItem = cache.GetCacheItem( token );
if ( cacheItem == null )
return null;
else
return cacheItem.CachedResponse;
}
/// <summary>
/// 创建一个标准缓存策略
/// </summary>
/// <param name="context">请求上下文</param>
/// <param name="token">缓存标示</param>
/// <param name="provider">缓存策略提供程序</param>
/// <param name="duration">缓存持续时间</param>
/// <param name="enableClientCache">是否启用客户端缓存</param>
public StandardCachePolicy( HttpContextBase context, CacheToken token, ICachePolicyProvider provider, TimeSpan duration, bool enableClientCache )
: this(context, token, provider, duration, enableClientCache, new WebCacheStorageProvider())
{
}
/// <summary>
/// 获取一个缓存项
/// </summary>
/// <param name="token">缓存标示</param>
/// <returns></returns>
public CacheItem GetCacheItem(CacheToken token)
{
return(_cache.GetCacheItem(token));
}
/// <summary>
/// 获取缓存项
/// </summary>
/// <param name="token">缓存标识</param>
/// <returns></returns>
public override CacheItem GetCacheItem( CacheToken token )
{
if ( EnableMemoryCache )
{
var cacheItem = HttpRuntime.Cache.GetCacheItem( token );
if ( cacheItem != null )
{
if ( !cacheItem.IsValid() )//缓存已过期
return null;
return cacheItem;
}
}
return base.GetCacheItem( token );
}
/// <summary> /// 创建持久化输出流 /// </summary> /// <param name="token"></param> /// <returns></returns> protected abstract Stream CreateSaveStream( CacheToken token );
/// <summary>
/// 创建持久化输入流
/// </summary>
/// <param name="token"></param>
/// <returns></returns>
protected override Stream CreateLoadStream( CacheToken token )
{
var path = Path.Combine( PhysicalPath, CreateFilename( token ) );
if ( File.Exists( path ) )
return File.OpenRead( path );
else
return null;
}
