[转载]ASP.NET性能优化之构建自定义文件缓存 – 陆敏技 – 博客园.
SP.NET的输出缓存(即静态HTML)在.NET4.0前一直是基于内存的。这意味着如果我们的站点含有大量的缓存,则很容易消耗掉本机内存。 现在,借助于.NET4.0中的OutputCacheProvider,我们可以有多种选择创建自己的缓存。如,我们可以把HTML输出缓存存储到 memcached分布式集群服务器,或者MongoDB中(一种常用的面向文档数据库,不妨阅读本篇http://msdn.microsoft.com/zh-cn/magazine/gg650661.aspx)。当然,我们也可以把缓存作为文件存储到硬盘上,考虑到可扩展性,这是一种最廉价的做法,本文就是介绍如果构建自定义文件缓存。
1:OutputCacheProvider
OutputCacheProvider是一个抽象基类,我们需要override其中的四个方法,它们分别是:
Add 方法,将指定项插入输出缓存中。
Get 方法,返回对输出缓存中指定项的引用。
Remove 方法,从输出缓存中移除指定项。
Set 方法,将指定项插入输出缓存中,如果该项已缓存,则覆盖该项。
2:创建自己的文件缓存处理类
该类型为FileCacheProvider,代码如下:
<span class = "kwd" > public </span><span class = "pln" > </span><span class = "kwd" > class </span><span class = "pln" > </span><span class = "typ" >FileCacheProvider</span><span class = "pln" > </span><span class = "pun" >:</span><span class = "pln" > </span><span class = "typ" >OutputCacheProvider</span><span class = "pln" > </span><span class = "pun" >{</span><span class = "pln" > </span><span class = "kwd" > private </span><span class = "pln" > </span><span class = "kwd" > static </span><span class = "pln" > </span><span class = "kwd" > readonly </span><span class = "pln" > </span><span class = "typ" >ILog</span><span class = "pln" > log </span><span class = "pun" >=</span><span class = "pln" > </span><span class = "typ" >LogManager</span><span class = "pun" >.</span><span class = "typ" >GetLogger</span><span class = "pun" >(</span><span class = "typ" >System</span><span class = "pun" >.</span><span class = "typ" >Reflection</span><span class = "pun" >.</span><span class = "typ" >MethodBase</span><span class = "pun" >.</span><span class = "typ" >GetCurrentMethod</span><span class = "pun" >().</span><span class = "typ" >DeclaringType</span><span class = "pun" >);</span><span class = "pln" > </span><span class = "kwd" > public </span><span class = "pln" > </span><span class = "kwd" > override </span><span class = "pln" > </span><span class = "kwd" > void </span><span class = "pln" > </span><span class = "typ" >Initialize</span><span class = "pun" >(</span><span class = "kwd" > string </span><span class = "pln" > name</span><span class = "pun" >,</span><span class = "pln" > </span><span class = "typ" >NameValueCollection</span><span class = "pln" > attributes</span><span class = "pun" >)</span><span class = "pln" > </span><span class = "pun" >{</span><span class = "pln" > </span><span class = "kwd" > base </span><span class = "pun" >.</span><span class = "typ" >Initialize</span><span class = "pun" >(</span><span class = "pln" >name</span><span class = "pun" >,</span><span class = "pln" > attributes</span><span class = "pun" >);</span><span class = "pln" > </span><span class = "typ" >CachePath</span><span class = "pln" > </span><span class = "pun" >=</span><span class = "pln" > </span><span class = "typ" >HttpContext</span><span class = "pun" >.</span><span class = "typ" >Current</span><span class = "pun" >.</span><span class = "typ" >Server</span><span class = "pun" >.</span><span class = "typ" >MapPath</span><span class = "pun" >(</span><span class = "pln" >attributes</span><span class = "pun" >[</span><span class = "str" > "cachePath" </span><span class = "pun" >]);</span><span class = "pln" > </span><span class = "pun" >}</span><span class = "pln" > </span><span class = "kwd" > public </span><span class = "pln" > </span><span class = "kwd" > override </span><span class = "pln" > </span><span class = "kwd" > object </span><span class = "pln" > </span><span class = "typ" >Add</span><span class = "pun" >(</span><span class = "kwd" > string </span><span class = "pln" > key</span><span class = "pun" >,</span><span class = "pln" > </span><span class = "kwd" > object </span><span class = "pln" > entry</span><span class = "pun" >,</span><span class = "pln" > </span><span class = "typ" >DateTime</span><span class = "pln" > utcExpiry</span><span class = "pun" >)</span><span class = "pln" > </span><span class = "pun" >{</span><span class = "pln" > </span><span class = "typ" >Object</span><span class = "pln" > obj </span><span class = "pun" >=</span><span class = "pln" > </span><span class = "typ" >Get</span><span class = "pun" >(</span><span class = "pln" >key</span><span class = "pun" >);</span><span class = "pln" > </span><span class = "kwd" > if </span><span class = "pln" > </span><span class = "pun" >(</span><span class = "pln" >obj </span><span class = "pun" >!=</span><span class = "pln" > </span><span class = "kwd" > null </span><span class = "pun" >)</span><span class = "pln" > </span><span class = "com" > //这一步很重要</span><span class="pln"> </span><span class = "pun" >{</span><span class = "pln" > </span><span class = "kwd" > return </span><span class = "pln" > obj</span><span class = "pun" >;</span><span class = "pln" > </span><span class = "pun" >}</span><span class = "pln" > </span><span class = "typ" >Set</span><span class = "pun" >(</span><span class = "pln" >key</span><span class = "pun" >,</span><span class = "pln" >entry</span><span class = "pun" >,</span><span class = "pln" >utcExpiry</span><span class = "pun" >);</span><span class = "pln" > </span><span class = "kwd" > return </span><span class = "pln" > entry</span><span class = "pun" >;</span><span class = "pln" > </span><span class = "pun" >}</span><span class = "pln" > </span><span class = "kwd" > public </span><span class = "pln" > </span><span class = "kwd" > override </span><span class = "pln" > </span><span class = "kwd" > object </span><span class = "pln" > </span><span class = "typ" >Get</span><span class = "pun" >(</span><span class = "kwd" > string </span><span class = "pln" > key</span><span class = "pun" >)</span><span class = "pln" > </span><span class = "pun" >{</span><span class = "pln" > </span><span class = "kwd" > string </span><span class = "pln" > path </span><span class = "pun" >=</span><span class = "pln" > </span><span class = "typ" >ConvertKeyToPath</span><span class = "pun" >(</span><span class = "pln" >key</span><span class = "pun" >);</span><span class = "pln" > </span><span class = "kwd" > if </span><span class = "pln" > </span><span class = "pun" >(!</span><span class = "typ" >File</span><span class = "pun" >.</span><span class = "typ" >Exists</span><span class = "pun" >(</span><span class = "pln" >path</span><span class = "pun" >))</span><span class = "pln" > </span><span class = "pun" >{</span><span class = "pln" > </span><span class = "kwd" > return </span><span class = "pln" > </span><span class = "kwd" > null </span><span class = "pun" >;</span><span class = "pln" > </span><span class = "pun" >}</span><span class = "pln" > </span><span class = "typ" >CacheItem</span><span class = "pln" > item </span><span class = "pun" >=</span><span class = "pln" > </span><span class = "kwd" > null </span><span class = "pun" >;</span><span class = "pln" > </span><span class = "kwd" > using </span><span class = "pln" > </span><span class = "pun" >(</span><span class = "typ" >FileStream</span><span class = "pln" > file </span><span class = "pun" >=</span><span class = "pln" > </span><span class = "typ" >File</span><span class = "pun" >.</span><span class = "typ" >OpenRead</span><span class = "pun" >(</span><span class = "pln" >path</span><span class = "pun" >))</span><span class = "pln" > </span><span class = "pun" >{</span><span class = "pln" > </span><span class = "kwd" > var </span><span class = "pln" > formatter </span><span class = "pun" >=</span><span class = "pln" > </span><span class = "kwd" > new </span><span class = "pln" > </span><span class = "typ" >BinaryFormatter</span><span class = "pun" >();</span><span class = "pln" > item </span><span class = "pun" >=</span><span class = "pln" > </span><span class = "pun" >(</span><span class = "typ" >CacheItem</span><span class = "pun" >)</span><span class = "pln" >formatter</span><span class = "pun" >.</span><span class = "typ" >Deserialize</span><span class = "pun" >(</span><span class = "pln" >file</span><span class = "pun" >);</span><span class = "pln" > </span><span class = "pun" >}</span><span class = "pln" > </span><span class = "kwd" > if </span><span class = "pln" > </span><span class = "pun" >(</span><span class = "pln" >item</span><span class = "pun" >.</span><span class = "typ" >ExpiryDate</span><span class = "pln" > </span><span class = "pun" >&</span><span class = "pln" >lt</span><span class = "pun" >;=</span><span class = "pln" > </span><span class = "typ" >DateTime</span><span class = "pun" >.</span><span class = "typ" >Now</span><span class = "pun" >.</span><span class = "typ" >ToUniversalTime</span><span class = "pun" >())</span><span class = "pln" > </span><span class = "pun" >{</span><span class = "pln" > log</span><span class = "pun" >.</span><span class = "typ" >Info</span><span class = "pun" >(</span><span class = "pln" >item</span><span class = "pun" >.</span><span class = "typ" >ExpiryDate</span><span class = "pln" > </span><span class = "pun" >+</span><span class = "pln" > </span><span class = "str" > "*" </span><span class = "pln" > </span><span class = "pun" >+</span><span class = "pln" > key</span><span class = "pun" >);</span><span class = "pln" > </span><span class = "typ" >Remove</span><span class = "pun" >(</span><span class = "pln" >key</span><span class = "pun" >);</span><span class = "pln" > </span><span class = "kwd" > return </span><span class = "pln" > </span><span class = "kwd" > null </span><span class = "pun" >;</span><span class = "pln" > </span><span class = "pun" >}</span><span class = "pln" > </span><span class = "kwd" > return </span><span class = "pln" > item</span><span class = "pun" >.</span><span class = "typ" >Item</span><span class = "pun" >;</span><span class = "pln" > </span><span class = "pun" >}</span><span class = "pln" > </span><span class = "kwd" > public </span><span class = "pln" > </span><span class = "kwd" > override </span><span class = "pln" > </span><span class = "kwd" > void </span><span class = "pln" > </span><span class = "typ" >Set</span><span class = "pun" >(</span><span class = "kwd" > string </span><span class = "pln" > key</span><span class = "pun" >,</span><span class = "pln" > </span><span class = "kwd" > object </span><span class = "pln" > entry</span><span class = "pun" >,</span><span class = "pln" > </span><span class = "typ" >DateTime</span><span class = "pln" > utcExpiry</span><span class = "pun" >)</span><span class = "pln" > </span><span class = "pun" >{</span><span class = "pln" > </span><span class = "typ" >CacheItem</span><span class = "pln" > item </span><span class = "pun" >=</span><span class = "pln" > </span><span class = "kwd" > new </span><span class = "pln" > </span><span class = "typ" >CacheItem</span><span class = "pun" >(</span><span class = "pln" >entry</span><span class = "pun" >,</span><span class = "pln" > utcExpiry</span><span class = "pun" >);</span><span class = "pln" > </span><span class = "kwd" > string </span><span class = "pln" > path </span><span class = "pun" >=</span><span class = "pln" > </span><span class = "typ" >ConvertKeyToPath</span><span class = "pun" >(</span><span class = "pln" >key</span><span class = "pun" >);</span><span class = "pln" > </span><span class = "kwd" > using </span><span class = "pln" > </span><span class = "pun" >(</span><span class = "typ" >FileStream</span><span class = "pln" > file </span><span class = "pun" >=</span><span class = "pln" > </span><span class = "typ" >File</span><span class = "pun" >.</span><span class = "typ" >OpenWrite</span><span class = "pun" >(</span><span class = "pln" >path</span><span class = "pun" >))</span><span class = "pln" > </span><span class = "pun" >{</span><span class = "pln" > </span><span class = "typ" >BinaryFormatter</span><span class = "pln" > formatter </span><span class = "pun" >=</span><span class = "pln" > </span><span class = "kwd" > new </span><span class = "pln" > </span><span class = "typ" >BinaryFormatter</span><span class = "pun" >();</span><span class = "pln" > formatter</span><span class = "pun" >.</span><span class = "typ" >Serialize</span><span class = "pun" >(</span><span class = "pln" >file</span><span class = "pun" >,</span><span class = "pln" > item</span><span class = "pun" >);</span><span class = "pln" > </span><span class = "pun" >}</span><span class = "pln" > </span><span class = "pun" >}</span><span class = "pln" > </span><span class = "kwd" > public </span><span class = "pln" > </span><span class = "kwd" > override </span><span class = "pln" > </span><span class = "kwd" > void </span><span class = "pln" > </span><span class = "typ" >Remove</span><span class = "pun" >(</span><span class = "kwd" > string </span><span class = "pln" > key</span><span class = "pun" >)</span><span class = "pln" > </span><span class = "pun" >{</span><span class = "pln" > </span><span class = "kwd" > string </span><span class = "pln" > path </span><span class = "pun" >=</span><span class = "pln" > </span><span class = "typ" >ConvertKeyToPath</span><span class = "pun" >(</span><span class = "pln" >key</span><span class = "pun" >);</span><span class = "pln" > </span><span class = "kwd" > if </span><span class = "pln" > </span><span class = "pun" >(</span><span class = "typ" >File</span><span class = "pun" >.</span><span class = "typ" >Exists</span><span class = "pun" >(</span><span class = "pln" >path</span><span class = "pun" >))</span><span class = "pln" > </span><span class = "typ" >File</span><span class = "pun" >.</span><span class = "typ" >Delete</span><span class = "pun" >(</span><span class = "pln" >path</span><span class = "pun" >);</span><span class = "pln" > </span><span class = "pun" >}</span><span class = "pln" > </span><span class = "kwd" > public </span><span class = "pln" > </span><span class = "kwd" > string </span><span class = "pln" > </span><span class = "typ" >CachePath</span><span class = "pln" > </span><span class = "pun" >{</span><span class = "pln" > </span><span class = "kwd" > get </span><span class = "pun" >;</span><span class = "pln" > </span><span class = "kwd" > set </span><span class = "pun" >;</span><span class = "pln" > </span><span class = "pun" >}</span><span class = "pln" > </span><span class = "kwd" > private </span><span class = "pln" > </span><span class = "kwd" > string </span><span class = "pln" > </span><span class = "typ" >ConvertKeyToPath</span><span class = "pun" >(</span><span class = "kwd" > string </span><span class = "pln" > key</span><span class = "pun" >)</span><span class = "pln" > </span><span class = "pun" >{</span><span class = "pln" > </span><span class = "kwd" > string </span><span class = "pln" > file </span><span class = "pun" >=</span><span class = "pln" > key</span><span class = "pun" >.</span><span class = "typ" >Replace</span><span class = "pun" >(</span><span class = "str" > '/' </span><span class = "pun" >,</span><span class = "pln" > </span><span class = "str" > '-' </span><span class = "pun" >);</span><span class = "pln" > file </span><span class = "pun" >+=</span><span class = "pln" > </span><span class = "str" > ".txt" </span><span class = "pun" >;</span><span class = "pln" > </span><span class = "kwd" > return </span><span class = "pln" > </span><span class = "typ" >Path</span><span class = "pun" >.</span><span class = "typ" >Combine</span><span class = "pun" >(</span><span class = "typ" >CachePath</span><span class = "pun" >,</span><span class = "pln" > file</span><span class = "pun" >);</span><span class = "pln" > </span><span class = "pun" >}</span><span class = "pln" > </span><span class = "pun" >}</span><span class = "pln" > </span><span class = "pun" >[</span><span class = "typ" >Serializable</span><span class = "pun" >]</span><span class = "pln" > </span><span class = "kwd" > public </span><span class = "pln" > </span><span class = "kwd" > class </span><span class = "pln" > </span><span class = "typ" >CacheItem</span><span class = "pln" > </span><span class = "pun" >{</span><span class = "pln" > </span><span class = "kwd" > public </span><span class = "pln" > </span><span class = "typ" >DateTime</span><span class = "pln" > </span><span class = "typ" >ExpiryDate</span><span class = "pun" >;</span><span class = "pln" > </span><span class = "kwd" > public </span><span class = "pln" > </span><span class = "kwd" > object </span><span class = "pln" > </span><span class = "typ" >Item</span><span class = "pun" >;</span><span class = "pln" > </span><span class = "kwd" > public </span><span class = "pln" > </span><span class = "typ" >CacheItem</span><span class = "pun" >(</span><span class = "kwd" > object </span><span class = "pln" > entry</span><span class = "pun" >,</span><span class = "pln" > </span><span class = "typ" >DateTime</span><span class = "pln" > utcExpiry</span><span class = "pun" >)</span><span class = "pln" > </span><span class = "pun" >{</span><span class = "pln" > </span><span class = "typ" >Item</span><span class = "pln" > </span><span class = "pun" >=</span><span class = "pln" > entry</span><span class = "pun" >;</span><span class = "pln" > </span><span class = "typ" >ExpiryDate</span><span class = "pln" > </span><span class = "pun" >=</span><span class = "pln" > utcExpiry</span><span class = "pun" >;</span><span class = "pln" > </span><span class = "pun" >}</span><span class = "pln" > </span><span class = "pun" >}</span> |
有两个地方需要特别说明:
在Add方法中,有一个条件判断,必须做出这样的处理,否则缓存机制将会缓存第一次的结果,过了有效期后缓存讲失效并不再重建;
在示例程序中,我们简单的将缓存放到了Cache目录下,在实际的项目实践中,考虑到缓存的页面将是成千上万的,所以我们必须要做目录分级,否则寻找并读取缓存文件将会成为效率瓶颈,这会耗尽CPU。
3:配置文件
我们需要在Web.config中配置缓存处理程序是自定义的FileCacheProvider,即在 <system.web>下添加节点:
4:缓存的使用
我们假设在MVC的控制中使用(如果要在ASP.NET页面中使用,则在页面中包含<%@OutputCache VaryByParam=”none” Duration=”10″ %>),可以看到,Index是未进行输出缓存的,而Index2进行了输出缓存,缓存时间为10秒。
<span class = "kwd" > public </span><span class = "pln" > </span><span class = "kwd" > class </span><span class = "pln" > </span><span class = "typ" >HomeController</span><span class = "pln" > </span><span class = "pun" >:</span><span class = "pln" > </span><span class = "typ" >Controller</span><span class = "pln" > </span><span class = "pun" >{</span><span class = "pln" > </span><span class = "kwd" > private </span><span class = "pln" > </span><span class = "kwd" > static </span><span class = "pln" > </span><span class = "kwd" > readonly </span><span class = "pln" > </span><span class = "typ" >ILog</span><span class = "pln" > log </span><span class = "pun" >=</span><span class = "pln" > </span><span class = "typ" >LogManager</span><span class = "pun" >.</span><span class = "typ" >GetLogger</span><span class = "pun" >(</span><span class = "typ" >System</span><span class = "pun" >.</span><span class = "typ" >Reflection</span><span class = "pun" >.</span><span class = "typ" >MethodBase</span><span class = "pun" >.</span><span class = "typ" >GetCurrentMethod</span><span class = "pun" >().</span><span class = "typ" >DeclaringType</span><span class = "pun" >);</span><span class = "pln" > </span><span class = "kwd" > static </span><span class = "pln" > </span><span class = "kwd" > string </span><span class = "pln" > s_conn </span><span class = "pun" >=</span><span class = "pln" > </span><span class = "str" > "Data Source=192.168.0.77;Initial Catalog=luminjidb;User Id=sa;Password=sa;" </span><span class = "pun" >;</span><span class = "pln" > </span><span class = "kwd" > public </span><span class = "pln" > </span><span class = "typ" >ActionResult</span><span class = "pln" > </span><span class = "typ" >Index</span><span class = "pun" >()</span><span class = "pln" > </span><span class = "pun" >{</span><span class = "pln" > </span><span class = "kwd" > using </span><span class = "pln" > </span><span class = "pun" >(</span><span class = "typ" >DataSet</span><span class = "pln" > ds </span><span class = "pun" >=</span><span class = "pln" > </span><span class = "typ" >Common</span><span class = "pun" >.</span><span class = "typ" >SqlHelper</span><span class = "pun" >.</span><span class = "typ" >ExecuteDataset</span><span class = "pun" >(</span><span class = "pln" >s_conn</span><span class = "pun" >,</span><span class = "pln" > </span><span class = "typ" >CommandType</span><span class = "pun" >.</span><span class = "typ" >Text</span><span class = "pun" >,</span><span class = "pln" > </span><span class = "str" > "select top 1* from NameTb a, DepTb b where a.DepID = b.ID ORDER BY NEWID()" </span><span class = "pun" >))</span><span class = "pln" > </span><span class = "pun" >{</span><span class = "pln" > </span><span class = "typ" >ViewBag</span><span class = "pun" >.</span><span class = "typ" >Message</span><span class = "pln" > </span><span class = "pun" >=</span><span class = "pln" > ds</span><span class = "pun" >.</span><span class = "typ" >Tables</span><span class = "pun" >[</span><span class = "lit" >0</span><span class = "pun" >].</span><span class = "typ" >Rows</span><span class = "pun" >[</span><span class = "lit" >0</span><span class = "pun" >][</span><span class = "str" > "name" </span><span class = "pun" >].</span><span class = "typ" >ToString</span><span class = "pun" >();</span><span class = "pln" > </span><span class = "pun" >}</span><span class = "pln" > </span><span class = "kwd" > return </span><span class = "pln" > </span><span class = "typ" >View</span><span class = "pun" >();</span><span class = "pln" > </span><span class = "pun" >}</span><span class = "pln" > </span><span class = "pun" >[</span><span class = "typ" >OutputCache</span><span class = "pun" >(</span><span class = "typ" >Duration</span><span class = "pln" > </span><span class = "pun" >=</span><span class = "pln" > </span><span class = "lit" >10</span><span class = "pun" >,</span><span class = "pln" > </span><span class = "typ" >VaryByParam</span><span class = "pln" > </span><span class = "pun" >=</span><span class = "pln" > </span><span class = "str" > "none" </span><span class = "pun" >)]</span><span class = "pln" > </span><span class = "kwd" > public </span><span class = "pln" > </span><span class = "typ" >ActionResult</span><span class = "pln" > </span><span class = "typ" >Index2</span><span class = "pun" >()</span><span class = "pln" > </span><span class = "pun" >{</span><span class = "pln" > </span><span class = "kwd" > using </span><span class = "pln" > </span><span class = "pun" >(</span><span class = "typ" >DataSet</span><span class = "pln" > ds </span><span class = "pun" >=</span><span class = "pln" > </span><span class = "typ" >Common</span><span class = "pun" >.</span><span class = "typ" >SqlHelper</span><span class = "pun" >.</span><span class = "typ" >ExecuteDataset</span><span class = "pun" >(</span><span class = "pln" >s_conn</span><span class = "pun" >,</span><span class = "pln" > </span><span class = "typ" >CommandType</span><span class = "pun" >.</span><span class = "typ" >Text</span><span class = "pun" >,</span><span class = "pln" > </span><span class = "str" > "select top 1* from NameTb a, DepTb b where a.DepID = b.ID ORDER BY NEWID()" </span><span class = "pun" >))</span><span class = "pln" > </span><span class = "pun" >{</span><span class = "pln" > </span><span class = "typ" >ViewBag</span><span class = "pun" >.</span><span class = "typ" >Message</span><span class = "pln" > </span><span class = "pun" >=</span><span class = "pln" > ds</span><span class = "pun" >.</span><span class = "typ" >Tables</span><span class = "pun" >[</span><span class = "lit" >0</span><span class = "pun" >].</span><span class = "typ" >Rows</span><span class = "pun" >[</span><span class = "lit" >0</span><span class = "pun" >][</span><span class = "str" > "name" </span><span class = "pun" >].</span><span class = "typ" >ToString</span><span class = "pun" >();</span><span class = "pln" > </span><span class = "pun" >}</span><span class = "pln" > </span><span class = "kwd" > return </span><span class = "pln" > </span><span class = "typ" >View</span><span class = "pun" >();</span><span class = "pln" > </span><span class = "pun" >}</span><span class = "pln" > </span><span class = "pun" >}</span> |
5:查看下效果
上面的代码,在访问了Index2后,将会在Cache文件夹下产生缓存文件,如下:
现在,我们开始评价下有输出缓存和无输出缓存的性能对比,模拟100个用户并发1000次请求如下:
可以看到,有输出缓存后,吞吐率明显提高了10倍。
6:代码下载
FileCacheProvider的原始代码来自于网络,我修改了其中的BUG,全部代码下载如下:MvcApplication20110907.rar