Use custom File Cache to improve ASP. NET Project Performance

Preface

As we all know, in order to improve the website access performance, various large websites use some caches to improve the application performance. The most commonly used method is to generate HTML pages. In a sense, it can be included in the file cache. However, this method has some drawbacks (for me). Without a complete HTML file management mechanism, a large number of HTMLCodeManagement is a headache.

Let's talk about another common and simple method today, that is, the output cache of ASP. NET.Outputcache

Outputcache

For web development Neter, it is assumed that outputcache will not be unfamiliar. In webform, we include outputcache settings at the top of the ASPX page: <% @ outputcache varybyparam = "NONE" Duration = "10" %> in ASP. in. Net MVC, we add this attribute to the Controller/Action to cache data for improvement.ProgramPerformance:

 Public   Class  Homecontroller: controller {  Public  Actionresult index () {viewbag. Message ="  Welcome to ASP. net mvc!  "  ;  Return  View ();} [outputcache (Duration = 10 , Varybyparam = "  None  "  )]  Public  Actionresult about (){  Return  View ();}} 

Disadvantages of outputcache

So what are the disadvantages of outputcache? We all know that the outputcache output cache is stored in the memory, that is to say, this practice has been limited to be used only in small websites, Because if our website contains a large number of memory-based caches, i'm afraid it will consume a lot of host memory.

Outputcache is complete

In view of the memory-based storage problem of outputcache, we need to extend outputcache to solve this problem. in net framework 4, outputcacheprovider. With outputcacheprovider, we can have multiple options to create our own cache. In this section, I will expand the outputcache to create a custom file cache.

Use outputcacheprovider to expand outputcache to create a custom File Cache

Create class: filecacheprovider, introduce using system. Web. caching; namespace, inherit from outputcacheprovider abstract class, rewrite four methods:

Add method to insert a specified item into the output cache.
The get method returns a reference to a specified item in the output cache.
Remove Method to remove a specified item from the output cache.
The Set Method inserts a specified item into the output cache. If the item has been cached, the item is overwritten.

 Public   Class  Filecacheprovider: outputcacheprovider {  Public  String Cachepath { Get ; Set  ;}  Private   String Convertkeytopath ( String  Key ){  String File = key. Replace ( '  /  ' , '  -  ' ); File + = "  . Txt  "  ;  Return  Path. Combine (cachepath, file );}  Public   Override   Void Initialize ( String  Name, system. Collections. Specialized. namevaluecollection config ){  Base . Initialize (name, config );  //  Read Cachepath = httpcontext. Current. server. mappath (config [ "  Cachepath  "  ]);}  Public   Override   Object Add ( String Key, Object  Entry, datetime utcexpiry ){  Object OBJ = Get (key );  If (OBJ! = Null  ){  Return  OBJ;} set (Key, entry, utcexpiry );  Return  Entry ;}  Public   Override   Object Get ( String  Key ){  String Path = Convertkeytopath (key );  If (! File. exists (PATH )){  Return   Null  ;} Cacheitem item = Null  ;  Using (Filestream file = File. openread (PATH )){  VaR Formatter = New Binaryformatter (); item = (Cacheitem) formatter. deserialize (File );}  If (Item. expirydate <= Datetime. Now. touniversaltime ()){  //  Log  Remove (key );  Return   Null  ;}  Return  Item. item ;} Public   Override   Void Set ( String Key, Object  Entry, datetime utcexpiry) {cacheitem item = New  Cacheitem (entry, utcexpiry );  String Path = Convertkeytopath (key );  Using (Filestream file = File. openwrite (PATH) {binaryformatter formatter =New  Binaryformatter (); formatter. serialize (file, item );}}  Public   Override   Void Remove ( String  Key ){  String Path = Convertkeytopath (key );  If  (File. exists (PATH) {file. Delete (PATH) ;}} [serializable]  Public  Class  Cacheitem {  Public  Datetime expirydate;  Public   Object  Item;  Public Cacheitem ( Object  Entry, datetime utcexpiry) {item = Entry; expirydate = Utcexpiry ;}} 

In the instance program, I put the cache in the cachepath directory configured in the config file. For details, see the initialize method.

Configuration File

You need to configure the cache handler driver in the web. config file.

  <  System. Web  >      <  Caching  >        <  Outputcache  Defaultprovider  = "Filecache"  >          <  Providers  >            <  Add Name  = "Filecache"  Type  = "Filecache. provider. filecacheprovider"  Cachepath  = "~ /Cache"  />          </  Providers  >        </  Outputcache  >      </  Caching  > 

How to use it?

After the above configuration, it is easy to use, because it is an extension of ASP. NET output cache outputcache, so the usage is the same as the previous usage. I use the following in MVC:

 Namespace  Filecache. controllers {  Public   Class  Homecontroller: controller {  Public  Actionresult index () {viewbag. Message = "  Welcome to ASP. net mvc!  "  ;  Return View ();} [outputcache (Duration = 10 , Varybyparam = "  None  "  )]  Public  Actionresult about (){  Return  View ();}}} 

As you can see, I marked [outputcache (duration = 10, varybyparam = "NONE")] on the about action, set the cache time to 10 minutes, and do not cache it again based on any parameters, run. You can view the cached file under the configured cache file:

After running the program, visit the about page and you will see that a cache file is generated in the cache folder.

Notes

I created the cache folder in advance in the project. Of course, the folder name can be obtained at will, just in the web. the Config ing is correct. If an error occurs during running, it may be because the folder does not exist, or you can check whether the cache folder exists in the cache expansion code. If not, the program can be created.

Legacy problems

We can see that the cached file is saved as TXT text. Can we save the cached file as an XML file? If XML is used, you can further modify and use generic classes to solve the XML serialization problem of different objects. If you have better suggestions, you may wish to raise them.