keeping information in memory that any user can access easily?

Question

User1322403867 posted

Hi,

I want to read some information from an xml file and store it ready in memory so that it can go out with every page response without being reloaded from the xml on every request.

 

What is the best way of doing this?

It looks to me like there are 2 options. Either create a class with static fields that the information is stored in. Or create a class with public fields that the info is stored in and create an instance of that class at application level.

Is that correct, are both of those options viable? or will I not be able to access the fields in the second method without creating an instance of the class in the code that responds to the page request(basically if you create an instance of a class at application level can you use that instance from within code anywhere in your website as long as it is public)?

Do I have any other options?

What are the pros and cons of each technique?

Thanks,

Duncan

Answer 1

User541108374 posted

Hi,

why don't you load it into the Cache object and when you need it retrieve it from there? Load it in Cache at startup or the first time you need it.

Grz, Kris.

Answer 2

User187056398 posted

I think you need to use the Cache object.  Here's the simplest example:

    private String GetFileData()
    {
        const String Key = "My_File";

        // see if the file  is in the cache.
        String Data = Page.Cache[Key] as String;

        if (Data != null)
            return Data;

        Data = File.ReadAllText(@"C:\Test.txt");

        // put it in the cache so we don't have to read the disk again           
        Page.Cache.Insert(Key, Data);

        return Data;
    }

 

 

Answer 3

User-525215917 posted

Two options:

• Class with static members or new static members in global application class. It is not very good solution although everything is strongly typed etc. You have to manage concurrency issues by yourself.
• Class for your data that is kept in cache. If you don't need changes to your data then you can keep it in Cache. Just create class that fits your needs, instantiate it and write it to cache.
  
  

  // Write to cache
  public void CreateInstance()
  {
      var cls = new MyClass();
      cls.LoadDataFromFile();
      Cache["MyData"] = cls;    
      return cls;
  }
  
  
  // Read from cache
  var cls = Cache["MyData"] as MyClass;
  if(cls == null)
      cls = CreateInstance();
  
  // Use cls here

Whatever you do I strongly recommend to test your code for concurrency issues so you can be sure that everything works fine when multiple users are visiting your page at same time.

Answer 4

User-37275327 posted

It is better to use cache object. storing in cache shares everypage. But too big object can reduce the performance of the web application.

Answer 5

User1322403867 posted

Thank you all for your replies!

I have heard of storing things in cache but I thought I had to make the cache myself I didn't realise there was a dedicated cashe object.

Is there some documentation explaining cache? i have had a look in the msdn library but I can't find it. If you know where to find the documentation and could give me a link that would be very useful.

 

Thanks, 

Answer 6

User-37275327 posted

Hope this would help

http://www.codeproject.com/KB/web-cache/singleLineCacheManager.aspx

Answer 7

User-1360095595 posted

http://msdn.microsoft.com/en-us/library/system.web.caching.cache.aspx

Answer 8

User541108374 posted

Hi,

some interesting video on how to store information in the Cache object can be found here: [How Do I]: Use the ASP.NET Cache Object to Cache Application Information.

Grz, Kris.