Thread: Caching
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Old May 31st, 2010, 04:00 AM
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Yes, that pretty much summarizes it. A few remarks though:

I don't see static fields or properties as a cache, although they could fulfill that purpose. I mainly use them for simple fields such as configuration. For example:

Code:
 
public class AppConfiguration
{
  public static string FromAddress
  {
    get
    {
      string result = WebConfigurationManager.AppSettings.Get("FromAddress");
      if (!string.IsNullOrEmpty(result))
      {
        return result;
      }
      throw new Exception("AppSetting FromAddress not found in web.config file.");
    }
  }
}
This static property can now be called as:

myMessage.From = new MailAddress(AppConfiguration.FromAddress);

Note that inside the getter you could "cache" the return value of WebConfigurationManager.AppSettings.Get in yet another static, and private field to avoid the overhead of accessing the configuration more than once. However, AFAIK, the WebConfigurationManager already minimizes the overhead.

So, the static field serves as a wrapper around the real data, in this example data stored in the web.config file.

The Cache, on the other hand, doesn't act as a wrapper, but serves as an alternative. The real data is copied (for example, the result of a DB query) and stored in the cache for quicker access. The benefits are quick access, at the cost of memory consumption and the risk of stale data.

Hope this helps,

Imar
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