SimpleLRUCache is a simple implementation of LRU algorithm for .NET.

Content

• Getting started
• How to use?
• Authors

Getting started

Install SimpleLRUCache via the NuGet package: SimpleLRUCache

PM> Install-Package SimpleLRUCache

How to use

There are two types of LRU cache, LRUCache and LRUCacheDisposable, which is a version of LRUCache who calls dispose, when a item is removed from cache.

Suppose you are working with a list of users, and wants to cache the last 100 recent accessed objects.

public class UsersService
{
    private readonly LRUCache<string, User> usersLRU;
    
    public UsersService()
    {
      // Creates a LRUCache from users object, with a limit of 100 items.
      this.usersLRU = new LRUCache<string,User>(100);
    }
    
    public User GetUser(int id)
    {
      var foundUser = usersLRU.Get(id);
      // if user isn't in cache, then we retrieve from persistence
      if(foundUser == null)
      {
        foundUser = usersPersistence.Get(id);
        // if user exists we add him to the list
        if(foundUser != null)
        {
          // key and the object to store
          usersLRU.Add(id, foundUser);
        }
      }
      return foundUser;
    }
}

If the class User, form above example, implements a Disposable interface, then you should use the LRUCacheDisposable. So when the list reaches the established limit, the Dispose method is called, before item removal. Exemple from above using LRUCacheDisposable:

public class UsersService
{
    private readonly LRUCacheDisposable<string, User> usersLRU;
    
    public UsersService()
    {
      // Creates a LRUCache from users object, with a limit of 100 items.
      this.usersLRU = new LRUCacheDisposable<string,User>(100);
    }

    …
}

Authors

Nicolás Caorsi (2015)