Object Caching in ASP.NET Core

Using NCache Distributed Caching

Let’s suppose our database contains information for a music store, including album information, genre, artist, order details and so on. We proceed to fetch the details for an album, which is stored as an object of the Album class.

In Startup.cs, use the AddNCacheDistributedCache() method to set NCache as the default cache for storing objects.

public void ConfigureServices(IServiceCollection services)
{
    services.SetNCacheSessionConfiguration(Configuration.GetSection("NCacheSettings"));
    services.AddNCacheDistributedCache();

}

NCache is now the underlying cache for IDistributedCache. The following code snippet attempts to get the album detail based on the cache key, where if there is no item existing in the cache, the item is fetched from the database.

If the album is retrieved from the database, it is stored in NCache with expiry value of 10 minutes. If the object is not fetched from the cache within the next 10 minutes, it is expired from the cache.

If the object is fetched successfully, the object is returned as an object of Album.

public async Task<IActionResult> Details(
             [FromServices] IDistributedCache cache,
             int id)
{
            var cacheKey = string.Format("album1", id);
            Album album;
            object value;

            if (!cache.TryGetValue(cacheKey, out value)){
                album = await DbContext.Albums
                                .Where(a => a.AlbumId == id)
                                .Include(a => a.Artist)
                                .Include(a => a.Genre)
                                .FirstOrDefaultAsync();

                if (album != null){
                    if (_appSettings.CacheDbResults){
                        //Remove it from cache if not retrieved in last 10 minutes
                        cache.SetObject(cacheKey, album, new DistributedCacheEntryOptions().SetSlidingExpiration(TimeSpan.FromMinutes(10)));
                    }
                }
            }
            else {
                album = value as Album;
            }
            if (album == null){
                return NotFound();
            }
            return View(album);
        }
}

Using NCache for Object Caching in ASP.NET Core

You can initialize an instance of the NCache cache within the application with the InitializeCache() method and proceed to perform operations over the objects stored in the cache.

To utilize the APIs, include the following namespace in your application: Alachisoft.NCache.Web.Caching;

public async Task<IActionResult> Details(int id)
{
    _cache = NCache.InitializeCache(_appSettings.CacheName); //initialize cache in NCache

    var cacheKey = string.Format("album_{0}", id);

    Album album = null;

    if (_cache != null){
        album = _cache.Get(cacheKey) as Album; //fetch Album object
    }
    if (album == null)
    {
        album = await DbContext.Albums
                        .Where(a => a.AlbumId == id)
                        .Include(a => a.Artist)
                        .Include(a => a.Genre)
                        .FirstOrDefaultAsync();

        if (album != null){
            if (_appSettings.CacheDbResults && _cache != null){
                //Remove it from cache if not retrieved in last 10 minutes
                _cache.Insert(cacheKey, album, null, Cache.NoAbsoluteExpiration, TimeSpan.FromMinutes(10),
                    Alachisoft.NCache.Runtime.CacheItemPriority.Default);
            }
        }
    }
    return View(album);
}