Fetching Data from Cache

Primarily a cache is only considered as effective as its ability to retrieve data. NCache utilizes the key-value architecture of its store to maximize the ways of data retrieval. Get method is the primary API provided to serve previously cached data; however basic indexer approach can also be used. Both of these methods are explained below.

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

Retrieving Data Using Get() Method

In this example, the basic Get method is used to retrieve item Product:1001. This item has previously been added to the cache. Get method returns general object which needs to be cast accordingly. If a key does not exist in cache null value is returned.

  string key = "Product:1001";
  Product product = null;
  try{
      //null is returned if key does not exist in the cache.    
      object result = cache.Get(key);
      if (result != null)
      {
          if (result is Product)
          {  
            product = (Product)result;
          }
      }
  }
  catch (OperationFailedException ex){
      // handle exception
  }

Retrieve a CacheItem from Cache

In this example, the basic GetCacheItem method is used to retrieve item Product:1001. This item has been added to the cache. This method returns CacheItem whose value property encapsulates the data; the Object value need to be cast accordingly.

  string key = "Product:1001";
  Product product = null;
  try{
      CacheItem result = cache.GetCacheItem(key);
      if (result != null)
      {
          if (result.Value is Product){  
            product = (Product)result.Value;
          }
      }
  }
  catch (OperationFailedException ex){
      //handle exception
  }

Checking if an Item Exists in Cache

NCache being a key-value paired structure lets the user perform operations like any other indexed based data structure. In this example a cache handle is used to directly access cached values using square brackets ”[]”.

string key = "Product:1001";try
{
    if (cache.Contains(key))
    {
        //do something
    }
    else
    {
        //do something
    }
}
catch (OperationFailedException ex){
    //handle exception
}