Using Write-Through with Basic Operations

This section will explain the use of Write-Through Provider after configuring and deploying it. NCache supports multiple Write-Through Providers with applications.

To utilize the IWriteThruProvider, include the following namespace in your application:

• Alachisoft.NCache.Web.Caching
• Alachisoft.NCache.Runtime.DatasourceProviders
• Alachisoft.NCache.Runtime

NCache provides Alachisoft.NCache.Web.Caching.DSWriteOption enum to specify Write thru/Write behind options in APIs.

Multiple Write-Through Providers can be configured through NCache. Default provider will be called if a specific provider name is not mentioned through API. You can also use providers other than default by using provider specific overloads of APIs.

Adding with Write-Through

Member	Description
CacheItemVersion Add(string key, CacheItem item, DSWriteOption dsWriteOption, DataSourceItemsAddedCallback onDataSourceItemAdded)	Adds item in cache using the default provider
CacheItemVersion Add(string key, CacheItem item, DSWriteOption dsWriteOption, string providerName, DataSourceItemsAddedCallback onDataSourceItemAdded)	Adds item in cache using the specified provider

Product product = new Product();
product.ProductID = 1001;
product.ProductName = "Chai";

CacheItem cacheItem = new CacheItem(product);
string key = "Product:" + product.ProductID ;

try{
  CacheItemVersion itemVersion = cache.Add(key, cacheItem, DSWriteOption.WriteThru, null);
}
catch (OperationFailedException exp){
  // handle exception
}

Updating with Write-Through

Member	Description
CacheItemVersion Insert(string key, CacheItem item, DSWriteOption dsWriteOption, DataSourceItemsAddedCallback onDataSourceItemAdded)	Inserts item in cache using the default provider
CacheItemVersion Insert(string key, CacheItem item, DSWriteOption dsWriteOption, string providerName, DataSourceItemsUpdatedCallback onDataSourceItemUpdatedCallback)	Inserts item in cache using the specified provider

  Product product = new Product();
  product.ProductID = 1001;
  product.ProductName = "Chai";

  CacheItem cacheItem = new CacheItem(product);
  string key = "Product:" + product.ProductID;

  CacheItemVersion updatedItemVersion;
  try{
      updatedItemVersion = cache.Insert(key, cacheItem, DSWriteOption.WriteThru, "XmlWriteThruProvider", null);
      if (updatedItemVersion.Version > 1)
      {
          //Item updated in cache. Perform further tasks.
      }
  }
  catch (OperationFailedException exp){
      //handle exception
  }

Deleting an Existing Item with Write-Through

Member	Description
Delete(string key, DSWriteOption dsWriteOption, DataSourceItemsRemovedCallback onDataSourceItemRemovedCallback)	Deletes item from cache using the default provider
Delete(string key, DSWriteOption dsWriteOption, string providerName, DataSourceItemsRemovedCallback onDataSourceItemRemovedCallback);	Deletes item from cache using the specified provider

string key = "Product:1001";
try{
  cache.Delete(key, DSWriteOption.WriteThru, null);
}
catch (OperationFailedException exp){
  // handle exception
}

Removing an Existing Item with Write-Through

Member	Description
object Remove(string key, DSWriteOption dsWriteOption, DataSourceItemsRemovedCallback onDataSourceItemRemovedCallback)	Removes item from cache using the default provider
object Remove(string key, DSWriteOption dsWriteOption, string providerName, DataSourceItemsRemovedCallback onDataSourceItemRemovedCallback);	Removes item from cache using the specified provider

string key = "Product:1001";
Product product = null;
try{
    Object returnObject = cache.Remove(key, DSWriteOption.WriteThru, null);

    //Verify the removed item from both cache and data source
    if (returnObject != null)
    {
        product = (Product)returnObject;
    }
}
catch (OperationFailedException exp){ 
    // handle exception
}