C# cache file

Caching with the C language is very easy. It exists in the System. MomoryCache: This class also comes under System. Caching and it represents the type that implements an in-cache memory. CacheItemPolicy: Represents a set of eviction and expiration details for a specific cache entry. Code Work: Storying information into a cache.

In this illustration I have kept some stock items in the cache memory for further use that is to understand the availability of a stock item in the future. When the application does not find any cached data in cache memory, it will redirect to the Get default stock function.

The following code is for storing information into cache memory. I have given one hour duration to expire cache memory and line number 04 stores information with a unique key and cache policy. WriteThrough I just added the WriteThrough option but it does not seem to fix the issue. Thank you in advance! Create, FileAccess. None, ; request. CopyTo loadStream ; loadStream. Flush ; loadStream. Flush true ; mimePDL. Close ; mimePDL.

Close ; loadStream. Dispose ; File. Delete FileStream loadStream. Name ;. Improve this question. Call the garbage collector: GC. Collect ; — LordPupazz. LordPupazz is it safe to do so?

Also consider enclosing you FileStream in a using statement to ensure it is disposed once out of scope. GeorgeKerwood I am doing this for one FileStream. I am actually using 2, and one of them can't be enclosed inside a using statement, but both seem to do the same thing. We'll address and overcome these issues in Step 4. Along with data retrieval methods, the Caching Layer needs to provide the same methods as the BLL for inserting, updating, and deleting data.

The CL s data modification methods do not modify the cached data, but rather call the BLL s corresponding data modification method and then invalidate the cache. As we saw in the preceding tutorial, this is the same behavior that the ObjectDataSource applies when its caching features are enabled and its Insert , Update , or Delete methods are invoked.

The following UpdateProduct overload illustrates how to implement the data modification methods in the CL:. The appropriate data modification Business Logic Layer method is invoked, but before its response is returned we need to invalidate the cache. When invalidating the cache, we need to remove all of the items that may have been added by the ProductsCL class.

This can be accomplished by associating a cache dependency with the each item added to the cache in the AddCacheItem key, value method. In general, a cache dependency can be another item in the cache, a file on the file system, or data from a Microsoft SQL Server database.

When the dependency changes or is removed from the cache, the cache items it is associated with are automatically evicted from the cache. For this tutorial, we want to create an additional item in the cache that serves as a cache dependency for all items added through the ProductsCL class. That way, all of these items can be removed from the cache by simply removing the cache dependency. Let s update the AddCacheItem key, value method so that each item added to the cache through this method is associated with a single cache dependency:.

First, a cache item is added to the cache and assigned the current date and time. If the cache item already exists, it is updated. Next, a cache dependency is created. The CacheDependency class s constructor has a number of overloads, but the one being used in here expects two string array inputs. The first one specifies the set of files to be used as dependencies. Since we don t want to use any file-based dependencies, a value of null is used for the first input parameter.

The second input parameter specifies the set of cache keys to use as dependencies. Here we specify our single dependency, MasterCacheKeyArray. The CacheDependency is then passed into the Insert method. With this modification to AddCacheItem key, value , invaliding the cache is as simple as removing the dependency. The Caching Layer s classes and methods can be used to work with data using the techniques we ve examined throughout these tutorials.

To illustrate working with cached data, save your changes to the ProductsCL class and then open the FromTheArchitecture. In the wizard s first step you should see the ProductsCL class as one of the options from the drop-down list.

After selecting ProductsCL , click Next. Since the UploadProducts overload used by the CL accepts only the edited product s name and price, limit the GridView so that only these fields are editable. Feel free to replicate this formatting and structure, in which case your GridView and ObjectDataSource s declarative markup should look similar to the following:.

At this point we have a page that uses the Caching Layer. Visit the page in a browser and step through the code when sorting and paging in order to see the data pulled from the cache. Then update a record and note that the cache is invalidated and, consequently, it is retrieved from the BLL when the data is rebound to the GridView. The Caching Layer provided in the download accompanying this article is not complete. It contains only one class, ProductsCL , which only sports a handful of methods.

Moreover, only a single ASP. If you plan on using a CL in your application, all calls from the Presentation Layer should go to the CL, which would require that the CL s classes and methods covered those classes and methods in the BLL currently used by the Presentation Layer.

NET 2. The Caching Layer needs to provide the same set of classes and methods that exist in the BLL and are called from the Presentation Layer. The Caching Layer examples we explored in this and the preceding tutorials exhibited reactive loading. With reactive loading, the data is loaded into the cache only when a request for the data is made and that data is missing from the cache. Data can also be proactively loaded into the cache, a technique that loads the data into the cache before it is actually needed.