I have worked through my first Velocity project today, and I would like to blog about the steps necessary to use caching.
First, you should read my previous post and install AppFabric on your machine.
I used Visual Studio 2010 beta 2 to create the solution. You can download the solution here. I create WPF project in order to prove that caching is not limited to web applications, although web farm would probably be an ideal application for caching. Once project is created, I added references to DLLs for Velocity. On my machine they were located in C:\Windows\System32\ApplicationServerExtensions. Two DLLs I needed were CacheBaseLibrary.dll and ClientLibrary.dll. They contain key classes that can be used to utilize caching. I could not add them directly from that folder, I was getting an error from Add Reference dialog. So, I copied them into a folder under my Solution (“Bin” folder).
Then I added a complex class that I intended to cache. I wanted to prove to myself that complex object graphs are OK since all the demos I saw just used strings. Here is the class I used:
public class CachablePerson
{
public string FirstName { get; set; }
public string LastName { get; set; }
public List<CachableAddress> Addresses { get; set; }
public CachablePerson()
{
FirstName = "Sergey";
LastName = "Barskiy";
Addresses = new List<CachableAddress>();
Addresses.Add(new CachableAddress() { Street = "Main Street", City = "Atlanta" });
Addresses.Add(new CachableAddress() { Street = "Second Street", City = "Lilburn" });
}
}
public class CachableAddress
{
public string Street { get; set; }
public string City { get; set; }
}
I put the class into its own project and referenced this project from two separate WPF application projects.
First step in using caching is to configure cache object. Here is how we can configure cache object using cache factory:
private void SetupCache()
{
DataCacheServerEndpoint[] servers = new DataCacheServerEndpoint[1];
servers[0] = new DataCacheServerEndpoint("Sergey-Laptop", 22233, "DistributedCacheService");
_cacheFactory = new DataCacheFactory(servers, false, true);
_defaultCache = _cacheFactory.GetCache("default");
}
Now we are ready to add object to cache. We will do this in steps. First we check to see if an object is already in cache, and if so, we will remove it from cache. Cache basically is using a string as the object key. In addition to that you can also version objects, thus having multiple copies of the same object with the same key existing in cache at any given time.
if (_defaultCache.Get("person") != null)
{
_defaultCache.Remove("person");
}
_defaultCache.Add("person", _person);
Now I am going to get the object from cache. Just as simple as adding it:
_person = (CachablePerson)_defaultCache.Get("person");
Simple and easy. I think Velocity is super powerful yet simple to use. Event though it would be an abuse, but one could possibly use caching to communicate between different applications.
You can download my sample solution here
