Key Question on Custom ICache Implementation

We have our own caching framework that works well and we like it. We'd like to wire it up to NHibernate rather than take a dependency one of the other caching implementations for NH.

I've written an implementation of NHibernate.Cache.ICache that bridges our framework with NH. I based my implementation almost entirely on this:

https://nhcontrib.svn.sourceforge.net/svnroot/nhcontrib/trunk/src/NHibernate.Caches/Velocity/NHibernate.Caches.Velocity/VelocityClient.cs

One thing that jumped out at me right off the bat is the cache keys in the ICache interface are of type object. Our framework key's the cache using strings. I noticed the Velocity implementation above just does a .ToString() on the key instance that's passed to the Get(object key) and Put(object key) methods. That made me a little nervous.

In my testing it appears the "key" object is of type string and it's the entity name.

My questions:

• Is blindly calling .ToString() on the key instance a safe approach (I'm checking for null)?
• If this implementation is indeed safe, does that mean it's always a string?
• If this is always a string, then why is this of type object?

The NH guys are smarter than me, so the fact it's of type object makes me as开发者_开发百科sume there's something I'm missing here. I really don't want to introduce some obscure, random session management bug with unsafe key usage in my cache implementation.

Any guidance would be appreciated - cheers

I didn't get any responses here, nor on the NH user groups thread [1]. I've concluded that calling key.ToString() in our custom implementation is safe, but I'm sad I didn't get some official guidance on this :(

See the user group thread for a bit more details.

Cheers

[1] http://groups.google.com/group/nhusers/browse_thread/thread/6d47ab21e85eb9b7/988ad6046528e7bc?lnk=gst&q=Custom+Cache#988ad6046528e7bc