Rewriting the XPO Semantic Kernel Memory Store to be Compatible with XAF

A few weeks ago, I forked the Semantic Kernel repository to experiment with it. One of my first experiments was to create a memory provider for XPO. The task was not too difficult; basically, I needed to implement the IMemoryStore interface, add some XPO boilerplate code, and just like that, we extended the Semantic Kernel memory store to support 10+ databases. You can check out the code for the XpoMemoryStore here.

My initial goal in creating the XpoMemoryStore was simply to see if XPO would be a good fit for handling embeddings. Spoiler alert: it was! To understand the basic functionality of the plugin, you can take a look at the integration test here.

As you can see, usage is straightforward. You start by connecting to the database that handles embedding collections, and all you need is a valid XPO connection string:

using XpoMemoryStore db = await XpoMemoryStore.ConnectAsync("XPO connection string");

In my original design, everything worked fine, but I faced some challenges when trying to use my new XpoMemoryStore in XAF. Here’s what I encountered:

1. The implementation of XpoMemoryStore uses its own data layer, which can lead to issues. This needs to be rewritten to use the same data layer as XAF.
2. The XpoEntry implementation cannot be extended. In some use cases, you might want to use a different object to store the embeddings, perhaps one that has an association with another object.

To address these problems, I introduced the IXpoEntryManager interface. The goal of this interface is to handle object creation and queries.

public interface IXpoEntryManager
{
    T CreateObject();
    public event EventHandler ObjectCreatedEvent;
    void Commit();
    IQueryable GetQuery(bool inTransaction = true);
    void Delete(object instance);
    void Dispose();
}
    

Now, object creation is handled through the CreateObject<T> method, allowing the underlying implementation to be changed to use a UnitOfWork or ObjectSpace. There’s also the ObjectCreatedEvent event, which lets you access the newly created object in case you need to associate it with another object. Lastly, the GetQuery<T> method enables redirecting the search for records to a different type.

I’ll keep updating the code as needed. If you’d like to discuss AI, XAF, or .NET, feel free to schedule a meeting: Schedule a Meeting with us.

Until next time, XAF out!

Related Article

https://www.jocheojeda.com/2024/09/04/using-the-imemorystore-interface-and-devexpress-xpo-orm-to-implement-a-custom-memory-store-for-semantic-kernel/