Immediate.Cache

Creating a cache

Create a class and apply the [CacheFor<>] attribute, targeting a handler. Add a TransformKey method to transform a request into a cache key. For example:

        [Handler]
public static partial class GetValue
{
	public sealed record Query(int Value);
	public sealed record Response(int Value);

	private static ValueTask<Response> HandleAsync(
		Query query,
		CancellationToken _
	) => ValueTask.FromResult(new Response(query.Value));
}

[CacheFor<GetValue>]
public sealed class GetValueCache
{
	protected override string TransformKey(GetValue.Query request) =>
		$"GetValue(query: {request.Value})";
}

      

In this case, the GetValueCache class will serve as a cache for the GetValue IH handler.

# Adding generated caches to the IServiceCollection collection

In your Program.cs, add a call to services.AddXxxCaches(), where Xxx is the application identifier. By default, this is the short form of the assembly name. For example:

• For a project named Web, it will be services.AddWebCaches()
• For a project named Application.Web, it will be services.AddApplicationWebCaches()

However, this name can be overridden using [assembly: ImmediateAssemblyIdentifierAttribute("SomeIdentifier")].

# Retrieve Data From the Cache

Using an instance of the GetValueCache class that you have created above, you can simply call:

        var response = await cache.GetValue(request, token);

      

If there is a cached value, it will be returned; otherwise a temporary scope will be used to create the handler and execute it; and the returned value will be stored.

# Removing Data From the Cache

Using an instance of the GetValueCache class that you have created above, you can remove cached data by calling:

        await cache.RemoveValue(request);

      

# Updating Data In the Cache

Using an instance of the GetValueCache class that you have created above, you can assign cached data by calling:

        await cache.SetValue(request, response);