Upgrade your gray matter

Created 2:56am, Sep 26, 2013

I’ve wanted to properly avail a useful software creation as open source for a long time, but work (both employment and entrepreneurial) had always preoccupied me. As my startup Blocvox matured, I saw in it the possibility to fulfill this desire. Recently my task list has been clearing up, so I spent the necessary few hours isolating, documenting and polishing some code for you, dear reader. Blocvox is fairly well decoupled and many parts are ripe for packaging, but there was one piece that stood out as particularly useful and well-contained. I give you, Blocvox.GrayMatter.

Blocvox uses a command-query responsibility separation (CQRS) architecture to simplify both the domain model and the user interface code, and to enhance performance by computing derived values once at write-time rather than repeatedly at read-time. Blocvox.GrayMatter plays a major role in connecting these two sides of the Blocvox brain, allowing them to remain simple and agnostic.

This is a custom Castle Windsor facility that allows easy registration of event handlers, and high-performance, decoupled attachment at resolve-time. On the registration side, the package provides a strongly-typed fluent API and a reflection-friendly API. On the resolution side, the facility dynamically constructs, compiles, and caches the code needed to add event handler Delegate instances to events, in order to remove the reflection performance hit. It also wraps the delegate to provide “just-in-time” resolution of the subscriber, in order to mitigate huge dependency graphs being resolved up-front which might not even be used. This takes advantage of, and reinforces, the decoupled semantics of the event keyword.

Call me old-fashioned, but I find event to be the Way to do decoupled event-driven programming in C#. No reactive/observer/observable ceremony and threading black boxes. And no God-awful pub-sub/service bus God objects. (Unless you’re dealing with significantly disparate business units, pub-sub is doing it oh-so-painfully-unnecessarily-wrong. But it’s easy, right?) Despite its own warts, nothing is as idiomatic, well-understood, and portable as event for decoupling event providers from subscribers.

It’s not a lot of code, but I’ve found it it to be immensely valuable, primarily in keeping the cognitive load of the codebase low. I hope it is of use to others. I plan to maintain and improve it, but I don’t foresee drastic changes in the near future.

I leave you with these timeless words from a futuristic poet: “Upgrade your gray matter, ’cause one day it may matter.”