When I launched my Patreon, I vowed to explain how computers work. But in 2019, computers rarely work in isolation. So let’s take the time to write a few articles about how computers talk to each other.

Let’s use the Advent of Code 2020, a series of programming challenges of increasing difficulty, to learn more about the Rust programming language.

Async fn in trait… not

I was planning on showing the in-progress async_fn_in_trait feature in the context of my website, but it turns out, I can’t!

My website uses two databases: one local SQLite database for content, and a shared Postgres database for user credentials, preferences etc. Migrations are run on startup, and each migration implements one of the following traits:

We’ve just spent a lot of time abstracting over LoadLibrary, but we still have all the gory details of the Win32 ICMP API straight in our main.rs file! That won’t do.

This time will be much quicker, since we already learned about carefully designing an API, hiding the low-level bits and so on.

Let’s add an icmp module to our program. Actually, we’ve been dealing with an IPAddr all this time, it also sounds like it could use its own package:

What’s a ktls

I started work on ktls and ktls-sys, a pair of crates exposing Kernel TLS offload to Rust, about two years ago.

kTLS lets the kernel (and, in turn, any network interface that supports it) take care of encryption, framing, etc., for the entire duration of a TLS connection… as soon as you have a TLS connection.

For the handshake itself (hellos, change cipher, encrypted extensions, certificate verification, etc.), you still have to use a userland TLS implementation.

Hi everyone. Has it been two months since I last posted something? Yes it has!

That seems like a nice round duration, so let’s break the silence with a few announcements.

I have a new website

If everything goes well, you’re on it right now.

Does it feel okay? Take a minute to accustom yourself to your new surroundings. Identify potential sources of fresh water. Gather some supplies with which to fashion a makeshift shelter.

Addressing the rumors

There have been rumors going around, in the Reddit thread for facet, my take on reflection in Rust, which happened a bit too early, but here we are, cat’s out of the bag, let’s talk about it!

Rumors that I, podcaster/youtuber fasterthanlime, want to kill serde, serialization / deserialization framework loved by many and which contributed greatly to Rust’s success, and I just wanted to address those rumors and say that…

It’s a new day, it’s a new advent of code puzzle.

In that one, we have to apparently cosplay as an IBM mainframe and just.. crunch them numbers. This doesn’t look fun, and I can’t think of a clever twist to make it fun, so let’s try to make it short and sweet.

Parsing

Our input looks like this:

Monkey 0: Starting items: 79, 98 Operation new = old divisible by true throw to monkey false throw to monkey items new = old + divisible by true throw to monkey false throw to monkey etc

In my previous article, I said I needed to stop thinking of Rust generics as Java generics, because in Rust, generic types are erased.

Someone gently pointed out that they are also erased in Java, the difference was elsewhere. And so, let’s learn the difference together.

Java generics

I learned Java first (a long, long time ago), and their approach to generics made sense to me at the time.

Another day, another problem.

This time the problem looks suspiciously like Conway’s Game of Life, or, I guess, any old Cellular automaton.

We have a map like so:

L.LL.LL.LL LLLLLLL.LL L.L.L..L.. LLLL.LL.LL L.LL.LL.LL L.LLLLL.LL ..L.L..... LLLLLLLLLL L.LLLLLL.L L.LLLLL.LL

And for each iteration:

• L symbols turn into # if there’s no # in any of the 8 adjacent cells