A Byte of Coding Issue 347

Howdy,

I recently rented a dedicated server and set up caprover (open-source platform as a service) on it. Super satisfied with it. I’ve been exploring some of the “one click apps” you can deploy and found a replacement for the feed aggregator I was using. It does mean I have to adjust the dashboard I made for myself to curate this newsletter to now pull articles from the new feed aggregator, which is slightly annoying. It also looks like I’ll have to finally get a good understanding of how docker works, because that’s how you have to deploy your own projects. Still, it’s super satisfying being able to spin up a DB or app in a couple of minutes and not have to deal with all of the server and nginx configs.

Anyway, here’s the issue.

Today’s Sponsor: Unblocked

Unblocked provides helpful and accurate answers to questions about your codebase. It generates insights by complementing your source code with relevant discussions from GitHub, Slack, Notion, JIRA and more. Spend less time hunting for information and more time doing what you love: writing great code.

Garbage Collection Without Unsafe Code

Published: 6 February 2024

Tags: rust, garbage collector

Nick Fitzgerald introduces a garbage collection library he implemented in Rust and dives into some of its internal workings, including how it tackles classic garbage collection footguns.

Some highlights:

• “safe-gc crate: a garbage collection library for Rust with zero unsafe code”

• doesn’t need an unsafe finalizer trait, or even any additional finalizer trait: it can just use Drop

• implemented using mark-and-sweep rather than a copying collector

Static Roots: Objects with Compile-Time Constant Addresses

Published: 5 February 2024

Tags: javascript, optimization

Olivier Flückiger concisely explains how and where core JavaScript objects are stored in the V8 JS engine.

Some highlights:

• these objects are called immovable immutable roots and they live in their own heap – the read-only heap

• they’re created and stored at compile time by V8

• quick comparison is done via memory address comparison of the objects

How we built it: Saving time and money with self-hosted runners on EC2 on-demand / spot instances

Published: 2 February 2024

Tags: sponsored, cicd, infrastructure

Unblocked discusses their experience switching their deployment pipeline from Github hosted runners to self-hosted ephemeral runners on AWS EC2 using Spot or On-Demand instances.

Some highlights:

• “GitHub’s hosted runners became a bottleneck for both cost and performance”

• “Up to 90% savings when using Spot instances, and 30-70% savings when using On-Demand”

• Includes example configuration for the custom Github Action, as well as a link to the repo

What is X-Forwarded-For and when can you trust it?

Published: 31 January 2024

Tags: http, networking

Phil Sturgeon has written a detailed rundown on the X-Forwarded-For HTTP header, including what it is, what it’s used for, its limitations, and alternatives.

Some highlights:

• works as a mechanism for conveying the original source IP addresses of clients, and not just across one hop, but through chains of multiple intermediaries

• used for user authentication, load balancing, data localization, geographic content delivery, access control and security, web application firewalls, fraud prevention, api rating limiting, localized advertising, and logging and analytics

• should be replaced by the Forwarded header, but still commonly used