The quirk is that it only allows you to fetch new articles once per day (or X days).
Why? Let me explain...
I want my internet content to be like a boring newspaper. You get it in the morning, and you read the whole thing while sipping your morning coffee, and then you're done! No more new information for today. No pings, no alerts, peace, quiet, zen, etc.
But with that, I needed it to be able to fetch all articles from my hundreds of feeds in one sitting. This is where Zig and curl optimisations come in. I tried to do all the tricks in the book. If I missed something, let me know!
First off, I'm using curl multi for the network layer. The cool thing is it automatically does HTTP/2 multiplexing, which means if your feeds are hosted on the same CDN it reuses the same connection. I've got it configured to handle 50 connections total with up to 6 per host, which seems to be the sweet spot before servers start getting suspicious. Also, conditional GETs. If a feed hasn't changed since last time, the server just says "Not Modified" and we bail immediately.
While curl is downloading feeds, I wouldn't want CPU just being idle so the moment curl finishes downloading a single feed, it fires a callback that immediately throws the XML into a worker thread pool for parsing. The main thread keeps managing all the network stuff while worker threads are chewing through XML in parallel. Zig's memory model is perfect for this. Each feed gets its own ArenaAllocator, which is basically a playground where you can allocate strings during parsing, then when we're done, we just nuke the entire arena in one go.
For parsing itself, I'm using libexpat because it doesn't load the entire XML into memory like a DOM parser would. This matters because some podcast feeds especially are like 10MB+ of XML. So with smart truncation we download the first few X mb's (configurable), scan backwards to find the last complete item tag, cut it there, and parse just that. Keeps memory usage sane even when feed sizes get massive.
And for the UI I just pipe everything to the system's "less" command. You get vim navigation, searching, and paging for free. Plus I'm using OSC 8 hyperlinks, so you can actually click links to open them on your browser. Zero TUI framework needed. I've also included OPML import/export and feed groups as additional features.
The result: content from hundreds of RSS feeds retrieved in matter of seconds, and peace of mind for the rest of the day.
The code is open source and MIT licensed. If you have ideas on how to make it even faster or better, comment below. Feature requests and other suggestions are also welcome, here or GitHub.
- I have created my own RSS readers, that contains 500+ sources. I do not doom scroll
- doom scrolling appears when social media algorithm feeds you data, even from a month ago
- I have various filters so I can browse whatever I want
So RSS should just have filters, categories, search extensive capabilities to solve doom scrolling, and on the other hand it will be able to provide you extensive amounts of data.
ETA: When I was a late teen I ended up managing a bunch of younger teams for a free mod for an indie PC game called Blockland. I had them code up IRC and RSS capabilities into the mod from scratch in the Torque Game Engine's custom TorcueScript. I couldn't believe what those kids were capable of. They all went into programming, engineering, or founding their own companies out of highschool and college. If one of them told me something was impossible I'd just tell them that I saw that a competing mod already figured it out. Magically my dudes had a solution really quick lol. Sometimes when you have limited resources and/or experience the old and proven ways are just as good.
Was great when they had all that XML experience in a weird scripting language and I asked them to implement Jabber in-game from my Dreamhost shared-hosting plan. Crazy what a bunch of teens can do for an online Lego-like game.
Thanks for letting this older dude wax nostalgic off the rails. Hope it reminds others on HN about early hacking days like OP's project.
Incidentally, I built my own calm RSS reader some time ago that has many similar ideas to yours: https://github.com/lukasknuth/briefly
first of all, i'm not trying to reinvent the wheel here. for xml parsing, i'm using libexpat, one of the most widely used c xml parsers.
for networking, i'm using libcurl, the industry standard.
i have some limits in place, too. the feed size is capped at 200 kb, and there are timeouts for hanging connections. there's also a sanitization step that strips control characters that could mess with the terminal emulator, mitigating escape sequences.
that said, i'm no security expert, and the source code is public. if anyone more knowledgeable spots a security hole, i'd be happy to merge a fix.
A severe case of mimetic desire. I suspect a lot of devs suffer from it.
I like the idea of the daily digest.
That gave me a good chuckle:
Starts in milliseconds and parses hundreds of items in seconds.
I really like the culture around Zig right now. Ship simple, fast, correct, useful software feels like the general set of goals for people writing software in Zig.
I never thought of that as an option. Thanks for the tip haha.
Write programs that do one thing and do it well.
Write programs to work together.
Write programs to handle text streams, because that is a universal interface.
As a user, I'm happier with copyleft. I like to take my Marshall smart speaker as an example: that thing doesn't get any updates, ever. But it connects to the Internet. The app absolutely sucks, the connectivity is passable at best (often frustrating), but the hardware itself is nice (it looks nice in my living room and the sound is good when it works).
If all the open source software running inside that thing was GPLv3, Marshall would have to provide me with a way to patch it. So at the very least I could make security updates myself. But because Marshall used permissively-licenced dependencies, they locked it down in such a way that I can't do that.
The permissive licence helped Marshall, but for me as a user, the code may as well be proprietary.
If I use a copyleft licence (I like EUPL or MPLv2), it doesn't mean that they will open clean PRs, but at least they have to publish their changes in their own fork. It has happened to me that I could go read a fork, find a few things that were interesting and bring them back to my project.
With permissive licences, the risk is that those (typically businesses) who keep their fork open source probably don't see a lot of value in their fork, otherwise they would have made it private, "just in case".
The main difference is that GPL3 is a copyleft license, whereas MIT is not. Meaning that legally there is nothing in the license preventing a company from taking your code and using it for their purposes without having to contribute to improve the code.
the reason i picked mit is because rss is in a rough spot right now. the tech isn't mainstream, and big companies are trying to squash it since it doesn't drive engagement like the infinite scroll. anything that helps rss move forward is a win, and the mit license makes that easier.
> the reason i picked mit is because rss is in a rough spot right now.
I don't think another client is the solution, just saying. There's about three billion of them out there (though I don't dispute that yours might have something unique).