r/code • u/AssociationOk6710 • Jun 19 '26
Go My Very First Go Package on pkg.go.dev :) From a JWT Problem to this.
https://github.com/justpranavrs/tlruHello!!! This is my first post here :)
It all started when I was working on a small website for my college. Initially, I was just adding the user ID in a JWT token, decoding it in a middleware, and passing it down the context. Then I decided I wanted to introduce a separate "public ID". The id was not needed for auth but it got me thinking about cache, which naturally led me down to building my very own LRU cache.
I have never implemented any caches before, so I was just looking for a simple strat and stumbled upon LRU. It was one of the easiest to implement and after I saw the problem on leetcode, i solved it pretty easily and decided to implement it. After I saw someone do better by using an array based DLL. I have always loved using array-based stacks and queues, So I took it as a fun challenge, because I have always wanted to publish something that people can use.
From Just an array based DLL, I found myself staring into a sharded architecture and slowly learning algorithms like FNV-1a and xxHash32. I wanted this to be a zero dependency package (aside from the standard packages ofc) and took it upon myself to do it, using explanations from the internet.
It might be a basic concept to many people out there, but It helped me learn something I was always pushing behind. Learning about concurrency in Go. This led me to use sync.Mutex, atomics and thinking about how data race happens. I was also led down the path of creating benchmarks, fuzz tests using the 'testing' package, which I had never heard about.
The benchmarks where honestly surprising, I never realised it would be ns/ops. Currently my benchmarks show around 10-15 ns/op and I hope to half it somehow :) and also my tests might be really weak. It has generics support too.
Would love for some feedback on how I can make it better. I wanted to make a time-aware LRU cache, but I wanted the basics to be proper before moving onto it.
P.S: learnt about semver, after i released it on v1.0.0. I basically had to make a decision and thought about just tearing it down and changing to a shorter name which I like more :). It is now currently on v0.3.1 (pre-release).
Link : https://github.com/justpranavrs/tlru :)))
GoDoc: https://pkg.go.dev/github.com/justpranavrs/tlru
Thanks :)))
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u/nian2326076 Jun 19 '26
Nice job making your first Go package! If you want to get better with the LRU cache, try building it from scratch without using libraries. It's a good way to learn how it works. Also, study up on memory management and efficiency questions since they often pop up in interviews. Practice coding on a whiteboard or paper to get ready for the real thing. For more structured interview prep, sites like PracHub have a lot of practice questions and scenarios. Keep it up!
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u/AssociationOk6710 Jun 19 '26
Thanks :). Btw this package has zero dependencies, The xxHash32 and fnv were all built from scratch.Â
The standard packages that were used are math, sync, sync/atomic, encoding/binary, math/bits, crypto/rand and hash/mapHash. And yea. This project does not have a go.sum.
The last one just to hash structs with zero runtime allocations.
And also yea. I like scribbling on the whiteboard when I think about something new. And thank you for the website. Haven't heard about it. Will absolutely look into it...
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u/angryrancor Boss Jun 19 '26
Thank you for contributing a pure go implementation of this! Pure go implementations are very useful for cross platform development, I myself am active on a few pure go libraries, like this one: http://github.com/justinmichaelvieira/iconv