Mastering Maps in Go: Everything You Need to Know

Maps, also known as associative arrays or hash tables, are vital data structures for solving algorithmic problems in programming. Understanding their features, operations, time and space complexities, and implementation in code is crucial for developers. With this knowledge and practical experience, developers can effectively apply maps to problem-solving scenarios.

This article offers a comprehensive guide to using maps, covering their overview, implementation in Go programming, and strategies for using them in concurrent code.

https://go.dev/blog/chacha8rand

Explore the recent advancements in randomness within the Go programming language. Authors Russ Cox and Filippo Valsorda, part of the Go team, look closely at the complexities of addressing security requirements for specific use cases and the implementation of the ChaCha(Rand8) algorithm. Discover how these improvements have enhanced random number generation in Go, culminating in the seamless security enhancements introduced in Go 1.22.

"ok" considered harmful?

“Just like there’s an unwritten law that every error variable in Go must be named err, there’s an unwritten law that every map existence variable in Go must be named ok.”

But Zach thinks we can, and should, look at doing better.

https://www.dolthub.com/blog/2024-05-10-ok-considered-harmful/

Okay based on the first reactions it seemed like the naming convention issue brought by Zach didn't get much reflection in you.

In this case, I'd like to share a more practical guidance I used recently when had to test a k8s operator setup locally.

The topic is:
Go: Testing Kubernetes Applications with EnvTest

Enjoy 🙂

https://blog.marcnuri.com/go-testing-kubernetes-applications-envtest

Profile-guided optimisation (PGO) is a technique where CPU profile data for an application is collected and fed back into the next compiler build of Go application. The compiler then uses this CPU profile data to optimise the performance of that build by around 2-14% currently (future releases could likely improve this figure further).

In this article, the Grab tech folks show off their wins and learnings, along with the Dockerfile used to make it happen.

https://engineering.grab.com/profile-guided-optimisation

Enjoy!

If you use Timer.Reset() in Go 1.22 or earlier, you may be doing it wrong. Even the book 100 Go Mistakes (which is usually right about Go nuances) got it wrong.

Let's see what the problem might be and how to work around it.

https://antonz.org/timer-reset/

The standard library of Go 1.23 now includes the new unique package. The purpose behind this package is to enable the canonicalization of comparable values. In other words, this package lets you deduplicate values so that they point to a single, canonical, unique copy, while efficiently managing the canonical copies under the hood. You might be familiar with this concept already, called “interning”.

Let’s dive in to see how it works, and why it’s useful.

https://go.dev/blog/unique

Go sync.Map: The Right Tool for the Right Job

In Go, sync.Map offers a thread-safe alternative to traditional maps. While sync.Map can be highly effective in scenarios involving heavy concurrent access, it isn't always the best choice. In this article by VictoriaMetrics, you'll learn when to opt for sync.Map, how it differs from regular maps, and the performance trade-offs involved.

https://victoriametrics.com/blog/go-sync-map/index.html

Go Blueprint: A Quick Way to Start Go Projects ⚒

The tool helps you setting up new Go projects fast, with ready-made templates and all the basic setup done for you.

While I’m not really into using tools like this, some might find it useful to save time and focus on development.

From the authors: "Powerful CLI tool designed to streamline the process of creating Go projects with a robust and standardized structure. Not only does Go Blueprint facilitate project initialization, but it also offers seamless integration with popular Go frameworks, allowing you to focus on your application's code from the very beginning."

https://docs.go-blueprint.dev/

Coming in Go 1.24: testing/synctest experiment for time and concurrency testing

Testing code that involves time or concurrency can be a struggle. It often leads to hard-to-debug flakes in CI or long-running tests.

Go 1.24 is scheduled to be released in February and the release freeze has begun.

It’s set to include an experimental testing/synctest package designed to make testing code that involves time or concurrency precise and fast.

https://danp.net/posts/synctest-experiment/

Hello, dear community!

I wish you Merry Christmas 🎄 Happy New Year 🎊 and great winter holidays ahead!☃️ ❄️

See you in 2025 👋

Go 1.24: A Major Improvement for Tooling: go tools 🛠

Hello, folks! The upcoming Go 1.24 (supposed to be coming this month, Feb 2025) introduces a new go tool command, aiming to significantly improve the way project-specific tools are managed. This update eliminates the need for the tools.go workaround, reduces dependency bloat, and improves performance through caching. So,
- No more tools.go hacks
- Faster execution with caching
- Cleaner and more efficient dependency management

How it works? Simple!

Add a tool:

go get -tool github.com/oapi-codegen/oapi-codegen/v2/cmd/[email protected]

Run it:

go tool github.com/oapi-codegen/oapi-codegen/v2/cmd/oapi-codegen --config=config.yaml openapi.yaml

List available tools:

go tool

Some people say this is one of the most useful changes to Go's tooling in years, making project setups more efficient and maintainable, so take a look in more details here https://www.jvt.iss.one/posts/2025/01/27/go-tools-124/ 🚀

PS More official docs can be found in the Go 1.24's release notes here: https://tip.golang.org/doc/go1.24#tools

Be Careful with Go Struct Embedding

Embedding structs can quietly mask deeper-nested fields: a duplicate field name isn’t ambiguous unless it appears at the same ‘depth’, meaning your program may choose an unintended value.

https://mattjhall.co.uk/posts/be-careful-with-go-struct-embedding.html

Hello, folks, it's been a while. Re-sharing an interetsting recording from GopherCon 2025:
Advancing Go Garbage Collection with Green Tea (youtube). TL;DR:

Go 1.25 includes a new experimental garbage collector called Green Tea, available by setting GOEXPERIMENT=greenteagc at build time. Many workloads spend around 10% less time in the garbage collector, but some workloads see a reduction of up to 40%!

There is an also official text version on the Green Tea Garbage Collector if one does not like to watch the video.

Thanks!