Blog Posts

Recent Posts

Full Category Index

Posts in “Go”

30 days of hacking Docker

Wed, Jun 11, 2014
Prelude Yesterday I finished my first 30-day streak on GitHub. Most of contributions were to Docker – the biggest opensource project on Go. I learned a lot in this month, and it was really cool. I think that this is mostly because of Go language. I’ve been programming on Python for five years and I was never so excited about open source, because Python is not even half so fun as Go.

Defer overhead in go

Wed, May 14, 2014

Prelude

This post based on real events in docker repository. When I revealed that my 20-percent-cooler refactoring made Pop function x4-x5 times slower, I did some research and concluded, that problem was in using defer statement for unlocking everywhere.

In this post I’ll write simple program and benchmarks from which we will see, that sometimes defer statement can slowdown your program a lot.

Let’s create simple queue with methods Put and Get. Next snippets shows such queue and benchmarks for it. Also I wrote duplicate methods with defer and without it.

Coverage for multiple packages in go

Tue, May 6, 2014
Prelude There is awesome coverage in go. You can read about it here. But also it has some limitations. For example let’s assume that we have next code structure: src ├── pkg1 │ ├── pkg11 │ └── pkg12 └── pkg2 ├── pkg21 └── pkg22 pkg2, pkg21, pkg22 uses pkg1, pkg11 and pkg12 in different cases. So question is – how we can compute overall coverage for our code base? Generating cover profiles Let’s consider some possible go test commands with -coveprofile: go test -coverprofile=cover.out pkg2 tests run only for pkg1 and cover profile generated only for pkg2 go test -coverprofile=cover.out -coverpkg=./...