Fountain codes and animated QR

(source: Anders Sune Berg) In the previous article I’ve described a weekend project called txqr for unidirectional data transfer using animated sequence of QR codes. The straightforward approach was to repeat the encoded sequence over and over until the receiver gets complete data. This simple repetition code was good enough for starter and trivial to implement, but also introduced long delays in case the receiver missed at least one frame.

Animated QR data transfer with Gomobile and Gopherjs

TL;DR: a weekend project for transferring data via animated QR codes, written in Go and using fountain erasure codes. The Go code is reused for mobile apps using Gomobile, and in a web application for automating testing QR codes parameters, built with GopherJS and Vecty framework. I’ll share my experience building it, some code and benchmark results of using animated QR as a data transfer method. The problem One day I was trying to find a viable solution for the following scenario:

WakeMeUpInTheMiddleOfTheNight log level

On the last Golang Barcelona meetup we decided to try new format of conversation and after the talk started open discussion on logging, tracing and metrics. The idea was to encourage people to read a very nice blog post by Peter Bourgon on this subject - “Metrics, Tracing and Logging” and discuss it in a free format. It went surprisingly well, and while most of the people were conscious about the topic, one thing seemed to be still confusing - what to log and when.

Misusing error interface

I used to think that misunderstanding interfaces in Go can lead, at most, to not very readable code and worse maintainability. From my observations misusing interfaces becomes visible usually during refactorings, where you questioning what this type or abstraction actually represents. But, at least, the code tends to work and it’s not buggy. The bug But here is the interesting piece of code that actually was buggy: err := SomeFunc() if _, ok := err.

How to avoid Go gotchas

TL;DR by learning internals a gotcha is a valid construct in a system, program or programming language that works as documented but is counter-intuitive and almost invites mistakes because it is both easy to invoke and unexpected or unreasonable in its outcome (source: wikipedia) Go programming language has some gotchas and there is a number of good articles explaining them. I find those articles very important, especially for the newcomers in Go, as I see people run into those gotchas every now and then.

My GopherCon experience

A couple of weeks ago I gave a talk at the largest Go conference, GopherCon, in Denver. It was the first time I attended GopherCon at all, and the first time ever I spoke in English in front of 1400+ people, and it was an absolutely incredible experience. Here is my story. My journey to GopherCon started on a cold winter day in the apartments in the center of Odessa, Ukraine, where I was living at that time.

go get for private repos in docker

As Go community slowly moving towards established and well understood patterns and practices of dependency management, there are still some confusing moments. One of them is automating repeatable build process using containers along with using dependencies in private repositories. Private repositories on Github are often is a source of confusion when using go get, but it has easy workaround by adding two lines to your .gitconfig: [url "git@github.com:"] insteadOf = https://github.

LeftPad and Go: can tooling help?

You’ve probably heard that story about NPM community and LeftPad package, that broke thousands JavaScript projects worldwide. There was a nice follow-up article titled “Have We Forget How To Program” and one guy even created left-pad.io - Left-Pad As A Service web service. People got a lot of fun discussing this story. I personally find this story amazing, because there is no single point of failure, but rather a set of things and coincidences resulted in a disaster.

Visualizing Concurrency in Go

If you prefer video over blog posts, here is my talk on this at GopherCon 2016: https://www.youtube.com/watch?v=KyuFeiG3Y60 One of the strongest sides of Go programming language is a built-in concurrency based on Tony Hoare’s CSP paper. Go is designed with concurrency in mind and allows us to build complex concurrent pipelines. But have you ever wondered - how various concurrency patterns look like? Of course, you have. We’re all thinking mostly by visualization in one form or another.

How to complain about Go

Over the years of existence of Go programming language, the articles with its critique was always popular, bringing a lot of discussion from both sides. Recently, Maksim Kochkin even created GitHub repo with curated list of articles complaining about golang’s imperfection. So, is it true that ranting about Go flaws is a trend nowadays? With carefully gathered links in the repository above, we can check this! :) Unfortunately, there are only 17 articles in the list, which is a bit disappointing because it’s not enough for fine statistical analysis, but we can use this anyway.