In Go, there is a type called slice which is built on top of array. It's a very convenient type when we want to handle a group of data. This post will explain a subtle but tricky difference between empty slice and nil slice.A nil slice is a slice has a length and capacity of zero and has no underlying array. The zero value of slice is nil. If a slice is declared like below, it is a nil slice.package mainimport "fmt"func main() { var a []string fmt.Println(a == nil)}The output will be true for above code snippet. An empty slice is a slice also has a length and capacity of zero but has unde...

MySQL 8 has changed its default authentication plugin from mysql_native_password to caching_sha2_password to improve its security. However many third party libraries seem act slowly to catch up with this change. This causes some compatible issues with their connection to MySQL. One of the issues is seen in Go libraries while it's trying to connect to MySQL 8.The specific error has been observed is "this authentication plugin is not supported". The root cause of this issue is that the go-sql-driver didn't support the new default authentication plugin. This bug has been reported a coup...

Subtitle: Wow Go’s net library is fastOn paternity leave for my second child, I found myself writing an in-memory hashmap (a poor-man’s memcached), in Go, Python and C. I was wondering how hard it would be to replace memcached, if we wanted to do something unusual with our key-value store. I also wanted to compare the languages, and, well, I get bored easily!The code is on github as Key-Value-Polyglot.Each version implements enough of the get and set commands from the memcached protocol that we can test them with a memcached client.If you write a version in a different language (...

This week there was a discussion on the golang-nuts mailing list about an idiomatic way to update a slice of structs. For example, consider this struct representing a set of counters. type E struct { A, B, C, D int}var e = make([]E, 1000)Updating these counters may take the form for i := range e { e[i].A += 1 e[i].B += 2 e[i].C += 3 e[i].D += 4}Which is good idiomatic Go code. It's pretty fast too BenchmarkManual 500000 4642 ns/opHowever there is a problem with this example. Each access the ith element of e requires the compiler to insert an...

During last semester I was attending Multiprocessor Architectures course, given at Facultad de Informática where I study my Computer Science degree.As part of the assignments due to pass the course, we had to do several programs written in C to benchmark matrix multiplication by testing different techniques and technologies. First of all we had to do a secuential program in three different versions:A normal one where the result matrix is ordered by rows and the loops range the matrix by rows tooAn “inter” version where the result matrix is ordered by rows but the loops range the...

This year I'm going to try a new programming language - Go. I had this notion that compiled, type based languages are overly complex and reduces developer efficiency. However, after doing some reading about Go, it appeared to take a different path from the rest and felt like something worth trying.Acquainting a programming language is a journey. First few steps you take with it will define your perception about it. These first few steps went well for me with Go and it felt like a good fit for my repertoire. I thought of sharing my learning experience, hoping it will help others who w...