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  New function signal.NotifyContext in GoLang 1.16

os/signal package in GoLang may not be frequently used but it provides some good features like Shutdown() which can be used to gracefully shutdown a running HTTP server. func (srv *Server) Shutdown(ctx context.Context) error With this function, there is no need to use third party library to gracefully shutdown HTTP server. How is it being used? package main import ( "context" "fmt" "net/http" "os" "os/signal" "time" ) func main() { server := http.Server{ Addr: ":8080", } http.Handl...

   GOLANG,NOTIFYCONTEXT,GRACEFUL SHUTDOWN     2021-06-19 01:07:10

  Implementing DESede/ECB/NoPadding cipher algorithm in GoLang

By default, GoLang doesn't provide the ECB mode cipher for DESede though there is CBC mode provided. In cases we need to encrypt/decrypt data with ECB mode, we need to implement those by ourselves. This mode is frequently used when encrypting/decrypting PIN block which is small block data less than 16 bytes. In this post, we will introduce how to implement the DESede/ECB/NoPadding algorithm in GoLang by using the existing cipher support. Here we will not cover how DESede works in detail, instead...

   SECURITY,SAMPLE,GOLANG,DES,DESEDE,3DES     2019-07-29 06:43:50

  Go channel explained

In Go, a channel is a type of concurrent data structure that allows two or more goroutines (Go's term for lightweight threads) to communicate with each other. Channels provide a way for goroutines to send and receive values, and they are an essential part of Go's concurrency model. Here's a simple example that demonstrates how to use channels in Go: package main import ( "fmt" ) func main() { // Create a new channel with the `make` function ch := make(chan int) // Start a new ...

   GOLANG,CHANNEL     2022-12-10 22:24:26

  Mastering Go Channels: How to Build Concurrent Applications Like a Pro

Introduction In the world of concurrent programming, Go channels have quickly become a popular tool for building fast and efficient applications. Utilizing channels can help you take full advantage of the power of Go's lightweight threads, or goroutines, and enable you to easily and effectively manage data sharing and synchronization. In this article, we'll dive deep into the world of Go channels and show you how to build concurrent applications like a pro. Understanding Go Channels To start, le...

   GOLANG,CHANNEL,CONCURRENCY     2023-04-21 14:47:47

  How to do pprof for gRPC service

gRPC is a RPC framework based on HTTP and is frequently used for communications among micro service inside the same organization network. However,  the service functions cannot be accessed via normal HTTP URL as it's not a WEB framework. In this case, how to do pprof on a gRPC service? The trick is starting a HTTP server asynchronously while starting the gRPC service. This HTTP server can be accessed to run prrof debug. go func(){ http.ListenAndServe(":10001", nil) }() Since it uses the de...

   GOLANG,PPROF,GRPC     2021-01-29 23:11:33

  A simple example on implementing progress bar in GoLang

Sometimes when handling a long running process, there would be need to track the progress so that people know something is still running instead of doubting something goes wrong. In this case, a progress bar which indicates the current status and progress would be desired. This post will show an example on how to implement progress bar using GoLang. Let's take a look at the final outcome first before jumping into the implementation detail. The key in the implementation is actually just the \r ...

   TUTORIAL,EXAMPLE,GOLANG,PROGRESS BAR     2020-08-08 23:53:15

  The hidden risk of passing slice as function parameter

In Go's source code or other open source libraries, there are lots of cases where a slice pointer is passed to function instead of slice itself. This brings up a doubt why not passing slice directly as its internal is backed by an array pointer to point to underlying data? For example, in log package, the formatHeader function takes a parameter buf as type *[]byte instead of []byte. func (l *Logger) formatHeader(buf *[]byte, t time.Time, file string, line int) {} Let's understand the r...

   GOLANG,SLICE,SLICE POINTER     2020-12-13 06:11:14

  new() and make() in GoLang

GoLang is a modern, statically typed, compiled programming language designed for building scalable, concurrent, and efficient software. It provides various built-in functions and features that help developers write concise and efficient code. Among them are the new() and make() functions, which may appear similar at first glance but serve different purposes in GoLang and are crucial for memory allocation and data initialization. In this blog article, we will explore the differences between the n...

   NEW,MAKE,GOLANG     2023-11-18 13:43:25

  Behavior of defer function in named return function

In Go, there is a special concept of named return value in function where a returned value can have name. For example, below is a named function in Go. func returnNamed() (i int) { i = 1 return } When the function returns, the return value i will have a value of 1.  Also, Go has a concept of defer which will execute a function just before the calling function exits. This is similar to what finally block does in other languages such as Java. For example, a defer function can be func deferF...

   GOLANG,DEFER,NAMED RETURN,DIFFERENCE     2018-11-20 09:04:07

  errGroup in GoLang explained

Today, let's talk about the usage and applicable scenarios of errGroup, which is often used. Why is it useful? Generally, when we use goroutine, we cannot return a value. If you want to pass out the result of the goroutine execution, you usually have to use the channel. The errGroup package is suitable if you want to know when the goroutine you opened encounters an error during execution and stop working, and I need to know the error value. errGroup usage The package needs to be downloaded and i...

   GOLANG,ERRGROUP,WAITHROUP,CONCURRENCY     2023-05-27 23:58:20

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