DEV Community: Akshansh Gusain

CSP - Oversimplified

Akshansh Gusain — Tue, 13 Sep 2022 10:50:04 +0000

CSP stands for communicating sequential processes which is a formal language for describing patterns of interaction in concurrent systems. First mentioned in Charles Antony Richard Hoare’s paper “Communicating Sequential Processes” in the Association for Computing Machinery(ACM). CSP is a simple concept of solving concurrency through two primitives of programming 1. Input 2. Output

The paper abbreviates the term processes to any individual logic that needs input to run and produce output. (You can visualise this as a Goroutine)

For communication between the processes, Hoare created input and output commands: ! for sending input into a process, and ? for reading output from a process. Each command had to specify either an output variable or a destination. Sometimes these two would refer to the same thing, in which case the two processes would be said to correspond. In other words, output from one process would flow directly into the input of another process. Go Channels! Sounds familiar?

Go is the first language to incorporate principles from CSP in its core, and bring this style of concurrent programming to the masses.

Websockets in Golang under 5 Minutes.

Akshansh Gusain — Sat, 04 Jun 2022 15:49:31 +0000

Lets start with a simple http endpoint.

Start off by building a simple HTTP server that returns Hello Devs whenever we hit it on port 8001. We’ll also define a simple HTTP endpoint that will act as the base of the WebSocket endpoint that we’ll be creating:

Upgrading the HTTP Connection

To create a WS endpoint we need to upgrade a standard HTTP connection to a WS connection. We'll be using gorilla/websocket package for this.

1. Define the Upgrader

This will hold information such as the Read and Write buffer size for our WS connection:

2. Take care of the CORS

This will determine whether or not an incoming request from a different domain is allowed to connect, and if it isn’t they’ll be hit with a CORS error. For now, we'll simply return true.

3. Upgrading the Connection

We can now start attempting to upgrade the incoming HTTP connection using the upgrader.Upgrade() function which will take in the Response Writer and the pointer to the HTTP Request and return us with a pointer to a WebSocket connection, or an error if it failed to upgrade.

Start Listening

Once the client is connected we can pass our WS to a reader function.

*A simple echo reader: *
A simple reader function that echos back every incoming message:

And that's it! We just created a WS endpoint in Go.

Why I am considering Go

Akshansh Gusain — Sat, 14 May 2022 12:45:51 +0000

1. Never Really Liked Javascript
JS is a great language and I am grateful for it but its flaky at times there have been instances when it made my life hell!
So when I heard about Go, I said to myself "Why not?!"

2. Relatively Easy to Learn
Its only my first week of learning Go and I already feel comfortable writing Go code. IMHO, if you have previous programming experience you should be up and running writing services in Go really quick.

3. Performance

Go is simply quicker and does what Python or NodeJS does but better. Higher max IO, faster arithmetic faster general operation.

But how fast?

That's exactly i wanted to know so I ran benchmarks with FastAPI(Python), ExpressJS(NodeJS) and Gin(Go).

Test setup:

8 Core CPU
8GB RAM

FastAPI with Uvicorn ASGI server scaled to 4 worker nodes with Gunicorn.(idk why but, when I tried to scale it more than 4 workers the performance got worse)

ExpressJS with Cluster Module scaled to 8 cores.

Go-Gin GOMAXPROCS=8.

My findings: