Dmytro culttm

INTRO

Concurrency is a domain I have wanted to explore for a long time because the locks and the race conditions have always intimidated me. I recall somebody suggesting concurrency patterns in golang because they said "you share the data and not the variables".

Amused by that, I searched for "concurrency in golang" and bumped into this awesome slide by Rob Pike: https://talks.golang.org/2012/waza.slide#1 which does a great job of explaining channels, concurrency patterns and a mini-architecture of load-balancer (also explains the above one-liner).

Let's dig in:

	package main

	import (
	"fmt"
	"log/slog"
	"os/exec"
	)

	func main() {
	imagePath := "metro_scan.jpg"

	/* function that used as middleware */

	accessToken: async (name) => {
	if (typeof document === "undefined") return "";
	let token = document.cookie
	.split(";")
	.filter((cookie) => cookie.startsWith("token"))[0];

	if (!token) {
	const response = await fetch("/api/refresh", { method: "POST" });

	type PathImpl<T, K extends keyof T> =
	K extends string
	? T[K] extends Record<string, any>
	? T[K] extends ArrayLike<any>
	? K \| `${K}.${PathImpl<T[K], Exclude<keyof T[K], keyof any[]>>}`
	: K \| `${K}.${PathImpl<T[K], keyof T[K]>}`
	: K
	: never;

	type Path<T> = PathImpl<T, keyof T> \| keyof T;

	// app/modules/authentication/authentication.controller.ts

	import { Body, Controller, Post } from '@nestjs/common'

	import { RegisterRequest } from './requests'

	import { User } from '../../modules/user'

	import { UsersService } from '../users/users.service'

	map $sent_http_content_type $expires {
	"text/html" epoch;
	"text/html; charset=utf-8" epoch;
	default off;
	}

	map $http_upgrade $connection_upgrade {
	default upgrade;
	'' close;
	}

	#!/bin/bash

	set -euo pipefail

	openssl req -new -text -passout pass:abcd -subj /CN=localhost -out server.req -keyout privkey.pem
	openssl rsa -in privkey.pem -passin pass:abcd -out server.key
	openssl req -x509 -in server.req -text -key server.key -out server.crt
	chmod 600 server.key
	test $(uname -s) = Linux && chown 70 server.key
	docker run -d --name postgres -e POSTGRES_HOST_AUTH_METHOD=trust -v "$(pwd)/server.crt:/var/lib/postgresql/server.crt:ro" -v "$(pwd)/server.key:/var/lib/postgresql/server.key:ro" postgres:12-alpine -c ssl=on -c ssl_cert_file=/var/lib/postgresql/server.crt -c ssl_key_file=/var/lib/postgresql/server.key

	version: '3.6'
	services:
	postgres:
	image: postgres:12
	restart: always
	ports:
	- "5432:5432"
	volumes:
	- ./db_data:/var/lib/postgresql/data
	environment:

	let isRefreshing = false;
	let refreshSubscribers = [];

	const instance = axios.create({
	baseURL: Config.API_URL,
	});

	instance.interceptors.response.use(response => {
	return response;
	}, error => {

Dmytro culttm

INTRO

Goroutines