map-bench.js

const { openSync, readSync } = require('fs')

const DEV_RANDOM = openSync('/dev/random')

function getVeryRandomString(length) {
  const buf = Buffer.alloc(length)
  readSync(DEV_RANDOM, buf, 0, length)
  return buf.toString()
}

const randInt = (from, to) => Math.ceil(from + Math.random() * to)

const urls = []

for (let i = 0; i < 100_000; i++) {
  urls.push('https://' + getVeryRandomString(randInt(15, 250)), i)
}


const queris = []
for (let i = 0; i < 10_000; i++) {
  queris.push(urls[randInt(0, urls.length)])
}

let map = new Map(urls.map((url, i) => [url, i]))
console.log(map.size)
let sum = 0
for (let run = 0; run < 10; run++) {
  console.time('run ' + run)
  
  for (let i = 0; i < queris.length; i++) {
    sum += map.get(queris[i])
  }
  console.timeEnd('run ' + run)
}

console.log('sum = ', sum)