hyperswarm-peer / daemon / js_peer.js

// The JS CONTROL for test_daemon_longlived.py.
//
// Same shape as session-daemon: join one topic on the public DHT and report
// `peers=N` on a pulse, so the SAME Python driver and the SAME accounting can
// measure both implementations. The point is not to test hyperswarm — it is to
// find out what the public DHT's own connect-failure rate looks like, so our
// number has something to be compared against.
//
//   node js_peer.js --topic <seed> [--seconds N]
//
// The topic is BLAKE2b(seed), exactly as daemon/main.cpp derives it, so a JS
// peer and a C++ daemon on the same seed land on the same topic.

const Hyperswarm = require('hyperswarm')
const sodium = require('sodium-universal')
const b4a = require('b4a')

const argv = process.argv.slice(2)
function arg (name, dflt) {
  const i = argv.indexOf(name)
  return i === -1 ? dflt : argv[i + 1]
}

const seed = arg('--topic', null)
const seconds = Number(arg('--seconds', '0'))
if (!seed) {
  console.error('usage: node js_peer.js --topic <seed> [--seconds N]')
  process.exit(1)
}

const topic = b4a.alloc(32)
sodium.crypto_generichash(topic, b4a.from(seed))

const swarm = new Hyperswarm()
let peers = 0

swarm.on('connection', (conn) => {
  peers++
  pulse()
  conn.on('error', () => {})
  conn.on('close', () => { peers--; pulse() })
  // Say something, so the connection is real rather than merely opened.
  conn.write(b4a.from('hello'))
  conn.on('data', () => {})
})

function pulse () {
  const dht = swarm.dht
  const up = dht && dht.bootstrapped ? 'up' : 'connecting'
  console.log(`[js] dht=${up} peers=${peers}`)
}

async function main () {
  await swarm.dht.ready()
  pulse()
  swarm.join(topic, { server: true, client: true })
  await swarm.flush()
  pulse()

  const timer = setInterval(pulse, 5000)
  if (seconds > 0) {
    setTimeout(async () => {
      clearInterval(timer)
      await swarm.destroy()
      process.exit(0)
    }, seconds * 1000)
  }
}

main().catch((err) => { console.error(err); process.exit(1) })