hypercore-protocol

example.js

const hypercore = require('hypercore')
const RAM = require('random-access-memory')
const hyperswarm = require('hyperswarm')
// const HypercoreProtocol = require('hypercore-protocol')
const createTestnet = require('@hyperswarm/testnet')

start()

async function start () {
  const { bootstrap } = await createTestnet(3)

  var feed1_key
  var feed1_topic
  var feed2_key
  var feed2_topic

  { // ALICE
    const feed1 = await make_feed()
    const feed2 = await make_feed()

    feed1_key = feed1.key
    feed1_topic = feed1.discoveryKey
    feed2_key = feed2.key
    feed2_topic = feed2.discoveryKey

    const swarm1 = new hyperswarm({ bootstrap })
    swarm1.on('connection', (conn, info) => {
      console.log('new connection swarm1')
      conn.on('error', onerror)

      const proto = hypercore.createProtocolStream(conn, { ondiscoverykey })

      /* const proto = new HypercoreProtocol(conn.isInitiator)
      conn.pipe(proto).pipe(conn)
      proto.on('discovery-key', ondiscoverykey) */

      function ondiscoverykey (discoveryKey) {
        console.log('ondiscoverykey', discoveryKey, [discoveryKey.equals(feed1.discoveryKey), discoveryKey.equals(feed2.discoveryKey)])
        if (discoveryKey.equals(feed1.discoveryKey)) return feed1.replicate(proto)
        if (discoveryKey.equals(feed2.discoveryKey)) return feed2.replicate(proto)
      }
    })

    await swarm1.join(feed1.discoveryKey, { server: true, client: false }).flushed()
    await swarm1.join(feed2.discoveryKey, { server: true, client: false }).flushed()
  }

  { // BOB
    const feed1 = new hypercore(RAM, feed1_key)
    const feed2 = new hypercore(RAM, feed2_key)
    await feed1.ready()
    await feed2.ready()

    const swarm2 = new hyperswarm({ bootstrap })
    swarm2.on('connection', async (conn, info) => {
      console.log('new connection swarm2')
      conn.on('error', onerror)

      const proto = hypercore.createProtocolStream(conn)

      /* const proto = new HypercoreProtocol(conn.isInitiator)
      conn.pipe(proto).pipe(conn) */

      for (var i = 0, len = info.topics.length; i < len; i++) {
        const topic = info.topics[i]
        console.log('[swarm2] info topic', topic, [topic.equals(feed1_topic), topic.equals(feed2_topic)])
        if (topic.equals(feed1_topic)) feed1.replicate(proto)
        if (topic.equals(feed2_topic)) feed2.replicate(proto)
      }
    })

    swarm2.join(feed1_topic, { client: true, server: false }).flushed()
    swarm2.join(feed2_topic, { client: true, server: false }).flushed()
    await swarm2.flush()

    const foo = await feed1.get(0)
    console.log({foo: foo.toString()})
    const bar = await feed2.get(0)
    console.log({bar: bar.toString()})
  }
}

async function make_feed () {
  const feed = new hypercore(RAM)
  await feed.ready()
  await feed.append(Buffer.from('hello world'))
  await feed.append(Buffer.from('hallo welt'))
  await feed.append(Buffer.from('pozdravljen svet'))
  await feed.append(Buffer.from('zdravo svete'))
  await feed.append(Buffer.from('juhuhu'))
  await feed.append(Buffer.from('halli hallo'))
  await feed.append(Buffer.from('hiya'))  
  const foo = await feed.get(0)
  console.log('make_feed', {foo: foo.toString()})
  return feed
}

function onerror (err) { console.error({err})}