hyperlog-seed

seed content hashes embedded in a hyperlog

example

First we will generate some elliptic curve keys:

$ node -pe "JSON.stringify(require('ssb-keys').generate())" > keys.json

Now we can seed content from stdin to webtorrent and write the magnet link to a swarmlog:

var webtorrent = require('webtorrent')
var parseTorrent = require('parse-torrent')
var level = require('level')
var swarmlog = require('swarmlog')

var log = swarmlog({
  keys: require('./keys.json'),
  db: level('/tmp/webtorrent-publish.db'),
  sodium: require('chloride'),
  valueEncoding: 'json',
  hubs: [ 'https://signalhub.mafintosh.com' ]
})

var client = webtorrent()
client.seed([process.stdin], { name: 'test.txt' }, function (torrent) {
  log.append({ link: torrent.magnetURI })
  console.log(torrent.magnetURI)
})

We can now write a mirroring service to download and seed everything published to our swarmlog:

var webtorrent = require('webtorrent')
var parseTorrent = require('parse-torrent')
var level = require('level')
var fs = require('fs')
var path = require('path')
var mkdirp = require('mkdirp')
var sub = require('subleveldown')
var swarmlog = require('swarmlog')

var db = level('/tmp/webtorrent-mirror.db')
var log = swarmlog({
  id: process.argv[2],
  db: sub(db, 'log'),
  sodium: require('chloride'),
  valueEncoding: 'json',
  hubs: [ 'https://signalhub.mafintosh.com' ]
})

var hseed = require('hyperlog-seed')
var seeder = hseed({
  db: sub(db, 'seed'),
  log: log,
  map: function (row) {
    if (row.link) return { type: 'put', link: row.link }
    if (row.unlink) return { type: 'del', link: row.unlink }
  }
})
var dir = '/tmp/webtorrent'

var client = webtorrent()

seeder.on('seed', function (link) {
  console.log('SEED', link)
  var t = parseTorrent(link)
  var tdir = path.join(dir, t.infoHash)
  fs.readdir(tdir, function (err, files) {
    if (!files) client.add(link, onadd)
    else {
      var tfiles = files.map(function (f) { return path.join(tdir, f) })
      client.seed(tfiles, onseed)
    }
  })
  function onadd (s) {
    var tdir = path.join(dir, t.infoHash)
    mkdirp(tdir, function () {
      t.files.forEach(function (file) {
        file.createReadStream()
          .pipe(fs.createWriteStream(path.join(tdir, t.infoHash)))
      })
    })
  }
  function onseed (s) {
    if (s.infoHash !== t.infoHash) {
      client.remove(s)
      client.add(link, onadd)
    }
  }
})
seeder.on('unseed', function (link) {
  console.log('UNSEED', link)
  var t = parseTorrent(link)
  for (var i = 0; i < client.torrents.length; i++) {
    var c = client.torrents[i]
    if (c.infoHash === t.infoHash) c.destroy()
  }
})

Given the public key from our publisher, we can mirror the webtorrent magnet links it posts to its swarmlog:

$ json public < keys.json
VtSrpZkaY9570yX4TQZEPDwFWkYApGt2otPsLN3Bw/0=.ed25519
$ electron-spawn mirror.js VtSrpZkaY9570yX4TQZEPDwFWkYApGt2otPsLN3Bw/0=.ed25519

Finally, we can publish torrents to the swarmlog:

$ echo OH HI HELLO | electron-spawn publish.js
magnet:?xt=urn:btih:5302fe31bf355f91a47f47cea74e57652b7fa3e3&dn=test.txt&tr=udp%3A%2F%2Fexodus.desync.com%3A6969&tr=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969&tr=udp%3A%2F%2Ftracker.internetwarriors.net%3A1337&tr=udp%3A%2F%2Ftracker.leechers-paradise.org%3A6969&tr=udp%3A%2F%2Ftracker.openbittorrent.com%3A80&tr=wss%3A%2F%2Ftracker.btorrent.xyz&tr=wss%3A%2F%2Ftracker.openwebtorrent.com&tr=wss%3A%2F%2Ftracker.webtorrent.io

and download them with webtorrent elsewhere, even when the publisher is offline:

$ electron-spawn `which webtorrent` 'magnet:?xt=urn:btih:5302fe31bf355f91a47f47cea74e57652b7fa3e3&dn=test.txt&tr=udp%3A%2F%2Fexodus.desync.com%3A6969&tr=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969&tr=udp%3A%2F%2Ftracker.internetwarriors.net%3A1337&tr=udp%3A%2F%2Ftracker.leechers-paradise.org%3A6969&tr=udp%3A%2F%2Ftracker.openbittorrent.com%3A80&tr=wss%3A%2F%2Ftracker.btorrent.xyz&tr=wss%3A%2F%2Ftracker.openwebtorrent.com&tr=wss%3A%2F%2Ftracker.webtorrent.io'

If you restart the mirror process, it will resume seeding torrents from the swarmlog feed. If you publish more torrents to the feed, these new torrents will also be mirrored.

api

var hseed = require('hyperlog-seed')

var seeder = hseed(opts)

Create a new seeder from:

• opts.db - a leveldb instance
• opts.log - a hyperlog instance
• opts.map(row) - a function mapping rows to link and unlink operations

To add a magnet link for seeding, opts.map should return:

{ type: 'put', link: 'magnet:...' }

To remove a magnet link from seeding, opts.map should return:

{ type: 'put', unlink: 'magnet:...' }

seeder.on('seed', function (link) {})

This event fires when the seeder should start seeding a magnet link. This happens when a new link is posted to the log and when the seeder resumes after a restart.

seeder.on('unseed', function (link) {})

This event fires when the seeder should stop seeding a magnet link. This happens when the log removes link.

license

BSD