ssb-exchange

fully exchange two secure-scuttlebutt databases over a duplex stream

Usage

var replicate = require('ssb-exchange')
var path = require('path')
var pull = require('pull-stream')

var alice = createDbAndFeed('alice')
var bob = createDbAndFeed('bob')

alice.feed.add({ type: 'post', text: 'alice\'s First Post!' }, function (err, msg, hash) {
  alice.feed.add({ type: 'post', text: 'alice\'s Second Post!' }, function (err, msg, hash) {
    bob.feed.add({ type: 'post', text: 'bob\'s First Post!' }, function (err, msg, hash) {
      sync()
    })
  })
})

function sync () {
  var r1 = exchange(alice.ssb, 'alice')
  var r2 = exchange(bob.ssb, 'bob')

  r1.pipe(r2).pipe(r1)

  r1.on('end', function () {
    pull(
      alice.ssb.createLogStream({keys: false, values: true}),
      pull.drain(console.log)
    )
  })
}

function createDbAndFeed (dir) {
  var keys = require('ssb-keys').loadOrCreateSync(path.join(dir, 'secret'))
  var ssb = require('secure-scuttlebutt/create')(path.join(dir, 'db'))
  var feed = ssb.createFeed(keys)
  return {ssb: ssb, feed: feed}
}

outputs

{ previous: null,
  sequence: 1,
  author: '@6VKBcLTLgL8vDuLHtgFlYEg/yTgYqI1WoPENQrzJNs4=.ed25519',
  timestamp: 1528823339650,
  hash: 'sha256',
  content: { type: 'post', text: 'alice\'s First Post!' },
  signature: 'aBLQHwohD2FlTtLU1tsrFovoRQk+cTjgEi2SWZw+A1/Z+RlkDuRvFDplwI9oATzAprWhm1KuA69D9dUAnzMICA==.sig.ed25519' }
{ previous: '%spHHU8AUpoLU7+tTvdPrfFoGmST/twD/xRH0Jd2Jhgw=.sha256',
  sequence: 2,
  author: '@6VKBcLTLgL8vDuLHtgFlYEg/yTgYqI1WoPENQrzJNs4=.ed25519',
  timestamp: 1528823339700,
  hash: 'sha256',
  content: { type: 'post', text: 'alice\'s Second Post!' },
  signature: 'mZJqo73/jHAyoOajkInsAMicSx/iTvZg0f5FONuXspuXfzkxKtVUH8atYFmL5JNPxEXc6IR0dhpeMhAN/CHZDg==.sig.ed25519' }
{ previous: null,
  sequence: 1,
  author: '@SWgLOnMBG7wEnmyP+vjueVluNj46IYRiktfyErVbjhA=.ed25519',
  timestamp: 1528823339717,
  hash: 'sha256',
  content: { type: 'post', text: 'bob\'s First Post!' },
  signature: 'xrhWyHx129zjk7Bg2CPUQtASqehoeK7Yp6m9n3Yd2DgtMLzDlj1LPBCQIEglnUK2h7uLzKZQnAFrDrYjLYopAQ==.sig.ed25519' }

API

var replicate = require('ssb-exchange')

var stream = replicate(ssb)

Returns a duplex stream, stream, that can be piped into another ssb-exchange duplex stream. The two will exchange information about what feeds they have, and send only new information to the other end. The stream terminates once all data has been sent and written to the local ssb database.

Install

With npm installed, run

$ npm install ssb-exchange

License

ISC