fix diff bug with datasets

index.js

@@ -570,6 +570,15 @@ Dat.prototype.createDiffStream = function (headA, headB, opts) {
    return 0 // nothing shared
  }

  var decode = function (obj) {
    var i = obj.key.indexOf('!')
    if (i > -1) {
      obj.key = obj.key.slice(i + 1)
      obj.dataset = obj.key.slice(0, i)
    }
    obj.value = self._encoding.decode(obj.value)
  }

  var fork = -1
  var filter = function (data, enc, cb) {
    if (fork === -1) fork = findFork()
@@ -580,8 +589,8 @@ Dat.prototype.createDiffStream = function (headA, headB, opts) {
    if (!a && !b) return cb()
    if (!a && b.type === 'del') return cb()
    if (!b && a.type === 'del') return cb()
    if (a) a.value = self._encoding.decode(a.value)
    if (b) b.value = self._encoding.decode(b.value)
    if (a) decode(a)
    if (b) decode(b)
    cb(null, data)
  }

@@ -648,29 +657,31 @@ Dat.prototype.createValueStream = function (opts) {
  return this.createReadStream(opts)
}

var toKey = function (data) {
  return data.key.slice(data.key.lastIndexOf('!') + 1)
}

var emptyStream = function () {
  var stream = through.obj()
  stream.end()
  return stream
}

var toKey = function (data) {
  return data.key.slice(data.key.lastIndexOf(data.key.lastIndexOf('!') + 1) + 1)
}

Dat.prototype.createReadStream = function (opts) {
  if (!this.opened) return this._createProxyStream(this.createReadStream, [opts])
  if (!opts) opts = {}

  var self = this
  var justKeys = opts.keys && !opts.values
  var justValues = opts.values && !opts.keys
  var all = !!opts.all
  var getOpts = all ? xtend(opts) : opts

  if (!this._layers.length) return emptyStream()

  var stream = this._layers
    .map(function (layer) {
      var prefix = '!latest!' + layer[1] + '!' + (opts.dataset || '') + '!'
      var prefix = '!latest!' + layer[1] + '!' + (all ? '' : (opts.dataset || '') + '!')
      var rs = self._index.data.createReadStream({
        gt: prefix + (opts.gt || ''),
        lt: prefix + (opts.lt || '\xff'),
@@ -685,13 +696,17 @@ Dat.prototype.createReadStream = function (opts) {
    })

  var write = function (data, enc, cb) {
    var key = data.key.slice(data.key.lastIndexOf('!') + 1)
    var i = data.key.lastIndexOf('!')
    var key = data.key.slice(i + 1)
    var dataset = data.key.slice(data.key.lastIndexOf('!', i - 1) + 1, i)

    self.get(key, opts, function (err, row) {
    if (dataset) getOpts.dataset = dataset
    self.get(key, getOpts, function (err, row) {
      if (err && err.notFound) return cb()
      if (err) return cb(err)
      if (justKeys) return cb(null, key)
      if (justValues) return cb(null, row.value)
      if (all && dataset) row.key = dataset + '!' + row.key
      cb(null, row)
    })
  }