Merge pull request #999 from MetaMask/obs-store2

background - introduce ObservableStore (mark II)

13 files changed, 386 insertions, 370 deletions

diff --git a/app/scripts/background.js b/app/scripts/background.js
index f3837a028..18882e5d5 100644
--- a/app/scripts/background.js
+++ b/app/scripts/background.js
@@ -1,162 +1,181 @@
 const urlUtil = require('url')
-const extend = require('xtend')
 const Dnode = require('dnode')
 const eos = require('end-of-stream')
+const asyncQ = require('async-q')
+const pipe = require('pump')
+const LocalStorageStore = require('obs-store/lib/localStorage')
+const storeTransform = require('obs-store/lib/transform')
+const Migrator = require('./lib/migrator/')
+const migrations = require('./migrations/')
 const PortStream = require('./lib/port-stream.js')
 const notification = require('./lib/notifications.js')
 const messageManager = require('./lib/message-manager')
 const setupMultiplex = require('./lib/stream-utils.js').setupMultiplex
 const MetamaskController = require('./metamask-controller')
 const extension = require('./lib/extension')
+const firstTimeState = require('./first-time-state')
 
 const STORAGE_KEY = 'metamask-config'
 const METAMASK_DEBUG = 'GULP_METAMASK_DEBUG'
-var popupIsOpen = false
-
-const controller = new MetamaskController({
-  // User confirmation callbacks:
-  showUnconfirmedMessage: triggerUi,
-  unlockAccountMessage: triggerUi,
-  showUnapprovedTx: triggerUi,
-  // Persistence Methods:
-  setData,
-  loadData,
-})
 
-function triggerUi () {
-  if (!popupIsOpen) notification.show()
-}
-// On first install, open a window to MetaMask website to how-it-works.
-extension.runtime.onInstalled.addListener(function (details) {
-  if ((details.reason === 'install') && (!METAMASK_DEBUG)) {
-    extension.tabs.create({url: 'https://metamask.io/#how-it-works'})
-  }
-})
-
-//
-// connect to other contexts
-//
+let popupIsOpen = false
 
-extension.runtime.onConnect.addListener(connectRemote)
-function connectRemote (remotePort) {
-  var isMetaMaskInternalProcess = remotePort.name === 'popup' || remotePort.name === 'notification'
-  var portStream = new PortStream(remotePort)
-  if (isMetaMaskInternalProcess) {
-    // communication with popup
-    popupIsOpen = remotePort.name === 'popup'
-    setupTrustedCommunication(portStream, 'MetaMask', remotePort.name)
-  } else {
-    // communication with page
-    var originDomain = urlUtil.parse(remotePort.sender.url).hostname
-    setupUntrustedCommunication(portStream, originDomain)
-  }
-}
-
-function setupUntrustedCommunication (connectionStream, originDomain) {
-  // setup multiplexing
-  var mx = setupMultiplex(connectionStream)
-  // connect features
-  controller.setupProviderConnection(mx.createStream('provider'), originDomain)
-  controller.setupPublicConfig(mx.createStream('publicConfig'))
-}
+// state persistence
+const diskStore = new LocalStorageStore({ storageKey: STORAGE_KEY })
 
-function setupTrustedCommunication (connectionStream, originDomain) {
-  // setup multiplexing
-  var mx = setupMultiplex(connectionStream)
-  // connect features
-  setupControllerConnection(mx.createStream('controller'))
-  controller.setupProviderConnection(mx.createStream('provider'), originDomain)
-}
+// initialization flow
+asyncQ.waterfall([
+  () => loadStateFromPersistence(),
+  (initState) => setupController(initState),
+])
+.then(() => console.log('MetaMask initialization complete.'))
+.catch((err) => { console.error(err) })
 
 //
-// remote features
+// State and Persistence
 //
 
-function setupControllerConnection (stream) {
-  controller.stream = stream
-  var api = controller.getApi()
-  var dnode = Dnode(api)
-  stream.pipe(dnode).pipe(stream)
-  dnode.on('remote', (remote) => {
-    // push updates to popup
-    var sendUpdate = remote.sendUpdate.bind(remote)
-    controller.on('update', sendUpdate)
-    // teardown on disconnect
-    eos(stream, () => {
-      controller.removeListener('update', sendUpdate)
-      popupIsOpen = false
-    })
-  })
+function loadStateFromPersistence() {
+  // migrations
+  let migrator = new Migrator({ migrations })
+  let initialState = migrator.generateInitialState(firstTimeState)
+  return asyncQ.waterfall([
+    // read from disk
+    () => Promise.resolve(diskStore.getState() || initialState),
+    // migrate data
+    (versionedData) => migrator.migrateData(versionedData),
+    // write to disk
+    (versionedData) => {
+      diskStore.putState(versionedData)
+      return Promise.resolve(versionedData)
+    },
+    // resolve to just data
+    (versionedData) => Promise.resolve(versionedData.data),
+  ])
 }
 
-//
-// plugin badge text
-//
+function setupController (initState) {
+
+  //
+  // MetaMask Controller
+  //
 
-controller.txManager.on('updateBadge', updateBadge)
-updateBadge()
-
-function updateBadge () {
-  var label = ''
-  var unapprovedTxCount = controller.txManager.unapprovedTxCount
-  var unconfMsgs = messageManager.unconfirmedMsgs()
-  var unconfMsgLen = Object.keys(unconfMsgs).length
-  var count = unapprovedTxCount + unconfMsgLen
-  if (count) {
-    label = String(count)
+  const controller = new MetamaskController({
+    // User confirmation callbacks:
+    showUnconfirmedMessage: triggerUi,
+    unlockAccountMessage: triggerUi,
+    showUnapprovedTx: triggerUi,
+    // initial state
+    initState,
+  })
+  global.metamaskController = controller
+
+  // setup state persistence
+  pipe(
+    controller.store,
+    storeTransform(versionifyData),
+    diskStore
+  )
+
+  function versionifyData(state) {
+    let versionedData = diskStore.getState()
+    versionedData.data = state
+    return versionedData
   }
-  extension.browserAction.setBadgeText({ text: label })
-  extension.browserAction.setBadgeBackgroundColor({ color: '#506F8B' })
-}
 
-// data :: setters/getters
+  //
+  // connect to other contexts
+  //
+
+  extension.runtime.onConnect.addListener(connectRemote)
+  function connectRemote (remotePort) {
+    var isMetaMaskInternalProcess = remotePort.name === 'popup' || remotePort.name === 'notification'
+    var portStream = new PortStream(remotePort)
+    if (isMetaMaskInternalProcess) {
+      // communication with popup
+      popupIsOpen = remotePort.name === 'popup'
+      setupTrustedCommunication(portStream, 'MetaMask', remotePort.name)
+    } else {
+      // communication with page
+      var originDomain = urlUtil.parse(remotePort.sender.url).hostname
+      setupUntrustedCommunication(portStream, originDomain)
+    }
+  }
 
-function loadData () {
-  var oldData = getOldStyleData()
-  var newData
-  try {
-    newData = JSON.parse(window.localStorage[STORAGE_KEY])
-  } catch (e) {}
+  function setupUntrustedCommunication (connectionStream, originDomain) {
+    // setup multiplexing
+    var mx = setupMultiplex(connectionStream)
+    // connect features
+    controller.setupProviderConnection(mx.createStream('provider'), originDomain)
+    controller.setupPublicConfig(mx.createStream('publicConfig'))
+  }
 
-  var data = extend({
-    meta: {
-      version: 0,
-    },
-    data: {
-      config: {
-        provider: {
-          type: 'testnet',
-        },
-      },
-    },
-  }, oldData || null, newData || null)
-  return data
-}
+  function setupTrustedCommunication (connectionStream, originDomain) {
+    // setup multiplexing
+    var mx = setupMultiplex(connectionStream)
+    // connect features
+    setupControllerConnection(mx.createStream('controller'))
+    controller.setupProviderConnection(mx.createStream('provider'), originDomain)
+  }
 
-function getOldStyleData () {
-  var config, wallet, seedWords
+  //
+  // remote features
+  //
+
+  function setupControllerConnection (stream) {
+    controller.stream = stream
+    var api = controller.getApi()
+    var dnode = Dnode(api)
+    stream.pipe(dnode).pipe(stream)
+    dnode.on('remote', (remote) => {
+      // push updates to popup
+      var sendUpdate = remote.sendUpdate.bind(remote)
+      controller.on('update', sendUpdate)
+      // teardown on disconnect
+      eos(stream, () => {
+        controller.removeListener('update', sendUpdate)
+        popupIsOpen = false
+      })
+    })
+  }
 
-  var result = {
-    meta: { version: 0 },
-    data: {},
+  //
+  // User Interface setup
+  //
+
+  updateBadge()
+  controller.txManager.on('updateBadge', updateBadge)
+
+  // plugin badge text
+  function updateBadge () {
+    var label = ''
+    var unapprovedTxCount = controller.txManager.unapprovedTxCount
+    var unconfMsgs = messageManager.unconfirmedMsgs()
+    var unconfMsgLen = Object.keys(unconfMsgs).length
+    var count = unapprovedTxCount + unconfMsgLen
+    if (count) {
+      label = String(count)
+    }
+    extension.browserAction.setBadgeText({ text: label })
+    extension.browserAction.setBadgeBackgroundColor({ color: '#506F8B' })
   }
 
-  try {
-    config = JSON.parse(window.localStorage['config'])
-    result.data.config = config
-  } catch (e) {}
-  try {
-    wallet = JSON.parse(window.localStorage['lightwallet'])
-    result.data.wallet = wallet
-  } catch (e) {}
-  try {
-    seedWords = window.localStorage['seedWords']
-    result.data.seedWords = seedWords
-  } catch (e) {}
-
-  return result
+  return Promise.resolve()
+
 }
 
-function setData (data) {
-  window.localStorage[STORAGE_KEY] = JSON.stringify(data)
+//
+// Etc...
+//
+
+// popup trigger
+function triggerUi () {
+  if (!popupIsOpen) notification.show()
 }
+
+// On first install, open a window to MetaMask website to how-it-works.
+extension.runtime.onInstalled.addListener(function (details) {
+  if ((details.reason === 'install') && (!METAMASK_DEBUG)) {
+    extension.tabs.create({url: 'https://metamask.io/#how-it-works'})
+  }
+})
\ No newline at end of file
diff --git a/app/scripts/first-time-state.js b/app/scripts/first-time-state.js
new file mode 100644
index 000000000..3196981ba
--- /dev/null
+++ b/app/scripts/first-time-state.js
@@ -0,0 +1,11 @@
+//
+// The default state of MetaMask
+//
+
+module.exports = {
+  config: {
+    provider: {
+      type: 'testnet',
+    },
+  },
+}
\ No newline at end of file
diff --git a/app/scripts/lib/config-manager.js b/app/scripts/lib/config-manager.js
index e927c78ec..6d088906c 100644
--- a/app/scripts/lib/config-manager.js
+++ b/app/scripts/lib/config-manager.js
@@ -1,6 +1,4 @@
-const Migrator = require('pojo-migrator')
 const MetamaskConfig = require('../config.js')
-const migrations = require('./migrations')
 const ethUtil = require('ethereumjs-util')
 const normalize = require('./sig-util').normalize
 
@@ -19,41 +17,18 @@ module.exports = ConfigManager
 function ConfigManager (opts) {
   // ConfigManager is observable and will emit updates
   this._subs = []
-
-  /* The migrator exported on the config-manager
-   * has two methods the user should be concerned with:
-   *
-   * getData(), which returns the app-consumable data object
-   * saveData(), which persists the app-consumable data object.
-   */
-  this.migrator = new Migrator({
-
-    // Migrations must start at version 1 or later.
-    // They are objects with a `version` number
-    // and a `migrate` function.
-    //
-    // The `migrate` function receives the previous
-    // config data format, and returns the new one.
-    migrations: migrations,
-
-    // How to load initial config.
-    // Includes step on migrating pre-pojo-migrator data.
-    loadData: opts.loadData,
-
-    // How to persist migrated config.
-    setData: opts.setData,
-  })
+  this.store = opts.store
 }
 
 ConfigManager.prototype.setConfig = function (config) {
-  var data = this.migrator.getData()
+  var data = this.getData()
   data.config = config
   this.setData(data)
   this._emitUpdates(config)
 }
 
 ConfigManager.prototype.getConfig = function () {
-  var data = this.migrator.getData()
+  var data = this.getData()
   if ('config' in data) {
     return data.config
   } else {
@@ -96,15 +71,15 @@ ConfigManager.prototype.getProvider = function () {
 }
 
 ConfigManager.prototype.setData = function (data) {
-  this.migrator.saveData(data)
+  this.store.putState(data)
 }
 
 ConfigManager.prototype.getData = function () {
-  return this.migrator.getData()
+  return this.store.getState()
 }
 
 ConfigManager.prototype.setWallet = function (wallet) {
-  var data = this.migrator.getData()
+  var data = this.getData()
   data.wallet = wallet
   this.setData(data)
 }
@@ -121,11 +96,11 @@ ConfigManager.prototype.getVault = function () {
 }
 
 ConfigManager.prototype.getKeychains = function () {
-  return this.migrator.getData().keychains || []
+  return this.getData().keychains || []
 }
 
 ConfigManager.prototype.setKeychains = function (keychains) {
-  var data = this.migrator.getData()
+  var data = this.getData()
   data.keychains = keychains
   this.setData(data)
 }
@@ -142,19 +117,19 @@ ConfigManager.prototype.setSelectedAccount = function (address) {
 }
 
 ConfigManager.prototype.getWallet = function () {
-  return this.migrator.getData().wallet
+  return this.getData().wallet
 }
 
 // Takes a boolean
 ConfigManager.prototype.setShowSeedWords = function (should) {
-  var data = this.migrator.getData()
+  var data = this.getData()
   data.showSeedWords = should
   this.setData(data)
 }
 
 
 ConfigManager.prototype.getShouldShowSeedWords = function () {
-  var data = this.migrator.getData()
+  var data = this.getData()
   return data.showSeedWords
 }
 
@@ -166,7 +141,7 @@ ConfigManager.prototype.setSeedWords = function (words) {
 
 ConfigManager.prototype.getSeedWords = function () {
   var data = this.getData()
-  return ('seedWords' in data) && data.seedWords
+  return data.seedWords
 }
 
 ConfigManager.prototype.getCurrentRpcAddress = function () {
@@ -188,16 +163,12 @@ ConfigManager.prototype.getCurrentRpcAddress = function () {
   }
 }
 
-ConfigManager.prototype.setData = function (data) {
-  this.migrator.saveData(data)
-}
-
 //
 // Tx
 //
 
 ConfigManager.prototype.getTxList = function () {
-  var data = this.migrator.getData()
+  var data = this.getData()
   if (data.transactions !== undefined) {
     return data.transactions
   } else {
@@ -206,7 +177,7 @@ ConfigManager.prototype.getTxList = function () {
 }
 
 ConfigManager.prototype.setTxList = function (txList) {
-  var data = this.migrator.getData()
+  var data = this.getData()
   data.transactions = txList
   this.setData(data)
 }
@@ -239,7 +210,7 @@ ConfigManager.prototype.setNicknameForWallet = function (account, nickname) {
 
 ConfigManager.prototype.getSalt = function () {
   var data = this.getData()
-  return ('salt' in data) && data.salt
+  return data.salt
 }
 
 ConfigManager.prototype.setSalt = function (salt) {
@@ -273,7 +244,7 @@ ConfigManager.prototype.setConfirmedDisclaimer = function (confirmed) {
 
 ConfigManager.prototype.getConfirmedDisclaimer = function () {
   var data = this.getData()
-  return ('isDisclaimerConfirmed' in data) && data.isDisclaimerConfirmed
+  return data.isDisclaimerConfirmed
 }
 
 ConfigManager.prototype.setTOSHash = function (hash) {
@@ -284,7 +255,7 @@ ConfigManager.prototype.setTOSHash = function (hash) {
 
 ConfigManager.prototype.getTOSHash = function () {
   var data = this.getData()
-  return ('TOSHash' in data) && data.TOSHash
+  return data.TOSHash
 }
 
 ConfigManager.prototype.setCurrentFiat = function (currency) {
@@ -295,7 +266,7 @@ ConfigManager.prototype.setCurrentFiat = function (currency) {
 
 ConfigManager.prototype.getCurrentFiat = function () {
   var data = this.getData()
-  return ('fiatCurrency' in data) && data.fiatCurrency
+  return data.fiatCurrency
 }
 
 ConfigManager.prototype.updateConversionRate = function () {
@@ -326,12 +297,12 @@ ConfigManager.prototype.setConversionDate = function (datestring) {
 
 ConfigManager.prototype.getConversionRate = function () {
   var data = this.getData()
-  return (('conversionRate' in data) && data.conversionRate) || 0
+  return (data.conversionRate) || 0
 }
 
 ConfigManager.prototype.getConversionDate = function () {
   var data = this.getData()
-  return (('conversionDate' in data) && data.conversionDate) || 'N/A'
+  return (data.conversionDate) || 'N/A'
 }
 
 ConfigManager.prototype.getShapeShiftTxList = function () {
@@ -370,7 +341,7 @@ ConfigManager.prototype.createShapeShiftTx = function (depositAddress, depositTy
 
 ConfigManager.prototype.getGasMultiplier = function () {
   var data = this.getData()
-  return ('gasMultiplier' in data) && data.gasMultiplier
+  return data.gasMultiplier
 }
 
 ConfigManager.prototype.setGasMultiplier = function (gasMultiplier) {
diff --git a/app/scripts/lib/inpage-provider.js b/app/scripts/lib/inpage-provider.js
index 11bd5cc3a..066916b4d 100644
--- a/app/scripts/lib/inpage-provider.js
+++ b/app/scripts/lib/inpage-provider.js
@@ -1,7 +1,7 @@
-const Streams = require('mississippi')
+const pipe = require('pump')
 const StreamProvider = require('web3-stream-provider')
+const LocalStorageStore = require('obs-store')
 const ObjectMultiplex = require('./obj-multiplex')
-const RemoteStore = require('./remote-store.js').RemoteStore
 const createRandomId = require('./random-id')
 
 module.exports = MetamaskInpageProvider
@@ -10,33 +10,30 @@ function MetamaskInpageProvider (connectionStream) {
   const self = this
 
   // setup connectionStream multiplexing
-  var multiStream = ObjectMultiplex()
-  Streams.pipe(connectionStream, multiStream, connectionStream, function (err) {
-    let warningMsg = 'MetamaskInpageProvider - lost connection to MetaMask'
-    if (err) warningMsg += '\n' + err.stack
-    console.warn(warningMsg)
-  })
-  self.multiStream = multiStream
-
-  // subscribe to metamask public config
-  var publicConfigStore = remoteStoreWithLocalStorageCache('MetaMask-Config')
-  var storeStream = publicConfigStore.createStream()
-  Streams.pipe(storeStream, multiStream.createStream('publicConfig'), storeStream, function (err) {
-    let warningMsg = 'MetamaskInpageProvider - lost connection to MetaMask publicConfig'
-    if (err) warningMsg += '\n' + err.stack
-    console.warn(warningMsg)
-  })
-  self.publicConfigStore = publicConfigStore
+  var multiStream = self.multiStream = ObjectMultiplex()
+  pipe(
+    connectionStream,
+    multiStream,
+    connectionStream,
+    (err) => logStreamDisconnectWarning('MetaMask', err)
+  )
+
+  // subscribe to metamask public config (one-way)
+  self.publicConfigStore = new LocalStorageStore({ storageKey: 'MetaMask-Config' })
+  pipe(
+    multiStream.createStream('publicConfig'),
+    self.publicConfigStore,
+    (err) => logStreamDisconnectWarning('MetaMask PublicConfigStore', err)
+  )
 
   // connect to async provider
-  var asyncProvider = new StreamProvider()
-  Streams.pipe(asyncProvider, multiStream.createStream('provider'), asyncProvider, function (err) {
-    let warningMsg = 'MetamaskInpageProvider - lost connection to MetaMask provider'
-    if (err) warningMsg += '\n' + err.stack
-    console.warn(warningMsg)
-  })
-  asyncProvider.on('error', console.error.bind(console))
-  self.asyncProvider = asyncProvider
+  const asyncProvider = self.asyncProvider = new StreamProvider()
+  pipe(
+    asyncProvider,
+    multiStream.createStream('provider'),
+    asyncProvider,
+    (err) => logStreamDisconnectWarning('MetaMask RpcProvider', err)
+  )
 
   self.idMap = {}
   // handle sendAsync requests via asyncProvider
@@ -72,13 +69,13 @@ MetamaskInpageProvider.prototype.send = function (payload) {
 
     case 'eth_accounts':
       // read from localStorage
-      selectedAccount = self.publicConfigStore.get('selectedAccount')
+      selectedAccount = self.publicConfigStore.getState().selectedAccount
       result = selectedAccount ? [selectedAccount] : []
       break
 
     case 'eth_coinbase':
       // read from localStorage
-      selectedAccount = self.publicConfigStore.get('selectedAccount')
+      selectedAccount = self.publicConfigStore.getState().selectedAccount
       result = selectedAccount || '0x0000000000000000000000000000000000000000'
       break
 
@@ -115,18 +112,6 @@ MetamaskInpageProvider.prototype.isMetaMask = true
 
 // util
 
-function remoteStoreWithLocalStorageCache (storageKey) {
-  // read local cache
-  var initState = JSON.parse(localStorage[storageKey] || '{}')
-  var store = new RemoteStore(initState)
-  // cache the latest state locally
-  store.subscribe(function (state) {
-    localStorage[storageKey] = JSON.stringify(state)
-  })
-
-  return store
-}
-
 function eachJsonMessage (payload, transformFn) {
   if (Array.isArray(payload)) {
     return payload.map(transformFn)
@@ -135,4 +120,10 @@ function eachJsonMessage (payload, transformFn) {
   }
 }
 
+function logStreamDisconnectWarning(remoteLabel, err){
+  let warningMsg = `MetamaskInpageProvider - lost connection to ${remoteLabel}`
+  if (err) warningMsg += '\n' + err.stack
+  console.warn(warningMsg)
+}
+
 function noop () {}
diff --git a/app/scripts/lib/migrations.js b/app/scripts/lib/migrations.js
deleted file mode 100644
index f026cbe53..000000000
--- a/app/scripts/lib/migrations.js
+++ /dev/null
@@ -1,5 +0,0 @@
-module.exports = [
-  require('../migrations/002'),
-  require('../migrations/003'),
-  require('../migrations/004'),
-]
diff --git a/app/scripts/lib/migrator/index.js b/app/scripts/lib/migrator/index.js
new file mode 100644
index 000000000..ab5a757b3
--- /dev/null
+++ b/app/scripts/lib/migrator/index.js
@@ -0,0 +1,40 @@
+const asyncQ = require('async-q')
+
+class Migrator {
+
+  constructor (opts = {}) {
+    let migrations = opts.migrations || []
+    this.migrations = migrations.sort((a, b) => a.version - b.version)
+    let lastMigration = this.migrations.slice(-1)[0]
+    // use specified defaultVersion or highest migration version
+    this.defaultVersion = opts.defaultVersion || (lastMigration && lastMigration.version) || 0
+  }
+
+  // run all pending migrations on meta in place
+  migrateData (versionedData = this.generateInitialState()) {
+    let remaining = this.migrations.filter(migrationIsPending)
+    
+    return (
+      asyncQ.eachSeries(remaining, (migration) => migration.migrate(versionedData))
+      .then(() => versionedData)
+    )
+
+    // migration is "pending" if hit has a higher
+    // version number than currentVersion
+    function migrationIsPending(migration) {
+      return migration.version > versionedData.meta.version
+    }
+  }
+
+  generateInitialState (initState) {
+    return {
+      meta: {
+        version: this.defaultVersion,
+      },
+      data: initState,
+    }
+  }
+
+}
+
+module.exports = Migrator
diff --git a/app/scripts/lib/remote-store.js b/app/scripts/lib/remote-store.js
deleted file mode 100644
index fbfab7bad..000000000
--- a/app/scripts/lib/remote-store.js
+++ /dev/null
@@ -1,97 +0,0 @@
-const Dnode = require('dnode')
-const inherits = require('util').inherits
-
-module.exports = {
-  HostStore: HostStore,
-  RemoteStore: RemoteStore,
-}
-
-function BaseStore (initState) {
-  this._state = initState || {}
-  this._subs = []
-}
-
-BaseStore.prototype.set = function (key, value) {
-  throw Error('Not implemented.')
-}
-
-BaseStore.prototype.get = function (key) {
-  return this._state[key]
-}
-
-BaseStore.prototype.subscribe = function (fn) {
-  this._subs.push(fn)
-  var unsubscribe = this.unsubscribe.bind(this, fn)
-  return unsubscribe
-}
-
-BaseStore.prototype.unsubscribe = function (fn) {
-  var index = this._subs.indexOf(fn)
-  if (index !== -1) this._subs.splice(index, 1)
-}
-
-BaseStore.prototype._emitUpdates = function (state) {
-  this._subs.forEach(function (handler) {
-    handler(state)
-  })
-}
-
-//
-// host
-//
-
-inherits(HostStore, BaseStore)
-function HostStore (initState, opts) {
-  BaseStore.call(this, initState)
-}
-
-HostStore.prototype.set = function (key, value) {
-  this._state[key] = value
-  process.nextTick(this._emitUpdates.bind(this, this._state))
-}
-
-HostStore.prototype.createStream = function () {
-  var dnode = Dnode({
-    // update: this._didUpdate.bind(this),
-  })
-  dnode.on('remote', this._didConnect.bind(this))
-  return dnode
-}
-
-HostStore.prototype._didConnect = function (remote) {
-  this.subscribe(function (state) {
-    remote.update(state)
-  })
-  remote.update(this._state)
-}
-
-//
-// remote
-//
-
-inherits(RemoteStore, BaseStore)
-function RemoteStore (initState, opts) {
-  BaseStore.call(this, initState)
-  this._remote = null
-}
-
-RemoteStore.prototype.set = function (key, value) {
-  this._remote.set(key, value)
-}
-
-RemoteStore.prototype.createStream = function () {
-  var dnode = Dnode({
-    update: this._didUpdate.bind(this),
-  })
-  dnode.once('remote', this._didConnect.bind(this))
-  return dnode
-}
-
-RemoteStore.prototype._didConnect = function (remote) {
-  this._remote = remote
-}
-
-RemoteStore.prototype._didUpdate = function (state) {
-  this._state = state
-  this._emitUpdates(state)
-}
diff --git a/app/scripts/metamask-controller.js b/app/scripts/metamask-controller.js
index 5c663255a..8f157a45e 100644
--- a/app/scripts/metamask-controller.js
+++ b/app/scripts/metamask-controller.js
@@ -1,13 +1,15 @@
 const EventEmitter = require('events')
 const extend = require('xtend')
 const promiseToCallback = require('promise-to-callback')
+const pipe = require('pump')
+const ObservableStore = require('obs-store')
+const storeTransform = require('obs-store/lib/transform')
 const EthStore = require('./lib/eth-store')
 const MetaMaskProvider = require('web3-provider-engine/zero.js')
 const KeyringController = require('./keyring-controller')
 const NoticeController = require('./notice-controller')
 const messageManager = require('./lib/message-manager')
 const TxManager = require('./transaction-manager')
-const HostStore = require('./lib/remote-store.js').HostStore
 const Web3 = require('web3')
 const ConfigManager = require('./lib/config-manager')
 const extension = require('./lib/extension')
@@ -15,19 +17,30 @@ const autoFaucet = require('./lib/auto-faucet')
 const nodeify = require('./lib/nodeify')
 const IdStoreMigrator = require('./lib/idStore-migrator')
 const accountImporter = require('./account-import-strategies')
+
 const version = require('../manifest.json').version
 
 module.exports = class MetamaskController extends EventEmitter {
 
   constructor (opts) {
     super()
-    this.state = { network: 'loading' }
     this.opts = opts
-    this.configManager = new ConfigManager(opts)
+    this.state = { network: 'loading' }
+
+    // observable state store
+    this.store = new ObservableStore(opts.initState)
+    // config manager
+    this.configManager = new ConfigManager({
+      store: this.store,
+    })
+    // key mgmt
     this.keyringController = new KeyringController({
       configManager: this.configManager,
       getNetwork: this.getStateNetwork.bind(this),
     })
+    this.keyringController.on('newAccount', (account) => {
+      autoFaucet(account)
+    })
     // notices
     this.noticeController = new NoticeController({
       configManager: this.configManager,
@@ -245,29 +258,23 @@ module.exports = class MetamaskController extends EventEmitter {
 
   initPublicConfigStore () {
     // get init state
-    var initPublicState = configToPublic(this.configManager.getConfig())
-    var publicConfigStore = new HostStore(initPublicState)
-
-    // subscribe to changes
-    this.configManager.subscribe(function (state) {
-      storeSetFromObj(publicConfigStore, configToPublic(state))
-    })
-
-    this.keyringController.on('newAccount', (account) => {
-      autoFaucet(account)
-    })
-
-    // config substate
-    function configToPublic (state) {
-      return {
-        selectedAccount: state.selectedAccount,
+    const publicConfigStore = new ObservableStore()
+
+    // sync publicConfigStore with transform
+    pipe(
+      this.store,
+      storeTransform(selectPublicState),
+      publicConfigStore
+    )
+
+    function selectPublicState(state) {
+      const result = { selectedAccount: undefined }
+      try {
+        result.selectedAccount = state.config.selectedAccount
+      } catch (_) {
+        // thats fine, im sure it will be there next time...
       }
-    }
-    // dump obj into store
-    function storeSetFromObj (store, obj) {
-      Object.keys(obj).forEach(function (key) {
-        store.set(key, obj[key])
-      })
+      return result
     }
 
     return publicConfigStore
@@ -310,9 +317,11 @@ module.exports = class MetamaskController extends EventEmitter {
     this.opts.showUnconfirmedMessage(msgParams, msgId)
   }
 
-  setupPublicConfig (stream) {
-    var storeStream = this.publicConfigStore.createStream()
-    stream.pipe(storeStream).pipe(stream)
+  setupPublicConfig (outStream) {
+    pipe(
+      this.publicConfigStore,
+      outStream
+    )
   }
 
   // Log blocks
diff --git a/app/scripts/migrations/002.js b/app/scripts/migrations/002.js
index 0b654f825..476b0a43a 100644
--- a/app/scripts/migrations/002.js
+++ b/app/scripts/migrations/002.js
@@ -1,13 +1,16 @@
+const version = 2
+
 module.exports = {
-  version: 2,
+  version,
 
-  migrate: function (data) {
+  migrate: function (versionedData) {
+    versionedData.meta.version = version
     try {
-      if (data.config.provider.type === 'etherscan') {
-        data.config.provider.type = 'rpc'
-        data.config.provider.rpcTarget = 'https://rpc.metamask.io/'
+      if (versionedData.data.config.provider.type === 'etherscan') {
+        versionedData.data.config.provider.type = 'rpc'
+        versionedData.data.config.provider.rpcTarget = 'https://rpc.metamask.io/'
       }
     } catch (e) {}
-    return data
+    return Promise.resolve(versionedData)
   },
 }
diff --git a/app/scripts/migrations/003.js b/app/scripts/migrations/003.js
index 617c55c09..eceaeaa4b 100644
--- a/app/scripts/migrations/003.js
+++ b/app/scripts/migrations/003.js
@@ -1,15 +1,17 @@
-var oldTestRpc = 'https://rawtestrpc.metamask.io/'
-var newTestRpc = 'https://testrpc.metamask.io/'
+const version = 3
+const oldTestRpc = 'https://rawtestrpc.metamask.io/'
+const newTestRpc = 'https://testrpc.metamask.io/'
 
 module.exports = {
-  version: 3,
+  version,
 
-  migrate: function (data) {
+  migrate: function (versionedData) {
+    versionedData.meta.version = version
     try {
-      if (data.config.provider.rpcTarget === oldTestRpc) {
-        data.config.provider.rpcTarget = newTestRpc
+      if (versionedData.data.config.provider.rpcTarget === oldTestRpc) {
+        versionedData.data.config.provider.rpcTarget = newTestRpc
       }
     } catch (e) {}
-    return data
+    return Promise.resolve(versionedData)
   },
 }
diff --git a/app/scripts/migrations/004.js b/app/scripts/migrations/004.js
index 1329a1eed..0f9850208 100644
--- a/app/scripts/migrations/004.js
+++ b/app/scripts/migrations/004.js
@@ -1,22 +1,25 @@
+const version = 4
+
 module.exports = {
-  version: 4,
+  version,  
 
-  migrate: function (data) {
+  migrate: function (versionedData) {
+    versionedData.meta.version = version
     try {
-      if (data.config.provider.type !== 'rpc') return data
-      switch (data.config.provider.rpcTarget) {
+      if (versionedData.data.config.provider.type !== 'rpc') return Promise.resolve(versionedData)
+      switch (versionedData.data.config.provider.rpcTarget) {
         case 'https://testrpc.metamask.io/':
-          data.config.provider = {
+          versionedData.data.config.provider = {
             type: 'testnet',
           }
           break
         case 'https://rpc.metamask.io/':
-          data.config.provider = {
+          versionedData.data.config.provider = {
             type: 'mainnet',
           }
           break
       }
     } catch (_) {}
-    return data
+    return Promise.resolve(versionedData)
   },
 }
diff --git a/app/scripts/migrations/_multi-keyring.js b/app/scripts/migrations/_multi-keyring.js
new file mode 100644
index 000000000..04c966d4d
--- /dev/null
+++ b/app/scripts/migrations/_multi-keyring.js
@@ -0,0 +1,51 @@
+const version = 5
+
+/*
+
+This is an incomplete migration bc it requires post-decrypted data
+which we dont have access to at the time of this writing.
+
+*/
+
+const ObservableStore = require('obs-store')
+const ConfigManager = require('../../app/scripts/lib/config-manager')
+const IdentityStoreMigrator = require('../../app/scripts/lib/idStore-migrator')
+const KeyringController = require('../../app/scripts/lib/keyring-controller')
+
+const password = 'obviously not correct'
+
+module.exports = {
+  version,  
+
+  migrate: function (versionedData) {
+    versionedData.meta.version = version
+
+    let store = new ObservableStore(versionedData.data)
+    let configManager = new ConfigManager({ store })
+    let idStoreMigrator = new IdentityStoreMigrator({ configManager })
+    let keyringController = new KeyringController({
+      configManager: configManager,
+    })
+
+    // attempt to migrate to multiVault
+    return idStoreMigrator.migratedVaultForPassword(password)
+    .then((result) => {
+      // skip if nothing to migrate
+      if (!result) return Promise.resolve(versionedData)
+      delete versionedData.data.wallet
+      // create new keyrings
+      const privKeys = result.lostAccounts.map(acct => acct.privateKey)
+      return Promise.all([
+        keyringController.restoreKeyring(result.serialized),
+        keyringController.restoreKeyring({ type: 'Simple Key Pair', data: privKeys }),
+      ]).then(() => {
+        return keyringController.persistAllKeyrings(password)
+      }).then(() => {
+        // copy result on to state object
+        versionedData.data = store.get()
+        return Promise.resolve(versionedData)
+      })
+    })
+
+  },
+}
diff --git a/app/scripts/migrations/index.js b/app/scripts/migrations/index.js
new file mode 100644
index 000000000..d2ac221b9
--- /dev/null
+++ b/app/scripts/migrations/index.js
@@ -0,0 +1,18 @@
+/* The migrator has two methods the user should be concerned with:
+ * 
+ * getData(), which returns the app-consumable data object
+ * saveData(), which persists the app-consumable data object.
+ */
+
+// Migrations must start at version 1 or later.
+// They are objects with a `version` number
+// and a `migrate` function.
+//
+// The `migrate` function receives the previous
+// config data format, and returns the new one.
+
+module.exports = [
+  require('./002'),
+  require('./003'),
+  require('./004'),
+]