Merge pull request #999 from MetaMask/obs-store2

background - introduce ObservableStore (mark II)

5 files changed, 93 insertions, 193 deletions

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)
-}