perf(db): Lazily deserialize models on the other side of the action bridge

Summary:
We send database `trigger()` events through the ActionBrige to all windows of the app. This means that during initial sync, we're serializing, IPCing and unserializing thousands of models a minute x "N" windows.

This diff converts the payload of the trigger method into an actual class that implements a custom toJSON. It converts the impacted `objects` into a string, and doesn't deserialize them until it's asked.

Bottom line: this means that in many scenarios, we can avoid creating Contact models, etc. in composer windows only to broadcast them and then gc them.

Test Plan: No new tests yet, but this should definitel be tested. #willfix.

Reviewers: juan, evan

Reviewed By: evan

Differential Revision: https://phab.nylas.com/D2236

spec/stores/database-store-spec.coffee

@@ -16,7 +16,7 @@ describe "DatabaseStore", ->
   beforeEach ->
     TestModel.configureBasic()
     spyOn(ModelQuery.prototype, 'where').andCallThrough()
-    spyOn(DatabaseStore, '_triggerSoon').andCallFake -> Promise.resolve()
+    spyOn(DatabaseStore, '_accumulateAndTrigger').andCallFake -> Promise.resolve()
 
     @performed = []
 
@@ -122,9 +122,9 @@ describe "DatabaseStore", ->
     it "should cause the DatabaseStore to trigger with a change that contains the model", ->
       waitsForPromise ->
         DatabaseStore.persistModel(testModelInstance).then ->
-          expect(DatabaseStore._triggerSoon).toHaveBeenCalled()
+          expect(DatabaseStore._accumulateAndTrigger).toHaveBeenCalled()
 
-          change = DatabaseStore._triggerSoon.mostRecentCall.args[0]
+          change = DatabaseStore._accumulateAndTrigger.mostRecentCall.args[0]
           expect(change).toEqual({objectClass: TestModel.name, objects: [testModelInstance], type:'persist'})
         .catch (err) ->
           console.log err
@@ -141,9 +141,9 @@ describe "DatabaseStore", ->
     it "should cause the DatabaseStore to trigger with a change that contains the models", ->
       waitsForPromise ->
         DatabaseStore.persistModels([testModelInstanceA, testModelInstanceB]).then ->
-          expect(DatabaseStore._triggerSoon).toHaveBeenCalled()
+          expect(DatabaseStore._accumulateAndTrigger).toHaveBeenCalled()
 
-          change = DatabaseStore._triggerSoon.mostRecentCall.args[0]
+          change = DatabaseStore._accumulateAndTrigger.mostRecentCall.args[0]
           expect(change).toEqual
             objectClass: TestModel.name,
             objects: [testModelInstanceA, testModelInstanceB]
@@ -171,9 +171,9 @@ describe "DatabaseStore", ->
     it "should cause the DatabaseStore to trigger() with a change that contains the model", ->
       waitsForPromise ->
         DatabaseStore.unpersistModel(testModelInstance).then ->
-          expect(DatabaseStore._triggerSoon).toHaveBeenCalled()
+          expect(DatabaseStore._accumulateAndTrigger).toHaveBeenCalled()
 
-          change = DatabaseStore._triggerSoon.mostRecentCall.args[0]
+          change = DatabaseStore._accumulateAndTrigger.mostRecentCall.args[0]
           expect(change).toEqual({objectClass: TestModel.name, objects: [testModelInstance], type:'unpersist'})
 
     describe "when the model provides additional sqlite config", ->
@@ -447,4 +447,4 @@ describe "DatabaseStore", ->
           expect(@performed[4].query).toBe "BEGIN EXCLUSIVE TRANSACTION"
           expect(@performed[5].query).toBe "COMMIT"
 
-describe "DatabaseStore::_triggerSoon", ->
+describe "DatabaseStore::_accumulateAndTrigger", ->

src/flux/action-bridge.coffee

@@ -80,7 +80,7 @@ class ActionBridge
 
       if name == Message.DATABASE_STORE_TRIGGER
         DatabaseStore.triggeringFromActionBridge = true
-        DatabaseStore.trigger(args...)
+        DatabaseStore.trigger(new DatabaseStore.ChangeRecord(args...))
         DatabaseStore.triggeringFromActionBridge = false
 
       else if Actions[name]

src/flux/attributes/attribute-collection.coffee

@@ -54,13 +54,17 @@ class AttributeCollection extends Attribute
     return [] unless json && json instanceof Array
     objs = []
     for objJSON in json
-      obj = new @itemClass(objJSON)
-      # Important: if no ids are in the JSON, don't make them up
-      # randomly.  This causes an object to be "different" each time it's
-      # de-serialized even if it's actually the same, makes React
-      # components re-render!
-      obj.clientId = undefined
-      obj.fromJSON(objJSON) if obj.fromJSON?
+      if @itemClass.prototype.fromJSON?
+        obj = new @itemClass
+        # Important: if no ids are in the JSON, don't make them up
+        # randomly.  This causes an object to be "different" each time it's
+        # de-serialized even if it's actually the same, makes React
+        # components re-render!
+        obj.clientId = undefined
+        obj.fromJSON(objJSON)
+      else
+        obj = new @itemClass(objJSON)
+        obj.clientId = undefined
       objs.push(obj)
     objs
 

src/flux/stores/database-change-record.coffee

@@ -0,0 +1,39 @@
+Utils = require '../models/utils'
+
+###
+DatabaseChangeRecord is the object emitted from the DatabaseStore when it triggers.
+The DatabaseChangeRecord contains information about what type of model changed,
+and references to the new model values. All mutations to the database produce these
+change records.
+###
+class DatabaseChangeRecord
+
+  constructor: (options) ->
+    @options = options
+
+    # When DatabaseChangeRecords are sent over IPC to other windows, their object
+    # payload is sub-serialized into a JSON string. This means that we can wait
+    # to deserialize models until someone in the window asks for `change.objects`
+    @_objects = options.objects
+    @_objectsString = options.objectsString
+
+    Object.defineProperty(@, 'type', {
+      get: -> options.type
+    })
+    Object.defineProperty(@, 'objectClass', {
+      get: -> options.objectClass
+    })
+    Object.defineProperty(@, 'objects', {
+      get: ->
+        @_objects ?= Utils.deserializeRegisteredObjects(@_objectsString)
+        @_objects
+    })
+
+  toJSON: =>
+    @_objectsString ?= Utils.serializeRegisteredObjects(@_objects)
+
+    type: @type
+    objectClass: @objectClass
+    objectsString: @_objectsString
+
+module.exports = DatabaseChangeRecord

src/flux/stores/database-store.coffee

@@ -10,6 +10,7 @@ ModelQuery = require '../models/query'
 NylasStore = require '../../global/nylas-store'
 PromiseQueue = require 'promise-queue'
 DatabaseSetupQueryBuilder = require './database-setup-query-builder'
+DatabaseChangeRecord = require './database-change-record'
 PriorityUICoordinator = require '../../priority-ui-coordinator'
 
 {AttributeCollection, AttributeJoinedData} = require '../attributes'
@@ -414,7 +415,7 @@ class DatabaseStore extends NylasStore
       throw new Error("DatabaseStore::persistModel - You must pass an instance of the Model class.")
 
     @_writeModels([model]).then =>
-      @_triggerSoon({objectClass: model.constructor.name, objects: [model], type: 'persist'})
+      @_accumulateAndTrigger({objectClass: model.constructor.name, objects: [model], type: 'persist'})
 
   # Public: Asynchronously writes `models` to the cache and triggers a single change
   # event. Note: Models must be of the same class to be persisted in a batch operation.
@@ -442,7 +443,7 @@ class DatabaseStore extends NylasStore
       ids[model.id] = true
 
     @_writeModels(models).then =>
-      @_triggerSoon({objectClass: models[0].constructor.name, objects: models, type: 'persist'})
+      @_accumulateAndTrigger({objectClass: models[0].constructor.name, objects: models, type: 'persist'})
 
   # Public: Asynchronously removes `model` from the cache and triggers a change event.
   #
@@ -455,12 +456,12 @@ class DatabaseStore extends NylasStore
   #     callbacks failed
   unpersistModel: (model) =>
     @_deleteModel(model).then =>
-      @_triggerSoon({objectClass: model.constructor.name, objects: [model], type: 'unpersist'})
+      @_accumulateAndTrigger({objectClass: model.constructor.name, objects: [model], type: 'unpersist'})
 
   persistJSONObject: (key, json) ->
     jsonString = serializeRegisteredObjects(json)
     @_query("REPLACE INTO `JSONObject` (`key`,`data`) VALUES (?,?)", [key, jsonString]).then =>
-      @trigger({objectClass: 'JSONObject', objects: [{key: key, json: json}], type: 'persist'})
+      @trigger(new DatabaseChangeRecord({objectClass: 'JSONObject', objects: [{key: key, json: json}], type: 'persist'}))
 
   findJSONObject: (key) ->
     @_query("SELECT `data` FROM `JSONObject` WHERE key = ? LIMIT 1", [key]).then (results) =>
@@ -486,19 +487,19 @@ class DatabaseStore extends NylasStore
   ########################### PRIVATE METHODS ############################
   ########################################################################
 
-  # _TriggerSoon is a guarded version of trigger that can accumulate changes.
+  # _accumulateAndTrigger is a guarded version of trigger that can accumulate changes.
   # This means that even if you're a bad person and call `persistModel` 100 times
   # from 100 task objects queued at the same time, it will only create one
   # `trigger` event. This is important since the database triggering impacts
   # the entire application.
-  _triggerSoon: (change) =>
+  _accumulateAndTrigger: (change) =>
     @_triggerPromise ?= new Promise (resolve, reject) =>
       @_resolve = resolve
 
     flush = =>
       return unless @_changeAccumulated
       clearTimeout(@_changeFireTimer) if @_changeFireTimer
-      @trigger(@_changeAccumulated)
+      @trigger(new DatabaseChangeRecord(@_changeAccumulated))
       @_changeAccumulated = null
       @_changeFireTimer = null
       @_resolve?()
@@ -662,3 +663,4 @@ class DatabaseStore extends NylasStore
 
 
 module.exports = new DatabaseStore()
+module.exports.ChangeRecord = DatabaseChangeRecord

src/flux/stores/preferences-section-store.coffee

@@ -20,7 +20,7 @@ class SectionConfig
 class PreferencesSectionStore extends NylasStore
   constructor: ->
     @_sectionConfigs = []
-    @_triggerSoon ?= _.debounce(( => @trigger()), 20)
+    @_accumulateAndTrigger ?= _.debounce(( => @trigger()), 20)
     @Section = {}
     @SectionConfig = SectionConfig
 
@@ -64,12 +64,12 @@ class PreferencesSectionStore extends NylasStore
     @Section[sectionConfig.sectionId] = sectionConfig.sectionId
     @_sectionConfigs.push(sectionConfig)
     @_sectionConfigs = _.sortBy(@_sectionConfigs, "order")
-    @_triggerSoon()
+    @_accumulateAndTrigger()
 
   unregisterPreferenceSection: (sectionId) ->
     delete @Section[sectionId]
     @_sectionConfigs = _.reject @_sectionConfigs, (sectionConfig) ->
       sectionConfig.sectionId is sectionId
-    @_triggerSoon()
+    @_accumulateAndTrigger()
 
 module.exports = new PreferencesSectionStore()