perf(delta): replaces API delta stream with direct in-memory one

Summary:
This replaces the API delta stream with a direct in-memory one

Addresses T7300

Test Plan: manual

Reviewers: jackie, halla, juan

Reviewed By: halla

Differential Revision: https://phab.nylas.com/D3548

packages/isomorphic-core/src/delta-stream-builder.js

@@ -2,9 +2,19 @@ const _ = require('underscore');
 const Rx = require('rx')
 const stream = require('stream');
 
-function stringifyTransactions(db, transactions = []) {
+/**
+ * A Transaction references objects that changed. This finds and inflates
+ * those objects.
+ *
+ * Resolves to an array of transactions with their `attributes` set to be
+ * the inflated model they reference.
+ */
+function inflateTransactions(db, accountId, transactions = []) {
   const transactionJSONs = transactions.map((t) => (t.toJSON ? t.toJSON() : t))
-  transactionJSONs.forEach((t) => { t.cursor = t.id });
+  transactionJSONs.forEach((t) => {
+    t.cursor = t.id;
+    t.accountId = accountId;
+  });
 
   const byModel = _.groupBy(transactionJSONs, "object");
   const byObjectIds = _.groupBy(transactionJSONs, "objectId");
@@ -22,6 +32,9 @@ function stringifyTransactions(db, transactions = []) {
       where: {id: modelIds},
       include: includes,
     }).then((models) => {
+      if (models.length !== modelIds.length) {
+        console.error("Couldn't find a model for some IDs", modelName, modelIds, models)
+      }
       for (const model of models) {
         const transactionsForModel = byObjectIds[model.id];
         for (const t of transactionsForModel) {
@@ -29,19 +42,26 @@ function stringifyTransactions(db, transactions = []) {
         }
       }
     });
-  })).then(() => {
+  })).then(() => transactionJSONs)
+}
+
+function stringifyTransactions(db, accountId, transactions = []) {
+  return inflateTransactions(db, accountId, transactions).then((transactionJSONs) => {
     return `${transactionJSONs.map(JSON.stringify).join("\n")}\n`;
   });
 }
 
-module.exports = {
-  buildStream(request, {databasePromise, cursor, accountId, deltasSource}) {
-    return databasePromise.then((db) => {
-      const initialSource = db.Transaction.streamAll({where: { id: {$gt: cursor}, accountId }});
+function transactionsSinceCursor(db, cursor, accountId) {
+  return db.Transaction.streamAll({where: { id: {$gt: cursor}, accountId }});
+}
 
+module.exports = {
+  buildAPIStream(request, {databasePromise, cursor, accountId, deltasSource}) {
+    return databasePromise.then((db) => {
+      const initialSource = transactionsSinceCursor(db, cursor, accountId);
       const source = Rx.Observable.merge(
-        initialSource.flatMap((t) => stringifyTransactions(db, t)),
-        deltasSource.flatMap((t) => stringifyTransactions(db, [t])),
+        initialSource.flatMap((ts) => stringifyTransactions(db, accountId, ts)),
+        deltasSource.flatMap((t) => stringifyTransactions(db, accountId, [t])),
         Rx.Observable.interval(1000).map(() => "\n")
       )
 
@@ -54,6 +74,14 @@ module.exports = {
     });
   },
 
+  buildDeltaObservable({db, cursor, accountId, deltasSource}) {
+    const initialSource = transactionsSinceCursor(db, cursor, accountId);
+    return Rx.Observable.merge(
+      initialSource.flatMap((ts) => inflateTransactions(db, accountId, ts)),
+      deltasSource.flatMap((t) => inflateTransactions(db, accountId, [t]))
+    )
+  },
+
   buildCursor({databasePromise}) {
     return databasePromise.then(({Transaction}) => {
       return Transaction.findOne({order: [['id', 'DESC']]}).then((t) => {

packages/local-sync/src/local-api/routes/delta.js

@@ -1,41 +0,0 @@
-const Joi = require('joi');
-const TransactionConnector = require('../../shared/transaction-connector')
-const {DeltaStreamBuilder} = require('isomorphic-core')
-
-module.exports = (server) => {
-  server.route({
-    method: 'GET',
-    path: '/delta/streaming',
-    config: {
-      validate: {
-        query: {
-          cursor: Joi.string().required(),
-        },
-      },
-    },
-    handler: (request, reply) => {
-      const account = request.auth.credentials;
-
-      DeltaStreamBuilder.buildStream(request, {
-        cursor: request.query.cursor,
-        accountId: account.id,
-        databasePromise: request.getAccountDatabase(),
-        deltasSource: TransactionConnector.getObservableForAccountId(account.id),
-      }).then((stream) => {
-        reply(stream)
-      });
-    },
-  });
-
-  server.route({
-    method: 'POST',
-    path: '/delta/latest_cursor',
-    handler: (request, reply) => {
-      DeltaStreamBuilder.buildCursor({
-        databasePromise: request.getAccountDatabase(),
-      }).then((cursor) => {
-        reply({cursor})
-      });
-    },
-  });
-};

packages/local-sync/src/local-sync-worker/imap/fetch-folder-list.js

@@ -129,39 +129,38 @@ class FetchFolderList {
     this._db = db;
 
     const boxes = await imap.getBoxes();
-    const {Folder, Label, sequelize} = this._db;
+    const {Folder, Label} = this._db;
 
-    return sequelize.transaction(async (transaction) => {
-      const {folders, labels} = await PromiseUtils.props({
-        folders: Folder.findAll({transaction}),
-        labels: Label.findAll({transaction}),
-      })
-      const all = [].concat(folders, labels);
-      const {next, created, deleted} = this._updateCategoriesWithBoxes(all, boxes);
+    const {folders, labels} = await PromiseUtils.props({
+      folders: Folder.findAll(),
+      labels: Label.findAll(),
+    })
+    const all = [].concat(folders, labels);
+    const {next, created, deleted} = this._updateCategoriesWithBoxes(all, boxes);
 
-      const categoriesByRoles = next.reduce((obj, cat) => {
-        const role = this._roleByName(cat.name);
-        if (role in obj) {
-          obj[role].push(cat);
-        } else {
-          obj[role] = [cat];
-        }
-        return obj;
-      }, {})
+    const categoriesByRoles = next.reduce((obj, cat) => {
+      const role = this._roleByName(cat.name);
+      if (role in obj) {
+        obj[role].push(cat);
+      } else {
+        obj[role] = [cat];
+      }
+      return obj;
+    }, {})
 
-      this._getMissingRoles(next).forEach((role) => {
-        if (categoriesByRoles[role] && categoriesByRoles[role].length === 1) {
-          categoriesByRoles[role][0].role = role;
-        }
-      })
+    this._getMissingRoles(next).forEach((role) => {
+      if (categoriesByRoles[role] && categoriesByRoles[role].length === 1) {
+        categoriesByRoles[role][0].role = role;
+      }
+    })
 
-      await Promise.all([].concat(
-        created.map(cat => cat.save({transaction})),
-        deleted.map(cat => cat.destroy({transaction}))
-      ))
+    for (const category of created) {
+      await category.save()
+    }
 
-      return Promise.resolve()
-    });
+    for (const category of deleted) {
+      await category.destroy()
+    }
   }
 }
 

packages/local-sync/src/local-sync-worker/imap/fetch-messages-in-folder.js

@@ -45,17 +45,10 @@ class FetchMessagesInFolder {
     // we just remove the category ID and UID. We may re-assign the same message
     // the same UID. Otherwise they're eventually garbage collected.
     const {Message} = this._db;
-    await this._db.sequelize.transaction((transaction) =>
-      Message.update({
-        folderImapUID: null,
-        folderId: null,
-      }, {
-        transaction: transaction,
-        where: {
-          folderId: this._folder.id,
-        },
-      })
-    )
+    await Message.update({
+      folderImapUID: null,
+      folderId: null,
+    }, {where: {folderId: this._folder.id}})
   }
 
   async _updateMessageAttributes(remoteUIDAttributes, localMessageAttributes) {
@@ -159,18 +152,10 @@ class FetchMessagesInFolder {
     //   removed_messages: removedUIDs.length,
     // }, `FetchMessagesInFolder: found messages no longer in the folder`)
 
-    await this._db.sequelize.transaction((transaction) =>
-       Message.update({
-         folderImapUID: null,
-         folderId: null,
-       }, {
-         transaction,
-         where: {
-           folderId: this._folder.id,
-           folderImapUID: removedUIDs,
-         },
-       })
-    );
+    await Message.update({
+      folderImapUID: null,
+      folderId: null,
+    }, {where: {folderId: this._folder.id, folderImapUID: removedUIDs}})
   }
 
   _getDesiredMIMEParts(struct) {

packages/local-sync/src/local-sync-worker/local-sync-delta-emitter.es6

@@ -0,0 +1,35 @@
+const TransactionConnector = require('../shared/transaction-connector')
+const {DeltaStreamBuilder} = require('isomorphic-core')
+
+export default class LocalSyncDeltaEmitter {
+  constructor(db, accountId) {
+    this._db = db;
+    this._accountId = accountId;
+    NylasEnv.localSyncEmitter.on("startDeltasFor", this._startDeltasFor)
+    NylasEnv.localSyncEmitter.on("endDeltasFor", this._endDeltasFor)
+    /**
+     * The local-sync/sync-worker starts up asynchronously. We need to
+     * notify N1 client that there are more deltas it should be looking
+     * for.
+     */
+    NylasEnv.localSyncEmitter.emit("refreshLocalDeltas", accountId)
+  }
+
+  _startDeltasFor = ({accountId, cursor}) => {
+    if (accountId !== this._accountId) return;
+    if (this._disp && this._disp.dispose) this._disp.dispose()
+    this._disp = DeltaStreamBuilder.buildDeltaObservable({
+      db: this._db,
+      cursor: cursor,
+      accountId: accountId,
+      deltasSource: TransactionConnector.getObservableForAccountId(accountId),
+    }).subscribe((deltas) => {
+      NylasEnv.localSyncEmitter.emit("localSyncDeltas", deltas)
+    })
+  }
+
+  _endDeltasFor = ({accountId}) => {
+    if (accountId !== this._accountId) return;
+    if (this._disp && this._disp.dispose) this._disp.dispose()
+  }
+}

packages/local-sync/src/local-sync-worker/sync-worker.js

@@ -14,6 +14,7 @@ const FetchFolderList = require('./imap/fetch-folder-list')
 const FetchMessagesInFolder = require('./imap/fetch-messages-in-folder')
 const SyncbackTaskFactory = require('./syncback-task-factory')
 const SyncMetricsReporter = require('./sync-metrics-reporter');
+const LocalSyncDeltaEmitter = require('./local-sync-delta-emitter').default
 
 const RESTART_THRESHOLD = 10
 
@@ -29,6 +30,7 @@ class SyncWorker {
     this._interrupted = false
     this._syncInProgress = false
     this._syncAttemptsWhileInProgress = 0
+    this._localDeltas = new LocalSyncDeltaEmitter(db, account.id)
 
     this._destroyed = false;
     this._syncTimer = setTimeout(() => {

packages/local-sync/src/models/message.js

@@ -212,8 +212,8 @@ module.exports = (sequelize, Sequelize) => {
           date: this.date ? this.date.getTime() / 1000.0 : null,
           unread: this.unread,
           starred: this.starred,
-          folder: this.folder,
-          labels: this.labels,
+          folder: this.folder.toJSON(),
+          labels: this.labels.map(l => l.toJSON()),
           thread_id: this.threadId,
         };
       },

packages/local-sync/src/models/thread.js

@@ -144,8 +144,8 @@ module.exports = (sequelize, Sequelize) => {
         const response = {
           id: `${this.id}`,
           object: 'thread',
-          folders: this.folders,
-          labels: this.labels,
+          folders: this.folders.map(f => f.toJSON()),
+          labels: this.labels.map(l => l.toJSON()),
           account_id: this.accountId,
           participants: this.participants,
           subject: this.subject,

packages/local-sync/src/new-message-processor/extract-contacts.js

@@ -37,21 +37,17 @@ async function extractContacts({db, message}) {
     },
   })
 
-  await db.sequelize.transaction(async (transaction) => {
-    const promises = []
-    for (const c of contactsDataById.values()) {
-      const existing = existingContacts.find(({id}) => id === c.id)
-      if (!existing) {
-        promises.push(Contact.create(c, {transaction}));
-      } else {
-        const updateRequired = (c.name !== existing.name);
-        if (updateRequired) {
-          promises.push(existing.update(c, {transaction}));
-        }
+  for (const c of contactsDataById.values()) {
+    const existing = existingContacts.find(({id}) => id === c.id)
+    if (!existing) {
+      await Contact.create(c)
+    } else {
+      const updateRequired = (c.name !== existing.name);
+      if (updateRequired) {
+        await existing.update(c)
       }
     }
-    await Promise.all(promises);
-  })
+  }
 
   return message;
 }

packages/local-sync/src/new-message-processor/extract-files.js

@@ -29,13 +29,13 @@ function collectFilesFromStruct({db, message, struct, fileIds = new Set()}) {
   return collected;
 }
 
-function extractFiles({db, message, imapMessage}) {
+async function extractFiles({db, message, imapMessage}) {
   const {attributes: {struct}} = imapMessage
   const files = collectFilesFromStruct({db, message, struct});
   if (files.length > 0) {
-    return db.sequelize.transaction((transaction) =>
-      Promise.all(files.map(f => f.save({transaction})))
-    )
+    for (const file of files) {
+      await file.save()
+    }
   }
   return Promise.resolve()
 }