From d16178638e6aa284a74307994da1a3f7e1c8f0a9 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Mon, 26 Mar 2018 14:57:10 -0400
Subject: [PATCH 01/56] Split database migrations into pre- and post-attachment
 migration

- Run light-weight migrations before attachment migration.
- Run regular migrations after attachments have been moved to disk.
---
 js/background.js                              |  17 +-
 js/database.js                                | 133 +-------------
 js/modules/migrations/17/index.js             |  55 ------
 ...rations_0_database_with_attachment_data.js | 166 ++++++++++++++++++
 ...ions_1_database_without_attachment_data.js |   9 +
 preload.js                                    |   6 +-
 6 files changed, 193 insertions(+), 193 deletions(-)
 delete mode 100644 js/modules/migrations/17/index.js
 create mode 100644 js/modules/migrations/migrations_0_database_with_attachment_data.js
 create mode 100644 js/modules/migrations/migrations_1_database_without_attachment_data.js

diff --git a/js/background.js b/js/background.js
index d72edc427..7fc323e8e 100644
--- a/js/background.js
+++ b/js/background.js
@@ -11,12 +11,13 @@
 /* global Whisper: false */
 /* global wrapDeferred: false */
 
-;(function() {
+;(async function() {
     'use strict';
 
     const { IdleDetector, MessageDataMigrator } = Signal.Workflow;
     const { Errors, Message } = window.Signal.Types;
     const { upgradeMessageSchema } = window.Signal.Migrations;
+    const { Migrations0DatabaseWithAttachmentData } = window.Signal.Database;
     const { Views } = window.Signal;
 
     // Implicitly used in `indexeddb-backbonejs-adapter`:
@@ -75,13 +76,17 @@
         return accountManager;
     };
 
-    const cancelInitializationMessage = Views.Initialization.setMessage();
-    console.log('Start IndexedDB migrations');
-    storage.fetch();
-
-
   /* eslint-enable */
   /* jshint ignore:start */
+  const cancelInitializationMessage = Views.Initialization.setMessage();
+  console.log('Start IndexedDB migrations');
+
+  console.log('Migrate database with attachments');
+  await Migrations0DatabaseWithAttachmentData.run({ Backbone });
+
+  console.log('Migrate database without attachments');
+  storage.fetch();
+
   const NUM_MESSAGE_UPGRADES_PER_IDLE = 2;
   const idleDetector = new IdleDetector();
   idleDetector.on('idle', async () => {
diff --git a/js/database.js b/js/database.js
index a7335abd3..db0688d35 100644
--- a/js/database.js
+++ b/js/database.js
@@ -2,13 +2,11 @@
 /* global Backbone: false */
 /* global _: false */
 
-/* eslint-disable more/no-then */
-
 // eslint-disable-next-line func-names
 (function () {
   'use strict';
 
-  const { Migrations } = window.Signal;
+  const { Migrations1DatabaseWithoutAttachmentData } = window.Signal.Database;
 
   window.Whisper = window.Whisper || {};
   window.Whisper.Database = window.Whisper.Database || {};
@@ -125,132 +123,5 @@
       request.onsuccess = resolve;
     }));
 
-  Whisper.Database.migrations = [
-    {
-      version: '12.0',
-      migrate(transaction, next) {
-        console.log('migration 12.0');
-        console.log('creating object stores');
-        const messages = transaction.db.createObjectStore('messages');
-        messages.createIndex('conversation', ['conversationId', 'received_at'], {
-          unique: false,
-        });
-        messages.createIndex('receipt', 'sent_at', { unique: false });
-        messages.createIndex('unread', ['conversationId', 'unread'], { unique: false });
-        messages.createIndex('expires_at', 'expires_at', { unique: false });
-
-        const conversations = transaction.db.createObjectStore('conversations');
-        conversations.createIndex('inbox', 'active_at', { unique: false });
-        conversations.createIndex('group', 'members', {
-          unique: false,
-          multiEntry: true,
-        });
-        conversations.createIndex('type', 'type', {
-          unique: false,
-        });
-        conversations.createIndex('search', 'tokens', {
-          unique: false,
-          multiEntry: true,
-        });
-
-        transaction.db.createObjectStore('groups');
-
-        transaction.db.createObjectStore('sessions');
-        transaction.db.createObjectStore('identityKeys');
-        transaction.db.createObjectStore('preKeys');
-        transaction.db.createObjectStore('signedPreKeys');
-        transaction.db.createObjectStore('items');
-
-        console.log('creating debug log');
-        transaction.db.createObjectStore('debug');
-
-        next();
-      },
-    },
-    {
-      version: '13.0',
-      migrate(transaction, next) {
-        console.log('migration 13.0');
-        console.log('Adding fields to identity keys');
-        const identityKeys = transaction.objectStore('identityKeys');
-        const request = identityKeys.openCursor();
-        const promises = [];
-        request.onsuccess = (event) => {
-          const cursor = event.target.result;
-          if (cursor) {
-            const attributes = cursor.value;
-            attributes.timestamp = 0;
-            attributes.firstUse = false;
-            attributes.nonblockingApproval = false;
-            attributes.verified = 0;
-            promises.push(new Promise(((resolve, reject) => {
-              const putRequest = identityKeys.put(attributes, attributes.id);
-              putRequest.onsuccess = resolve;
-              putRequest.onerror = (e) => {
-                console.log(e);
-                reject(e);
-              };
-            })));
-            cursor.continue();
-          } else {
-            // no more results
-            Promise.all(promises).then(() => {
-              next();
-            });
-          }
-        };
-        request.onerror = (event) => {
-          console.log(event);
-        };
-      },
-    },
-    {
-      version: '14.0',
-      migrate(transaction, next) {
-        console.log('migration 14.0');
-        console.log('Adding unprocessed message store');
-        const unprocessed = transaction.db.createObjectStore('unprocessed');
-        unprocessed.createIndex('received', 'timestamp', { unique: false });
-        next();
-      },
-    },
-    {
-      version: '15.0',
-      migrate(transaction, next) {
-        console.log('migration 15.0');
-        console.log('Adding messages index for de-duplication');
-        const messages = transaction.objectStore('messages');
-        messages.createIndex('unique', ['source', 'sourceDevice', 'sent_at'], {
-          unique: true,
-        });
-        next();
-      },
-    },
-    {
-      version: '16.0',
-      migrate(transaction, next) {
-        console.log('migration 16.0');
-        console.log('Dropping log table, since we now log to disk');
-        transaction.db.deleteObjectStore('debug');
-        next();
-      },
-    },
-    {
-      version: 17,
-      async migrate(transaction, next) {
-        console.log('migration 17');
-        console.log('Start migration to database version 17');
-
-        const start = Date.now();
-        await Migrations.V17.run(transaction);
-        const duration = Date.now() - start;
-
-        console.log(
-          'Complete migration to database version 17.',
-          `Duration: ${duration}ms`
-        );
-        next();
-      },
-    },
-  ];
+  Whisper.Database.migrations = Migrations1DatabaseWithoutAttachmentData.migrations;
 }());
diff --git a/js/modules/migrations/17/index.js b/js/modules/migrations/17/index.js
deleted file mode 100644
index feffbb058..000000000
--- a/js/modules/migrations/17/index.js
+++ /dev/null
@@ -1,55 +0,0 @@
-const Message = require('../../types/message');
-
-
-exports.run = async (transaction) => {
-  const messagesStore = transaction.objectStore('messages');
-
-  console.log('Initialize messages schema version');
-  const numUpgradedMessages = await _initializeMessageSchemaVersion(messagesStore);
-  console.log('Complete messages schema version initialization', { numUpgradedMessages });
-
-  console.log('Create index from attachment schema version to attachment');
-  messagesStore.createIndex('schemaVersion', 'schemaVersion', { unique: false });
-};
-
-const _initializeMessageSchemaVersion = messagesStore =>
-  new Promise((resolve, reject) => {
-    const messagePutOperations = [];
-
-    const cursorRequest = messagesStore.openCursor();
-    cursorRequest.onsuccess = async (event) => {
-      const cursor = event.target.result;
-      const hasMoreData = Boolean(cursor);
-      if (!hasMoreData) {
-        await Promise.all(messagePutOperations);
-        return resolve(messagePutOperations.length);
-      }
-
-      const message = cursor.value;
-      const messageWithSchemaVersion = Message.initializeSchemaVersion(message);
-      messagePutOperations.push(putItem(
-        messagesStore,
-        messageWithSchemaVersion,
-        messageWithSchemaVersion.id
-      ));
-
-      return cursor.continue();
-    };
-
-    cursorRequest.onerror = event =>
-      reject(event.target.error);
-  });
-
-//    putItem :: IDBObjectStore -> Item -> Key -> Promise Item
-const putItem = (store, item, key) =>
-  new Promise((resolve, reject) => {
-    try {
-      const request = store.put(item, key);
-      request.onsuccess = event =>
-        resolve(event.target.result);
-      request.onerror = event =>
-        reject(event.target.error);
-    } catch (error) {
-      reject(error);
-    }
-  });
diff --git a/js/modules/migrations/migrations_0_database_with_attachment_data.js b/js/modules/migrations/migrations_0_database_with_attachment_data.js
new file mode 100644
index 000000000..45fc11505
--- /dev/null
+++ b/js/modules/migrations/migrations_0_database_with_attachment_data.js
@@ -0,0 +1,166 @@
+const isFunction = require('lodash/isFunction');
+const isObject = require('lodash/isObject');
+
+
+// IMPORTANT: The migrations below are run on a database that may be very large
+// due to attachments being directly stored inside the database. Please avoid
+// any expensive operations, e.g. modifying all messages / attachments, etc., as
+// it may cause out-of-memory errors for users with long histories:
+// https://github.com/signalapp/Signal-Desktop/issues/2163
+const migrations = [
+  {
+    version: '12.0',
+    migrate(transaction, next) {
+      console.log('Migration 12');
+      console.log('creating object stores');
+      const messages = transaction.db.createObjectStore('messages');
+      messages.createIndex('conversation', ['conversationId', 'received_at'], {
+        unique: false,
+      });
+      messages.createIndex('receipt', 'sent_at', { unique: false });
+      messages.createIndex('unread', ['conversationId', 'unread'], { unique: false });
+      messages.createIndex('expires_at', 'expires_at', { unique: false });
+
+      const conversations = transaction.db.createObjectStore('conversations');
+      conversations.createIndex('inbox', 'active_at', { unique: false });
+      conversations.createIndex('group', 'members', {
+        unique: false,
+        multiEntry: true,
+      });
+      conversations.createIndex('type', 'type', {
+        unique: false,
+      });
+      conversations.createIndex('search', 'tokens', {
+        unique: false,
+        multiEntry: true,
+      });
+
+      transaction.db.createObjectStore('groups');
+
+      transaction.db.createObjectStore('sessions');
+      transaction.db.createObjectStore('identityKeys');
+      transaction.db.createObjectStore('preKeys');
+      transaction.db.createObjectStore('signedPreKeys');
+      transaction.db.createObjectStore('items');
+
+      console.log('creating debug log');
+      transaction.db.createObjectStore('debug');
+
+      next();
+    },
+  },
+  {
+    version: '13.0',
+    migrate(transaction, next) {
+      console.log('Migration 13');
+      console.log('Adding fields to identity keys');
+      const identityKeys = transaction.objectStore('identityKeys');
+      const request = identityKeys.openCursor();
+      const promises = [];
+      request.onsuccess = (event) => {
+        const cursor = event.target.result;
+        if (cursor) {
+          const attributes = cursor.value;
+          attributes.timestamp = 0;
+          attributes.firstUse = false;
+          attributes.nonblockingApproval = false;
+          attributes.verified = 0;
+          promises.push(new Promise(((resolve, reject) => {
+            const putRequest = identityKeys.put(attributes, attributes.id);
+            putRequest.onsuccess = resolve;
+            putRequest.onerror = (e) => {
+              console.log(e);
+              reject(e);
+            };
+          })));
+          cursor.continue();
+        } else {
+          // no more results
+          // eslint-disable-next-line more/no-then
+          Promise.all(promises).then(() => {
+            next();
+          });
+        }
+      };
+      request.onerror = (event) => {
+        console.log(event);
+      };
+    },
+  },
+  {
+    version: '14.0',
+    migrate(transaction, next) {
+      console.log('Migration 14');
+      console.log('Adding unprocessed message store');
+      const unprocessed = transaction.db.createObjectStore('unprocessed');
+      unprocessed.createIndex('received', 'timestamp', { unique: false });
+      next();
+    },
+  },
+  {
+    version: '15.0',
+    migrate(transaction, next) {
+      console.log('Migration 15');
+      console.log('Adding messages index for de-duplication');
+      const messages = transaction.objectStore('messages');
+      messages.createIndex('unique', ['source', 'sourceDevice', 'sent_at'], {
+        unique: true,
+      });
+      next();
+    },
+  },
+  {
+    version: '16.0',
+    migrate(transaction, next) {
+      console.log('Migration 16');
+      console.log('Dropping log table, since we now log to disk');
+      transaction.db.deleteObjectStore('debug');
+      next();
+    },
+  },
+  {
+    version: 17,
+    async migrate(transaction, next) {
+      console.log('Migration 17');
+      console.log('Start migration to database version 17');
+
+      const start = Date.now();
+
+      const messagesStore = transaction.objectStore('messages');
+      console.log('Create index from attachment schema version to attachment');
+      messagesStore.createIndex('schemaVersion', 'schemaVersion', { unique: false });
+
+      const duration = Date.now() - start;
+
+      console.log(
+        'Complete migration to database version 17.',
+        `Duration: ${duration}ms`
+      );
+      next();
+    },
+  },
+];
+
+const database = {
+  id: 'signal',
+  nolog: true,
+  migrations,
+};
+
+exports.run = ({ Backbone } = {}) => {
+  if (!isObject(Backbone) || !isObject(Backbone.Collection) ||
+      !isFunction(Backbone.Collection.extend)) {
+    throw new TypeError('"Backbone" is required');
+  }
+
+  const migrationCollection = new (Backbone.Collection.extend({
+    database,
+    storeName: 'conversations',
+  }))();
+
+  return new Promise((resolve) => {
+    // NOTE: This `then` refers to a jQuery `Deferred`:
+    // eslint-disable-next-line more/no-then
+    migrationCollection.fetch().then(() => resolve());
+  });
+};
diff --git a/js/modules/migrations/migrations_1_database_without_attachment_data.js b/js/modules/migrations/migrations_1_database_without_attachment_data.js
new file mode 100644
index 000000000..5cb5446c8
--- /dev/null
+++ b/js/modules/migrations/migrations_1_database_without_attachment_data.js
@@ -0,0 +1,9 @@
+exports.migrations = [
+  {
+    version: 18,
+    async migrate(transaction, next) {
+      console.log('Migration 18');
+      next();
+    },
+  },
+];
diff --git a/preload.js b/preload.js
index c10ed563a..a2feb6736 100644
--- a/preload.js
+++ b/preload.js
@@ -127,12 +127,16 @@
   window.Signal = {};
   window.Signal.Backup = require('./js/modules/backup');
   window.Signal.Crypto = require('./js/modules/crypto');
+  window.Signal.Database = {};
+  window.Signal.Database.Migrations0DatabaseWithAttachmentData =
+    require('./js/modules/migrations/migrations_0_database_with_attachment_data');
+  window.Signal.Database.Migrations1DatabaseWithoutAttachmentData =
+    require('./js/modules/migrations/migrations_1_database_without_attachment_data');
   window.Signal.Logs = require('./js/modules/logs');
   window.Signal.Migrations = {};
   window.Signal.Migrations.loadAttachmentData = Attachment.loadData(readAttachmentData);
   window.Signal.Migrations.deleteAttachmentData = Attachment.deleteData(deleteAttachmentData);
   window.Signal.Migrations.upgradeMessageSchema = upgradeMessageSchema;
-  window.Signal.Migrations.V17 = require('./js/modules/migrations/17');
   window.Signal.OS = require('./js/modules/os');
   window.Signal.Types = {};
   window.Signal.Types.Attachment = Attachment;

From d7c8d33edb5d90e5acb4501b51f7f91fa5a33649 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Mon, 26 Mar 2018 15:17:19 -0400
Subject: [PATCH 02/56] Extract `runMigrations`

---
 ...rations_0_database_with_attachment_data.js | 22 +++------------
 js/modules/migrations/run_migrations.js       | 27 +++++++++++++++++++
 2 files changed, 30 insertions(+), 19 deletions(-)
 create mode 100644 js/modules/migrations/run_migrations.js

diff --git a/js/modules/migrations/migrations_0_database_with_attachment_data.js b/js/modules/migrations/migrations_0_database_with_attachment_data.js
index 45fc11505..6f8f99079 100644
--- a/js/modules/migrations/migrations_0_database_with_attachment_data.js
+++ b/js/modules/migrations/migrations_0_database_with_attachment_data.js
@@ -1,5 +1,4 @@
-const isFunction = require('lodash/isFunction');
-const isObject = require('lodash/isObject');
+const { runMigrations } = require('./run_migrations');
 
 
 // IMPORTANT: The migrations below are run on a database that may be very large
@@ -147,20 +146,5 @@ const database = {
   migrations,
 };
 
-exports.run = ({ Backbone } = {}) => {
-  if (!isObject(Backbone) || !isObject(Backbone.Collection) ||
-      !isFunction(Backbone.Collection.extend)) {
-    throw new TypeError('"Backbone" is required');
-  }
-
-  const migrationCollection = new (Backbone.Collection.extend({
-    database,
-    storeName: 'conversations',
-  }))();
-
-  return new Promise((resolve) => {
-    // NOTE: This `then` refers to a jQuery `Deferred`:
-    // eslint-disable-next-line more/no-then
-    migrationCollection.fetch().then(() => resolve());
-  });
-};
+exports.run = ({ Backbone } = {}) =>
+  runMigrations({ Backbone, database });
diff --git a/js/modules/migrations/run_migrations.js b/js/modules/migrations/run_migrations.js
new file mode 100644
index 000000000..cdd26dd97
--- /dev/null
+++ b/js/modules/migrations/run_migrations.js
@@ -0,0 +1,27 @@
+const isFunction = require('lodash/isFunction');
+const isObject = require('lodash/isObject');
+const isString = require('lodash/isString');
+
+
+exports.runMigrations = ({ Backbone, database } = {}) => {
+  if (!isObject(Backbone) || !isObject(Backbone.Collection) ||
+      !isFunction(Backbone.Collection.extend)) {
+    throw new TypeError('"Backbone" is required');
+  }
+
+  if (!isObject(database) || !isString(database.id) ||
+      !Array.isArray(database.migrations)) {
+    throw new TypeError('"database" is required');
+  }
+
+  const migrationCollection = new (Backbone.Collection.extend({
+    database,
+    storeName: 'items',
+  }))();
+
+  return new Promise((resolve) => {
+    // NOTE: This `then` refers to a jQuery `Deferred`:
+    // eslint-disable-next-line more/no-then
+    migrationCollection.fetch().then(() => resolve());
+  });
+};

From e2f1339ab97fa4d6e475dcc298390adac8549eb4 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Mon, 26 Mar 2018 15:17:35 -0400
Subject: [PATCH 03/56] Explicitly run post-attachment migrations

---
 js/background.js                                      | 11 ++++++++++-
 .../migrations_1_database_without_attachment_data.js  |  6 ++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/js/background.js b/js/background.js
index 7fc323e8e..e21c45e28 100644
--- a/js/background.js
+++ b/js/background.js
@@ -17,7 +17,10 @@
     const { IdleDetector, MessageDataMigrator } = Signal.Workflow;
     const { Errors, Message } = window.Signal.Types;
     const { upgradeMessageSchema } = window.Signal.Migrations;
-    const { Migrations0DatabaseWithAttachmentData } = window.Signal.Database;
+    const {
+        Migrations0DatabaseWithAttachmentData,
+        Migrations1DatabaseWithoutAttachmentData,
+    } = window.Signal.Database;
     const { Views } = window.Signal;
 
     // Implicitly used in `indexeddb-backbonejs-adapter`:
@@ -85,6 +88,12 @@
   await Migrations0DatabaseWithAttachmentData.run({ Backbone });
 
   console.log('Migrate database without attachments');
+  await Migrations1DatabaseWithoutAttachmentData.run({
+    Backbone,
+    Database: Whisper.Database,
+  });
+
+  console.log('Storage fetch');
   storage.fetch();
 
   const NUM_MESSAGE_UPGRADES_PER_IDLE = 2;
diff --git a/js/modules/migrations/migrations_1_database_without_attachment_data.js b/js/modules/migrations/migrations_1_database_without_attachment_data.js
index 5cb5446c8..04bacb870 100644
--- a/js/modules/migrations/migrations_1_database_without_attachment_data.js
+++ b/js/modules/migrations/migrations_1_database_without_attachment_data.js
@@ -1,3 +1,6 @@
+const { runMigrations } = require('./run_migrations');
+
+
 exports.migrations = [
   {
     version: 18,
@@ -7,3 +10,6 @@ exports.migrations = [
     },
   },
 ];
+
+exports.run = ({ Backbone, Database } = {}) =>
+  runMigrations({ Backbone, database: Database });

From c765422fa14888bebb274e383efe08d56d5c948f Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Mon, 26 Mar 2018 15:30:51 -0400
Subject: [PATCH 04/56] Extract `deferredToPromise`

---
 js/modules/deferred_to_promise.js | 3 +++
 preload.js                        | 7 ++-----
 2 files changed, 5 insertions(+), 5 deletions(-)
 create mode 100644 js/modules/deferred_to_promise.js

diff --git a/js/modules/deferred_to_promise.js b/js/modules/deferred_to_promise.js
new file mode 100644
index 000000000..d6409b09f
--- /dev/null
+++ b/js/modules/deferred_to_promise.js
@@ -0,0 +1,3 @@
+exports.deferredToPromise = deferred =>
+  // eslint-disable-next-line more/no-then
+  new Promise((resolve, reject) => deferred.then(resolve, reject));
diff --git a/preload.js b/preload.js
index a2feb6736..9509f30fe 100644
--- a/preload.js
+++ b/preload.js
@@ -7,17 +7,14 @@
   const Attachment = require('./js/modules/types/attachment');
   const Attachments = require('./app/attachments');
   const Message = require('./js/modules/types/message');
+  const { deferredToPromise } = require('./js/modules/deferred_to_promise');
 
   const { app } = electron.remote;
 
 
   window.PROTO_ROOT = 'protos';
   window.config = require('url').parse(window.location.toString(), true).query;
-  window.wrapDeferred = function(deferred) {
-    return new Promise(function(resolve, reject) {
-      deferred.then(resolve, reject);
-    });
-  };
+  window.wrapDeferred = deferredToPromise;
 
   const ipc = electron.ipcRenderer;
   window.config.localeMessages = ipc.sendSync('locale-data');

From fcd30cd91943036d94473e14731d3d1ee09d9bed Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Mon, 26 Mar 2018 15:34:36 -0400
Subject: [PATCH 05/56] Close database after migration

This is not 100% reliable as database connections are closed in a separate
thread according to the documentation:
- https://developer.mozilla.org/en-US/docs/Web/API/IDBDatabase/close
- https://stackoverflow.com/a/18639298
- https://github.com/superfeedr/indexeddb-backbonejs-adapter/blob/80c7a06d5c0a75296106e9a62663230459cef857/backbone-indexeddb.js#L558-L565
---
 js/background.js                                 |  5 ++++-
 ...migrations_0_database_with_attachment_data.js |  4 ++--
 ...rations_1_database_without_attachment_data.js |  4 ++--
 js/modules/migrations/run_migrations.js          | 16 ++++++++++------
 4 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/js/background.js b/js/background.js
index e21c45e28..7eea361d9 100644
--- a/js/background.js
+++ b/js/background.js
@@ -85,11 +85,14 @@
   console.log('Start IndexedDB migrations');
 
   console.log('Migrate database with attachments');
-  await Migrations0DatabaseWithAttachmentData.run({ Backbone });
+  const closeDatabase = () =>
+    Whisper.Database.close();
+  await Migrations0DatabaseWithAttachmentData.run({ Backbone, closeDatabase });
 
   console.log('Migrate database without attachments');
   await Migrations1DatabaseWithoutAttachmentData.run({
     Backbone,
+    closeDatabase,
     Database: Whisper.Database,
   });
 
diff --git a/js/modules/migrations/migrations_0_database_with_attachment_data.js b/js/modules/migrations/migrations_0_database_with_attachment_data.js
index 6f8f99079..0fa12cc97 100644
--- a/js/modules/migrations/migrations_0_database_with_attachment_data.js
+++ b/js/modules/migrations/migrations_0_database_with_attachment_data.js
@@ -146,5 +146,5 @@ const database = {
   migrations,
 };
 
-exports.run = ({ Backbone } = {}) =>
-  runMigrations({ Backbone, database });
+exports.run = ({ Backbone, closeDatabase } = {}) =>
+  runMigrations({ Backbone, closeDatabase, database });
diff --git a/js/modules/migrations/migrations_1_database_without_attachment_data.js b/js/modules/migrations/migrations_1_database_without_attachment_data.js
index 04bacb870..46ca5aedd 100644
--- a/js/modules/migrations/migrations_1_database_without_attachment_data.js
+++ b/js/modules/migrations/migrations_1_database_without_attachment_data.js
@@ -11,5 +11,5 @@ exports.migrations = [
   },
 ];
 
-exports.run = ({ Backbone, Database } = {}) =>
-  runMigrations({ Backbone, database: Database });
+exports.run = ({ Backbone, closeDatabase, Database } = {}) =>
+  runMigrations({ Backbone, closeDatabase, database: Database });
diff --git a/js/modules/migrations/run_migrations.js b/js/modules/migrations/run_migrations.js
index cdd26dd97..878ef3bad 100644
--- a/js/modules/migrations/run_migrations.js
+++ b/js/modules/migrations/run_migrations.js
@@ -2,13 +2,19 @@ const isFunction = require('lodash/isFunction');
 const isObject = require('lodash/isObject');
 const isString = require('lodash/isString');
 
+const { deferredToPromise } = require('../deferred_to_promise');
 
-exports.runMigrations = ({ Backbone, database } = {}) => {
+
+exports.runMigrations = async ({ Backbone, closeDatabase, database } = {}) => {
   if (!isObject(Backbone) || !isObject(Backbone.Collection) ||
       !isFunction(Backbone.Collection.extend)) {
     throw new TypeError('"Backbone" is required');
   }
 
+  if (!isFunction(closeDatabase)) {
+    throw new TypeError('"closeDatabase" is required');
+  }
+
   if (!isObject(database) || !isString(database.id) ||
       !Array.isArray(database.migrations)) {
     throw new TypeError('"database" is required');
@@ -19,9 +25,7 @@ exports.runMigrations = ({ Backbone, database } = {}) => {
     storeName: 'items',
   }))();
 
-  return new Promise((resolve) => {
-    // NOTE: This `then` refers to a jQuery `Deferred`:
-    // eslint-disable-next-line more/no-then
-    migrationCollection.fetch().then(() => resolve());
-  });
+  await deferredToPromise(migrationCollection.fetch());
+  await closeDatabase();
+  return;
 };

From 106ce21c49da96960150a675715209a3da42a36a Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Mon, 26 Mar 2018 16:18:56 -0400
Subject: [PATCH 06/56] Remove redundant log message

---
 .../migrations/migrations_0_database_with_attachment_data.js     | 1 -
 1 file changed, 1 deletion(-)

diff --git a/js/modules/migrations/migrations_0_database_with_attachment_data.js b/js/modules/migrations/migrations_0_database_with_attachment_data.js
index 0fa12cc97..d26697b34 100644
--- a/js/modules/migrations/migrations_0_database_with_attachment_data.js
+++ b/js/modules/migrations/migrations_0_database_with_attachment_data.js
@@ -121,7 +121,6 @@ const migrations = [
     version: 17,
     async migrate(transaction, next) {
       console.log('Migration 17');
-      console.log('Start migration to database version 17');
 
       const start = Date.now();
 

From da144edc56613e7b2669a718645f50795a792c48 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Mon, 26 Mar 2018 16:23:34 -0400
Subject: [PATCH 07/56] Manually close database connection after migration

---
 js/background.js                              |  8 ++---
 ...rations_0_database_with_attachment_data.js |  4 +--
 ...ions_1_database_without_attachment_data.js |  4 +--
 js/modules/migrations/run_migrations.js       | 31 ++++++++++++++-----
 4 files changed, 31 insertions(+), 16 deletions(-)

diff --git a/js/background.js b/js/background.js
index 7eea361d9..c03ea2562 100644
--- a/js/background.js
+++ b/js/background.js
@@ -11,7 +11,8 @@
 /* global Whisper: false */
 /* global wrapDeferred: false */
 
-;(async function() {
+
+;(/* jshint ignore:start */ async /* jshint ignore:end */function() {
     'use strict';
 
     const { IdleDetector, MessageDataMigrator } = Signal.Workflow;
@@ -85,14 +86,11 @@
   console.log('Start IndexedDB migrations');
 
   console.log('Migrate database with attachments');
-  const closeDatabase = () =>
-    Whisper.Database.close();
-  await Migrations0DatabaseWithAttachmentData.run({ Backbone, closeDatabase });
+  await Migrations0DatabaseWithAttachmentData.run({ Backbone });
 
   console.log('Migrate database without attachments');
   await Migrations1DatabaseWithoutAttachmentData.run({
     Backbone,
-    closeDatabase,
     Database: Whisper.Database,
   });
 
diff --git a/js/modules/migrations/migrations_0_database_with_attachment_data.js b/js/modules/migrations/migrations_0_database_with_attachment_data.js
index d26697b34..19b9d7063 100644
--- a/js/modules/migrations/migrations_0_database_with_attachment_data.js
+++ b/js/modules/migrations/migrations_0_database_with_attachment_data.js
@@ -145,5 +145,5 @@ const database = {
   migrations,
 };
 
-exports.run = ({ Backbone, closeDatabase } = {}) =>
-  runMigrations({ Backbone, closeDatabase, database });
+exports.run = ({ Backbone } = {}) =>
+  runMigrations({ Backbone, database });
diff --git a/js/modules/migrations/migrations_1_database_without_attachment_data.js b/js/modules/migrations/migrations_1_database_without_attachment_data.js
index 46ca5aedd..04bacb870 100644
--- a/js/modules/migrations/migrations_1_database_without_attachment_data.js
+++ b/js/modules/migrations/migrations_1_database_without_attachment_data.js
@@ -11,5 +11,5 @@ exports.migrations = [
   },
 ];
 
-exports.run = ({ Backbone, closeDatabase, Database } = {}) =>
-  runMigrations({ Backbone, closeDatabase, database: Database });
+exports.run = ({ Backbone, Database } = {}) =>
+  runMigrations({ Backbone, database: Database });
diff --git a/js/modules/migrations/run_migrations.js b/js/modules/migrations/run_migrations.js
index 878ef3bad..7296debb6 100644
--- a/js/modules/migrations/run_migrations.js
+++ b/js/modules/migrations/run_migrations.js
@@ -1,3 +1,5 @@
+/* eslint-env browser */
+
 const isFunction = require('lodash/isFunction');
 const isObject = require('lodash/isObject');
 const isString = require('lodash/isString');
@@ -5,16 +7,32 @@ const isString = require('lodash/isString');
 const { deferredToPromise } = require('../deferred_to_promise');
 
 
-exports.runMigrations = async ({ Backbone, closeDatabase, database } = {}) => {
+const closeDatabase = name =>
+  new Promise((resolve, reject) => {
+    const request = window.indexedDB.open(name);
+    request.onblocked = () => {
+      reject(new Error(`Database '${name}' blocked`));
+    };
+    request.onupgradeneeded = (event) => {
+      reject(new Error('Unexpected database upgraded needed:' +
+        ` oldVersion: ${event.oldVersion}, newVersion: ${event.newVersion}`));
+    };
+    request.onerror = (event) => {
+      reject(event.target.error);
+    };
+    request.onsuccess = (event) => {
+      const connection = event.target.result;
+      connection.close();
+      resolve();
+    };
+  });
+
+exports.runMigrations = async ({ Backbone, database } = {}) => {
   if (!isObject(Backbone) || !isObject(Backbone.Collection) ||
       !isFunction(Backbone.Collection.extend)) {
     throw new TypeError('"Backbone" is required');
   }
 
-  if (!isFunction(closeDatabase)) {
-    throw new TypeError('"closeDatabase" is required');
-  }
-
   if (!isObject(database) || !isString(database.id) ||
       !Array.isArray(database.migrations)) {
     throw new TypeError('"database" is required');
@@ -26,6 +44,5 @@ exports.runMigrations = async ({ Backbone, closeDatabase, database } = {}) => {
   }))();
 
   await deferredToPromise(migrationCollection.fetch());
-  await closeDatabase();
-  return;
+  await closeDatabase(database.id);
 };

From 40c40c800a9247ddab10d8a41641a916d4d5a36b Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Mon, 26 Mar 2018 16:32:22 -0400
Subject: [PATCH 08/56] Prefer `exports`

---
 js/modules/messages_data_migrator.js | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index c1b4f3e0d..9ccb8c98a 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -3,7 +3,7 @@ const isFunction = require('lodash/isFunction');
 const Message = require('./types/message');
 
 
-const processNext = async ({
+exports.processNext = async ({
   BackboneMessage,
   BackboneMessageCollection,
   count,
@@ -92,8 +92,3 @@ const _fetchMessagesRequiringSchemaUpgrade =
       resolve(messages);
     }));
   };
-
-
-module.exports = {
-  processNext,
-};

From 579b01283e73422b8223b47032999156a82fa01f Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Mon, 26 Mar 2018 16:33:23 -0400
Subject: [PATCH 09/56] Replace `wrapDeferred` with `deferredToPromise`

---
 js/background.js                     |  1 -
 js/modules/messages_data_migrator.js | 13 +++++--------
 2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/js/background.js b/js/background.js
index c03ea2562..18a4c6d4e 100644
--- a/js/background.js
+++ b/js/background.js
@@ -105,7 +105,6 @@
       BackboneMessageCollection: Whisper.MessageCollection,
       count: NUM_MESSAGE_UPGRADES_PER_IDLE,
       upgradeMessageSchema,
-      wrapDeferred,
     });
     console.log('Upgrade message schema:', results);
 
diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index 9ccb8c98a..2df16daff 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -1,6 +1,8 @@
 const isNumber = require('lodash/isNumber');
 const isFunction = require('lodash/isFunction');
+
 const Message = require('./types/message');
+const { deferredToPromise } = require('./deferred_to_promise');
 
 
 exports.processNext = async ({
@@ -8,7 +10,6 @@ exports.processNext = async ({
   BackboneMessageCollection,
   count,
   upgradeMessageSchema,
-  wrapDeferred,
 } = {}) => {
   if (!isFunction(BackboneMessage)) {
     throw new TypeError('`BackboneMessage` (Whisper.Message) constructor is required');
@@ -27,10 +28,6 @@ exports.processNext = async ({
     throw new TypeError('`upgradeMessageSchema` is required');
   }
 
-  if (!isFunction(wrapDeferred)) {
-    throw new TypeError('`wrapDeferred` is required');
-  }
-
   const startTime = Date.now();
 
   const startFetchTime = Date.now();
@@ -44,7 +41,7 @@ exports.processNext = async ({
   const upgradeDuration = Date.now() - startUpgradeTime;
 
   const startSaveTime = Date.now();
-  const saveMessage = _saveMessage({ BackboneMessage, wrapDeferred });
+  const saveMessage = _saveMessage({ BackboneMessage });
   await Promise.all(upgradedMessages.map(saveMessage));
   const saveDuration = Date.now() - startSaveTime;
 
@@ -61,9 +58,9 @@ exports.processNext = async ({
   };
 };
 
-const _saveMessage = ({ BackboneMessage, wrapDeferred } = {}) => (message) => {
+const _saveMessage = ({ BackboneMessage } = {}) => (message) => {
   const backboneMessage = new BackboneMessage(message);
-  return wrapDeferred(backboneMessage.save());
+  return deferredToPromise(backboneMessage.save());
 };
 
 const _fetchMessagesRequiringSchemaUpgrade =

From 172616ca4fbd12d13f224dd7ad5ddc4feb77ab4d Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Mon, 26 Mar 2018 17:13:25 -0400
Subject: [PATCH 10/56] Add log message for dummy migration 18

---
 .../migrations/migrations_1_database_without_attachment_data.js  | 1 +
 1 file changed, 1 insertion(+)

diff --git a/js/modules/migrations/migrations_1_database_without_attachment_data.js b/js/modules/migrations/migrations_1_database_without_attachment_data.js
index 04bacb870..2b7c010c4 100644
--- a/js/modules/migrations/migrations_1_database_without_attachment_data.js
+++ b/js/modules/migrations/migrations_1_database_without_attachment_data.js
@@ -6,6 +6,7 @@ exports.migrations = [
     version: 18,
     async migrate(transaction, next) {
       console.log('Migration 18');
+      console.log('Attachments stored on disk');
       next();
     },
   },

From 8ea257ad4dbfd2f51ff8d28f3743d5bb15ff8867 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Mon, 26 Mar 2018 19:04:38 -0400
Subject: [PATCH 11/56] Use double quotes for identifiers in error messages

---
 js/modules/messages_data_migrator.js | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index 2df16daff..dc4bbd377 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -12,20 +12,20 @@ exports.processNext = async ({
   upgradeMessageSchema,
 } = {}) => {
   if (!isFunction(BackboneMessage)) {
-    throw new TypeError('`BackboneMessage` (Whisper.Message) constructor is required');
+    throw new TypeError('"BackboneMessage" (Whisper.Message) constructor is required');
   }
 
   if (!isFunction(BackboneMessageCollection)) {
-    throw new TypeError('`BackboneMessageCollection` (Whisper.MessageCollection)' +
+    throw new TypeError('"BackboneMessageCollection" (Whisper.MessageCollection)' +
       ' constructor is required');
   }
 
   if (!isNumber(count)) {
-    throw new TypeError('`count` is required');
+    throw new TypeError('"count" is required');
   }
 
   if (!isFunction(upgradeMessageSchema)) {
-    throw new TypeError('`upgradeMessageSchema` is required');
+    throw new TypeError('"upgradeMessageSchema" is required');
   }
 
   const startTime = Date.now();
@@ -66,12 +66,12 @@ const _saveMessage = ({ BackboneMessage } = {}) => (message) => {
 const _fetchMessagesRequiringSchemaUpgrade =
   async ({ BackboneMessageCollection, count } = {}) => {
     if (!isFunction(BackboneMessageCollection)) {
-      throw new TypeError('`BackboneMessageCollection` (Whisper.MessageCollection)' +
+      throw new TypeError('"BackboneMessageCollection" (Whisper.MessageCollection)' +
         ' constructor is required');
     }
 
     if (!isNumber(count)) {
-      throw new TypeError('`count` is required');
+      throw new TypeError('"count" is required');
     }
 
     const collection = new BackboneMessageCollection();

From 457bf7ab9ddb33a3b9110799e2ab0a45dd213d35 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Mon, 26 Mar 2018 19:07:50 -0400
Subject: [PATCH 12/56] Add `createCollection` function

---
 ...rations_0_database_with_attachment_data.js | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/js/modules/migrations/migrations_0_database_with_attachment_data.js b/js/modules/migrations/migrations_0_database_with_attachment_data.js
index 19b9d7063..e00f71870 100644
--- a/js/modules/migrations/migrations_0_database_with_attachment_data.js
+++ b/js/modules/migrations/migrations_0_database_with_attachment_data.js
@@ -1,3 +1,7 @@
+const isFunction = require('lodash/isFunction');
+const isObject = require('lodash/isObject');
+const isString = require('lodash/isString');
+
 const { runMigrations } = require('./run_migrations');
 
 
@@ -147,3 +151,21 @@ const database = {
 
 exports.run = ({ Backbone } = {}) =>
   runMigrations({ Backbone, database });
+
+exports.createCollection = ({ Backbone, storeName }) => {
+  if (!isObject(Backbone) || !isObject(Backbone.Collection) ||
+      !isFunction(Backbone.Collection.extend)) {
+    throw new TypeError('"Backbone" is required');
+  }
+
+  if (!isString(storeName)) {
+    throw new TypeError('"database" is required');
+  }
+
+  const collection = new (Backbone.Collection.extend({
+    database,
+    storeName,
+  }))();
+
+  return collection;
+};

From b6e978f74c75eddbeef4291afc72635b439f7ddf Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Mon, 26 Mar 2018 19:09:06 -0400
Subject: [PATCH 13/56] Implement `MessagesDataMigrator.processAll`

---
 js/modules/messages_data_migrator.js | 63 +++++++++++++++++++++++++++-
 1 file changed, 61 insertions(+), 2 deletions(-)

diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index dc4bbd377..e3ce66c89 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -1,9 +1,12 @@
-const isNumber = require('lodash/isNumber');
 const isFunction = require('lodash/isFunction');
+const isNumber = require('lodash/isNumber');
+const isObject = require('lodash/isObject');
+const isString = require('lodash/isString');
 
 const Message = require('./types/message');
 const { deferredToPromise } = require('./deferred_to_promise');
-
+const Migrations0DatabaseWithAttachmentData =
+  require('./migrations/migrations_0_database_with_attachment_data');
 
 exports.processNext = async ({
   BackboneMessage,
@@ -58,6 +61,32 @@ exports.processNext = async ({
   };
 };
 
+exports.processAll = async ({
+  Backbone,
+  storage,
+  upgradeMessageSchema,
+} = {}) => {
+  if (!isObject(Backbone)) {
+    throw new TypeError('"Backbone" is required');
+  }
+
+  if (!isObject(storage)) {
+    throw new TypeError('"storage" is required');
+  }
+
+  if (!isFunction(upgradeMessageSchema)) {
+    throw new TypeError('"upgradeMessageSchema" is required');
+  }
+
+  const lastIndex = null;
+  const unprocessedMessages =
+    await _dangerouslyFetchMessagesRequiringSchemaUpgradeWithoutIndex({
+      Backbone,
+      count: 10,
+      lastIndex,
+    });
+};
+
 const _saveMessage = ({ BackboneMessage } = {}) => (message) => {
   const backboneMessage = new BackboneMessage(message);
   return deferredToPromise(backboneMessage.save());
@@ -89,3 +118,33 @@ const _fetchMessagesRequiringSchemaUpgrade =
       resolve(messages);
     }));
   };
+
+const MAX_MESSAGE_KEY = 'ffffffff-ffff-ffff-ffff-ffffffffffff';
+const _dangerouslyFetchMessagesRequiringSchemaUpgradeWithoutIndex =
+  async ({ Backbone, count, lastIndex } = {}) => {
+    if (!isObject(Backbone)) {
+      throw new TypeError('"Backbone" is required');
+    }
+
+    if (!isNumber(count)) {
+      throw new TypeError('"count" is required');
+    }
+
+    if (lastIndex && !isString(lastIndex)) {
+      throw new TypeError('"lastIndex" must be a string');
+    }
+
+    const storeName = 'messages';
+    const collection =
+      Migrations0DatabaseWithAttachmentData.createCollection({ Backbone, storeName });
+
+    const range = lastIndex ? [lastIndex, MAX_MESSAGE_KEY] : null;
+    await deferredToPromise(collection.fetch({
+      limit: count,
+      range,
+    }));
+
+    const models = collection.models || [];
+    const messages = models.map(model => model.toJSON());
+    return messages;
+  };

From 178a3cc2624b3f5fd45bb3d448f500a7fb3a9ece Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Mon, 26 Mar 2018 19:11:21 -0400
Subject: [PATCH 14/56] Reduce work for verifying transaction completion

---
 js/modules/migrations/run_migrations.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/js/modules/migrations/run_migrations.js b/js/modules/migrations/run_migrations.js
index 7296debb6..992895373 100644
--- a/js/modules/migrations/run_migrations.js
+++ b/js/modules/migrations/run_migrations.js
@@ -43,6 +43,6 @@ exports.runMigrations = async ({ Backbone, database } = {}) => {
     storeName: 'items',
   }))();
 
-  await deferredToPromise(migrationCollection.fetch());
+  await deferredToPromise(migrationCollection.fetch({ limit: 1 }));
   await closeDatabase(database.id);
 };

From b8a0bc34235e44ac14a5f0f0db8074fece5ccb6a Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Mon, 26 Mar 2018 19:12:38 -0400
Subject: [PATCH 15/56] Run attachment to disk migration on startup

---
 js/background.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/js/background.js b/js/background.js
index 18a4c6d4e..dce1de980 100644
--- a/js/background.js
+++ b/js/background.js
@@ -88,6 +88,9 @@
   console.log('Migrate database with attachments');
   await Migrations0DatabaseWithAttachmentData.run({ Backbone });
 
+  console.log('Migrate attachments to disk');
+  await MessageDataMigrator.processAll({ Backbone, storage, upgradeMessageSchema });
+
   console.log('Migrate database without attachments');
   await Migrations1DatabaseWithoutAttachmentData.run({
     Backbone,

From 070235b59b738a1fb86fda2600fc32352060de3b Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Tue, 27 Mar 2018 11:51:21 -0400
Subject: [PATCH 16/56] Implement `MessageDataMigrator.processAll`

Upgrades schema of all messags upon startup.
---
 js/modules/messages_data_migrator.js | 223 ++++++++++++++++++++++++---
 1 file changed, 198 insertions(+), 25 deletions(-)

diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index e3ce66c89..1ba211e0f 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -1,12 +1,20 @@
+/* eslint-env browser */
+
 const isFunction = require('lodash/isFunction');
 const isNumber = require('lodash/isNumber');
 const isObject = require('lodash/isObject');
 const isString = require('lodash/isString');
+const last = require('lodash/last');
 
 const Message = require('./types/message');
 const { deferredToPromise } = require('./deferred_to_promise');
-const Migrations0DatabaseWithAttachmentData =
-  require('./migrations/migrations_0_database_with_attachment_data');
+
+
+const DATABASE_NAME = 'signal';
+// Last version with attachment data stored in database:
+const EXPECTED_DATABASE_VERSION = 17;
+const MESSAGES_STORE_NAME = 'messages';
+const ITEMS_STORE_NAME = 'items';
 
 exports.processNext = async ({
   BackboneMessage,
@@ -44,7 +52,7 @@ exports.processNext = async ({
   const upgradeDuration = Date.now() - startUpgradeTime;
 
   const startSaveTime = Date.now();
-  const saveMessage = _saveMessage({ BackboneMessage });
+  const saveMessage = _saveMessageBackbone({ BackboneMessage });
   await Promise.all(upgradedMessages.map(saveMessage));
   const saveDuration = Date.now() - startSaveTime;
 
@@ -78,20 +86,91 @@ exports.processAll = async ({
     throw new TypeError('"upgradeMessageSchema" is required');
   }
 
-  const lastIndex = null;
-  const unprocessedMessages =
-    await _dangerouslyFetchMessagesRequiringSchemaUpgradeWithoutIndex({
-      Backbone,
-      count: 10,
-      lastIndex,
+  const connection = await openDatabase(DATABASE_NAME, EXPECTED_DATABASE_VERSION);
+  const isComplete = await isMigrationComplete(connection);
+  console.log('Is attachment migration complete?', isComplete);
+  if (isComplete) {
+    return;
+  }
+
+  const migrationStartTime = Date.now();
+  let unprocessedMessages = [];
+  do {
+    // eslint-disable-next-line no-await-in-loop
+    const lastProcessedIndex = (await getLastProcessedIndex(connection)) || null;
+
+    const fetchUnprocessedMessagesStartTime = Date.now();
+    unprocessedMessages =
+      // eslint-disable-next-line no-await-in-loop
+      await _dangerouslyFetchMessagesRequiringSchemaUpgradeWithoutIndex({
+        connection,
+        count: 10,
+        lastIndex: lastProcessedIndex,
+      });
+    const fetchDuration = Date.now() - fetchUnprocessedMessagesStartTime;
+    const numUnprocessedMessages = unprocessedMessages.length;
+
+    const upgradeStartTime = Date.now();
+    const upgradedMessages =
+      // eslint-disable-next-line no-await-in-loop
+      await Promise.all(unprocessedMessages.map(upgradeMessageSchema));
+    const upgradeDuration = Date.now() - upgradeStartTime;
+
+    const saveMessagesStartTime = Date.now();
+    const transaction = connection.transaction(MESSAGES_STORE_NAME, 'readwrite');
+    const transactionCompletion = completeTransaction(transaction);
+    // eslint-disable-next-line no-await-in-loop
+    await Promise.all(upgradedMessages.map(_saveMessage({ transaction })));
+    // eslint-disable-next-line no-await-in-loop
+    await transactionCompletion;
+    const saveDuration = Date.now() - saveMessagesStartTime;
+
+    // TODO: Confirm transaction is complete
+
+    const lastMessage = last(upgradedMessages);
+    const newLastProcessedIndex = lastMessage ? lastMessage.id : null;
+    if (newLastProcessedIndex) {
+      // eslint-disable-next-line no-await-in-loop
+      await setLastProcessedIndex(connection, newLastProcessedIndex);
+    }
+
+    console.log('Upgrade message schema on startup:', {
+      lastProcessedIndex,
+      numUnprocessedMessages,
+      fetchDuration,
+      saveDuration,
+      upgradeDuration,
+      newLastProcessedIndex,
     });
+  } while (unprocessedMessages.length > 0);
+
+  await markMigrationComplete(connection);
+  connection.close();
+
+  const totalDuration = Date.now() - migrationStartTime;
+  console.log('Attachment migration complete:', { totalDuration });
 };
 
-const _saveMessage = ({ BackboneMessage } = {}) => (message) => {
+const _saveMessageBackbone = ({ BackboneMessage } = {}) => (message) => {
   const backboneMessage = new BackboneMessage(message);
   return deferredToPromise(backboneMessage.save());
 };
 
+const _saveMessage = ({ transaction } = {}) => (message) => {
+  if (!isObject(transaction)) {
+    throw new TypeError('"transaction" is required');
+  }
+
+  const messagesStore = transaction.objectStore(MESSAGES_STORE_NAME);
+  const request = messagesStore.put(message, message.id);
+  return new Promise((resolve, reject) => {
+    request.onsuccess = () =>
+      resolve();
+    request.onerror = event =>
+      reject(event.target.error);
+  });
+};
+
 const _fetchMessagesRequiringSchemaUpgrade =
   async ({ BackboneMessageCollection, count } = {}) => {
     if (!isFunction(BackboneMessageCollection)) {
@@ -119,11 +198,10 @@ const _fetchMessagesRequiringSchemaUpgrade =
     }));
   };
 
-const MAX_MESSAGE_KEY = 'ffffffff-ffff-ffff-ffff-ffffffffffff';
 const _dangerouslyFetchMessagesRequiringSchemaUpgradeWithoutIndex =
-  async ({ Backbone, count, lastIndex } = {}) => {
-    if (!isObject(Backbone)) {
-      throw new TypeError('"Backbone" is required');
+  ({ connection, count, lastIndex } = {}) => {
+    if (!isObject(connection)) {
+      throw new TypeError('"connection" is required');
     }
 
     if (!isNumber(count)) {
@@ -134,17 +212,112 @@ const _dangerouslyFetchMessagesRequiringSchemaUpgradeWithoutIndex =
       throw new TypeError('"lastIndex" must be a string');
     }
 
-    const storeName = 'messages';
-    const collection =
-      Migrations0DatabaseWithAttachmentData.createCollection({ Backbone, storeName });
+    const hasLastIndex = Boolean(lastIndex);
 
-    const range = lastIndex ? [lastIndex, MAX_MESSAGE_KEY] : null;
-    await deferredToPromise(collection.fetch({
-      limit: count,
-      range,
-    }));
+    const transaction = connection.transaction(MESSAGES_STORE_NAME, 'readonly');
+    const messagesStore = transaction.objectStore(MESSAGES_STORE_NAME);
 
-    const models = collection.models || [];
-    const messages = models.map(model => model.toJSON());
-    return messages;
+    const excludeLowerBound = true;
+    const query = hasLastIndex
+      ? IDBKeyRange.lowerBound(lastIndex, excludeLowerBound)
+      : undefined;
+    const request = messagesStore.getAll(query, count);
+    return new Promise((resolve, reject) => {
+      request.onsuccess = event =>
+        resolve(event.target.result);
+      request.onerror = event =>
+        reject(event.target.error);
+    });
   };
+
+const openDatabase = (name, version) => {
+  const request = window.indexedDB.open(name, version);
+  return new Promise((resolve, reject) => {
+    request.onblocked = () =>
+      reject(new Error('Database blocked'));
+
+    request.onupgradeneeded = event =>
+      reject(new Error('Unexpected database upgrade required:' +
+        `oldVersion: ${event.oldVersion}, newVersion: ${event.newVersion}`));
+
+    request.onerror = event =>
+      reject(event.target.error);
+
+    request.onsuccess = (event) => {
+      const connection = event.target.result;
+      resolve(connection);
+    };
+  });
+};
+
+const LAST_PROCESSED_INDEX_KEY = 'attachmentMigration_lastProcessedIndex';
+const IS_MIGRATION_COMPLETE_KEY = 'attachmentMigration_isComplete';
+
+const getLastProcessedIndex = connection =>
+  getItem(connection, LAST_PROCESSED_INDEX_KEY);
+
+const setLastProcessedIndex = (connection, value) =>
+  setItem(connection, LAST_PROCESSED_INDEX_KEY, value);
+
+const isMigrationComplete = async (connection) => {
+  const value = await getItem(connection, IS_MIGRATION_COMPLETE_KEY);
+  return Boolean(value);
+};
+
+const markMigrationComplete = connection =>
+  setItem(connection, IS_MIGRATION_COMPLETE_KEY, true);
+
+const getItem = (connection, key) => {
+  if (!isObject(connection)) {
+    throw new TypeError('"connection" is required');
+  }
+
+  if (!isString(key)) {
+    throw new TypeError('"key" must be a string');
+  }
+
+  const transaction = connection.transaction(ITEMS_STORE_NAME, 'readonly');
+  const itemsStore = transaction.objectStore(ITEMS_STORE_NAME);
+  const request = itemsStore.get(key);
+  return new Promise((resolve, reject) => {
+    request.onerror = event =>
+      reject(event.target.error);
+
+    request.onsuccess = event =>
+      resolve(event.target.result);
+  });
+};
+
+const setItem = (connection, key, value) => {
+  if (!isObject(connection)) {
+    throw new TypeError('"connection" is required');
+  }
+
+  if (!isString(key)) {
+    throw new TypeError('"key" must be a string');
+  }
+
+  const transaction = connection.transaction(ITEMS_STORE_NAME, 'readwrite');
+  const itemsStore = transaction.objectStore(ITEMS_STORE_NAME);
+  const request = itemsStore.put(value, key);
+  return new Promise((resolve, reject) => {
+    request.onerror = event =>
+      reject(event.target.error);
+
+    request.onsuccess = () =>
+      resolve();
+  });
+};
+
+const completeTransaction = transaction =>
+  new Promise((resolve, reject) => {
+    // eslint-disable-next-line no-param-reassign
+    transaction.onabort = event =>
+      reject(event.target.error);
+    // eslint-disable-next-line no-param-reassign
+    transaction.onerror = event =>
+      reject(event.target.error);
+    // eslint-disable-next-line no-param-reassign
+    transaction.oncomplete = () =>
+      resolve();
+  });

From 7de7fcf56147a2a125b009984e2b399b8c3cacde Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Tue, 27 Mar 2018 12:13:25 -0400
Subject: [PATCH 17/56] Avoid `no-param-reassign` violation

---
 js/modules/messages_data_migrator.js | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index 1ba211e0f..7b07ad03c 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -311,13 +311,7 @@ const setItem = (connection, key, value) => {
 
 const completeTransaction = transaction =>
   new Promise((resolve, reject) => {
-    // eslint-disable-next-line no-param-reassign
-    transaction.onabort = event =>
-      reject(event.target.error);
-    // eslint-disable-next-line no-param-reassign
-    transaction.onerror = event =>
-      reject(event.target.error);
-    // eslint-disable-next-line no-param-reassign
-    transaction.oncomplete = () =>
-      resolve();
+    transaction.addEventListener('abort', event => reject(event.target.error));
+    transaction.addEventListener('error', event => reject(event.target.error));
+    transaction.addEventListener('complete', () => resolve());
   });

From 85788d3c4a1de1c866314ede9952258c891e9700 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Tue, 27 Mar 2018 12:13:46 -0400
Subject: [PATCH 18/56] Match `items` storage format to Backbone adapter

---
 js/modules/messages_data_migrator.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index 7b07ad03c..047243b71 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -97,7 +97,7 @@ exports.processAll = async ({
   let unprocessedMessages = [];
   do {
     // eslint-disable-next-line no-await-in-loop
-    const lastProcessedIndex = (await getLastProcessedIndex(connection)) || null;
+    const lastProcessedIndex = await getLastProcessedIndex(connection);
 
     const fetchUnprocessedMessagesStartTime = Date.now();
     unprocessedMessages =
@@ -284,7 +284,7 @@ const getItem = (connection, key) => {
       reject(event.target.error);
 
     request.onsuccess = event =>
-      resolve(event.target.result);
+      resolve(event.target.result ? event.target.result.value : null);
   });
 };
 
@@ -299,7 +299,7 @@ const setItem = (connection, key, value) => {
 
   const transaction = connection.transaction(ITEMS_STORE_NAME, 'readwrite');
   const itemsStore = transaction.objectStore(ITEMS_STORE_NAME);
-  const request = itemsStore.put(value, key);
+  const request = itemsStore.put({id: key, value}, key);
   return new Promise((resolve, reject) => {
     request.onerror = event =>
       reject(event.target.error);

From 3c57dbfb567ba084f3faf8312a04b7257aa2aa70 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Tue, 27 Mar 2018 12:15:14 -0400
Subject: [PATCH 19/56] Extract `NUM_MESSAGES_PER_BATCH`

---
 js/modules/messages_data_migrator.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index 047243b71..50508c3d3 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -15,6 +15,7 @@ const DATABASE_NAME = 'signal';
 const EXPECTED_DATABASE_VERSION = 17;
 const MESSAGES_STORE_NAME = 'messages';
 const ITEMS_STORE_NAME = 'items';
+const NUM_MESSAGES_PER_BATCH = 50;
 
 exports.processNext = async ({
   BackboneMessage,
@@ -104,7 +105,7 @@ exports.processAll = async ({
       // eslint-disable-next-line no-await-in-loop
       await _dangerouslyFetchMessagesRequiringSchemaUpgradeWithoutIndex({
         connection,
-        count: 10,
+        count: NUM_MESSAGES_PER_BATCH,
         lastIndex: lastProcessedIndex,
       });
     const fetchDuration = Date.now() - fetchUnprocessedMessagesStartTime;

From 3e2d575506af019773adf67546a2a1c8fcabcad0 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Tue, 27 Mar 2018 12:19:40 -0400
Subject: [PATCH 20/56] Document `MessageDataMigrator` module design

---
 js/modules/messages_data_migrator.js | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index 50508c3d3..8142922be 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -1,5 +1,12 @@
 /* eslint-env browser */
 
+// Module to upgrade the schema of messages, e.g. migrate attachments to disk.
+// `processAll` is meant to be run after the initial database migrations
+// (12 – 17) and purposely doesn’t rely on our Backbone IndexedDB adapter to
+// prevent subsequent migrations to run (18+) but rather uses direct IndexedDB
+// access. This includes avoiding usage of `storage` module which uses Backbone
+// under the hood.
+
 const isFunction = require('lodash/isFunction');
 const isNumber = require('lodash/isNumber');
 const isObject = require('lodash/isObject');

From 8966e802848cd1149361b0829946c8ea1c052e18 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Tue, 27 Mar 2018 12:19:55 -0400
Subject: [PATCH 21/56] Improve identifier names

---
 js/modules/messages_data_migrator.js | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index 8142922be..9587d0300 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -49,20 +49,20 @@ exports.processNext = async ({
 
   const startTime = Date.now();
 
-  const startFetchTime = Date.now();
+  const fetchStartTime = Date.now();
   const messagesRequiringSchemaUpgrade =
     await _fetchMessagesRequiringSchemaUpgrade({ BackboneMessageCollection, count });
-  const fetchDuration = Date.now() - startFetchTime;
+  const fetchDuration = Date.now() - fetchStartTime;
 
-  const startUpgradeTime = Date.now();
+  const upgradeStartTime = Date.now();
   const upgradedMessages =
     await Promise.all(messagesRequiringSchemaUpgrade.map(upgradeMessageSchema));
-  const upgradeDuration = Date.now() - startUpgradeTime;
+  const upgradeDuration = Date.now() - upgradeStartTime;
 
-  const startSaveTime = Date.now();
+  const saveStartTime = Date.now();
   const saveMessage = _saveMessageBackbone({ BackboneMessage });
   await Promise.all(upgradedMessages.map(saveMessage));
-  const saveDuration = Date.now() - startSaveTime;
+  const saveDuration = Date.now() - saveStartTime;
 
   const totalDuration = Date.now() - startTime;
   const numProcessed = messagesRequiringSchemaUpgrade.length;

From d5d0eabdfda2f1945f643606c9467fbbca87f259 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Tue, 27 Mar 2018 12:20:07 -0400
Subject: [PATCH 22/56] Remove usage of `storage` module

---
 js/background.js                     |  2 +-
 js/modules/messages_data_migrator.js | 10 +---------
 2 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/js/background.js b/js/background.js
index dce1de980..a81311790 100644
--- a/js/background.js
+++ b/js/background.js
@@ -89,7 +89,7 @@
   await Migrations0DatabaseWithAttachmentData.run({ Backbone });
 
   console.log('Migrate attachments to disk');
-  await MessageDataMigrator.processAll({ Backbone, storage, upgradeMessageSchema });
+  await MessageDataMigrator.processAll({ Backbone, upgradeMessageSchema });
 
   console.log('Migrate database without attachments');
   await Migrations1DatabaseWithoutAttachmentData.run({
diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index 9587d0300..165905bc2 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -77,19 +77,11 @@ exports.processNext = async ({
   };
 };
 
-exports.processAll = async ({
-  Backbone,
-  storage,
-  upgradeMessageSchema,
-} = {}) => {
+exports.processAll = async ({ Backbone, upgradeMessageSchema } = {}) => {
   if (!isObject(Backbone)) {
     throw new TypeError('"Backbone" is required');
   }
 
-  if (!isObject(storage)) {
-    throw new TypeError('"storage" is required');
-  }
-
   if (!isFunction(upgradeMessageSchema)) {
     throw new TypeError('"upgradeMessageSchema" is required');
   }

From 85490fbc98c88fbb477b3809f63f88e689c6f1ac Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 10:10:09 -0400
Subject: [PATCH 23/56] Disable JSHint for `background.js`
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

It doesn’t recognize `async` and I couldn’t figure out how to ignore a top-level
`async` without cascading errors.
---
 Gruntfile.js     | 1 +
 js/background.js | 7 +------
 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/Gruntfile.js b/Gruntfile.js
index 78cba0c41..ed99860fe 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -97,6 +97,7 @@ module.exports = function(grunt) {
       files: [
         'Gruntfile.js',
         'js/**/*.js',
+        '!js/background.js',
         '!js/jquery.js',
         '!js/libtextsecure.js',
         '!js/WebAudioRecorderMp3.js',
diff --git a/js/background.js b/js/background.js
index a81311790..1e09efa44 100644
--- a/js/background.js
+++ b/js/background.js
@@ -11,8 +11,7 @@
 /* global Whisper: false */
 /* global wrapDeferred: false */
 
-
-;(/* jshint ignore:start */ async /* jshint ignore:end */function() {
+;(async function() {
     'use strict';
 
     const { IdleDetector, MessageDataMigrator } = Signal.Workflow;
@@ -81,7 +80,6 @@
     };
 
   /* eslint-enable */
-  /* jshint ignore:start */
   const cancelInitializationMessage = Views.Initialization.setMessage();
   console.log('Start IndexedDB migrations');
 
@@ -115,7 +113,6 @@
       idleDetector.stop();
     }
   });
-  /* jshint ignore:end */
   /* eslint-disable */
 
     // We need this 'first' check because we don't want to start the app up any other time
@@ -575,7 +572,6 @@
     }
 
   /* eslint-enable */
-  /* jshint ignore:start */
 
   // Descriptors
   const getGroupDescriptor = group => ({
@@ -684,7 +680,6 @@
     getMessageDescriptor: getDescriptorForSent,
     createMessage: createSentMessage,
   });
-  /* jshint ignore:end */
   /* eslint-disable */
 
     function isMessageDuplicate(message) {

From 1df6dc8378a26fd85a03653595cf91eca493a45b Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 10:10:45 -0400
Subject: [PATCH 24/56] Abort processing if there are no more messages

---
 js/modules/messages_data_migrator.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index 165905bc2..c00c27b6c 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -110,6 +110,10 @@ exports.processAll = async ({ Backbone, upgradeMessageSchema } = {}) => {
     const fetchDuration = Date.now() - fetchUnprocessedMessagesStartTime;
     const numUnprocessedMessages = unprocessedMessages.length;
 
+    if (numUnprocessedMessages === 0) {
+      break;
+    }
+
     const upgradeStartTime = Date.now();
     const upgradedMessages =
       // eslint-disable-next-line no-await-in-loop

From eca930770c0287b3094a318dcb4943f339cfd7fa Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 10:23:36 -0400
Subject: [PATCH 25/56] Remove hard-coded database connection settings

---
 js/background.js                              |  8 ++++-
 js/modules/messages_data_migrator.js          | 29 ++++++++++++-------
 ...rations_0_database_with_attachment_data.js |  6 ++++
 3 files changed, 32 insertions(+), 11 deletions(-)

diff --git a/js/background.js b/js/background.js
index 1e09efa44..e287db1c0 100644
--- a/js/background.js
+++ b/js/background.js
@@ -87,7 +87,13 @@
   await Migrations0DatabaseWithAttachmentData.run({ Backbone });
 
   console.log('Migrate attachments to disk');
-  await MessageDataMigrator.processAll({ Backbone, upgradeMessageSchema });
+  const database = Migrations0DatabaseWithAttachmentData.getDatabase();
+  await MessageDataMigrator.processAll({
+    Backbone,
+    databaseName: database.name,
+    databaseVersion: database.version,
+    upgradeMessageSchema,
+  });
 
   console.log('Migrate database without attachments');
   await Migrations1DatabaseWithoutAttachmentData.run({
diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index c00c27b6c..c240e7f2d 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -1,11 +1,10 @@
 /* eslint-env browser */
 
 // Module to upgrade the schema of messages, e.g. migrate attachments to disk.
-// `processAll` is meant to be run after the initial database migrations
-// (12 – 17) and purposely doesn’t rely on our Backbone IndexedDB adapter to
-// prevent subsequent migrations to run (18+) but rather uses direct IndexedDB
-// access. This includes avoiding usage of `storage` module which uses Backbone
-// under the hood.
+// `processAll` purposely doesn’t rely on our Backbone IndexedDB adapter to
+// prevent automatic migrations. Rather, it uses direct IndexedDB access.
+// This includes avoiding usage of `storage` module which uses Backbone under
+// the hood.
 
 const isFunction = require('lodash/isFunction');
 const isNumber = require('lodash/isNumber');
@@ -17,9 +16,6 @@ const Message = require('./types/message');
 const { deferredToPromise } = require('./deferred_to_promise');
 
 
-const DATABASE_NAME = 'signal';
-// Last version with attachment data stored in database:
-const EXPECTED_DATABASE_VERSION = 17;
 const MESSAGES_STORE_NAME = 'messages';
 const ITEMS_STORE_NAME = 'items';
 const NUM_MESSAGES_PER_BATCH = 50;
@@ -77,16 +73,29 @@ exports.processNext = async ({
   };
 };
 
-exports.processAll = async ({ Backbone, upgradeMessageSchema } = {}) => {
+exports.processAll = async ({
+    Backbone,
+    databaseName,
+    databaseVersion,
+    upgradeMessageSchema,
+  } = {}) => {
   if (!isObject(Backbone)) {
     throw new TypeError('"Backbone" is required');
   }
 
+  if (!isString(databaseName)) {
+    throw new TypeError('"databaseName" must be a string');
+  }
+
+  if (!isNumber(databaseVersion)) {
+    throw new TypeError('"databaseVersion" must be a number');
+  }
+
   if (!isFunction(upgradeMessageSchema)) {
     throw new TypeError('"upgradeMessageSchema" is required');
   }
 
-  const connection = await openDatabase(DATABASE_NAME, EXPECTED_DATABASE_VERSION);
+  const connection = await openDatabase(databaseName, databaseVersion);
   const isComplete = await isMigrationComplete(connection);
   console.log('Is attachment migration complete?', isComplete);
   if (isComplete) {
diff --git a/js/modules/migrations/migrations_0_database_with_attachment_data.js b/js/modules/migrations/migrations_0_database_with_attachment_data.js
index e00f71870..02cd097ff 100644
--- a/js/modules/migrations/migrations_0_database_with_attachment_data.js
+++ b/js/modules/migrations/migrations_0_database_with_attachment_data.js
@@ -1,6 +1,7 @@
 const isFunction = require('lodash/isFunction');
 const isObject = require('lodash/isObject');
 const isString = require('lodash/isString');
+const last = require('lodash/last');
 
 const { runMigrations } = require('./run_migrations');
 
@@ -169,3 +170,8 @@ exports.createCollection = ({ Backbone, storeName }) => {
 
   return collection;
 };
+
+exports.getDatabase = () => ({
+  name: database.id,
+  version: last(migrations).version,
+});

From f7f24b5822ab039faba6c57edee9833496a0b261 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 10:24:07 -0400
Subject: [PATCH 26/56] Log total number of processed messages

---
 js/modules/messages_data_migrator.js | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index c240e7f2d..2fa04573f 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -104,6 +104,7 @@ exports.processAll = async ({
 
   const migrationStartTime = Date.now();
   let unprocessedMessages = [];
+  let totalMessagesProcessed = 0;
   do {
     // eslint-disable-next-line no-await-in-loop
     const lastProcessedIndex = await getLastProcessedIndex(connection);
@@ -147,9 +148,11 @@ exports.processAll = async ({
       await setLastProcessedIndex(connection, newLastProcessedIndex);
     }
 
-    console.log('Upgrade message schema on startup:', {
+    totalMessagesProcessed += numUnprocessedMessages;
+    console.log('Upgrade message schema:', {
       lastProcessedIndex,
       numUnprocessedMessages,
+      numCumulativeMessagesProcessed: totalMessagesProcessed,
       fetchDuration,
       saveDuration,
       upgradeDuration,
@@ -161,7 +164,10 @@ exports.processAll = async ({
   connection.close();
 
   const totalDuration = Date.now() - migrationStartTime;
-  console.log('Attachment migration complete:', { totalDuration });
+  console.log('Attachment migration complete:', {
+    totalDuration,
+    totalMessagesProcessed,
+  });
 };
 
 const _saveMessageBackbone = ({ BackboneMessage } = {}) => (message) => {

From ce5b450fdbab4c0d6050099d33a6ac91755527bd Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 10:24:49 -0400
Subject: [PATCH 27/56] Log `targetSchemaVersion`

---
 js/modules/messages_data_migrator.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index 2fa04573f..70268ce06 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -157,6 +157,7 @@ exports.processAll = async ({
       saveDuration,
       upgradeDuration,
       newLastProcessedIndex,
+      targetSchemaVersion: Message.CURRENT_SCHEMA_VERSION,
     });
   } while (unprocessedMessages.length > 0);
 

From 3720c3f3bbeeb55eec5f2885c598e74862c4c866 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 10:25:22 -0400
Subject: [PATCH 28/56] Improve log message

---
 js/modules/messages_data_migrator.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index 70268ce06..86bebcf36 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -97,7 +97,7 @@ exports.processAll = async ({
 
   const connection = await openDatabase(databaseName, databaseVersion);
   const isComplete = await isMigrationComplete(connection);
-  console.log('Is attachment migration complete?', isComplete);
+  console.log('Attachment migration status:', isComplete ? 'complete' : 'incomplete');
   if (isComplete) {
     return;
   }

From 4ff8bc3357254cc491fafe3e687d046750cb222c Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 10:37:11 -0400
Subject: [PATCH 29/56] Use `camelCase` for non-constructors

---
 js/background.js                                               | 2 +-
 .../migrations_1_database_without_attachment_data.js           | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/js/background.js b/js/background.js
index e287db1c0..991414f06 100644
--- a/js/background.js
+++ b/js/background.js
@@ -98,7 +98,7 @@
   console.log('Migrate database without attachments');
   await Migrations1DatabaseWithoutAttachmentData.run({
     Backbone,
-    Database: Whisper.Database,
+    database: Whisper.Database,
   });
 
   console.log('Storage fetch');
diff --git a/js/modules/migrations/migrations_1_database_without_attachment_data.js b/js/modules/migrations/migrations_1_database_without_attachment_data.js
index 2b7c010c4..b10106ef2 100644
--- a/js/modules/migrations/migrations_1_database_without_attachment_data.js
+++ b/js/modules/migrations/migrations_1_database_without_attachment_data.js
@@ -12,5 +12,4 @@ exports.migrations = [
   },
 ];
 
-exports.run = ({ Backbone, Database } = {}) =>
-  runMigrations({ Backbone, database: Database });
+exports.run = runMigrations;

From f50e9ae364023481461869839c09498d71d55f17 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 10:37:21 -0400
Subject: [PATCH 30/56] Log closing connection of database

---
 js/modules/messages_data_migrator.js | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index 86bebcf36..f5d3301df 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -162,6 +162,8 @@ exports.processAll = async ({
   } while (unprocessedMessages.length > 0);
 
   await markMigrationComplete(connection);
+
+  console.log('Close database connection');
   connection.close();
 
   const totalDuration = Date.now() - migrationStartTime;

From 5bea894abda85ffe4b3ca809a6c77ad0e82e5619 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 10:38:05 -0400
Subject: [PATCH 31/56] Close database connection via Backbone IDB adapter

---
 js/modules/migrations/run_migrations.js | 24 ++++--------------------
 1 file changed, 4 insertions(+), 20 deletions(-)

diff --git a/js/modules/migrations/run_migrations.js b/js/modules/migrations/run_migrations.js
index 992895373..af1c70af8 100644
--- a/js/modules/migrations/run_migrations.js
+++ b/js/modules/migrations/run_migrations.js
@@ -7,25 +7,8 @@ const isString = require('lodash/isString');
 const { deferredToPromise } = require('../deferred_to_promise');
 
 
-const closeDatabase = name =>
-  new Promise((resolve, reject) => {
-    const request = window.indexedDB.open(name);
-    request.onblocked = () => {
-      reject(new Error(`Database '${name}' blocked`));
-    };
-    request.onupgradeneeded = (event) => {
-      reject(new Error('Unexpected database upgraded needed:' +
-        ` oldVersion: ${event.oldVersion}, newVersion: ${event.newVersion}`));
-    };
-    request.onerror = (event) => {
-      reject(event.target.error);
-    };
-    request.onsuccess = (event) => {
-      const connection = event.target.result;
-      connection.close();
-      resolve();
-    };
-  });
+const closeDatabase = ({ Backbone } = {}) =>
+  deferredToPromise(Backbone.sync('closeall'))
 
 exports.runMigrations = async ({ Backbone, database } = {}) => {
   if (!isObject(Backbone) || !isObject(Backbone.Collection) ||
@@ -44,5 +27,6 @@ exports.runMigrations = async ({ Backbone, database } = {}) => {
   }))();
 
   await deferredToPromise(migrationCollection.fetch({ limit: 1 }));
-  await closeDatabase(database.id);
+  console.log('Close database connection');
+  await closeDatabase({ Backbone });
 };

From 016432826bec416da6cea886ff53f6eddf94918c Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 10:54:01 -0400
Subject: [PATCH 32/56] Extract `database` and `settings` modules

---
 js/modules/database.js                  |  33 +++++++
 js/modules/messages_data_migrator.js    | 121 ++++--------------------
 js/modules/migrations/run_migrations.js |   2 +-
 js/modules/settings.js                  |  63 ++++++++++++
 4 files changed, 117 insertions(+), 102 deletions(-)
 create mode 100644 js/modules/database.js
 create mode 100644 js/modules/settings.js

diff --git a/js/modules/database.js b/js/modules/database.js
new file mode 100644
index 000000000..c287d5109
--- /dev/null
+++ b/js/modules/database.js
@@ -0,0 +1,33 @@
+/* global indexedDB */
+
+// Module for interacting with IndexedDB without Backbone IndexedDB adapter
+// and using promises. Revisit use of `idb` dependency as it might cover
+// this functionality.
+
+exports.open = (name, version) => {
+  const request = indexedDB.open(name, version);
+  return new Promise((resolve, reject) => {
+    request.onblocked = () =>
+      reject(new Error('Database blocked'));
+
+    request.onupgradeneeded = event =>
+      reject(new Error('Unexpected database upgrade required:' +
+        `oldVersion: ${event.oldVersion}, newVersion: ${event.newVersion}`));
+
+    request.onerror = event =>
+      reject(event.target.error);
+
+    request.onsuccess = (event) => {
+      const connection = event.target.result;
+      resolve(connection);
+    };
+  });
+};
+
+exports.completeTransaction = transaction =>
+  new Promise((resolve, reject) => {
+    transaction.addEventListener('abort', event => reject(event.target.error));
+    transaction.addEventListener('error', event => reject(event.target.error));
+    transaction.addEventListener('complete', () => resolve());
+  });
+
diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index f5d3301df..e554d7208 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -1,23 +1,24 @@
-/* eslint-env browser */
-
 // Module to upgrade the schema of messages, e.g. migrate attachments to disk.
 // `processAll` purposely doesn’t rely on our Backbone IndexedDB adapter to
 // prevent automatic migrations. Rather, it uses direct IndexedDB access.
 // This includes avoiding usage of `storage` module which uses Backbone under
 // the hood.
 
+/* global IDBKeyRange */
+
 const isFunction = require('lodash/isFunction');
 const isNumber = require('lodash/isNumber');
 const isObject = require('lodash/isObject');
 const isString = require('lodash/isString');
 const last = require('lodash/last');
 
+const database = require('./database');
 const Message = require('./types/message');
+const settings = require('./settings');
 const { deferredToPromise } = require('./deferred_to_promise');
 
 
 const MESSAGES_STORE_NAME = 'messages';
-const ITEMS_STORE_NAME = 'items';
 const NUM_MESSAGES_PER_BATCH = 50;
 
 exports.processNext = async ({
@@ -74,11 +75,11 @@ exports.processNext = async ({
 };
 
 exports.processAll = async ({
-    Backbone,
-    databaseName,
-    databaseVersion,
-    upgradeMessageSchema,
-  } = {}) => {
+  Backbone,
+  databaseName,
+  databaseVersion,
+  upgradeMessageSchema,
+} = {}) => {
   if (!isObject(Backbone)) {
     throw new TypeError('"Backbone" is required');
   }
@@ -95,8 +96,8 @@ exports.processAll = async ({
     throw new TypeError('"upgradeMessageSchema" is required');
   }
 
-  const connection = await openDatabase(databaseName, databaseVersion);
-  const isComplete = await isMigrationComplete(connection);
+  const connection = await database.open(databaseName, databaseVersion);
+  const isComplete = await settings.isAttachmentMigrationComplete(connection);
   console.log('Attachment migration status:', isComplete ? 'complete' : 'incomplete');
   if (isComplete) {
     return;
@@ -106,8 +107,9 @@ exports.processAll = async ({
   let unprocessedMessages = [];
   let totalMessagesProcessed = 0;
   do {
-    // eslint-disable-next-line no-await-in-loop
-    const lastProcessedIndex = await getLastProcessedIndex(connection);
+    const lastProcessedIndex =
+      // eslint-disable-next-line no-await-in-loop
+      await settings.getAttachmentMigrationLastProcessedIndex(connection);
 
     const fetchUnprocessedMessagesStartTime = Date.now();
     unprocessedMessages =
@@ -132,7 +134,7 @@ exports.processAll = async ({
 
     const saveMessagesStartTime = Date.now();
     const transaction = connection.transaction(MESSAGES_STORE_NAME, 'readwrite');
-    const transactionCompletion = completeTransaction(transaction);
+    const transactionCompletion = database.completeTransaction(transaction);
     // eslint-disable-next-line no-await-in-loop
     await Promise.all(upgradedMessages.map(_saveMessage({ transaction })));
     // eslint-disable-next-line no-await-in-loop
@@ -145,7 +147,10 @@ exports.processAll = async ({
     const newLastProcessedIndex = lastMessage ? lastMessage.id : null;
     if (newLastProcessedIndex) {
       // eslint-disable-next-line no-await-in-loop
-      await setLastProcessedIndex(connection, newLastProcessedIndex);
+      await settings.setAttachmentMigrationLastProcessedIndex(
+        connection,
+        newLastProcessedIndex
+      );
     }
 
     totalMessagesProcessed += numUnprocessedMessages;
@@ -161,7 +166,7 @@ exports.processAll = async ({
     });
   } while (unprocessedMessages.length > 0);
 
-  await markMigrationComplete(connection);
+  await settings.markAttachmentMigrationComplete(connection);
 
   console.log('Close database connection');
   connection.close();
@@ -251,89 +256,3 @@ const _dangerouslyFetchMessagesRequiringSchemaUpgradeWithoutIndex =
         reject(event.target.error);
     });
   };
-
-const openDatabase = (name, version) => {
-  const request = window.indexedDB.open(name, version);
-  return new Promise((resolve, reject) => {
-    request.onblocked = () =>
-      reject(new Error('Database blocked'));
-
-    request.onupgradeneeded = event =>
-      reject(new Error('Unexpected database upgrade required:' +
-        `oldVersion: ${event.oldVersion}, newVersion: ${event.newVersion}`));
-
-    request.onerror = event =>
-      reject(event.target.error);
-
-    request.onsuccess = (event) => {
-      const connection = event.target.result;
-      resolve(connection);
-    };
-  });
-};
-
-const LAST_PROCESSED_INDEX_KEY = 'attachmentMigration_lastProcessedIndex';
-const IS_MIGRATION_COMPLETE_KEY = 'attachmentMigration_isComplete';
-
-const getLastProcessedIndex = connection =>
-  getItem(connection, LAST_PROCESSED_INDEX_KEY);
-
-const setLastProcessedIndex = (connection, value) =>
-  setItem(connection, LAST_PROCESSED_INDEX_KEY, value);
-
-const isMigrationComplete = async (connection) => {
-  const value = await getItem(connection, IS_MIGRATION_COMPLETE_KEY);
-  return Boolean(value);
-};
-
-const markMigrationComplete = connection =>
-  setItem(connection, IS_MIGRATION_COMPLETE_KEY, true);
-
-const getItem = (connection, key) => {
-  if (!isObject(connection)) {
-    throw new TypeError('"connection" is required');
-  }
-
-  if (!isString(key)) {
-    throw new TypeError('"key" must be a string');
-  }
-
-  const transaction = connection.transaction(ITEMS_STORE_NAME, 'readonly');
-  const itemsStore = transaction.objectStore(ITEMS_STORE_NAME);
-  const request = itemsStore.get(key);
-  return new Promise((resolve, reject) => {
-    request.onerror = event =>
-      reject(event.target.error);
-
-    request.onsuccess = event =>
-      resolve(event.target.result ? event.target.result.value : null);
-  });
-};
-
-const setItem = (connection, key, value) => {
-  if (!isObject(connection)) {
-    throw new TypeError('"connection" is required');
-  }
-
-  if (!isString(key)) {
-    throw new TypeError('"key" must be a string');
-  }
-
-  const transaction = connection.transaction(ITEMS_STORE_NAME, 'readwrite');
-  const itemsStore = transaction.objectStore(ITEMS_STORE_NAME);
-  const request = itemsStore.put({id: key, value}, key);
-  return new Promise((resolve, reject) => {
-    request.onerror = event =>
-      reject(event.target.error);
-
-    request.onsuccess = () =>
-      resolve();
-  });
-};
-
-const completeTransaction = transaction =>
-  new Promise((resolve, reject) => {
-    transaction.addEventListener('abort', event => reject(event.target.error));
-    transaction.addEventListener('error', event => reject(event.target.error));
-    transaction.addEventListener('complete', () => resolve());
-  });
diff --git a/js/modules/migrations/run_migrations.js b/js/modules/migrations/run_migrations.js
index af1c70af8..948d1802d 100644
--- a/js/modules/migrations/run_migrations.js
+++ b/js/modules/migrations/run_migrations.js
@@ -8,7 +8,7 @@ const { deferredToPromise } = require('../deferred_to_promise');
 
 
 const closeDatabase = ({ Backbone } = {}) =>
-  deferredToPromise(Backbone.sync('closeall'))
+  deferredToPromise(Backbone.sync('closeall'));
 
 exports.runMigrations = async ({ Backbone, database } = {}) => {
   if (!isObject(Backbone) || !isObject(Backbone.Collection) ||
diff --git a/js/modules/settings.js b/js/modules/settings.js
new file mode 100644
index 000000000..9d1cc018e
--- /dev/null
+++ b/js/modules/settings.js
@@ -0,0 +1,63 @@
+const isObject = require('lodash/isObject');
+const isString = require('lodash/isString');
+
+
+const ITEMS_STORE_NAME = 'items';
+const LAST_PROCESSED_INDEX_KEY = 'attachmentMigration_lastProcessedIndex';
+const IS_MIGRATION_COMPLETE_KEY = 'attachmentMigration_isComplete';
+
+// Public API
+exports.getAttachmentMigrationLastProcessedIndex = connection =>
+  getItem(connection, LAST_PROCESSED_INDEX_KEY);
+
+exports.setAttachmentMigrationLastProcessedIndex = (connection, value) =>
+  setItem(connection, LAST_PROCESSED_INDEX_KEY, value);
+
+exports.isAttachmentMigrationComplete = async connection =>
+  Boolean(await getItem(connection, IS_MIGRATION_COMPLETE_KEY));
+
+exports.markAttachmentMigrationComplete = connection =>
+  setItem(connection, IS_MIGRATION_COMPLETE_KEY, true);
+
+// Private API
+const getItem = (connection, key) => {
+  if (!isObject(connection)) {
+    throw new TypeError('"connection" is required');
+  }
+
+  if (!isString(key)) {
+    throw new TypeError('"key" must be a string');
+  }
+
+  const transaction = connection.transaction(ITEMS_STORE_NAME, 'readonly');
+  const itemsStore = transaction.objectStore(ITEMS_STORE_NAME);
+  const request = itemsStore.get(key);
+  return new Promise((resolve, reject) => {
+    request.onerror = event =>
+      reject(event.target.error);
+
+    request.onsuccess = event =>
+      resolve(event.target.result ? event.target.result.value : null);
+  });
+};
+
+const setItem = (connection, key, value) => {
+  if (!isObject(connection)) {
+    throw new TypeError('"connection" is required');
+  }
+
+  if (!isString(key)) {
+    throw new TypeError('"key" must be a string');
+  }
+
+  const transaction = connection.transaction(ITEMS_STORE_NAME, 'readwrite');
+  const itemsStore = transaction.objectStore(ITEMS_STORE_NAME);
+  const request = itemsStore.put({ id: key, value }, key);
+  return new Promise((resolve, reject) => {
+    request.onerror = event =>
+      reject(event.target.error);
+
+    request.onsuccess = () =>
+      resolve();
+  });
+};

From 6aea36240d52ae412ab2e396f3570603d03550dd Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 13:00:52 -0400
Subject: [PATCH 33/56] Rename `closeDatabase` to `closeDatabaseConnection`

---
 js/modules/migrations/run_migrations.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/js/modules/migrations/run_migrations.js b/js/modules/migrations/run_migrations.js
index 948d1802d..ac130d847 100644
--- a/js/modules/migrations/run_migrations.js
+++ b/js/modules/migrations/run_migrations.js
@@ -7,7 +7,7 @@ const isString = require('lodash/isString');
 const { deferredToPromise } = require('../deferred_to_promise');
 
 
-const closeDatabase = ({ Backbone } = {}) =>
+const closeDatabaseConnection = ({ Backbone } = {}) =>
   deferredToPromise(Backbone.sync('closeall'));
 
 exports.runMigrations = async ({ Backbone, database } = {}) => {
@@ -28,5 +28,5 @@ exports.runMigrations = async ({ Backbone, database } = {}) => {
 
   await deferredToPromise(migrationCollection.fetch({ limit: 1 }));
   console.log('Close database connection');
-  await closeDatabase({ Backbone });
+  await closeDatabaseConnection({ Backbone });
 };

From c5c94bc3ab0deb8a6848d93943287f10f4bd1948 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 13:05:49 -0400
Subject: [PATCH 34/56] Extract `getMigrationVersions`

---
 js/modules/migrations/run_migrations.js | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/js/modules/migrations/run_migrations.js b/js/modules/migrations/run_migrations.js
index ac130d847..84635542a 100644
--- a/js/modules/migrations/run_migrations.js
+++ b/js/modules/migrations/run_migrations.js
@@ -3,6 +3,8 @@
 const isFunction = require('lodash/isFunction');
 const isObject = require('lodash/isObject');
 const isString = require('lodash/isString');
+const head = require('lodash/head');
+const last = require('lodash/last');
 
 const { deferredToPromise } = require('../deferred_to_promise');
 
@@ -30,3 +32,17 @@ exports.runMigrations = async ({ Backbone, database } = {}) => {
   console.log('Close database connection');
   await closeDatabaseConnection({ Backbone });
 };
+
+const getMigrationVersions = (database) => {
+  if (!isObject(database) || !Array.isArray(database.migrations)) {
+    throw new TypeError('"database" is required');
+  }
+
+  const firstMigration = head(database.migrations);
+  const lastMigration = last(database.migrations);
+
+  const firstVersion = firstMigration ? parseInt(firstMigration.version, 10) : null;
+  const lastVersion = lastMigration ? parseInt(lastMigration.version, 10) : null;
+
+  return { firstVersion, lastVersion };
+};

From 417511ffd2785ef7bcc43bd6361a98c7af1d0a88 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 13:09:09 -0400
Subject: [PATCH 35/56] Add `database.getVersion`

---
 js/modules/database.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/js/modules/database.js b/js/modules/database.js
index c287d5109..f89bac595 100644
--- a/js/modules/database.js
+++ b/js/modules/database.js
@@ -31,3 +31,9 @@ exports.completeTransaction = transaction =>
     transaction.addEventListener('complete', () => resolve());
   });
 
+exports.getVersion = async (name) => {
+  const connection = await exports.open(name);
+  const { version } = connection;
+  connection.close();
+  return version;
+};

From 921c3dba7ca18ad4ba284d6f86bee5ec343c54fa Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 13:10:54 -0400
Subject: [PATCH 36/56] Skip migrations that have already been applied

---
 js/modules/migrations/run_migrations.js | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/js/modules/migrations/run_migrations.js b/js/modules/migrations/run_migrations.js
index 84635542a..b66057c19 100644
--- a/js/modules/migrations/run_migrations.js
+++ b/js/modules/migrations/run_migrations.js
@@ -6,6 +6,7 @@ const isString = require('lodash/isString');
 const head = require('lodash/head');
 const last = require('lodash/last');
 
+const db = require('../database');
 const { deferredToPromise } = require('../deferred_to_promise');
 
 
@@ -23,6 +24,25 @@ exports.runMigrations = async ({ Backbone, database } = {}) => {
     throw new TypeError('"database" is required');
   }
 
+  const {
+    firstVersion: firstMigrationVersion,
+    lastVersion: lastMigrationVersion,
+  } = getMigrationVersions(database);
+
+  const databaseVersion = await db.getVersion(database.id);
+  const isAlreadyUpgraded = databaseVersion >= lastMigrationVersion;
+
+  console.log('Database state', {
+    firstMigrationVersion,
+    lastMigrationVersion,
+    databaseVersion,
+    isAlreadyUpgraded,
+  });
+
+  if (isAlreadyUpgraded) {
+    return;
+  }
+
   const migrationCollection = new (Backbone.Collection.extend({
     database,
     storeName: 'items',

From efe3cd67fcc425101270661b7dd6033c3aa12339 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 14:45:07 -0400
Subject: [PATCH 37/56] Allow attachment migration run on higher database
 version

---
 js/background.js                        |  2 +-
 js/modules/messages_data_migrator.js    | 20 ++++++++++++++++----
 js/modules/migrations/run_migrations.js |  2 +-
 3 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/js/background.js b/js/background.js
index 991414f06..3516cb0e7 100644
--- a/js/background.js
+++ b/js/background.js
@@ -91,7 +91,7 @@
   await MessageDataMigrator.processAll({
     Backbone,
     databaseName: database.name,
-    databaseVersion: database.version,
+    minDatabaseVersion: database.version,
     upgradeMessageSchema,
   });
 
diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index e554d7208..a331aac80 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -77,7 +77,7 @@ exports.processNext = async ({
 exports.processAll = async ({
   Backbone,
   databaseName,
-  databaseVersion,
+  minDatabaseVersion,
   upgradeMessageSchema,
 } = {}) => {
   if (!isObject(Backbone)) {
@@ -88,15 +88,27 @@ exports.processAll = async ({
     throw new TypeError('"databaseName" must be a string');
   }
 
-  if (!isNumber(databaseVersion)) {
-    throw new TypeError('"databaseVersion" must be a number');
+  if (!isNumber(minDatabaseVersion)) {
+    throw new TypeError('"minDatabaseVersion" must be a number');
   }
 
   if (!isFunction(upgradeMessageSchema)) {
     throw new TypeError('"upgradeMessageSchema" is required');
   }
 
-  const connection = await database.open(databaseName, databaseVersion);
+  const connection = await database.open(databaseName);
+  const databaseVersion = connection.version;
+  const isValidDatabaseVersion = databaseVersion >= minDatabaseVersion;
+  console.log('Database status', {
+    databaseVersion,
+    isValidDatabaseVersion,
+    minDatabaseVersion,
+  });
+  if (!isValidDatabaseVersion) {
+    throw new Error(`Expected database version (${databaseVersion})` +
+      ` to be at least ${minDatabaseVersion}`);
+  }
+
   const isComplete = await settings.isAttachmentMigrationComplete(connection);
   console.log('Attachment migration status:', isComplete ? 'complete' : 'incomplete');
   if (isComplete) {
diff --git a/js/modules/migrations/run_migrations.js b/js/modules/migrations/run_migrations.js
index b66057c19..ce3e3cee1 100644
--- a/js/modules/migrations/run_migrations.js
+++ b/js/modules/migrations/run_migrations.js
@@ -32,7 +32,7 @@ exports.runMigrations = async ({ Backbone, database } = {}) => {
   const databaseVersion = await db.getVersion(database.id);
   const isAlreadyUpgraded = databaseVersion >= lastMigrationVersion;
 
-  console.log('Database state', {
+  console.log('Database status', {
     firstMigrationVersion,
     lastMigrationVersion,
     databaseVersion,

From 5910f84af4d0ca8752f4e7652756f518adc82985 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 16:05:36 -0400
Subject: [PATCH 38/56] Remove outdated documentation

---
 js/modules/types/attachment.js | 2 --
 1 file changed, 2 deletions(-)

diff --git a/js/modules/types/attachment.js b/js/modules/types/attachment.js
index d37a95454..07e8c825d 100644
--- a/js/modules/types/attachment.js
+++ b/js/modules/types/attachment.js
@@ -17,7 +17,6 @@ const { migrateDataToFileSystem } = require('./attachment/migrate_data_to_file_s
 //   key: ArrayBuffer
 //   size: integer
 //   thumbnail: ArrayBuffer
-//   schemaVersion: integer
 // }
 
 // // Outgoing message attachment fields
@@ -26,7 +25,6 @@ const { migrateDataToFileSystem } = require('./attachment/migrate_data_to_file_s
 //   data: ArrayBuffer
 //   fileName: string
 //   size: integer
-//   schemaVersion: integer
 // }
 
 // Returns true if `rawAttachment` is a valid attachment based on our current schema.

From a18e46281770cca3f662ea1f328082f3a7c19103 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 17:04:17 -0400
Subject: [PATCH 39/56] Move migrations to `Signal.Migrations`

---
 js/background.js | 2 +-
 js/database.js   | 2 +-
 preload.js       | 9 ++++-----
 3 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/js/background.js b/js/background.js
index 3516cb0e7..38d1c683c 100644
--- a/js/background.js
+++ b/js/background.js
@@ -20,7 +20,7 @@
     const {
         Migrations0DatabaseWithAttachmentData,
         Migrations1DatabaseWithoutAttachmentData,
-    } = window.Signal.Database;
+    } = window.Signal.Migrations;
     const { Views } = window.Signal;
 
     // Implicitly used in `indexeddb-backbonejs-adapter`:
diff --git a/js/database.js b/js/database.js
index db0688d35..6b1bb9f93 100644
--- a/js/database.js
+++ b/js/database.js
@@ -6,7 +6,7 @@
 (function () {
   'use strict';
 
-  const { Migrations1DatabaseWithoutAttachmentData } = window.Signal.Database;
+  const { Migrations1DatabaseWithoutAttachmentData } = window.Signal.Migrations;
 
   window.Whisper = window.Whisper || {};
   window.Whisper.Database = window.Whisper.Database || {};
diff --git a/preload.js b/preload.js
index 9509f30fe..4ff2e4d41 100644
--- a/preload.js
+++ b/preload.js
@@ -124,16 +124,15 @@
   window.Signal = {};
   window.Signal.Backup = require('./js/modules/backup');
   window.Signal.Crypto = require('./js/modules/crypto');
-  window.Signal.Database = {};
-  window.Signal.Database.Migrations0DatabaseWithAttachmentData =
-    require('./js/modules/migrations/migrations_0_database_with_attachment_data');
-  window.Signal.Database.Migrations1DatabaseWithoutAttachmentData =
-    require('./js/modules/migrations/migrations_1_database_without_attachment_data');
   window.Signal.Logs = require('./js/modules/logs');
   window.Signal.Migrations = {};
   window.Signal.Migrations.loadAttachmentData = Attachment.loadData(readAttachmentData);
   window.Signal.Migrations.deleteAttachmentData = Attachment.deleteData(deleteAttachmentData);
   window.Signal.Migrations.upgradeMessageSchema = upgradeMessageSchema;
+  window.Signal.Migrations.Migrations0DatabaseWithAttachmentData =
+    require('./js/modules/migrations/migrations_0_database_with_attachment_data');
+  window.Signal.Migrations.Migrations1DatabaseWithoutAttachmentData =
+    require('./js/modules/migrations/migrations_1_database_without_attachment_data');
   window.Signal.OS = require('./js/modules/os');
   window.Signal.Types = {};
   window.Signal.Types.Attachment = Attachment;

From 696a144ab72aa032da760adb15690df5af4d1b9e Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 17:05:21 -0400
Subject: [PATCH 40/56] Add `settings.deleteItem`

---
 js/modules/settings.js | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/js/modules/settings.js b/js/modules/settings.js
index 9d1cc018e..9cae70735 100644
--- a/js/modules/settings.js
+++ b/js/modules/settings.js
@@ -61,3 +61,24 @@ const setItem = (connection, key, value) => {
       resolve();
   });
 };
+
+const deleteItem = (connection, key) => {
+  if (!isObject(connection)) {
+    throw new TypeError('"connection" is required');
+  }
+
+  if (!isString(key)) {
+    throw new TypeError('"key" must be a string');
+  }
+
+  const transaction = connection.transaction(ITEMS_STORE_NAME, 'readwrite');
+  const itemsStore = transaction.objectStore(ITEMS_STORE_NAME);
+  const request = itemsStore.delete(key);
+  return new Promise((resolve, reject) => {
+    request.onerror = event =>
+      reject(event.target.error);
+
+    request.onsuccess = () =>
+      resolve();
+  });
+};

From 08f73b84207d0016bd062bcfd80413cf5868d68d Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 17:12:51 -0400
Subject: [PATCH 41/56] Remove last processed index after attachment migration

---
 js/modules/messages_data_migrator.js |  1 +
 js/modules/settings.js               | 17 ++++++++++-------
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index a331aac80..24f9d23f0 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -179,6 +179,7 @@ exports.processAll = async ({
   } while (unprocessedMessages.length > 0);
 
   await settings.markAttachmentMigrationComplete(connection);
+  await settings.deleteAttachmentMigrationLastProcessedIndex(connection);
 
   console.log('Close database connection');
   connection.close();
diff --git a/js/modules/settings.js b/js/modules/settings.js
index 9cae70735..9786be7fc 100644
--- a/js/modules/settings.js
+++ b/js/modules/settings.js
@@ -8,19 +8,22 @@ const IS_MIGRATION_COMPLETE_KEY = 'attachmentMigration_isComplete';
 
 // Public API
 exports.getAttachmentMigrationLastProcessedIndex = connection =>
-  getItem(connection, LAST_PROCESSED_INDEX_KEY);
+  exports._getItem(connection, LAST_PROCESSED_INDEX_KEY);
 
 exports.setAttachmentMigrationLastProcessedIndex = (connection, value) =>
-  setItem(connection, LAST_PROCESSED_INDEX_KEY, value);
+  exports._setItem(connection, LAST_PROCESSED_INDEX_KEY, value);
+
+exports.deleteAttachmentMigrationLastProcessedIndex = connection =>
+  exports._deleteItem(connection, LAST_PROCESSED_INDEX_KEY);
 
 exports.isAttachmentMigrationComplete = async connection =>
-  Boolean(await getItem(connection, IS_MIGRATION_COMPLETE_KEY));
+  Boolean(await exports._getItem(connection, IS_MIGRATION_COMPLETE_KEY));
 
 exports.markAttachmentMigrationComplete = connection =>
-  setItem(connection, IS_MIGRATION_COMPLETE_KEY, true);
+  exports._setItem(connection, IS_MIGRATION_COMPLETE_KEY, true);
 
 // Private API
-const getItem = (connection, key) => {
+exports._getItem = (connection, key) => {
   if (!isObject(connection)) {
     throw new TypeError('"connection" is required');
   }
@@ -41,7 +44,7 @@ const getItem = (connection, key) => {
   });
 };
 
-const setItem = (connection, key, value) => {
+exports._setItem = (connection, key, value) => {
   if (!isObject(connection)) {
     throw new TypeError('"connection" is required');
   }
@@ -62,7 +65,7 @@ const setItem = (connection, key, value) => {
   });
 };
 
-const deleteItem = (connection, key) => {
+exports._deleteItem = (connection, key) => {
   if (!isObject(connection)) {
     throw new TypeError('"connection" is required');
   }

From 21147a20a078f36de56e115d1f3670a121e3268a Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 17:13:11 -0400
Subject: [PATCH 42/56] Add `sleep` module

---
 js/modules/sleep.js | 4 ++++
 1 file changed, 4 insertions(+)
 create mode 100644 js/modules/sleep.js

diff --git a/js/modules/sleep.js b/js/modules/sleep.js
new file mode 100644
index 000000000..4cc0fc61f
--- /dev/null
+++ b/js/modules/sleep.js
@@ -0,0 +1,4 @@
+/* global setTimeout */
+
+exports.sleep = ms =>
+  new Promise(resolve => setTimeout(resolve, ms));

From 02354ce65593a366ec69e63134fb412e2c86e29b Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 17:13:41 -0400
Subject: [PATCH 43/56] Expose `Signal.Database` module

---
 preload.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/preload.js b/preload.js
index 4ff2e4d41..97d0d3c10 100644
--- a/preload.js
+++ b/preload.js
@@ -124,6 +124,7 @@
   window.Signal = {};
   window.Signal.Backup = require('./js/modules/backup');
   window.Signal.Crypto = require('./js/modules/crypto');
+  window.Signal.Database = require('./js/modules/database');
   window.Signal.Logs = require('./js/modules/logs');
   window.Signal.Migrations = {};
   window.Signal.Migrations.loadAttachmentData = Attachment.loadData(readAttachmentData);

From ce8fd3d84755c25a7a839830ecc505589bff7965 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 17:13:55 -0400
Subject: [PATCH 44/56] Expose `Signal.Settings` module

---
 preload.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/preload.js b/preload.js
index 97d0d3c10..54944514e 100644
--- a/preload.js
+++ b/preload.js
@@ -135,6 +135,7 @@
   window.Signal.Migrations.Migrations1DatabaseWithoutAttachmentData =
     require('./js/modules/migrations/migrations_1_database_without_attachment_data');
   window.Signal.OS = require('./js/modules/os');
+  window.Signal.Settings = require('./js/modules/settings');
   window.Signal.Types = {};
   window.Signal.Types.Attachment = Attachment;
   window.Signal.Types.Errors = require('./js/modules/types/errors');

From 30037e53087a14992f69169b2e5ab6884602dba6 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 18:14:26 -0400
Subject: [PATCH 45/56] Reduce attachment migration batch size to 1
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This prevents ‘Maximum IPC message size exceeded’ due to IDB `getAll` operation.

- https://github.com/zincbase/zincdb/issues/17
- https://cs.chromium.org/chromium/src/content/browser/indexed_db/indexed_db_database.cc?q=%22Maximum+IPC+message+size+exceeded%22&sq=package:chromium&l=1160
---
 js/modules/messages_data_migrator.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index 24f9d23f0..43730020b 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -19,7 +19,7 @@ const { deferredToPromise } = require('./deferred_to_promise');
 
 
 const MESSAGES_STORE_NAME = 'messages';
-const NUM_MESSAGES_PER_BATCH = 50;
+const NUM_MESSAGES_PER_BATCH = 1;
 
 exports.processNext = async ({
   BackboneMessage,

From d3c9de4712cd90dff1c1654ece39575f7ce3fe94 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Wed, 28 Mar 2018 18:16:35 -0400
Subject: [PATCH 46/56] Add debug module

Lets us generate large conversations with large attachments.
---
 js/modules/debug.js | 132 ++++++++++++++++++++++++++++++++++++++++++++
 preload.js          |   1 +
 2 files changed, 133 insertions(+)
 create mode 100644 js/modules/debug.js

diff --git a/js/modules/debug.js b/js/modules/debug.js
new file mode 100644
index 000000000..7a3f7fd28
--- /dev/null
+++ b/js/modules/debug.js
@@ -0,0 +1,132 @@
+const isFunction = require('lodash/isFunction');
+const isNumber = require('lodash/isNumber');
+const isObject = require('lodash/isObject');
+const isString = require('lodash/isString');
+const random = require('lodash/random');
+const range = require('lodash/range');
+const sample = require('lodash/sample');
+
+const Message = require('./types/message');
+const { deferredToPromise } = require('./deferred_to_promise');
+const { sleep } = require('./sleep');
+
+
+// See: https://en.wikipedia.org/wiki/Fictitious_telephone_number#North_American_Numbering_Plan
+const SENDER_ID = '+12126647665';
+
+exports.createConversation = async ({
+  ConversationController,
+  numMessages,
+  WhisperMessage,
+} = {}) => {
+  if (!isObject(ConversationController) ||
+      !isFunction(ConversationController.getOrCreateAndWait)) {
+    throw new TypeError('"ConversationController" is required');
+  }
+
+  if (!isNumber(numMessages) || numMessages <= 0) {
+    throw new TypeError('"numMessages" must be a positive number');
+  }
+
+  if (!isFunction(WhisperMessage)) {
+    throw new TypeError('"WhisperMessage" is required');
+  }
+
+  const conversation =
+    await ConversationController.getOrCreateAndWait(SENDER_ID, 'private');
+  conversation.set({
+    active_at: Date.now(),
+    unread: numMessages,
+  });
+  await deferredToPromise(conversation.save());
+
+  const conversationId = conversation.get('id');
+
+  await Promise.all(range(0, numMessages).map(async (index) => {
+    await sleep(index * 100);
+    console.log(`Create message ${index + 1}`);
+    const message = new WhisperMessage(createRandomMessage({ conversationId }));
+    return deferredToPromise(message.save());
+  }));
+};
+
+const SAMPLE_MESSAGES = [
+  'Lorem ipsum dolor sit amet, consectetur adipiscing elit.',
+  'Integer et rutrum leo, eu ultrices ligula.',
+  'Nam vel aliquam quam.',
+  'Suspendisse posuere nunc vitae pulvinar lobortis.',
+  'Nunc et sapien ex.',
+  'Duis nec neque eu arcu ultrices ullamcorper in et mauris.',
+  'Praesent mi felis, hendrerit a nulla id, mattis consectetur est.',
+  'Duis venenatis posuere est sit amet congue.',
+  'Vestibulum vitae sapien ultricies, auctor purus vitae, laoreet lacus.',
+  'Fusce laoreet nisi dui, a bibendum metus consequat in.',
+  'Nulla sed iaculis odio, sed lobortis lacus.',
+  'Etiam massa felis, gravida at nibh viverra, tincidunt convallis justo.',
+  'Maecenas ut egestas urna.',
+  'Pellentesque consectetur mattis imperdiet.',
+  'Maecenas pulvinar efficitur justo a cursus.',
+];
+
+const ATTACHMENT_SAMPLE_RATE = 0.33;
+const createRandomMessage = ({ conversationId } = {}) => {
+  if (!isString(conversationId)) {
+    throw new TypeError('"conversationId" must be a string');
+  }
+
+  const sentAt = Date.now() - random(100 * 24 * 60 * 60 * 1000);
+  const receivedAt = sentAt + random(30 * 1000);
+
+  const hasAttachment = Math.random() <= ATTACHMENT_SAMPLE_RATE;
+  const attachments = hasAttachment
+    ? [createRandomInMemoryAttachment()] : [];
+  const type = sample(['incoming', 'outgoing']);
+  const commonProperties = {
+    attachments,
+    body: sample(SAMPLE_MESSAGES),
+    conversationId,
+    received_at: receivedAt,
+    sent_at: sentAt,
+    timestamp: receivedAt,
+    type,
+  };
+
+  const message = (() => {
+    switch (type) {
+      case 'incoming':
+        return Object.assign({}, commonProperties, {
+          flags: 0,
+          source: conversationId,
+          sourceDevice: 1,
+        });
+      case 'outgoing':
+        return Object.assign({}, commonProperties, {
+          delivered: 1,
+          delivered_to: [conversationId],
+          expireTimer: 0,
+          recipients: [conversationId],
+          sent_to: [conversationId],
+          synced: true,
+        });
+      default:
+        throw new TypeError(`Unknown message type: '${type}'`);
+    }
+  })();
+
+  return Message.initializeSchemaVersion(message);
+};
+
+const MEGA_BYTE = 1e6;
+const createRandomInMemoryAttachment = () => {
+  const numBytes = (1 + Math.ceil((Math.random() * 50))) * MEGA_BYTE;
+  const array = new Uint32Array(numBytes).fill(1);
+  const data = array.buffer;
+  const fileName = Math.random().toString().slice(2);
+
+  return {
+    contentType: 'application/octet-stream',
+    data,
+    fileName,
+    size: numBytes,
+  };
+};
diff --git a/preload.js b/preload.js
index 54944514e..99e8d5f88 100644
--- a/preload.js
+++ b/preload.js
@@ -125,6 +125,7 @@
   window.Signal.Backup = require('./js/modules/backup');
   window.Signal.Crypto = require('./js/modules/crypto');
   window.Signal.Database = require('./js/modules/database');
+  window.Signal.Debug = require('./js/modules/debug');
   window.Signal.Logs = require('./js/modules/logs');
   window.Signal.Migrations = {};
   window.Signal.Migrations.loadAttachmentData = Attachment.loadData(readAttachmentData);

From a4ecf1a9d6a597e602bb37a29e15bd5cd8b08866 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Thu, 29 Mar 2018 13:11:32 -0400
Subject: [PATCH 47/56] Define constant after creating idle detector

---
 js/background.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/js/background.js b/js/background.js
index 38d1c683c..c8bb9171c 100644
--- a/js/background.js
+++ b/js/background.js
@@ -104,8 +104,9 @@
   console.log('Storage fetch');
   storage.fetch();
 
-  const NUM_MESSAGE_UPGRADES_PER_IDLE = 2;
   const idleDetector = new IdleDetector();
+
+  const NUM_MESSAGE_UPGRADES_PER_IDLE = 2;
   idleDetector.on('idle', async () => {
     const results = await MessageDataMigrator.processNext({
       BackboneMessage: Whisper.Message,

From 0c40f3562387f4061ad6463a83c6b86614ea38b8 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Thu, 29 Mar 2018 13:12:18 -0400
Subject: [PATCH 48/56] Document disadvantage of fetching messages without
 index

---
 js/modules/messages_data_migrator.js | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index 43730020b..1e2a5b309 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -238,6 +238,8 @@ const _fetchMessagesRequiringSchemaUpgrade =
     }));
   };
 
+// NOTE: Named ‘dangerous’ because it is not as efficient as using our
+// `messages` `schemaVersion` index:
 const _dangerouslyFetchMessagesRequiringSchemaUpgradeWithoutIndex =
   ({ connection, count, lastIndex } = {}) => {
     if (!isObject(connection)) {

From 77f8f598de6259d2eb887e2c2ca38a6e16a2cc01 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Thu, 29 Mar 2018 15:08:23 -0400
Subject: [PATCH 49/56] Add `disk-usage.sh` script for testing

---
 .../disk-usage.sh                              | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100755 scripts/features/2193-migrate-attachments-on-startup/disk-usage.sh

diff --git a/scripts/features/2193-migrate-attachments-on-startup/disk-usage.sh b/scripts/features/2193-migrate-attachments-on-startup/disk-usage.sh
new file mode 100755
index 000000000..ffde28a24
--- /dev/null
+++ b/scripts/features/2193-migrate-attachments-on-startup/disk-usage.sh
@@ -0,0 +1,18 @@
+#!/bin/bash
+ROOT=$1
+
+if [[ "$1" == "" ]]; then
+    echo "Usage: $(basename "$0") <signal-profile-path>"
+    exit 1
+fi
+
+while true
+do
+    echo -n "$(date -u +"%Y-%m-%dT%H:%M:%SZ    ")"
+    du -sm "$ROOT/attachments.noindex"
+
+    echo -n "$(date -u +"%Y-%m-%dT%H:%M:%SZ    ")"
+    du -sm "$ROOT/IndexedDB"
+
+    sleep 1
+done

From c67c2a858a2b5df134b533b55a2976e8fd854d85 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Thu, 29 Mar 2018 15:38:05 -0400
Subject: [PATCH 50/56] Remove Backbone references for attachment migration

It has to run without any other migrations interfering.
---
 js/modules/messages_data_migrator.js | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index 1e2a5b309..2071f69df 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -75,15 +75,10 @@ exports.processNext = async ({
 };
 
 exports.processAll = async ({
-  Backbone,
   databaseName,
   minDatabaseVersion,
   upgradeMessageSchema,
 } = {}) => {
-  if (!isObject(Backbone)) {
-    throw new TypeError('"Backbone" is required');
-  }
-
   if (!isString(databaseName)) {
     throw new TypeError('"databaseName" must be a string');
   }

From 1f8556b049f705079105993894933defb8bffe95 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Thu, 29 Mar 2018 15:44:37 -0400
Subject: [PATCH 51/56] Remove unused `createCollection`

---
 ...rations_0_database_with_attachment_data.js | 21 -------------------
 1 file changed, 21 deletions(-)

diff --git a/js/modules/migrations/migrations_0_database_with_attachment_data.js b/js/modules/migrations/migrations_0_database_with_attachment_data.js
index 02cd097ff..c47f032a5 100644
--- a/js/modules/migrations/migrations_0_database_with_attachment_data.js
+++ b/js/modules/migrations/migrations_0_database_with_attachment_data.js
@@ -1,6 +1,3 @@
-const isFunction = require('lodash/isFunction');
-const isObject = require('lodash/isObject');
-const isString = require('lodash/isString');
 const last = require('lodash/last');
 
 const { runMigrations } = require('./run_migrations');
@@ -153,24 +150,6 @@ const database = {
 exports.run = ({ Backbone } = {}) =>
   runMigrations({ Backbone, database });
 
-exports.createCollection = ({ Backbone, storeName }) => {
-  if (!isObject(Backbone) || !isObject(Backbone.Collection) ||
-      !isFunction(Backbone.Collection.extend)) {
-    throw new TypeError('"Backbone" is required');
-  }
-
-  if (!isString(storeName)) {
-    throw new TypeError('"database" is required');
-  }
-
-  const collection = new (Backbone.Collection.extend({
-    database,
-    storeName,
-  }))();
-
-  return collection;
-};
-
 exports.getDatabase = () => ({
   name: database.id,
   version: last(migrations).version,

From 0fdc1140dd3956e72c38b1bcee517eff7ff5de6c Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Thu, 29 Mar 2018 16:15:23 -0400
Subject: [PATCH 52/56] Add `Database.getCount` function

---
 js/modules/database.js | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/js/modules/database.js b/js/modules/database.js
index f89bac595..f780a4031 100644
--- a/js/modules/database.js
+++ b/js/modules/database.js
@@ -4,6 +4,9 @@
 // and using promises. Revisit use of `idb` dependency as it might cover
 // this functionality.
 
+const isObject = require('lodash/isObject');
+
+
 exports.open = (name, version) => {
   const request = indexedDB.open(name, version);
   return new Promise((resolve, reject) => {
@@ -37,3 +40,17 @@ exports.getVersion = async (name) => {
   connection.close();
   return version;
 };
+
+exports.getCount = async ({ store } = {}) => {
+  if (!isObject(store)) {
+    throw new TypeError('"store" is required');
+  }
+
+  const request = store.count();
+  return new Promise((resolve, reject) => {
+    request.onerror = event =>
+      reject(event.target.error);
+    request.onsuccess = event =>
+      resolve(event.target.result);
+  });
+};

From 11f98474baeec18704065a65f7a650ad6456d9b4 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Thu, 29 Mar 2018 16:21:52 -0400
Subject: [PATCH 53/56] Capture how many messages we have to process

---
 js/modules/messages_data_migrator.js | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index 2071f69df..7357b9a6b 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -110,6 +110,12 @@ exports.processAll = async ({
     return;
   }
 
+  let numTotalMessages = null;
+  // eslint-disable-next-line more/no-then
+  getNumMessages({ connection }).then((numMessages) => {
+    numTotalMessages = numMessages;
+  });
+
   const migrationStartTime = Date.now();
   let unprocessedMessages = [];
   let totalMessagesProcessed = 0;
@@ -165,6 +171,7 @@ exports.processAll = async ({
       lastProcessedIndex,
       numUnprocessedMessages,
       numCumulativeMessagesProcessed: totalMessagesProcessed,
+      numTotalMessages,
       fetchDuration,
       saveDuration,
       upgradeDuration,
@@ -266,3 +273,16 @@ const _dangerouslyFetchMessagesRequiringSchemaUpgradeWithoutIndex =
         reject(event.target.error);
     });
   };
+
+const getNumMessages = async ({ connection } = {}) => {
+  if (!isObject(connection)) {
+    throw new TypeError('"connection" is required');
+  }
+
+  const transaction = connection.transaction(MESSAGES_STORE_NAME, 'readonly');
+  const messagesStore = transaction.objectStore(MESSAGES_STORE_NAME);
+  const numTotalMessages = await database.getCount({ store: messagesStore });
+  await database.completeTransaction(transaction);
+
+  return numTotalMessages;
+};

From b7b6195cfc4bf558179fa90cab573eacf3101a54 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Mon, 2 Apr 2018 12:10:29 -0400
Subject: [PATCH 54/56] Extract IIFE into separate function

---
 js/modules/debug.js | 45 +++++++++++++++++++++++----------------------
 1 file changed, 23 insertions(+), 22 deletions(-)

diff --git a/js/modules/debug.js b/js/modules/debug.js
index 7a3f7fd28..cfa39cd45 100644
--- a/js/modules/debug.js
+++ b/js/modules/debug.js
@@ -91,31 +91,32 @@ const createRandomMessage = ({ conversationId } = {}) => {
     type,
   };
 
-  const message = (() => {
-    switch (type) {
-      case 'incoming':
-        return Object.assign({}, commonProperties, {
-          flags: 0,
-          source: conversationId,
-          sourceDevice: 1,
-        });
-      case 'outgoing':
-        return Object.assign({}, commonProperties, {
-          delivered: 1,
-          delivered_to: [conversationId],
-          expireTimer: 0,
-          recipients: [conversationId],
-          sent_to: [conversationId],
-          synced: true,
-        });
-      default:
-        throw new TypeError(`Unknown message type: '${type}'`);
-    }
-  })();
-
+  const message = _createMessage({ commonProperties, conversationId, type });
   return Message.initializeSchemaVersion(message);
 };
 
+const _createMessage = ({ commonProperties, conversationId, type } = {}) => {
+  switch (type) {
+    case 'incoming':
+      return Object.assign({}, commonProperties, {
+        flags: 0,
+        source: conversationId,
+        sourceDevice: 1,
+      });
+    case 'outgoing':
+      return Object.assign({}, commonProperties, {
+        delivered: 1,
+        delivered_to: [conversationId],
+        expireTimer: 0,
+        recipients: [conversationId],
+        sent_to: [conversationId],
+        synced: true,
+      });
+    default:
+      throw new TypeError(`Unknown message type: '${type}'`);
+  }
+};
+
 const MEGA_BYTE = 1e6;
 const createRandomInMemoryAttachment = () => {
   const numBytes = (1 + Math.ceil((Math.random() * 50))) * MEGA_BYTE;

From d9be6a0f9446e2b3942675002a0a7a017647ed85 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Mon, 2 Apr 2018 15:08:53 -0400
Subject: [PATCH 55/56] Destructure Lodash `require`s

---
 app/attachments.js                               |  6 +++---
 app/menu.js                                      |  2 +-
 js/modules/database.js                           |  2 +-
 js/modules/debug.js                              | 16 +++++++++-------
 js/modules/messages_data_migrator.js             | 12 +++++++-----
 ...migrations_0_database_with_attachment_data.js |  2 +-
 js/modules/migrations/run_migrations.js          | 13 ++++++++-----
 js/modules/privacy.js                            | 10 ++++++----
 js/modules/settings.js                           |  3 +--
 js/modules/types/attachment.js                   |  3 +--
 .../attachment/migrate_data_to_file_system.js    | 10 ++++++----
 js/modules/types/message.js                      |  2 +-
 js/modules/types/schema_version.js               |  2 +-
 13 files changed, 46 insertions(+), 37 deletions(-)

diff --git a/app/attachments.js b/app/attachments.js
index 0b7b5a068..46dca8589 100644
--- a/app/attachments.js
+++ b/app/attachments.js
@@ -1,9 +1,9 @@
 const crypto = require('crypto');
-const fse = require('fs-extra');
-const isArrayBuffer = require('lodash/isArrayBuffer');
-const isString = require('lodash/isString');
 const path = require('path');
+
+const fse = require('fs-extra');
 const toArrayBuffer = require('to-arraybuffer');
+const { isArrayBuffer, isString } = require('lodash');
 
 
 const PATH = 'attachments.noindex';
diff --git a/app/menu.js b/app/menu.js
index 16c0fe23f..ecc1f654b 100644
--- a/app/menu.js
+++ b/app/menu.js
@@ -1,4 +1,4 @@
-const isString = require('lodash/isString');
+const { isString } = require('lodash');
 
 
 exports.createTemplate = (options, messages) => {
diff --git a/js/modules/database.js b/js/modules/database.js
index f780a4031..24c20555e 100644
--- a/js/modules/database.js
+++ b/js/modules/database.js
@@ -4,7 +4,7 @@
 // and using promises. Revisit use of `idb` dependency as it might cover
 // this functionality.
 
-const isObject = require('lodash/isObject');
+const { isObject } = require('lodash');
 
 
 exports.open = (name, version) => {
diff --git a/js/modules/debug.js b/js/modules/debug.js
index cfa39cd45..75e4e6513 100644
--- a/js/modules/debug.js
+++ b/js/modules/debug.js
@@ -1,10 +1,12 @@
-const isFunction = require('lodash/isFunction');
-const isNumber = require('lodash/isNumber');
-const isObject = require('lodash/isObject');
-const isString = require('lodash/isString');
-const random = require('lodash/random');
-const range = require('lodash/range');
-const sample = require('lodash/sample');
+const {
+  isFunction,
+  isNumber,
+  isObject,
+  isString,
+  random,
+  range,
+  sample,
+} = require('lodash');
 
 const Message = require('./types/message');
 const { deferredToPromise } = require('./deferred_to_promise');
diff --git a/js/modules/messages_data_migrator.js b/js/modules/messages_data_migrator.js
index 7357b9a6b..f97872389 100644
--- a/js/modules/messages_data_migrator.js
+++ b/js/modules/messages_data_migrator.js
@@ -6,11 +6,13 @@
 
 /* global IDBKeyRange */
 
-const isFunction = require('lodash/isFunction');
-const isNumber = require('lodash/isNumber');
-const isObject = require('lodash/isObject');
-const isString = require('lodash/isString');
-const last = require('lodash/last');
+const {
+  isFunction,
+  isNumber,
+  isObject,
+  isString,
+  last,
+} = require('lodash');
 
 const database = require('./database');
 const Message = require('./types/message');
diff --git a/js/modules/migrations/migrations_0_database_with_attachment_data.js b/js/modules/migrations/migrations_0_database_with_attachment_data.js
index c47f032a5..2c42b9e90 100644
--- a/js/modules/migrations/migrations_0_database_with_attachment_data.js
+++ b/js/modules/migrations/migrations_0_database_with_attachment_data.js
@@ -1,4 +1,4 @@
-const last = require('lodash/last');
+const { last } = require('lodash');
 
 const { runMigrations } = require('./run_migrations');
 
diff --git a/js/modules/migrations/run_migrations.js b/js/modules/migrations/run_migrations.js
index ce3e3cee1..cc54a408c 100644
--- a/js/modules/migrations/run_migrations.js
+++ b/js/modules/migrations/run_migrations.js
@@ -1,10 +1,13 @@
 /* eslint-env browser */
 
-const isFunction = require('lodash/isFunction');
-const isObject = require('lodash/isObject');
-const isString = require('lodash/isString');
-const head = require('lodash/head');
-const last = require('lodash/last');
+const {
+  head,
+  isFunction,
+  isObject,
+  isString,
+  last,
+} = require('lodash');
+
 
 const db = require('../database');
 const { deferredToPromise } = require('../deferred_to_promise');
diff --git a/js/modules/privacy.js b/js/modules/privacy.js
index 9e5f26646..1a90884c5 100644
--- a/js/modules/privacy.js
+++ b/js/modules/privacy.js
@@ -2,10 +2,12 @@
 
 const Path = require('path');
 
-const compose = require('lodash/fp/compose');
-const escapeRegExp = require('lodash/escapeRegExp');
-const isRegExp = require('lodash/isRegExp');
-const isString = require('lodash/isString');
+const {
+  escapeRegExp,
+  isRegExp,
+  isString,
+} = require('lodash');
+const { compose } = require('lodash/fp');
 
 
 const PHONE_NUMBER_PATTERN = /\+\d{7,12}(\d{3})/g;
diff --git a/js/modules/settings.js b/js/modules/settings.js
index 9786be7fc..d99bfdeb9 100644
--- a/js/modules/settings.js
+++ b/js/modules/settings.js
@@ -1,5 +1,4 @@
-const isObject = require('lodash/isObject');
-const isString = require('lodash/isString');
+const { isObject, isString } = require('lodash');
 
 
 const ITEMS_STORE_NAME = 'items';
diff --git a/js/modules/types/attachment.js b/js/modules/types/attachment.js
index 07e8c825d..c807afc2b 100644
--- a/js/modules/types/attachment.js
+++ b/js/modules/types/attachment.js
@@ -1,5 +1,4 @@
-const isFunction = require('lodash/isFunction');
-const isString = require('lodash/isString');
+const { isFunction, isString } = require('lodash');
 
 const MIME = require('./mime');
 const { arrayBufferToBlob, blobToArrayBuffer, dataURLToBlob } = require('blob-util');
diff --git a/js/modules/types/attachment/migrate_data_to_file_system.js b/js/modules/types/attachment/migrate_data_to_file_system.js
index ed21cb2ab..d2709d90f 100644
--- a/js/modules/types/attachment/migrate_data_to_file_system.js
+++ b/js/modules/types/attachment/migrate_data_to_file_system.js
@@ -1,7 +1,9 @@
-const isArrayBuffer = require('lodash/isArrayBuffer');
-const isFunction = require('lodash/isFunction');
-const isUndefined = require('lodash/isUndefined');
-const omit = require('lodash/omit');
+const {
+  isArrayBuffer,
+  isFunction,
+  isUndefined,
+  omit,
+} = require('lodash');
 
 
 // type Context :: {
diff --git a/js/modules/types/message.js b/js/modules/types/message.js
index a43e9c664..d501532e7 100644
--- a/js/modules/types/message.js
+++ b/js/modules/types/message.js
@@ -1,4 +1,4 @@
-const isFunction = require('lodash/isFunction');
+const { isFunction } = require('lodash');
 
 const Attachment = require('./attachment');
 const Errors = require('./errors');
diff --git a/js/modules/types/schema_version.js b/js/modules/types/schema_version.js
index 3a0d08980..058a36a1e 100644
--- a/js/modules/types/schema_version.js
+++ b/js/modules/types/schema_version.js
@@ -1,4 +1,4 @@
-const isNumber = require('lodash/isNumber');
+const { isNumber } = require('lodash');
 
 
 exports.isValid = value =>

From bfbeedab5ce1cdbff14f3709e5749bd912ed8aa6 Mon Sep 17 00:00:00 2001
From: Daniel Gasienica <daniel@signal.org>
Date: Mon, 2 Apr 2018 15:26:23 -0400
Subject: [PATCH 56/56] Temporarily disable post-attachment migration
 migrations

---
 js/background.js                              | 28 +++++++++----------
 js/database.js                                |  4 +--
 ...rations_0_database_with_attachment_data.js |  6 ++--
 ...ions_1_database_without_attachment_data.js | 16 +++++------
 4 files changed, 27 insertions(+), 27 deletions(-)

diff --git a/js/background.js b/js/background.js
index c8bb9171c..5c72a636f 100644
--- a/js/background.js
+++ b/js/background.js
@@ -19,7 +19,7 @@
     const { upgradeMessageSchema } = window.Signal.Migrations;
     const {
         Migrations0DatabaseWithAttachmentData,
-        Migrations1DatabaseWithoutAttachmentData,
+        // Migrations1DatabaseWithoutAttachmentData,
     } = window.Signal.Migrations;
     const { Views } = window.Signal;
 
@@ -86,20 +86,20 @@
   console.log('Migrate database with attachments');
   await Migrations0DatabaseWithAttachmentData.run({ Backbone });
 
-  console.log('Migrate attachments to disk');
-  const database = Migrations0DatabaseWithAttachmentData.getDatabase();
-  await MessageDataMigrator.processAll({
-    Backbone,
-    databaseName: database.name,
-    minDatabaseVersion: database.version,
-    upgradeMessageSchema,
-  });
+  // console.log('Migrate attachments to disk');
+  // const database = Migrations0DatabaseWithAttachmentData.getDatabase();
+  // await MessageDataMigrator.processAll({
+  //   Backbone,
+  //   databaseName: database.name,
+  //   minDatabaseVersion: database.version,
+  //   upgradeMessageSchema,
+  // });
 
-  console.log('Migrate database without attachments');
-  await Migrations1DatabaseWithoutAttachmentData.run({
-    Backbone,
-    database: Whisper.Database,
-  });
+  // console.log('Migrate database without attachments');
+  // await Migrations1DatabaseWithoutAttachmentData.run({
+  //   Backbone,
+  //   database: Whisper.Database,
+  // });
 
   console.log('Storage fetch');
   storage.fetch();
diff --git a/js/database.js b/js/database.js
index 6b1bb9f93..242e91a7b 100644
--- a/js/database.js
+++ b/js/database.js
@@ -6,7 +6,7 @@
 (function () {
   'use strict';
 
-  const { Migrations1DatabaseWithoutAttachmentData } = window.Signal.Migrations;
+  const { Migrations0DatabaseWithAttachmentData } = window.Signal.Migrations;
 
   window.Whisper = window.Whisper || {};
   window.Whisper.Database = window.Whisper.Database || {};
@@ -123,5 +123,5 @@
       request.onsuccess = resolve;
     }));
 
-  Whisper.Database.migrations = Migrations1DatabaseWithoutAttachmentData.migrations;
+  Whisper.Database.migrations = Migrations0DatabaseWithAttachmentData.migrations;
 }());
diff --git a/js/modules/migrations/migrations_0_database_with_attachment_data.js b/js/modules/migrations/migrations_0_database_with_attachment_data.js
index 2c42b9e90..a12e788ff 100644
--- a/js/modules/migrations/migrations_0_database_with_attachment_data.js
+++ b/js/modules/migrations/migrations_0_database_with_attachment_data.js
@@ -8,7 +8,7 @@ const { runMigrations } = require('./run_migrations');
 // any expensive operations, e.g. modifying all messages / attachments, etc., as
 // it may cause out-of-memory errors for users with long histories:
 // https://github.com/signalapp/Signal-Desktop/issues/2163
-const migrations = [
+exports.migrations = [
   {
     version: '12.0',
     migrate(transaction, next) {
@@ -144,7 +144,7 @@ const migrations = [
 const database = {
   id: 'signal',
   nolog: true,
-  migrations,
+  migrations: exports.migrations,
 };
 
 exports.run = ({ Backbone } = {}) =>
@@ -152,5 +152,5 @@ exports.run = ({ Backbone } = {}) =>
 
 exports.getDatabase = () => ({
   name: database.id,
-  version: last(migrations).version,
+  version: last(exports.migrations).version,
 });
diff --git a/js/modules/migrations/migrations_1_database_without_attachment_data.js b/js/modules/migrations/migrations_1_database_without_attachment_data.js
index b10106ef2..a4fb3e870 100644
--- a/js/modules/migrations/migrations_1_database_without_attachment_data.js
+++ b/js/modules/migrations/migrations_1_database_without_attachment_data.js
@@ -2,14 +2,14 @@ const { runMigrations } = require('./run_migrations');
 
 
 exports.migrations = [
-  {
-    version: 18,
-    async migrate(transaction, next) {
-      console.log('Migration 18');
-      console.log('Attachments stored on disk');
-      next();
-    },
-  },
+  // {
+  //   version: 18,
+  //   async migrate(transaction, next) {
+  //     console.log('Migration 18');
+  //     console.log('Attachments stored on disk');
+  //     next();
+  //   },
+  // },
 ];
 
 exports.run = runMigrations;