WIP: Use sync worker

demos/django-todolist/.metadata

@@ -0,0 +1,45 @@
+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: "5874a72aa4c779a02553007c47dacbefba2374dc"
+  channel: "stable"
+
+project_type: app
+
+# Tracks metadata for the flutter migrate command
+migration:
+  platforms:
+    - platform: root
+      create_revision: 5874a72aa4c779a02553007c47dacbefba2374dc
+      base_revision: 5874a72aa4c779a02553007c47dacbefba2374dc
+    - platform: android
+      create_revision: 5874a72aa4c779a02553007c47dacbefba2374dc
+      base_revision: 5874a72aa4c779a02553007c47dacbefba2374dc
+    - platform: ios
+      create_revision: 5874a72aa4c779a02553007c47dacbefba2374dc
+      base_revision: 5874a72aa4c779a02553007c47dacbefba2374dc
+    - platform: linux
+      create_revision: 5874a72aa4c779a02553007c47dacbefba2374dc
+      base_revision: 5874a72aa4c779a02553007c47dacbefba2374dc
+    - platform: macos
+      create_revision: 5874a72aa4c779a02553007c47dacbefba2374dc
+      base_revision: 5874a72aa4c779a02553007c47dacbefba2374dc
+    - platform: web
+      create_revision: 5874a72aa4c779a02553007c47dacbefba2374dc
+      base_revision: 5874a72aa4c779a02553007c47dacbefba2374dc
+    - platform: windows
+      create_revision: 5874a72aa4c779a02553007c47dacbefba2374dc
+      base_revision: 5874a72aa4c779a02553007c47dacbefba2374dc
+
+  # User provided section
+
+  # List of Local paths (relative to this file) that should be
+  # ignored by the migrate tool.
+  #
+  # Files that are not part of the templates will be ignored by default.
+  unmanaged_files:
+    - 'lib/main.dart'
+    - 'ios/Runner.xcodeproj/project.pbxproj'

demos/django-todolist/android/app/src/main/kotlin/co/powersync/django_todolist/MainActivity.kt

@@ -0,0 +1,5 @@
+package co.powersync.django_todolist
+
+import io.flutter.embedding.android.FlutterActivity
+
+class MainActivity: FlutterActivity()

demos/django-todolist/ios/RunnerTests/RunnerTests.swift

@@ -0,0 +1,12 @@
+import Flutter
+import UIKit
+import XCTest
+
+class RunnerTests: XCTestCase {
+
+  func testExample() {
+    // If you add code to the Runner application, consider adding tests here.
+    // See https://developer.apple.com/documentation/xctest for more information about using XCTest.
+  }
+
+}

demos/django-todolist/lib/powersync.dart

@@ -1,4 +1,5 @@
 // This file performs setup of the PowerSync database
+import 'package:flutter/foundation.dart';
 import 'package:logging/logging.dart';
 import 'package:path/path.dart';
 import 'package:path_provider/path_provider.dart';
@@ -99,8 +100,14 @@ Future<bool> isLoggedIn() async {
 }
 
 Future<String> getDatabasePath() async {
+  const dbFilename = 'powersync-demo.db';
+  // getApplicationSupportDirectory is not supported on Web
+  if (kIsWeb) {
+    return dbFilename;
+  }
+
   final dir = await getApplicationSupportDirectory();
-  return join(dir.path, 'powersync-demo.db');
+  return join(dir.path, dbFilename);
 }
 
 // opens the database and connects if logged in

demos/django-todolist/pubspec.lock

@@ -164,18 +164,18 @@ packages:
     dependency: transitive
     description:
       name: leak_tracker
-      sha256: "7f0df31977cb2c0b88585095d168e689669a2cc9b97c309665e3386f3e9d341a"
+      sha256: "3f87a60e8c63aecc975dda1ceedbc8f24de75f09e4856ea27daf8958f2f0ce05"
       url: "https://pub.dev"
     source: hosted
-    version: "10.0.4"
+    version: "10.0.5"
   leak_tracker_flutter_testing:
     dependency: transitive
     description:
       name: leak_tracker_flutter_testing
-      sha256: "06e98f569d004c1315b991ded39924b21af84cf14cc94791b8aea337d25b57f8"
+      sha256: "932549fb305594d82d7183ecd9fa93463e9914e1b67cacc34bc40906594a1806"
       url: "https://pub.dev"
     source: hosted
-    version: "3.0.3"
+    version: "3.0.5"
   leak_tracker_testing:
     dependency: transitive
     description:
@@ -212,18 +212,18 @@ packages:
     dependency: transitive
     description:
       name: material_color_utilities
-      sha256: "0e0a020085b65b6083975e499759762399b4475f766c21668c4ecca34ea74e5a"
+      sha256: f7142bb1154231d7ea5f96bc7bde4bda2a0945d2806bb11670e30b850d56bdec
       url: "https://pub.dev"
     source: hosted
-    version: "0.8.0"
+    version: "0.11.1"
   meta:
     dependency: transitive
     description:
       name: meta
-      sha256: "7687075e408b093f36e6bbf6c91878cc0d4cd10f409506f7bc996f68220b9136"
+      sha256: bdb68674043280c3428e9ec998512fb681678676b3c54e773629ffe74419f8c7
       url: "https://pub.dev"
     source: hosted
-    version: "1.12.0"
+    version: "1.15.0"
   mutex:
     dependency: transitive
     description:
@@ -479,10 +479,10 @@ packages:
     dependency: transitive
     description:
       name: test_api
-      sha256: "9955ae474176f7ac8ee4e989dadfb411a58c30415bcfb648fa04b2b8a03afa7f"
+      sha256: "5b8a98dafc4d5c4c9c72d8b31ab2b23fc13422348d2997120294d3bac86b4ddb"
       url: "https://pub.dev"
     source: hosted
-    version: "0.7.0"
+    version: "0.7.2"
   typed_data:
     dependency: transitive
     description:
@@ -519,10 +519,10 @@ packages:
     dependency: transitive
     description:
       name: vm_service
-      sha256: "3923c89304b715fb1eb6423f017651664a03bf5f4b29983627c4da791f74a4ec"
+      sha256: "5c5f338a667b4c644744b661f309fb8080bb94b18a7e91ef1dbd343bed00ed6d"
       url: "https://pub.dev"
     source: hosted
-    version: "14.2.1"
+    version: "14.2.5"
   web:
     dependency: transitive
     description:

demos/django-todolist/pubspec.yaml

@@ -24,5 +24,9 @@ dev_dependencies:
 
   flutter_lints: ^3.0.1
 
+dependency_overrides:
+  sqlite_async:
+    path: /home/simon/src/sqlite_async.dart/packages/sqlite_async
+
 flutter:
   uses-material-design: true

demos/django-todolist/web/index.html

@@ -0,0 +1,38 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <!--
+    If you are serving your web app in a path other than the root, change the
+    href value below to reflect the base path you are serving from.
+
+    The path provided below has to start and end with a slash "/" in order for
+    it to work correctly.
+
+    For more details:
+    * https://developer.mozilla.org/en-US/docs/Web/HTML/Element/base
+
+    This is a placeholder for base href that will be replaced by the value of
+    the `--base-href` argument provided to `flutter build`.
+  -->
+  <base href="$FLUTTER_BASE_HREF">
+
+  <meta charset="UTF-8">
+  <meta content="IE=Edge" http-equiv="X-UA-Compatible">
+  <meta name="description" content="A new Flutter project.">
+
+  <!-- iOS meta tags & icons -->
+  <meta name="apple-mobile-web-app-capable" content="yes">
+  <meta name="apple-mobile-web-app-status-bar-style" content="black">
+  <meta name="apple-mobile-web-app-title" content="django_todolist">
+  <link rel="apple-touch-icon" href="icons/Icon-192.png">
+
+  <!-- Favicon -->
+  <link rel="icon" type="image/png" href="favicon.png"/>
+
+  <title>django_todolist</title>
+  <link rel="manifest" href="manifest.json">
+</head>
+<body>
+  <script src="flutter_bootstrap.js" async></script>
+</body>
+</html>

demos/django-todolist/web/manifest.json

@@ -0,0 +1,35 @@
+{
+    "name": "django_todolist",
+    "short_name": "django_todolist",
+    "start_url": ".",
+    "display": "standalone",
+    "background_color": "#0175C2",
+    "theme_color": "#0175C2",
+    "description": "A new Flutter project.",
+    "orientation": "portrait-primary",
+    "prefer_related_applications": false,
+    "icons": [
+        {
+            "src": "icons/Icon-192.png",
+            "sizes": "192x192",
+            "type": "image/png"
+        },
+        {
+            "src": "icons/Icon-512.png",
+            "sizes": "512x512",
+            "type": "image/png"
+        },
+        {
+            "src": "icons/Icon-maskable-192.png",
+            "sizes": "192x192",
+            "type": "image/png",
+            "purpose": "maskable"
+        },
+        {
+            "src": "icons/Icon-maskable-512.png",
+            "sizes": "512x512",
+            "type": "image/png",
+            "purpose": "maskable"
+        }
+    ]
+}

demos/supabase-anonymous-auth/pubspec.yaml

@@ -25,5 +25,9 @@ dev_dependencies:
 
   flutter_lints: ^3.0.1
 
+dependency_overrides:
+  sqlite_async:
+    path: /home/simon/src/sqlite_async.dart/packages/sqlite_async
+
 flutter:
   uses-material-design: true

demos/supabase-edge-function-auth/pubspec.yaml

@@ -25,5 +25,9 @@ dev_dependencies:
 
   flutter_lints: ^3.0.1
 
+dependency_overrides:
+  sqlite_async:
+    path: /home/simon/src/sqlite_async.dart/packages/sqlite_async
+
 flutter:
   uses-material-design: true

demos/supabase-simple-chat/pubspec.yaml

@@ -54,6 +54,10 @@ dev_dependencies:
   # rules and activating additional ones.
   flutter_lints: ^3.0.1
 
+dependency_overrides:
+  sqlite_async:
+    path: /home/simon/src/sqlite_async.dart/packages/sqlite_async
+
 # For information on the generic Dart part of this file, see the
 # following page: https://dart.dev/tools/pub/pubspec
 

demos/supabase-todolist/pubspec.yaml

@@ -27,5 +27,9 @@ dev_dependencies:
 
   flutter_lints: ^3.0.1
 
+dependency_overrides:
+  sqlite_async:
+    path: /home/simon/src/sqlite_async.dart/packages/sqlite_async
+
 flutter:
   uses-material-design: true

packages/powersync/lib/src/database/powersync_db_mixin.dart

@@ -71,11 +71,7 @@ mixin PowerSyncDatabaseMixin implements SqliteConnection {
   @protected
   Future<void> baseInit() async {
     statusStream = statusStreamController.stream;
-    updates = database.updates
-        .map((update) =>
-            PowerSyncUpdateNotification.fromUpdateNotification(update))
-        .where((update) => update.isNotEmpty)
-        .cast<UpdateNotification>();
+    updates = powerSyncUpdateNotifications(database.updates);
 
     await database.initialize();
     await _checkVersion();
@@ -466,3 +462,12 @@ mixin PowerSyncDatabaseMixin implements SqliteConnection {
     await database.refreshSchema();
   }
 }
+
+Stream<UpdateNotification> powerSyncUpdateNotifications(
+    Stream<UpdateNotification> inner) {
+  return inner
+      .map((update) =>
+          PowerSyncUpdateNotification.fromUpdateNotification(update))
+      .where((update) => update.isNotEmpty)
+      .cast<UpdateNotification>();
+}

packages/powersync/lib/src/database/web/web_powersync_database.dart

@@ -15,6 +15,8 @@ import 'package:powersync/src/streaming_sync.dart';
 import 'package:sqlite_async/sqlite_async.dart';
 import 'package:powersync/src/schema_logic.dart' as schema_logic;
 
+import '../../web/sync_controller.dart';
+
 /// A PowerSync managed database.
 ///
 /// Web implementation for [PowerSyncDatabase]
@@ -93,7 +95,8 @@ class PowerSyncDatabaseImpl
       Logger? logger}) {
     final db = SqliteDatabase.withFactory(openFactory, maxReaders: 1);
     return PowerSyncDatabaseImpl.withDatabase(
-        schema: schema, logger: logger, database: db);
+        schema: schema, logger: logger, database: db)
+      ..openFactory = openFactory;
   }
 
   /// Open a PowerSyncDatabase on an existing [SqliteDatabase].
@@ -119,14 +122,15 @@ class PowerSyncDatabaseImpl
   /// The connection is automatically re-opened if it fails for any reason.
   ///
   /// Status changes are reported on [statusStream].
-  baseConnect(
-      {required PowerSyncBackendConnector connector,
-
-      /// Throttle time between CRUD operations
-      /// Defaults to 10 milliseconds.
-      required Duration crudThrottleTime,
-      required Future<void> Function() reconnect,
-      Map<String, dynamic>? params}) async {
+  baseConnect({
+    required PowerSyncBackendConnector connector,
+
+    /// Throttle time between CRUD operations
+    /// Defaults to 10 milliseconds.
+    required Duration crudThrottleTime,
+    required Future<void> Function() reconnect,
+    Map<String, dynamic>? params,
+  }) async {
     await initialize();
 
     // Disconnect if connected
@@ -135,9 +139,23 @@ class PowerSyncDatabaseImpl
 
     await isInitialized;
 
-    // TODO better multitab support
     final storage = BucketStorage(database);
-    final sync = StreamingSyncImplementation(
+    StreamingSync sync;
+    // Try using a shared worker for the synchronization implementation to avoid
+    // duplicating work across tabs.
+    try {
+      sync = await SyncWorkerHandle.start(
+        this,
+        connector,
+        Uri.base.resolve('/powersync_sync.worker.js'),
+      );
+    } catch (e) {
+      logger.warning(
+        'Could not use shared worker for synchronization, falling back to locks.',
+        e,
+      );
+
+      sync = StreamingSyncImplementation(
         adapter: storage,
         credentialsCallback: connector.getCredentialsCached,
         invalidCredentialsCallback: connector.fetchCredentials,
@@ -148,7 +166,10 @@ class PowerSyncDatabaseImpl
         syncParameters: params,
         // Only allows 1 sync implementation to run at a time per database
         // This should be global (across tabs) when using Navigator locks.
-        identifier: database.openFactory.path);
+        identifier: database.openFactory.path,
+      );
+    }
+
     sync.statusStream.listen((event) {
       setStatus(event);
     });