Sync streams

.github/workflows/build_and_test.yaml

@@ -14,25 +14,13 @@ jobs:
         uses: maxim-lobanov/setup-xcode@v1
         with:
           xcode-version: latest-stable
-      - name: Build and Test
+
+      - name: Test on iOS simulator
         run: |
           xcodebuild test -scheme PowerSync-Package -destination "platform=iOS Simulator,name=iPhone 16"
-          xcodebuild test -scheme PowerSync-Package -destination "platform=macOS,arch=arm64,name=My Mac"
-          xcodebuild test -scheme PowerSync-Package -destination "platform=watchOS Simulator,arch=arm64,name=Apple Watch Ultra 2 (49mm)"
-
-  buildSwift6:
-    name: Build and test with Swift 6
-    runs-on: macos-latest
-    steps:
-      - uses: actions/checkout@v4
-      - name: Set up XCode
-        uses: maxim-lobanov/setup-xcode@v1
-        with:
-          xcode-version: latest-stable
-      - name: Use Swift 6
+      - name: Test on macOS
         run: |
-          sed -i '' 's|^// swift-tools-version:.*$|// swift-tools-version:6.1|' Package.swift
-      - name: Build and Test
+          xcodebuild test -scheme PowerSync-Package -destination "platform=macOS,arch=arm64,name=My Mac"
+      - name: Test on watchOS simulator
         run: |
-          swift build -Xswiftc -strict-concurrency=complete
-          swift test -Xswiftc -strict-concurrency=complete
+          xcodebuild test -scheme PowerSync-Package -destination "platform=watchOS Simulator,arch=arm64,name=Apple Watch Ultra 2 (49mm)"

CHANGELOG.md

@@ -1,8 +1,9 @@
 # Changelog
 
-## 1.6.1 (unreleased)
+## 1.7.0 (unreleased)
 
-* Update Kotlin SDK to 1.7.0.
+* Update Kotlin SDK to 1.8.0.
+* Add experimental support for [sync streams](https://docs.powersync.com/usage/sync-streams).
 
 ## 1.6.0
 

Demo/PowerSyncExample.xcodeproj/project.pbxproj

@@ -3,7 +3,7 @@
 	archiveVersion = 1;
 	classes = {
 	};
-	objectVersion = 56;
+	objectVersion = 60;
 	objects = {
 
 /* Begin PBXBuildFile section */

Demo/PowerSyncExample/Components/TodoListView.swift

@@ -1,5 +1,6 @@
 import AVFoundation
 import IdentifiedCollections
+import PowerSync
 import SwiftUI
 import SwiftUINavigation
 
@@ -11,6 +12,7 @@ struct TodoListView: View {
     @State private var error: Error?
     @State private var newTodo: NewTodo?
     @State private var editing: Bool = false
+    @State private var loadingListItems: Bool = false
 
 #if os(iOS)
     // Called when a photo has been captured. Individual widgets should register the listener
@@ -33,6 +35,10 @@ struct TodoListView: View {
                     }
                 }
             }
+
+            if (loadingListItems) {
+                ProgressView()
+            }
 
             ForEach(todos) { todo in
 #if os(iOS)
@@ -142,6 +148,22 @@ struct TodoListView: View {
                 }
             }
         }
+        .task {
+            if (Secrets.previewSyncStreams) {
+                // With sync streams, todo items are not loaded by default. We have to request them while we need them.
+                // Thanks to builtin caching, navingating to the same list multiple times does not have to fetch items again.
+                loadingListItems = true
+                do {
+                    // This will make the sync client request items from this list as long as we keep a reference to the stream subscription,
+                    // and a default TTL of one day afterwards.
+                    let streamSubscription = try await system.db.syncStream(name: "todos", params: ["list": JsonValue.string(listId)]).subscribe()
+                    try await streamSubscription.waitForFirstSync()
+                } catch {
+                    print("Error subscribing to list stream \(error)")
+                }
+                loadingListItems = false
+            }
+        }
     }
 
     func toggleCompletion(of todo: Todo) async {

Demo/PowerSyncExample/PowerSync/SystemManager.swift

@@ -78,11 +78,12 @@ final class SystemManager {
                 options: ConnectOptions(
                     clientConfiguration: SyncClientConfiguration(
                         requestLogger: SyncRequestLoggerConfiguration(
-                            requestLevel: .headers
+                            requestLevel: .all
                         ) { message in
                             self.db.logger.debug(message, tag: "SyncRequest")
                         }
-                    )
+                    ),
+                    newClientImplementation: true,
                 )
             )
             try await attachments?.startSync()

Demo/PowerSyncExample/Screens/HomeScreen.swift

@@ -8,7 +8,6 @@ struct HomeScreen: View {
 
 
     var body: some View {
-
         ListView()
             .toolbar {
                 ToolbarItem(placement: .cancellationAction) {

Demo/PowerSyncExample/Secrets.template.swift

@@ -17,4 +17,24 @@ extension Secrets {
     static var supabaseStorageBucket: String? {
         return nil
     }
+
+    static var previewSyncStreams: Bool {
+        /* 
+        Set to true to preview https://docs.powersync.com/usage/sync-streams.
+        When enabling this, also set your sync rules to the following:
+
+        streams:
+          lists:
+            query: SELECT * FROM lists WHERE owner_id = auth.user_id()
+            auto_subscribe: true
+          todos:
+            query: SELECT * FROM todos WHERE list_id = subscription.parameter('list') AND list_id IN (SELECT id FROM lists WHERE owner_id = auth.user_id())
+
+        config:
+          edition: 2
+
+        */
+
+        false
+    }
 }

Demo/PowerSyncExample/_Secrets.swift

@@ -6,6 +6,7 @@ protocol SecretsProvider {
     static var supabaseURL: URL { get }
     static var supabaseAnonKey: String { get }
     static var supabaseStorageBucket: String? { get }
+    static var previewSyncStreams: Bool { get }
 }
 
 // Default conforming type

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version: 5.7
+// swift-tools-version: 6.1
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
@@ -7,7 +7,7 @@ let packageName = "PowerSync"
 
 // Set this to the absolute path of your Kotlin SDK checkout if you want to use a local Kotlin
 // build. Also see docs/LocalBuild.md for details
-let localKotlinSdkOverride: String? = nil
+let localKotlinSdkOverride: String? = "/Users/simon/src/powersync-kotlin"
 
 // Set this to the absolute path of your powersync-sqlite-core checkout if you want to use a
 // local build of the core extension.
@@ -18,22 +18,43 @@ let localCoreExtension: String? = nil
 // a binary target.
 // With a local SDK, we point to a `Package.swift` within the Kotlin SDK containing a target pointing
 // towards a local framework build
-var conditionalDependencies: [Package.Dependency] = []
+var conditionalDependencies: [Package.Dependency] = [
+    .package(
+        url: "https://github.com/sbooth/CSQLite.git",
+        from: "3.50.4",
+        traits: [
+            .defaults,
+            // CSQLite uses THREADSAFE=0 by default, which breaks PowerSync because we're using SQLite on
+            // multiple threads (it can lead to race conditions when closing connections sharing resources
+            // like shared memory, causing crashes).
+            // THREADSAFE=2 overrides the default, and is safe to use as long as a single SQLite connection
+            // is not shared between threads.
+            // TODO: Technically, we should not use .defaults because there's a logical conflict between
+            // the threadsafe options. Instead, we should spell out all defaults again and remove that
+            // thread-safety option.
+            // However, despite the docs explicitly saying something else, it looks like there's no way to
+            // disable default traits anyway (XCode compiles sqlite3.c with the default option even without
+            // .defaults being included here).
+            "THREADSAFE_2",
+            "ENABLE_SESSION"
+        ]
+    )
+]
 var conditionalTargets: [Target] = []
 var kotlinTargetDependency = Target.Dependency.target(name: "PowerSyncKotlin")
 
 if let kotlinSdkPath = localKotlinSdkOverride {
     // We can't depend on local XCFrameworks outside of this project's root, so there's a Package.swift
     // in the PowerSyncKotlin project pointing towards a local build.
-    conditionalDependencies.append(.package(path: "\(kotlinSdkPath)/PowerSyncKotlin"))
+    conditionalDependencies.append(.package(path: "\(kotlinSdkPath)/internal/PowerSyncKotlin"))
 
     kotlinTargetDependency = .product(name: "PowerSyncKotlin", package: "PowerSyncKotlin")
 } else {
     // Not using a local build, so download from releases
     conditionalTargets.append(.binaryTarget(
         name: "PowerSyncKotlin",
-        url: "https://github.com/powersync-ja/powersync-kotlin/releases/download/v1.7.0/PowersyncKotlinRelease.zip",
-        checksum: "836ac106c26a184c10373c862745d9af195737ad01505bb965f197797aa88535"
+        url: "https://github.com/powersync-ja/powersync-kotlin/releases/download/v1.8.0/PowersyncKotlinRelease.zip",
+        checksum: "31ac7c5e11d747e11bceb0b34f30438d37033e700c621b0a468aa308d887587f"
     ))
 }
 
@@ -45,7 +66,7 @@ if let corePath = localCoreExtension {
     // Not using a local build, so download from releases
     conditionalDependencies.append(.package(
         url: "https://github.com/powersync-ja/powersync-sqlite-core-swift.git",
-        exact: "0.4.6"
+        exact: "0.4.8"
     ))
 }
 
@@ -81,7 +102,8 @@ let package = Package(
             name: packageName,
             dependencies: [
                 kotlinTargetDependency,
-                .product(name: "PowerSyncSQLiteCore", package: corePackageName)
+                .product(name: "PowerSyncSQLiteCore", package: corePackageName),
+                .product(name: "CSQLite", package: "CSQLite")
             ]
         ),
         .testTarget(

Sources/PowerSync/Kotlin/KotlinAdapter.swift

@@ -49,7 +49,8 @@ enum KotlinAdapter {
             return PowerSyncKotlin.RawTable(
                 name: table.name,
                 put: translateStatement(table.put),
-                delete: translateStatement(table.delete)
+                delete: translateStatement(table.delete),
+                clear: table.clear,
             );
         }
 

Sources/PowerSync/Kotlin/KotlinPowerSyncDatabaseImpl.swift

@@ -1,5 +1,6 @@
 import Foundation
 import PowerSyncKotlin
+import CSQLite
 
 final class KotlinPowerSyncDatabaseImpl: PowerSyncDatabaseProtocol,
     // `PowerSyncKotlin.PowerSyncDatabase` cannot be marked as Sendable
@@ -15,7 +16,12 @@ final class KotlinPowerSyncDatabaseImpl: PowerSyncDatabaseProtocol,
         dbFilename: String,
         logger: DatabaseLogger
     ) {
-        let factory = PowerSyncKotlin.DatabaseDriverFactory()
+        let rc = sqlite3_initialize();
+        if (rc != 0) {
+            fatalError("Call to sqlite3_initialize() failed with \(rc)")
+        }
+
+        let factory = sqlite3DatabaseFactory(initialStatements: [])
         kotlinDatabase = PowerSyncDatabase(
             factory: factory,
             schema: KotlinAdapter.Schema.toKotlin(schema),
@@ -87,9 +93,10 @@ final class KotlinPowerSyncDatabaseImpl: PowerSyncDatabaseProtocol,
         try await kotlinDatabase.disconnect()
     }
 
-    func disconnectAndClear(clearLocal: Bool = true) async throws {
+    func disconnectAndClear(clearLocal: Bool, soft: Bool) async throws {
         try await kotlinDatabase.disconnectAndClear(
-            clearLocal: clearLocal
+            clearLocal: clearLocal,
+            soft: soft
         )
     }
 
@@ -322,6 +329,11 @@ final class KotlinPowerSyncDatabaseImpl: PowerSyncDatabaseProtocol,
     func close() async throws {
         try await kotlinDatabase.close()
     }
+
+    func syncStream(name: String, params: JsonParam?) -> any SyncStream {
+        let rawStream = kotlinDatabase.syncStream(name: name, parameters: params?.mapValues { $0.toKotlinMap() });
+        return KotlinSyncStream(kotlinStream: rawStream)
+    }
 
     /// Tries to convert Kotlin PowerSyncExceptions to Swift Exceptions
     private func wrapPowerSyncException<R: Sendable>(

Sources/PowerSync/Kotlin/sync/KotlinSyncStatusData.swift

@@ -72,6 +72,24 @@ extension KotlinSyncStatusDataProtocol {
             )
         )
     }
+
+    var syncStreams: [SyncStreamStatus]? {
+        return base.syncStreams?.map(mapSyncStreamStatus)
+    }
+
+    func forStream(stream: SyncStreamDescription) -> SyncStreamStatus? {
+        var rawStatus: Optional<PowerSyncKotlin.SyncStreamStatus>
+        if let kotlinStream = stream as? any HasKotlinStreamDescription {
+            // Fast path: Reuse Kotlin stream object for lookup.
+            rawStatus = base.forStream(stream: kotlinStream.kotlinDescription)
+        } else {
+            // Custom stream description, we have to convert parameters to a Kotlin map.
+            let parameters = stream.parameters?.mapValues { $0.toValue() }
+            rawStatus = syncStatusForStream(status: base, name: stream.name, parameters: parameters)
+        }
+
+        return rawStatus.map(mapSyncStreamStatus)
+    }
 
     private func mapPriorityStatus(_ status: PowerSyncKotlin.PriorityStatusEntry) -> PriorityStatusEntry {
         var lastSyncedAt: Date?