Fix GRDB tests

Author: simolus3

CHANGELOG.md

@@ -2,10 +2,12 @@
 
 ## 1.14.0 (unreleased)
 
+* Remove internal dependency on the PowerSync Kotlin SDK. Going forward, the Swift SDK is implemented in Swift!
+  __Important__: While these changes are tested, they are a full rewrite of the internal connection pool logic.
+  Please also test queries in your app after upgrading.
 * Add `opDataTyped` and `previousValuesTyped` to `CrudEntry`, providing typed values instead of strings.
 * Make `CrudBatch`, `CrudEntry` and `CrudTransaction` a concrete struct. Note that these can no longer be created in user code.
 * Remove the internal `withSession` API.
-* Remove internal dependency on the PowerSync Kotlin SDK. Going forward, the Swift SDK is implemented in Swift!
 * Breaking (for internal `SQLiteConnectionPoolProtocol` implementers): Make callbacks generic.
 * Breaking (for internal `SQLiteConnectionLease` implementers): Add methods to run statements.
 

Demos/GRDBDemo/GRDBDemo.xcodeproj/project.pbxproj

@@ -314,7 +314,7 @@
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = AccentColor;
 				CODE_SIGN_STYLE = Automatic;
 				CURRENT_PROJECT_VERSION = 1;
-				DEVELOPMENT_TEAM = ZGT7463CVJ;
+				DEVELOPMENT_TEAM = N2FNDTNV98;
 				ENABLE_APP_SANDBOX = YES;
 				ENABLE_HARDENED_RUNTIME = YES;
 				ENABLE_INCOMING_NETWORK_CONNECTIONS = NO;
@@ -368,7 +368,7 @@
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = AccentColor;
 				CODE_SIGN_STYLE = Automatic;
 				CURRENT_PROJECT_VERSION = 1;
-				DEVELOPMENT_TEAM = ZGT7463CVJ;
+				DEVELOPMENT_TEAM = N2FNDTNV98;
 				ENABLE_APP_SANDBOX = YES;
 				ENABLE_HARDENED_RUNTIME = YES;
 				ENABLE_INCOMING_NETWORK_CONNECTIONS = NO;

Demos/GRDBDemo/GRDBDemo.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved

@@ -118,15 +118,6 @@ Feel free to use the `DatabasePool` for view logic and the `PowerSyncDatabase` f
 - Updating the PowerSync schema, with `updateSchema`, is not currently fully supported with GRDB connections.
 - This integration currently requires statically linking PowerSync and GRDB.
 - This implementation requires defining the PowerSync Schema and GRDB data types. This results in some duplication.
-- This implementation uses the SQLite session API to track updates made by the PowerSync SDK. This could use more memory compared to the Standard PowerSync SQLite implementation.
-- This implementation can cause warnings such as "Thread Performance Checker: Thread running at User-interactive quality-of-service class waiting on a lower QoS thread running at Default quality-of-service class. Investigate ways to avoid priority inversions". This will be addressed in a future release.
-
-## Underlying Kotlin Dependency
-
-The PowerSync Swift SDK makes use of the [PowerSync Kotlin SDK](https://github.com/powersync-ja/powersync-kotlin) and the API tool [SKIE](https://skie.touchlab.co/) under the hood to implement the Swift package.
-However, this dependency is resolved internally and all public APIs are written entirely in Swift.
-
-For more details, see the [Swift SDK reference](https://docs.powersync.com/client-sdk-references/swift) and generated [API references](https://powersync-ja.github.io/powersync-swift/documentation/powersync/).
 
 ## Attachments
 

README.md

@@ -102,9 +102,9 @@ final class AsyncConnectionPool: SQLiteConnectionPoolProtocol {
         if isWriter {
             // Older versions of the SDK used to set up an empty schema and raise the user version to 1.
             // Keep doing that for consistency.
-            let version = try context.withIterator(sql: "pragma user_version", parameters: []) { rows in
-                try rows.next { try $0.getInt(index: 0) }
-            }
+            var stmt = try context.iterate(sql: "pragma user_version", parameters: [])
+            let version = try stmt.stepWithCursor { try $0.getInt(index: 0) }
+            let _ = consume stmt
             if let version, version < 1 {
                 let _ = try context.execute(sql: "pragma user_version = 1", parameters: [])
             }

Sources/PowerSync/Implementation/AsyncConnectionPool.swift

@@ -31,31 +31,31 @@ final class ConnectionLeaseContext: ConnectionContext {
 
     func getOptional<RowType>(sql: String, parameters: [(any Sendable)?]?, mapper: @escaping @Sendable (any SqlCursor) throws -> RowType) throws -> RowType? {
         try lease.withLock { lease in
-            try lease.withIterator(sql: sql, parameters: mapParameters(parameters)) { rows in
-                return try rows.next(callback: mapper)
-            }
+            var stmt = try lease.iterate(sql: sql, parameters: mapParameters(parameters))
+            return try stmt.stepWithCursor(callback: mapper)
         }
     }
 
     func getAll<RowType>(sql: String, parameters: [(any Sendable)?]?, mapper: @escaping @Sendable (any SqlCursor) throws -> RowType) throws -> [RowType] {
         try lease.withLock { lease in
-            try lease.withIterator(sql: sql, parameters: mapParameters(parameters)) { rows in
-                var result: [RowType] = []
-                while let row = try rows.next(callback: mapper) {
-                    result.append(row)
-                }
-                return result
+            var stmt = try lease.iterate(sql: sql, parameters: mapParameters(parameters))
+            var result: [RowType] = []
+
+            while let row = try stmt.stepWithCursor(callback: mapper) {
+                result.append(row)
             }
+            return result
         }
     }
 
     func get<RowType>(sql: String, parameters: [(any Sendable)?]?, mapper: @escaping @Sendable (any SqlCursor) throws -> RowType) throws -> RowType {
         try lease.withLock { lease in
-            try lease.withIterator(sql: sql, parameters: mapParameters(parameters)) { rows in
-                guard let cursor = try rows.next(callback: mapper) else {
-                    throw PowerSyncError.operationFailed(message: "Expected \(sql) to return a row, but got an empty result set.")
-                }
-                return cursor
+            var stmt = try lease.iterate(sql: sql, parameters: mapParameters(parameters))
+
+            if let row = try stmt.stepWithCursor(callback: mapper) {
+                return row
+            } else {
+                throw PowerSyncError.operationFailed(message: "Expected \(sql) to return a row, but got an empty result set.")
             }
         }
     }

Sources/PowerSync/Implementation/queries/LeaseContext.swift

@@ -37,15 +37,14 @@ final class NativeConnectionPool: Sendable {
 
     private func dispatchWrites(lease: NativeConnectionLease) {
         do {
-            try lease.withIterator(sql: "SELECT powersync_update_hooks('get')", parameters: []) { rows in
-                let affectedTables = try rows.next {
-                    let decoder = JSONDecoder()
-                    return try decoder.decode(Set<String>.self, from: try $0.getString(index: 0).data(using: .utf8)!)
-                }
+            var stmt = try lease.iterate(sql: "SELECT powersync_update_hooks('get')", parameters: [])
+            let affectedTables = try stmt.stepWithCursor {
+                let decoder = JSONDecoder()
+                return try decoder.decode(Set<String>.self, from: try $0.getString(index: 0).data(using: .utf8)!)
+            }
 
-                if let affectedTables, !affectedTables.isEmpty {
-                    self.handleUpdates(affectedTables)
-                }
+            if let affectedTables, !affectedTables.isEmpty {
+                self.handleUpdates(affectedTables)
             }
         } catch {
             logger.warning("Could not read affected tables", tag: "NativeConnectionPool")
@@ -138,39 +137,4 @@ struct RawSqliteConnection: ~Copyable {
 // We can't generally assume SQLite connections to be thread-safe.
 struct NativeConnectionLease: SQLiteConnectionLease, @unchecked Sendable {
     let pointer: OpaquePointer
-
-    func execute(sql: String, parameters: [PowerSyncDataType?]) throws -> Int64 {
-        do {
-            var stmt = try NativeSqliteStatement(db: pointer, sql: sql)
-            try stmt.bindValues(parameters)
-            while try stmt.step() {
-                // Iterate through the statement.
-            }
-        }
-
-        return sqlite3_changes64(pointer)
-    }
-
-    func withIterator<T>(sql: String, parameters: [PowerSyncDataType?], callback: (SQLiteStatementIteratorProtocol) throws -> T) throws -> T {
-        var stmt = try NativeSqliteStatement(db: pointer, sql: sql)
-        try stmt.bindValues(parameters)
-        return try withUnsafeMutablePointer(to: &stmt) { ptr in
-            let iterator = NativeStatementIterator(stmt: ptr)
-            return try callback(iterator)
-        }
-    }
-}
-
-private struct NativeStatementIterator: SQLiteStatementIteratorProtocol {
-    var stmt: UnsafeMutablePointer<NativeSqliteStatement>
-    
-    func next<T>(callback: (any SqlCursor) throws -> T) throws -> T? {
-        if try stmt.pointee.step() {
-            let cursor = StatementCursor(stmt)
-            defer { cursor.invalidate() }
-            return try callback(cursor)
-        } else {
-            return nil
-        }
-    }
 }

Sources/PowerSync/Implementation/sqlite3/NativeConnectionPool.swift

@@ -0,0 +1,22 @@
+import CSQLite
+
+/// Implements functions to execute and iterate through SQL statements based on a SQLite connection pointer.
+extension SQLiteConnectionLease {
+    func execute(sql: String, parameters: [PowerSyncDataType?]) throws -> Int64 {
+        do {
+            var stmt = try NativeSqliteStatement(db: pointer, sql: sql)
+            try stmt.bindValues(parameters)
+            while try stmt.step() {
+                // Iterate through the statement.
+            }
+        }
+
+        return sqlite3_changes64(pointer)
+    }
+
+    func iterate(sql: String, parameters: [PowerSyncDataType?]) throws -> NativeSqliteStatement {
+        let stmt = try NativeSqliteStatement(db: pointer, sql: sql)
+        try stmt.bindValues(parameters)
+        return stmt
+    }
+}

Sources/PowerSync/Implementation/sqlite3/NativeLeaseUtils.swift

@@ -125,4 +125,18 @@ struct NativeSqliteStatement: ~Copyable {
             try throwDatabaseError(db: self.db, sql: self.sql)
         }
     }
+    
+    mutating func stepWithCursor<T>(callback: (any SqlCursor) throws -> T) throws -> T? {
+        if try step() {
+            // Turn the static ~Copyable lifetime into a dynamic lifetime with explicit
+            // invalidation.
+            return try withUnsafePointer(to: self) { ptr in
+                let cursor = StatementCursor(ptr)
+                defer { cursor.invalidate() }
+                return try callback(cursor)
+            }
+        } else {
+            return nil
+        }
+    }
 }

Sources/PowerSync/Implementation/sqlite3/NativeStatement.swift

@@ -5,15 +5,6 @@ public protocol SQLiteConnectionLease {
     /// Pointer to the underlying SQLite connection.
     /// This pointer should not be used outside of the closure which provided the lease.
     var pointer: OpaquePointer { borrowing get }
-
-    /// Executes an SQL statement and returns the amount of rows affected.
-    func execute(sql: String, parameters: [PowerSyncDataType?]) throws -> Int64
-
-    func withIterator<T>(sql: String, parameters: [PowerSyncDataType?], callback: (_: SQLiteStatementIteratorProtocol) throws -> T) throws -> T
-}
-
-public protocol SQLiteStatementIteratorProtocol {
-    func next<T>(callback: (_ cursor: SqlCursor) throws -> T) throws -> T?
 }
 
 /// An implementation of a connection pool providing asynchronous access to a single writer and multiple readers.