ffi: Remove isolate proxy

moor_ffi/CHANGELOG.md

@@ -2,6 +2,7 @@
 
 - Remove the `background` flag from the moor apis provided by this package. Use the moor isolate api
   instead.
+- Remove builtin support for background execution from the low-level `Database` api
 - Support Dart 2.6, drop support for older versions
 
 ## 0.0.1

moor_ffi/example/main_async.dart

@@ -1,28 +0,0 @@
-import 'package:moor_ffi/database.dart';
-
-const _createTable = r''' 
-CREATE TABLE frameworks (
-  id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
-  name VARCHAR NOT NULL
-);
-''';
-
-void main() async {
-  final db = await IsolateDb.openMemory();
-  await db.execute(_createTable);
-
-  final insertStmt =
-      await db.prepare('INSERT INTO frameworks(name) VALUES (?)');
-  await insertStmt.execute(['Flutter']);
-  await insertStmt.execute(['AngularDart']);
-  await insertStmt.close();
-
-  final selectStmt = await db.prepare('SELECT * FROM frameworks ORDER BY name');
-  final result = await selectStmt.select();
-  for (var row in result) {
-    print('${row['id']}: ${row['name']}');
-  }
-
-  await selectStmt.close();
-  await db.close();
-}

moor_ffi/lib/database.dart

@@ -1,11 +1,9 @@
-/// Exports the low-level [Database] and [IsolateDb] classes to run operations
+/// Exports the low-level [Database] class to run operations on a sqlite
-/// on a sqflite database.
+/// database via `dart:ffi`.
 library database;
 
 import 'package:moor_ffi/src/bindings/types.dart';
-import 'src/impl/isolate/isolate_db.dart';
 
-export 'src/api/database.dart';
 export 'src/api/result.dart';
-export 'src/impl/database.dart' show SqliteException, Database;
+export 'src/impl/database.dart'
-export 'src/impl/isolate/isolate_db.dart';
+    show SqliteException, Database, PreparedStatement;

moor_ffi/lib/src/api/database.dart

@@ -1,44 +0,0 @@
-import 'dart:async';
-
-import 'package:moor_ffi/database.dart';
-
-/// A opened sqlite database.
-abstract class BaseDatabase {
-  /// Closes this database connection and releases the resources it uses. If
-  /// an error occurs while closing the database, an exception will be thrown.
-  /// The allocated memory will be freed either way.
-  FutureOr<void> close();
-
-  /// Executes the [sql] statement and ignores the result. Will throw if an
-  /// error occurs while executing.
-  FutureOr<void> execute(String sql);
-
-  /// Prepares the [sql] statement.
-  FutureOr<BasePreparedStatement> prepare(String sql);
-
-  /// Get the application defined version of this database.
-  FutureOr<int> userVersion();
-
-  /// Update the application defined version of this database.
-  FutureOr<void> setUserVersion(int version);
-
-  /// Returns the amount of rows affected by the last INSERT, UPDATE or DELETE
-  /// statement.
-  FutureOr<int> getUpdatedRows();
-
-  /// Returns the row-id of the last inserted row.
-  FutureOr<int> getLastInsertId();
-}
-
-/// A prepared statement that can be executed multiple times.
-abstract class BasePreparedStatement {
-  /// Executes this prepared statement as a select statement. The returned rows
-  /// will be returned.
-  FutureOr<Result> select([List<dynamic> args]);
-
-  /// Executes this prepared statement.
-  FutureOr<void> execute([List<dynamic> params]);
-
-  /// Closes this prepared statement and releases its resources.
-  FutureOr<void> close();
-}

moor_ffi/lib/src/impl/database.dart

@@ -16,7 +16,8 @@ part 'prepared_statement.dart';
 
 const _openingFlags = Flags.SQLITE_OPEN_READWRITE | Flags.SQLITE_OPEN_CREATE;
 
-class Database implements BaseDatabase {
+/// A opened sqlite database.
+class Database {
   final Pointer<types.Database> _db;
   final List<PreparedStatement> _preparedStmt = [];
   bool _isClosed = false;
@@ -56,7 +57,9 @@ class Database implements BaseDatabase {
     }
   }
 
-  @override
+  /// Closes this database connection and releases the resources it uses. If
+  /// an error occurs while closing the database, an exception will be thrown.
+  /// The allocated memory will be freed either way.
   void close() {
     // close all prepared statements first
     _isClosed = true;
@@ -84,7 +87,8 @@ class Database implements BaseDatabase {
     }
   }
 
-  @override
+  /// Executes the [sql] statement and ignores the result. Will throw if an
+  /// error occurs while executing.
   void execute(String sql) {
     _ensureOpen();
 
@@ -111,7 +115,7 @@ class Database implements BaseDatabase {
     }
   }
 
-  @override
+  /// Prepares the [sql] statement.
   PreparedStatement prepare(String sql) {
     _ensureOpen();
 
@@ -137,7 +141,7 @@ class Database implements BaseDatabase {
     return prepared;
   }
 
-  @override
+  /// Get the application defined version of this database.
   int userVersion() {
     final stmt = prepare('PRAGMA user_version');
     final result = stmt.select();
@@ -146,18 +150,19 @@ class Database implements BaseDatabase {
     return result.first.columnAt(0) as int;
   }
 
-  @override
+  /// Update the application defined version of this database.
   void setUserVersion(int version) {
     execute('PRAGMA user_version = $version');
   }
 
-  @override
+  /// Returns the amount of rows affected by the last INSERT, UPDATE or DELETE
+  /// statement.
   int getUpdatedRows() {
     _ensureOpen();
     return bindings.sqlite3_changes(_db);
   }
 
-  @override
+  /// Returns the row-id of the last inserted row.
   int getLastInsertId() {
     _ensureOpen();
     return bindings.sqlite3_last_insert_rowid(_db);

moor_ffi/lib/src/impl/isolate/background.dart

@@ -1,194 +0,0 @@
-import 'dart:async';
-import 'dart:isolate';
-
-import 'package:moor_ffi/database.dart';
-import 'package:moor_ffi/src/impl/database.dart';
-
-enum IsolateCommandType {
-  openDatabase,
-  closeDatabase,
-  executeSqlDirectly,
-  prepareStatement,
-  getUserVersion,
-  setUserVersion,
-  getUpdatedRows,
-  getLastInsertId,
-  preparedSelect,
-  preparedExecute,
-  preparedClose
-}
-
-class IsolateCommand {
-  final int requestId;
-  final IsolateCommandType type;
-  final dynamic data;
-
-  /// If this command operates on a prepared statement, contains the id of that
-  /// statement as sent by the background isolate.
-  int preparedStatementId;
-
-  IsolateCommand(this.requestId, this.type, this.data);
-}
-
-class IsolateResponse {
-  final int requestId;
-  final dynamic response;
-  final dynamic error;
-
-  IsolateResponse(this.requestId, this.response, this.error);
-}
-
-/// Communicates with a background isolate over an RPC-like api.
-class DbOperationProxy {
-  /// Stream of messages received by the background isolate.
-  final StreamController<dynamic> backgroundMsgs;
-  final ReceivePort _receivePort;
-  final Map<int, Completer> _pendingRequests = {};
-
-  final SendPort send;
-  final Isolate isolate;
-
-  var closed = false;
-
-  int _currentRequestId = 0;
-
-  DbOperationProxy(
-      this.backgroundMsgs, this._receivePort, this.send, this.isolate) {
-    backgroundMsgs.stream.listen(_handleResponse);
-  }
-
-  Future<dynamic> sendRequest(IsolateCommandType type, dynamic data,
-      {int preparedStmtId}) {
-    if (closed) {
-      throw StateError('Tried to call a database method after .close()');
-    }
-
-    final id = _currentRequestId++;
-    final cmd = IsolateCommand(id, type, data)
-      ..preparedStatementId = preparedStmtId;
-    final completer = Completer();
-    _pendingRequests[id] = completer;
-
-    send.send(cmd);
-
-    return completer.future;
-  }
-
-  void _handleResponse(dynamic response) {
-    if (response is IsolateResponse) {
-      final completer = _pendingRequests.remove(response.requestId);
-      if (response.error != null) {
-        completer.completeError(response.error);
-      } else {
-        completer.complete(response.response);
-      }
-    }
-  }
-
-  void close() {
-    closed = true;
-    _receivePort.close();
-    backgroundMsgs.close();
-    isolate.kill();
-  }
-
-  static Future<DbOperationProxy> spawn() async {
-    final foregroundReceive = ReceivePort();
-    final backgroundSend = foregroundReceive.sendPort;
-    final isolate = await Isolate.spawn(_entryPoint, backgroundSend,
-        debugName: 'moor_ffi background isolate');
-
-    final controller = StreamController.broadcast();
-    foregroundReceive.listen(controller.add);
-
-    final foregroundSend = await controller.stream
-        .firstWhere((msg) => msg is SendPort) as SendPort;
-
-    return DbOperationProxy(
-        controller, foregroundReceive, foregroundSend, isolate);
-  }
-
-  static void _entryPoint(SendPort backgroundSend) {
-    final backgroundReceive = ReceivePort();
-    final foregroundSend = backgroundReceive.sendPort;
-
-    // inform the main isolate about the created send port
-    backgroundSend.send(foregroundSend);
-
-    BackgroundIsolateRunner(backgroundReceive, backgroundSend).start();
-  }
-}
-
-class BackgroundIsolateRunner {
-  final ReceivePort receive;
-  final SendPort send;
-
-  Database db;
-  List<PreparedStatement> stmts = [];
-
-  BackgroundIsolateRunner(this.receive, this.send);
-
-  void start() {
-    receive.listen((data) {
-      if (data is IsolateCommand) {
-        try {
-          final response = _handleCommand(data);
-          send.send(IsolateResponse(data.requestId, response, null));
-        } catch (e) {
-          if (e is Error) {
-            // errors contain a StackTrace, which cannot be sent. So we just
-            // send the description of that stacktrace.
-            final exception =
-                Exception('Error in background isolate: $e\n${e.stackTrace}');
-            send.send(IsolateResponse(data.requestId, null, exception));
-          } else {
-            send.send(IsolateResponse(data.requestId, null, e));
-          }
-        }
-      }
-    });
-  }
-
-  dynamic _handleCommand(IsolateCommand cmd) {
-    switch (cmd.type) {
-      case IsolateCommandType.openDatabase:
-        assert(db == null);
-        db = Database.open(cmd.data as String);
-        break;
-      case IsolateCommandType.closeDatabase:
-        db?.close();
-        stmts.clear();
-        db = null;
-        break;
-      case IsolateCommandType.executeSqlDirectly:
-        db.execute(cmd.data as String);
-        break;
-      case IsolateCommandType.prepareStatement:
-        final stmt = db.prepare(cmd.data as String);
-        stmts.add(stmt);
-        return stmts.length - 1;
-      case IsolateCommandType.getUserVersion:
-        return db.userVersion();
-      case IsolateCommandType.setUserVersion:
-        final version = cmd.data as int;
-        db.setUserVersion(version);
-        break;
-      case IsolateCommandType.getUpdatedRows:
-        return db.getUpdatedRows();
-      case IsolateCommandType.getLastInsertId:
-        return db.getLastInsertId();
-      case IsolateCommandType.preparedSelect:
-        final stmt = stmts[cmd.preparedStatementId];
-        return stmt.select(cmd.data as List);
-      case IsolateCommandType.preparedExecute:
-        final stmt = stmts[cmd.preparedStatementId];
-        stmt.execute(cmd.data as List);
-        break;
-      case IsolateCommandType.preparedClose:
-        final index = cmd.preparedStatementId;
-        stmts[index].close();
-        stmts.removeAt(index);
-        break;
-    }
-  }
-}

moor_ffi/lib/src/impl/isolate/isolate_db.dart

@@ -1,105 +0,0 @@
-import 'dart:async';
-import 'dart:io';
-
-import 'package:moor_ffi/database.dart';
-import 'package:moor_ffi/src/impl/database.dart';
-import 'package:moor_ffi/src/impl/isolate/background.dart';
-
-class IsolateDb implements BaseDatabase {
-  /// Spawns a background isolate and opens the [file] on that isolate. The file
-  /// will be created if it doesn't exist.
-  static Future<IsolateDb> openFile(File file) => open(file.absolute.path);
-
-  /// Opens a in-memory database on a background isolates.
-  ///
-  /// If you're not using extensive queries, a synchronous [Database] will
-  /// provide better performance for in-memory databases!
-  static Future<IsolateDb> openMemory() => open(':memory:');
-
-  /// Spawns a background isolate and opens a sqlite3 database from its
-  /// filename.
-  static Future<IsolateDb> open(String path) async {
-    final proxy = await DbOperationProxy.spawn();
-
-    final isolate = IsolateDb._(proxy);
-    await isolate._open(path);
-
-    return isolate;
-  }
-
-  final DbOperationProxy _proxy;
-  IsolateDb._(this._proxy);
-
-  Future<int> _sendAndAssumeInt(IsolateCommandType type, [dynamic data]) async {
-    return await _proxy.sendRequest(type, data) as int;
-  }
-
-  Future<void> _open(String path) {
-    return _proxy.sendRequest(IsolateCommandType.openDatabase, path);
-  }
-
-  @override
-  Future<void> close() async {
-    await _proxy.sendRequest(IsolateCommandType.closeDatabase, null);
-    _proxy.close();
-  }
-
-  @override
-  Future<void> execute(String sql) async {
-    await _proxy.sendRequest(IsolateCommandType.executeSqlDirectly, sql);
-  }
-
-  @override
-  Future<int> getLastInsertId() async {
-    return _sendAndAssumeInt(IsolateCommandType.getLastInsertId);
-  }
-
-  @override
-  Future<int> getUpdatedRows() async {
-    return _sendAndAssumeInt(IsolateCommandType.getUpdatedRows);
-  }
-
-  @override
-  FutureOr<BasePreparedStatement> prepare(String sql) async {
-    final id =
-        await _sendAndAssumeInt(IsolateCommandType.prepareStatement, sql);
-    return IsolatePreparedStatement(this, id);
-  }
-
-  @override
-  Future<void> setUserVersion(int version) async {
-    await _proxy.sendRequest(IsolateCommandType.setUserVersion, version);
-  }
-
-  @override
-  Future<int> userVersion() async {
-    return _sendAndAssumeInt(IsolateCommandType.getUserVersion);
-  }
-}
-
-class IsolatePreparedStatement implements BasePreparedStatement {
-  final IsolateDb _db;
-  final int _id;
-
-  IsolatePreparedStatement(this._db, this._id);
-
-  @override
-  Future<void> close() async {
-    await _db._proxy.sendRequest(IsolateCommandType.preparedClose, null,
-        preparedStmtId: _id);
-  }
-
-  @override
-  Future<void> execute([List params]) async {
-    await _db._proxy.sendRequest(IsolateCommandType.preparedExecute, params,
-        preparedStmtId: _id);
-  }
-
-  @override
-  Future<Result> select([List params]) async {
-    final response = await _db._proxy.sendRequest(
-        IsolateCommandType.preparedSelect, params,
-        preparedStmtId: _id);
-    return response as Result;
-  }
-}

moor_ffi/lib/src/impl/prepared_statement.dart

@@ -1,6 +1,7 @@
 part of 'database.dart';
 
-class PreparedStatement implements BasePreparedStatement {
+/// A prepared statement that can be executed multiple times.
+class PreparedStatement {
   final Pointer<types.Statement> _stmt;
   final Database _db;
   bool _closed = false;
@@ -10,7 +11,7 @@ class PreparedStatement implements BasePreparedStatement {
 
   PreparedStatement._(this._stmt, this._db);
 
-  @override
+  /// Closes this prepared statement and releases its resources.
   void close() {
     if (!_closed) {
       _reset();
@@ -26,7 +27,8 @@ class PreparedStatement implements BasePreparedStatement {
     }
   }
 
-  @override
+  /// Executes this prepared statement as a select statement. The returned rows
+  /// will be returned.
   Result select([List<dynamic> params]) {
     _ensureNotFinalized();
     _reset();
@@ -71,7 +73,7 @@ class PreparedStatement implements BasePreparedStatement {
     }
   }
 
-  @override
+  /// Executes this prepared statement.
   void execute([List<dynamic> params]) {
     _ensureNotFinalized();
     _reset();

moor_ffi/test/database/insert_test.dart

@@ -0,0 +1,16 @@
+import 'package:moor_ffi/database.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('insert statements report their id', () {
+    final opened = Database.memory();
+    opened.execute('CREATE TABLE tbl(a INTEGER PRIMARY KEY AUTOINCREMENT)');
+
+    for (var i = 0; i < 5; i++) {
+      opened.execute('INSERT INTO tbl DEFAULT VALUES');
+      expect(opened.getLastInsertId(), i + 1);
+    }
+
+    opened.close();
+  });
+}

moor_ffi/test/database/prepared_statements_test.dart

@@ -0,0 +1,43 @@
+import 'package:moor_ffi/database.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('prepared statements can be used multiple times', () {
+    final opened = Database.memory();
+    opened.execute('CREATE TABLE tbl (a TEXT);');
+
+    final stmt = opened.prepare('INSERT INTO tbl(a) VALUES(?)');
+    stmt.execute(['a']);
+    stmt.execute(['b']);
+    stmt.close();
+
+    final select = opened.prepare('SELECT * FROM tbl ORDER BY a');
+    final result = select.select();
+
+    expect(result, hasLength(2));
+    expect(result.map((row) => row['a']), ['a', 'b']);
+
+    select.close();
+
+    opened.close();
+  });
+
+  test('prepared statements cannot be used after close', () {
+    final opened = Database.memory();
+
+    final stmt = opened.prepare('SELECT ?');
+    stmt.close();
+
+    expect(stmt.select, throwsA(anything));
+
+    opened.close();
+  });
+
+  test('prepared statements cannot be used after db is closed', () {
+    final opened = Database.memory();
+    final stmt = opened.prepare('SELECT 1');
+    opened.close();
+
+    expect(stmt.select, throwsA(anything));
+  });
+}

moor_ffi/test/database/select_test.dart

@@ -0,0 +1,20 @@
+import 'package:moor_ffi/database.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('select statements return expected value', () {
+    final opened = Database.memory();
+
+    final prepared = opened.prepare('SELECT ?');
+
+    final result1 = prepared.select([1]);
+    expect(result1.columnNames, ['?']);
+    expect(result1.single.columnAt(0), 1);
+
+    final result2 = prepared.select([2]);
+    expect(result2.columnNames, ['?']);
+    expect(result2.single.columnAt(0), 2);
+
+    opened.close();
+  });
+}

moor_ffi/test/database/user_version_test.dart

@@ -0,0 +1,29 @@
+import 'dart:io';
+
+import 'package:moor_ffi/database.dart';
+import 'package:test/test.dart';
+import 'package:path/path.dart' as p;
+
+void main() {
+  test('can set the user version on a database', () {
+    final file = File(p.join(
+        Directory.systemTemp.absolute.path, 'moor_ffi_test_user_version.db'));
+    final opened = Database.openFile(file);
+
+    var version = opened.userVersion();
+    expect(version, 0);
+
+    opened.setUserVersion(3);
+    version = opened.userVersion();
+    expect(version, 3);
+
+    // ensure that the version is stored on file
+    opened.close();
+
+    final another = Database.openFile(file);
+    expect(another.userVersion(), 3);
+    another.close();
+
+    file.deleteSync();
+  });
+}

moor_ffi/test/ffi_test.dart

@@ -1,68 +0,0 @@
-import 'dart:async';
-import 'dart:io';
-
-import 'package:path/path.dart' as p;
-import 'package:test/test.dart';
-import 'package:moor_ffi/database.dart';
-
-import 'suite/insert.dart' as insert;
-import 'suite/prepared_statements.dart' as prepared_statements;
-import 'suite/select.dart' as select;
-import 'suite/user_version.dart' as user_version;
-
-var _tempFileCounter = 0;
-List<File> _createdFiles = [];
-File temporaryFile() {
-  final count = _tempFileCounter++;
-  final path =
-      p.join(Directory.systemTemp.absolute.path, 'moor_ffi_test_$count.db');
-  final file = File(path);
-  _createdFiles.add(file);
-  return file;
-}
-
-abstract class TestedDatabase {
-  FutureOr<BaseDatabase> openFile(File file);
-  FutureOr<BaseDatabase> openMemory();
-}
-
-class TestRegularDatabase implements TestedDatabase {
-  @override
-  BaseDatabase openFile(File file) => Database.openFile(file);
-
-  @override
-  BaseDatabase openMemory() => Database.memory();
-}
-
-class TestIsolateDatabase implements TestedDatabase {
-  @override
-  Future<BaseDatabase> openFile(File file) => IsolateDb.openFile(file);
-
-  @override
-  FutureOr<BaseDatabase> openMemory() => IsolateDb.openMemory();
-}
-
-void main() {
-  group('regular database', () {
-    _declareAll(TestRegularDatabase());
-  });
-
-  group('isolate database', () {
-    _declareAll(TestIsolateDatabase());
-  });
-
-  tearDownAll(() async {
-    for (var file in _createdFiles) {
-      if (await file.exists()) {
-        await file.delete();
-      }
-    }
-  });
-}
-
-void _declareAll(TestedDatabase db) {
-  insert.main(db);
-  prepared_statements.main(db);
-  select.main(db);
-  user_version.main(db);
-}

moor_ffi/test/suite/insert.dart

@@ -1,18 +0,0 @@
-import 'package:test/test.dart';
-
-import '../ffi_test.dart';
-
-void main(TestedDatabase db) {
-  test('insert statements report their id', () async {
-    final opened = await db.openMemory();
-    await opened
-        .execute('CREATE TABLE tbl(a INTEGER PRIMARY KEY AUTOINCREMENT)');
-
-    for (var i = 0; i < 5; i++) {
-      await opened.execute('INSERT INTO tbl DEFAULT VALUES');
-      expect(await opened.getLastInsertId(), i + 1);
-    }
-
-    await opened.close();
-  });
-}

moor_ffi/test/suite/prepared_statements.dart

@@ -1,44 +0,0 @@
-import 'package:test/test.dart';
-
-import '../ffi_test.dart';
-
-void main(TestedDatabase db) {
-  test('prepared statements can be used multiple times', () async {
-    final opened = await db.openMemory();
-    await opened.execute('CREATE TABLE tbl (a TEXT);');
-
-    final stmt = await opened.prepare('INSERT INTO tbl(a) VALUES(?)');
-    await stmt.execute(['a']);
-    await stmt.execute(['b']);
-    await stmt.close();
-
-    final select = await opened.prepare('SELECT * FROM tbl ORDER BY a');
-    final result = await select.select();
-
-    expect(result, hasLength(2));
-    expect(result.map((row) => row['a']), ['a', 'b']);
-
-    await select.close();
-
-    await opened.close();
-  });
-
-  test('prepared statements cannot be used after close', () async {
-    final opened = await db.openMemory();
-
-    final stmt = await opened.prepare('SELECT ?');
-    await stmt.close();
-
-    expect(stmt.select, throwsA(anything));
-
-    await opened.close();
-  });
-
-  test('prepared statements cannot be used after db is closed', () async {
-    final opened = await db.openMemory();
-    final stmt = await opened.prepare('SELECT 1');
-    await opened.close();
-
-    expect(stmt.select, throwsA(anything));
-  });
-}

moor_ffi/test/suite/select.dart

@@ -1,21 +0,0 @@
-import 'package:test/test.dart';
-
-import '../ffi_test.dart';
-
-void main(TestedDatabase db) {
-  test('select statements return expected value', () async {
-    final opened = await db.openMemory();
-
-    final prepared = await opened.prepare('SELECT ?');
-
-    final result1 = await prepared.select([1]);
-    expect(result1.columnNames, ['?']);
-    expect(result1.single.columnAt(0), 1);
-
-    final result2 = await prepared.select([2]);
-    expect(result2.columnNames, ['?']);
-    expect(result2.single.columnAt(0), 2);
-
-    await opened.close();
-  });
-}

moor_ffi/test/suite/user_version.dart

@@ -1,24 +0,0 @@
-import 'package:test/test.dart';
-
-import '../ffi_test.dart';
-
-void main(TestedDatabase db) {
-  test('can set the user version on a database', () async {
-    final file = temporaryFile();
-    final opened = await db.openFile(file);
-
-    var version = await opened.userVersion();
-    expect(version, 0);
-
-    await opened.setUserVersion(3);
-    version = await opened.userVersion();
-    expect(version, 3);
-
-    // ensure that the version is stored on file
-    await opened.close();
-
-    final another = await db.openFile(file);
-    expect(await another.userVersion(), 3);
-    await another.close();
-  });
-}