Add database adapters (#75)

analysis_options.yaml

@@ -15,7 +15,7 @@ linter:
     # the Dart Lint rules page to make maintenance easier
     # https://github.com/dart-lang/linter/blob/master/example/all.yaml
     - always_declare_return_types
-    - always_put_control_body_on_new_line
+#    - always_put_control_body_on_new_line
     # - always_put_required_named_parameters_first # we prefer having parameters in the same order as fields https://github.com/flutter/flutter/issues/10219
     # - always_require_non_null_named_parameters
     # - always_specify_types

floor/lib/floor.dart

@@ -1,5 +1,10 @@
 library floor;
 
+export 'package:floor/src/adapter/deletion_adapter.dart';
+export 'package:floor/src/adapter/insertion_adapter.dart';
+export 'package:floor/src/adapter/migration_adapter.dart';
+export 'package:floor/src/adapter/query_adapter.dart';
+export 'package:floor/src/adapter/update_adapter.dart';
 export 'package:floor/src/database.dart';
 export 'package:floor/src/migration.dart';
 export 'package:floor_annotation/floor_annotation.dart';

floor/lib/src/adapter/deletion_adapter.dart

@@ -0,0 +1,72 @@
+import 'package:sqflite/sqflite.dart';
+
+class DeletionAdapter<T> {
+  final DatabaseExecutor _database;
+  final String _entityName;
+  final String _primaryKeyColumnName;
+  final Map<String, dynamic> Function(T) _valueMapper;
+
+  DeletionAdapter(
+    final DatabaseExecutor database,
+    final String entityName,
+    final String primaryKeyColumnName,
+    final Map<String, dynamic> Function(T) valueMapper,
+  )   : assert(database != null),
+        assert(entityName != null),
+        assert(entityName.isNotEmpty),
+        assert(primaryKeyColumnName != null),
+        assert(primaryKeyColumnName.isNotEmpty),
+        assert(valueMapper != null),
+        _database = database,
+        _entityName = entityName,
+        _primaryKeyColumnName = primaryKeyColumnName,
+        _valueMapper = valueMapper;
+
+  Future<void> delete(final T item) async {
+    await _delete(item);
+  }
+
+  Future<void> deleteList(final List<T> items) async {
+    if (items.isEmpty) return;
+
+    final batch = _database.batch();
+    _deleteList(batch, items);
+    await batch.commit(noResult: true);
+  }
+
+  Future<int> deleteAndReturnChangedRows(final T item) {
+    return _delete(item);
+  }
+
+  Future<int> deleteListAndReturnChangedRows(final List<T> items) async {
+    if (items.isEmpty) return 0;
+
+    final batch = _database.batch();
+    _deleteList(batch, items);
+    return (await batch.commit(noResult: false))
+        .cast<int>()
+        .reduce((sum, element) => sum + element);
+  }
+
+  Future<int> _delete(final T item) {
+    final int primaryKey = _valueMapper(item)[_primaryKeyColumnName];
+
+    return _database.delete(
+      _entityName,
+      where: '$_primaryKeyColumnName = ?',
+      whereArgs: <int>[primaryKey],
+    );
+  }
+
+  void _deleteList(final Batch batch, final List items) {
+    for (final item in items) {
+      final int primaryKey = _valueMapper(item)[_primaryKeyColumnName];
+
+      batch.delete(
+        _entityName,
+        where: '$_primaryKeyColumnName = ?',
+        whereArgs: <int>[primaryKey],
+      );
+    }
+  }
+}

floor/lib/src/adapter/insertion_adapter.dart

@@ -0,0 +1,77 @@
+import 'package:sqflite/sqflite.dart';
+
+class InsertionAdapter<T> {
+  final DatabaseExecutor _database;
+  final String _entityName;
+  final Map<String, dynamic> Function(T) _valueMapper;
+
+  InsertionAdapter(
+    final DatabaseExecutor database,
+    final String entityName,
+    final Map<String, dynamic> Function(T) valueMapper,
+  )   : assert(database != null),
+        assert(entityName != null),
+        assert(entityName.isNotEmpty),
+        assert(valueMapper != null),
+        _database = database,
+        _entityName = entityName,
+        _valueMapper = valueMapper;
+
+  Future<void> insert(
+    final T item,
+    final ConflictAlgorithm conflictAlgorithm,
+  ) async {
+    await _insert(item, conflictAlgorithm);
+  }
+
+  Future<void> insertList(
+    final List<T> items,
+    final ConflictAlgorithm conflictAlgorithm,
+  ) async {
+    if (items.isEmpty) return;
+
+    final batch = _database.batch();
+    _insertList(batch, items, conflictAlgorithm);
+    await batch.commit(noResult: true);
+  }
+
+  Future<int> insertAndReturnId(
+    final T item,
+    final ConflictAlgorithm conflictAlgorithm,
+  ) {
+    return _insert(item, conflictAlgorithm);
+  }
+
+  Future<List<int>> insertListAndReturnIds(
+    final List<T> items,
+    final ConflictAlgorithm conflictAlgorithm,
+  ) async {
+    if (items.isEmpty) return [];
+
+    final batch = _database.batch();
+    _insertList(batch, items, conflictAlgorithm);
+    return (await batch.commit(noResult: false)).cast<int>();
+  }
+
+  Future<int> _insert(final T item, final ConflictAlgorithm conflictAlgorithm) {
+    return _database.insert(
+      _entityName,
+      _valueMapper(item),
+      conflictAlgorithm: conflictAlgorithm,
+    );
+  }
+
+  void _insertList(
+    final Batch batch,
+    final List<T> items,
+    final ConflictAlgorithm conflictAlgorithm,
+  ) {
+    for (final item in items) {
+      batch.insert(
+        _entityName,
+        _valueMapper(item),
+        conflictAlgorithm: conflictAlgorithm,
+      );
+    }
+  }
+}

floor/lib/src/adapter/migration_adapter.dart

@@ -0,0 +1,30 @@
+import 'package:floor/src/migration.dart';
+import 'package:sqflite/sqflite.dart';
+
+abstract class MigrationAdapter {
+  /// Runs the given [migrations] for migrating the database schema and data.
+  static void runMigrations(
+    final Database migrationDatabase,
+    final int startVersion,
+    final int endVersion,
+    final List<Migration> migrations,
+  ) {
+    final relevantMigrations = migrations
+        .where((migration) => migration.startVersion >= startVersion)
+        .toList()
+          ..sort((first, second) =>
+              first.startVersion.compareTo(second.startVersion));
+
+    if (relevantMigrations.isEmpty ||
+        relevantMigrations.last.endVersion != endVersion) {
+      throw StateError(
+        'There is no migration supplied to update the database to the current version.'
+            ' Aborting the migration.',
+      );
+    }
+
+    for (final migration in relevantMigrations) {
+      migration.migrate(migrationDatabase);
+    }
+  }
+}

floor/lib/src/adapter/query_adapter.dart

@@ -0,0 +1,37 @@
+import 'package:sqflite/sqflite.dart';
+
+/// This class knows how to execute database queries.
+class QueryAdapter {
+  final DatabaseExecutor _database;
+
+  QueryAdapter(final DatabaseExecutor database)
+      : assert(database != null),
+        _database = database;
+
+  Future<T> query<T>(
+    final String sql,
+    final T Function(Map<String, dynamic>) mapper,
+  ) async {
+    final rows = await _database.rawQuery(sql);
+
+    if (rows.isEmpty) {
+      return null;
+    } else if (rows.length > 1) {
+      throw StateError("Query returned more than one row for '$sql'");
+    }
+
+    return mapper(rows.first);
+  }
+
+  Future<List<T>> queryList<T>(
+    final String sql,
+    final T Function(Map<String, dynamic>) mapper,
+  ) async {
+    final rows = await _database.rawQuery(sql);
+    return rows.map((row) => mapper(row)).toList();
+  }
+
+  Future<void> queryNoReturn(final String sql) async {
+    await _database.rawQuery(sql);
+  }
+}

floor/lib/src/adapter/update_adapter.dart

@@ -0,0 +1,94 @@
+import 'package:sqflite/sqflite.dart';
+
+class UpdateAdapter<T> {
+  final DatabaseExecutor _database;
+  final String _entityName;
+  final String _primaryKeyColumnName;
+  final Map<String, dynamic> Function(T) _valueMapper;
+
+  UpdateAdapter(
+    final DatabaseExecutor database,
+    final String entityName,
+    final String primaryKeyColumnName,
+    final Map<String, dynamic> Function(T) valueMapper,
+  )   : assert(database != null),
+        assert(entityName != null),
+        assert(entityName.isNotEmpty),
+        assert(primaryKeyColumnName != null),
+        assert(primaryKeyColumnName.isNotEmpty),
+        assert(valueMapper != null),
+        _database = database,
+        _entityName = entityName,
+        _valueMapper = valueMapper,
+        _primaryKeyColumnName = primaryKeyColumnName;
+
+  Future<void> update(
+    final T item,
+    final ConflictAlgorithm conflictAlgorithm,
+  ) async {
+    await _update(item, conflictAlgorithm);
+  }
+
+  Future<void> updateList(
+    final List<T> items,
+    final ConflictAlgorithm conflictAlgorithm,
+  ) async {
+    if (items.isEmpty) return;
+
+    final batch = _database.batch();
+    _updateList(batch, items, conflictAlgorithm);
+    await batch.commit(noResult: true);
+  }
+
+  Future<int> updateAndReturnChangedRows(
+    final T item,
+    final ConflictAlgorithm conflictAlgorithm,
+  ) {
+    return _update(item, conflictAlgorithm);
+  }
+
+  Future<int> updateListAndReturnChangedRows(
+    final List<T> items,
+    final ConflictAlgorithm conflictAlgorithm,
+  ) async {
+    if (items.isEmpty) return 0;
+
+    final batch = _database.batch();
+    _updateList(batch, items, conflictAlgorithm);
+    return (await batch.commit(noResult: false))
+        .cast<int>()
+        .reduce((sum, element) => sum + element);
+  }
+
+  Future<int> _update(final T item, final ConflictAlgorithm conflictAlgorithm) {
+    final values = _valueMapper(item);
+    final int primaryKey = values[_primaryKeyColumnName];
+
+    return _database.update(
+      _entityName,
+      values,
+      where: '$_primaryKeyColumnName = ?',
+      whereArgs: <int>[primaryKey],
+      conflictAlgorithm: conflictAlgorithm,
+    );
+  }
+
+  void _updateList(
+    final Batch batch,
+    final List<T> items,
+    final ConflictAlgorithm conflictAlgorithm,
+  ) {
+    for (final item in items) {
+      final values = _valueMapper(item);
+      final int primaryKey = values[_primaryKeyColumnName];
+
+      batch.update(
+        _entityName,
+        values,
+        where: '$_primaryKeyColumnName = ?',
+        whereArgs: <int>[primaryKey],
+        conflictAlgorithm: conflictAlgorithm,
+      );
+    }
+  }
+}

floor/lib/src/database.dart

@@ -1,5 +1,4 @@
 import 'package:floor/floor.dart';
-import 'package:meta/meta.dart';
 import 'package:sqflite/sqflite.dart' as sqflite;
 
 /// Extend this class to enable database functionality.
@@ -19,31 +18,4 @@ abstract class FloorDatabase {
       await immutableDatabase.close();
     }
   }
-
-  /// Runs the given [migrations] for migrating the database schema and data.
-  @protected
-  void runMigrations(
-    final sqflite.Database migrationDatabase,
-    final int startVersion,
-    final int endVersion,
-    final List<Migration> migrations,
-  ) {
-    final relevantMigrations = migrations
-        .where((migration) => migration.startVersion >= startVersion)
-        .toList()
-          ..sort((first, second) =>
-              first.startVersion.compareTo(second.startVersion));
-
-    if (relevantMigrations.isEmpty ||
-        relevantMigrations.last.endVersion != endVersion) {
-      throw StateError(
-        'There is no migration supplied to update the database to the current version.'
-            ' Aborting the migration.',
-      );
-    }
-
-    for (final migration in relevantMigrations) {
-      migration.migrate(migrationDatabase);
-    }
-  }
 }