blob: 4b388a33cc43c45c76c26d59ad2e12f4780df18b [file] [log] [blame]
// Copyright (c) 2017, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
/// A memory + physical file system used to mock input for tests but provide
/// sdk sources from disk.
library front_end.src.hybrid_file_system;
import 'dart:async';
import '../api_prototype/file_system.dart';
import '../api_prototype/memory_file_system.dart';
import '../api_prototype/standard_file_system.dart';
/// A file system that mixes files from memory and a physical file system. All
/// memory entities take priotity over file system entities.
class HybridFileSystem implements FileSystem {
final MemoryFileSystem memory;
final FileSystem physical;
HybridFileSystem(this.memory, [FileSystem _physical])
: physical = _physical ?? StandardFileSystem.instance;
FileSystemEntity entityForUri(Uri uri) =>
new HybridFileSystemEntity(uri, this);
/// Entity that delegates to an underlying memory or phisical file system
/// entity.
class HybridFileSystemEntity implements FileSystemEntity {
final Uri uri;
FileSystemEntity _delegate;
final HybridFileSystem _fs;
HybridFileSystemEntity(this.uri, this._fs);
Future<FileSystemEntity> get delegate async {
if (_delegate != null) return _delegate;
FileSystemEntity entity = _fs.memory.entityForUri(uri);
if (((uri.scheme != 'file' && uri.scheme != 'data') &&
_fs.physical is StandardFileSystem) ||
await entity.exists()) {
_delegate = entity;
return _delegate;
return _delegate = _fs.physical.entityForUri(uri);
Future<bool> exists() async => (await delegate).exists();
Future<List<int>> readAsBytes() async => (await delegate).readAsBytes();
Future<String> readAsString() async => (await delegate).readAsString();