blob: 194393b62760b7362e6d7f5dfb35e157dade6dc3 [file] [log] [blame]
// Copyright (c) 2016, 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.
library front_end.memory_file_system;
import 'dart:convert';
import 'dart:typed_data';
import 'file_system.dart';
/// Concrete implementation of [FileSystem] which performs its operations on an
/// in-memory virtual file system.
///
/// Not intended to be implemented or extended by clients.
class MemoryFileSystem implements FileSystem {
final Map<Uri, Uint8List> _files = {};
final Set<Uri> _directories = new Set<Uri>();
/// The "current directory" in the in-memory virtual file system.
///
/// This is used to convert relative URIs to absolute URIs.
///
/// Always ends in a trailing '/'.
Uri currentDirectory;
MemoryFileSystem(Uri currentDirectory)
: currentDirectory = _addTrailingSlash(currentDirectory) {
_directories.add(currentDirectory);
}
@override
MemoryFileSystemEntity entityForUri(Uri uri) {
return new MemoryFileSystemEntity._(
this, currentDirectory.resolveUri(uri).normalizePath());
}
String get debugString {
StringBuffer sb = new StringBuffer();
_files.forEach((uri, _) => sb.write("- $uri\n"));
_directories.forEach((uri) => sb.write("- $uri\n"));
return '$sb';
}
static Uri _addTrailingSlash(Uri uri) {
if (!uri.path.endsWith('/')) {
uri = uri.replace(path: uri.path + '/');
}
return uri;
}
}
/// Concrete implementation of [FileSystemEntity] for use by
/// [MemoryFileSystem].
class MemoryFileSystemEntity implements FileSystemEntity {
final MemoryFileSystem _fileSystem;
@override
final Uri uri;
MemoryFileSystemEntity._(this._fileSystem, this.uri);
@override
int get hashCode => uri.hashCode;
@override
bool operator ==(Object other) =>
other is MemoryFileSystemEntity &&
other.uri == uri &&
identical(other._fileSystem, _fileSystem);
/// Create a directory for this file system entry.
///
/// If the entry is an existing file, this is an error.
void createDirectory() {
if (_fileSystem._files[uri] != null) {
throw new FileSystemException(uri, 'Entry $uri is a file.');
}
_fileSystem._directories.add(uri);
}
@override
Future<bool> exists() async {
return _fileSystem._files[uri] != null ||
_fileSystem._directories.contains(uri);
}
@override
Future<List<int>> readAsBytes() async {
Uint8List? contents = _fileSystem._files[uri];
if (contents == null) {
throw new FileSystemException(uri, 'File $uri does not exist.');
}
return contents;
}
@override
Future<String> readAsString() async {
List<int> bytes = await readAsBytes();
try {
return utf8.decode(bytes);
} on FormatException catch (e) {
throw new FileSystemException(uri, e.message);
}
}
/// Writes the given raw bytes to this file system entity.
///
/// If no file exists, one is created. If a file exists already, it is
/// overwritten.
void writeAsBytesSync(List<int> bytes) {
if (bytes is Uint8List) {
_update(uri, bytes);
} else {
_update(uri, new Uint8List.fromList(bytes));
}
}
/// Writes the given string to this file system entity.
///
/// The string is encoded as UTF-8.
///
/// If no file exists, one is created. If a file exists already, it is
/// overwritten.
void writeAsStringSync(String s) {
// Note: the return type of utf8.encode is List<int>, but in practice it
// always returns Uint8List. We rely on that for efficiency, so that we
// don't have to make an extra copy.
_update(uri, utf8.encode(s) as Uint8List);
}
void _update(Uri uri, Uint8List data) {
if (_fileSystem._directories.contains(uri)) {
throw new FileSystemException(uri, 'Entry $uri is a directory.');
}
_fileSystem._files[uri] = data;
}
}