import 'dart:async'; import 'dart:collection'; import 'dart:io' show ContentType, Directory, File, FileStat, FileSystemEntity, FileSystemException, HttpHeaders, HttpRequest, HttpServer, Link, Platform, exit, stderr, stdin, stdout; import 'dart:isolate'; import 'package:angel_framework/angel_framework.dart'; import 'package:angel_websocket/server.dart'; import 'package:charcode/ascii.dart'; import 'package:dart2_constant/convert.dart'; import 'package:dart2_constant/io.dart'; import 'package:glob/glob.dart'; import 'package:html_builder/elements.dart'; import 'package:html_builder/html_builder.dart'; import 'package:io/ansi.dart'; import 'package:vm_service_lib/vm_service_lib.dart' as vm; import 'package:vm_service_lib/vm_service_lib_io.dart' as vm; import 'package:watcher/watcher.dart'; /// A utility class that watches the filesystem for changes, and starts new instances of an Angel server. class HotReloader { vm.VmService _client; vm.IsolateRef _mainIsolate; final StreamController _onChange = new StreamController.broadcast(); final List _paths = []; final StringRenderer _renderer = new StringRenderer(pretty: false); final Queue _requestQueue = new Queue(); AngelHttp _server; Duration _timeout; vm.VM _vmachine; /// If `true` (default), then developers can `press 'r' to reload` the application on-the-fly. /// /// This option triggers printing a Flutter-like output to the terminal. final bool enableHotkeys; /// Invoked to load a new instance of [Angel] on file changes. final FutureOr Function() generator; /// Fires whenever a file change. You might consider using this to trigger /// page reloads in a client. Stream get onChange => _onChange.stream; /// The maximum amount of time to queue incoming requests for if there is no [server] available. /// /// If the timeout expires, then the request will be immediately terminated with a `502 Bad Gateway` error. /// Default: `5s` Duration get timeout => _timeout; /// The Dart VM service host. /// /// Default: `localhost`. final String vmServiceHost; /// The port to connect to the Dart VM service. /// /// Default: `8181`. final int vmServicePort; /// Initializes a hot reloader that proxies the server created by [generator]. /// /// [paths] can contain [FileSystemEntity], [Uri], [String] and [Glob] only. /// URI's can be `package:` URI's as well. HotReloader(this.generator, Iterable paths, {Duration timeout, this.vmServiceHost: 'localhost', this.vmServicePort: 8181, this.enableHotkeys: true}) { _timeout = timeout ?? new Duration(seconds: 5); _paths.addAll(paths ?? []); } Future close() async { _onChange.close(); } void sendError(HttpRequest request, int status, String title_, e) { var doc = html(lang: 'en', c: [ head(c: [ meta(name: 'viewport', content: 'width=device-width, initial-scale=1'), title(c: [text(title_)]) ]), body(c: [ h1(c: [text(title_)]), i(c: [text(e.toString())]) ]) ]); var response = request.response; response.statusCode = HttpStatus.badGateway; response.headers ..contentType = ContentType.html ..set(HttpHeaders.serverHeader, 'angel_hot'); if (request.headers .value(HttpHeaders.acceptEncodingHeader) ?.toLowerCase() ?.contains('gzip') == true) { response ..headers.set(HttpHeaders.contentEncodingHeader, 'gzip') ..add(gzip.encode(utf8.encode(_renderer.render(doc)))); } else response.write(_renderer.render(doc)); response.close(); } Future _handle(HttpRequest request) { return _server.handleRequest(request); } Future handleRequest(HttpRequest request) async { if (_server != null) return await _handle(request); else if (timeout == null) _requestQueue.add(request); else { _requestQueue.add(request); new Timer(timeout, () { if (_requestQueue.remove(request)) { // Send 502 response sendError(request, HttpStatus.badGateway, '502 Bad Gateway', 'Request timed out after ${timeout.inMilliseconds}ms.'); } }); } } Future _generateServer() async { var s = await generator(); await Future.forEach(s.startupHooks, s.configure); s.optimizeForProduction(); return new AngelHttp(s); } /// Starts listening to requests and filesystem events. Future startServer([address, int port]) async { var isHot = true; _server = await _generateServer(); if (_paths?.isNotEmpty != true) print(yellow.wrap( 'WARNING: You have instantiated a HotReloader without providing any filesystem paths to watch.')); if (!Platform.executableArguments.contains('--observe') && !Platform.executableArguments.contains('--enable-vm-service')) { stderr.writeln(yellow.wrap( 'WARNING: You have instantiated a HotReloader without passing `--enable-vm-service` or `--observe` to the Dart VM. Hot reloading will be disabled.')); isHot = false; } else { _client = await vm.vmServiceConnect( vmServiceHost ?? 'localhost', vmServicePort ?? 8181); _vmachine ??= await _client.getVM(); _mainIsolate ??= _vmachine.isolates.first; await _client.setExceptionPauseMode(_mainIsolate.id, 'None'); await _listenToFilesystem(); } _onChange.stream //.transform(new _Debounce(new Duration(seconds: 1))) .listen(_handleWatchEvent); while (!_requestQueue.isEmpty) await _handle(_requestQueue.removeFirst()); var server = await HttpServer.bind(address ?? '127.0.0.1', port ?? 0); server.listen(handleRequest); // Print a Flutter-like prompt... if (enableHotkeys) { var serverUri = new Uri( scheme: 'http', host: server.address.address, port: server.port); var host = vmServiceHost == 'localhost' ? '127.0.0.1' : vmServiceHost; var observatoryUri = new Uri(scheme: 'http', host: host, port: vmServicePort); print(styleBold.wrap( '\n🔥 To hot reload changes while running, press "r". To hot restart (and rebuild state), press "R".')); stdout.write('Your Angel server is listening at: '); print(wrapWith('$serverUri', [cyan, styleUnderlined])); stdout.write( 'An Observatory debugger and profiler on ${Platform.operatingSystem} is available at: '); print(wrapWith('$observatoryUri', [cyan, styleUnderlined])); print( 'For a more detailed help message, press "h". To quit, press "q".\n'); if (_paths.isNotEmpty) { print(darkGray.wrap( 'Changes to the following path(s) will also trigger a hot reload:')); for (var p in _paths) { print(darkGray.wrap(' * $p')); } stdout.writeln(); } // Listen for hotkeys stdin.lineMode = stdin.echoMode = false; StreamSubscription sub; sub = stdin.expand((l) => l).listen((ch) async { var ch = stdin.readByteSync(); if (ch == $r) { _handleWatchEvent( new WatchEvent(ChangeType.MODIFY, '[manual-reload]'), isHot); } if (ch == $R) { //print('Manually restarting server...\n'); _handleWatchEvent( new WatchEvent(ChangeType.MODIFY, '[manual-restart]'), false); } else if (ch == $q) { stdin.echoMode = stdin.lineMode = true; close(); sub.cancel(); exit(0); } else if (ch == $h) { print( 'Press "r" to hot reload the Dart VM, and restart the active server.'); print( 'Press "R" to restart the server, WITHOUT a hot reload of the VM.'); print('Press "q" to quit the server.'); print('Press "h" to display this help information.'); stdout.writeln(); } }); } return server; } _listenToFilesystem() async { for (var path in _paths) { if (path is String) { await _listenToStat(path); } else if (path is Glob) { await for (var entity in path.list()) { await _listenToStat(entity.path); } } else if (path is FileSystemEntity) { await _listenToStat(path.path); } else if (path is Uri) { if (path.scheme == 'package') { var uri = await Isolate.resolvePackageUri(path); if (uri != null) await _listenToStat(uri.toFilePath()); else await _listenToStat(path.toFilePath()); } else await _listenToStat(path.toFilePath()); } else { throw new ArgumentError( 'Hot reload paths must be a FileSystemEntity, a Uri, a String or a Glob. You provided: $path'); } } } _listenToStat(String path) async { _listen() async { try { var stat = await FileStat.stat(path); if (stat.type == FileSystemEntityType.link) { var lnk = new Link(path); var p = await lnk.resolveSymbolicLinks(); return await _listenToStat(p); } else if (stat.type == FileSystemEntityType.file) { var file = new File(path); if (!await file.exists()) return null; } else if (stat.type == FileSystemEntityType.directory) { var dir = new Directory(path); if (!await dir.exists()) return null; } else return null; var watcher = new Watcher(path); watcher.events.listen(_onChange.add, onError: (e) { stderr.writeln('Could not listen to file changes at ${path}: $e'); }); // print('Listening for file changes at ${path}...'); return true; } catch (e) { if (e is! FileSystemException) rethrow; } } var r = await _listen(); if (r == null) { print( 'WARNING: Unable to watch path "$path" from working directory "${Directory.current.path}". Please ensure that it exists.'); } } _handleWatchEvent(WatchEvent e, [bool hot = true]) async { print('${e.path} changed. Reloading server...\n'); var old = _server; if (old != null) { // Do this asynchronously, because we really don't care about the old server anymore. new Future(() async { // Disconnect active WebSockets try { var ws = old.app.container.make(); for (var client in ws.clients) { try { await client.close(WebSocketStatus.goingAway); } catch (e) { stderr.writeln( 'Couldn\'t close WebSocket from session #${client.request.session.id}: $e'); } } await Future.forEach(old.app.shutdownHooks, old.app.configure); } catch (_) { // Fail silently... } }); } _server = null; if (hot) { var report = await _client.reloadSources(_mainIsolate.id); if (!report.success) { stderr.writeln('Hot reload failed!!!'); stderr.writeln(report.toString()); exit(1); } } var s = await _generateServer(); _server = s; while (!_requestQueue.isEmpty) await _handle(_requestQueue.removeFirst()); } } /* class _Debounce extends StreamTransformerBase { final Duration _delay; const _Debounce(this._delay); Stream bind(Stream stream) { var initial = new DateTime.now(); var next = initial.subtract(this._delay); return stream.where((S data) { var now = new DateTime.now(); if (now.isAfter(next)) { next = now.add(this._delay); return true; } else { return false; } }); } } */