| // Copyright (c) 2019, 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. |
| |
| import 'dart:async'; |
| import 'dart:io'; |
| |
| import 'package:nnbd_migration/src/front_end/migration_state.dart'; |
| import 'package:nnbd_migration/src/preview/preview_site.dart'; |
| |
| /// Instances of the class [AbstractGetHandler] handle GET requests. |
| abstract class AbstractGetHandler { |
| /// Handle a GET request received by the HTTP server. |
| Future<void> handleGetRequest(HttpRequest request); |
| } |
| |
| /// Instances of the class [AbstractPostHandler] handle POST requests. |
| abstract class AbstractPostHandler { |
| /// Handle a POST request received by the HTTP server. |
| Future<void> handlePostRequest(HttpRequest request); |
| } |
| |
| /// Instances of the class [HttpPreviewServer] implement a simple HTTP server |
| /// that serves up dartfix preview pages. |
| class HttpPreviewServer { |
| /// The state of the migration being previewed. |
| final MigrationState migrationState; |
| |
| /// The [PreviewSite] that can handle GET and POST requests. |
| PreviewSite previewSite; |
| |
| /// Future that is completed with the HTTP server once it is running. |
| Future<HttpServer> _serverFuture; |
| |
| // A function which allows the migration to be rerun, taking changed paths. |
| final Future<MigrationState> Function() rerunFunction; |
| |
| /// Integer for a port to run the preview server on. If null or zero, allow |
| /// [HttpServer.bind] to pick one. |
| final int preferredPort; |
| |
| /// Initialize a newly created HTTP server. |
| HttpPreviewServer( |
| this.migrationState, this.rerunFunction, this.preferredPort); |
| |
| Future<String> get authToken async { |
| await _serverFuture; |
| previewSite ??= PreviewSite(migrationState, rerunFunction); |
| return previewSite.serviceAuthToken; |
| } |
| |
| /// Return the port this server is bound to. |
| Future<int> get boundPort async { |
| return (await _serverFuture)?.port; |
| } |
| |
| void close() { |
| _serverFuture?.then((HttpServer server) { |
| server.close(); |
| }); |
| } |
| |
| /// Begin serving HTTP requests over the given port. |
| Future<int> serveHttp() async { |
| if (_serverFuture != null) { |
| return boundPort; |
| } |
| |
| try { |
| _serverFuture = |
| HttpServer.bind(InternetAddress.loopbackIPv4, preferredPort ?? 0); |
| |
| var server = await _serverFuture; |
| _handleServer(server); |
| return server.port; |
| } catch (ignore) { |
| // If we can't bind to the specified port, don't remember the broken |
| // server. |
| _serverFuture = null; |
| // TODO(jcollins-g): Display a better error message? |
| rethrow; |
| } |
| } |
| |
| /// Handle a GET request received by the HTTP server. |
| Future<void> _handleGetRequest(HttpRequest request) async { |
| previewSite ??= PreviewSite(migrationState, rerunFunction); |
| await previewSite.handleGetRequest(request); |
| } |
| |
| /// Handle a POST request received by the HTTP server. |
| Future<void> _handlePostRequest(HttpRequest request) async { |
| previewSite ??= PreviewSite(migrationState, rerunFunction); |
| await previewSite.handlePostRequest(request); |
| } |
| |
| /// Attach a listener to a newly created HTTP server. |
| void _handleServer(HttpServer httpServer) { |
| httpServer.listen((HttpRequest request) async { |
| var updateValues = request.headers[HttpHeaders.upgradeHeader]; |
| if (request.method == 'GET') { |
| await _handleGetRequest(request); |
| } else if (request.method == 'POST') { |
| await _handlePostRequest(request); |
| } else if (updateValues != null && updateValues.contains('websocket')) { |
| // We do not support serving analysis server communications over |
| // WebSocket connections. |
| var response = request.response; |
| response.statusCode = HttpStatus.notFound; |
| response.headers.contentType = ContentType.text; |
| response.write( |
| 'WebSocket connections not supported (${request.uri.path}).'); |
| response.close(); |
| } else { |
| _returnUnknownRequest(request); |
| } |
| }); |
| } |
| |
| /// Return an error in response to an unrecognized request received by the HTTP |
| /// server. |
| void _returnUnknownRequest(HttpRequest request) { |
| var response = request.response; |
| response.statusCode = HttpStatus.notFound; |
| response.headers.contentType = ContentType.text; |
| response.write('Not found'); |
| response.close(); |
| } |
| } |