Allow print() to be used for debugging analysis server.

pkg/analysis_server/lib/http_server.dart

 // Copyright (c) 2014, 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 http.server;
 
 import 'dart:async';
 import 'dart:io';
 
 import 'package:analysis_server/src/channel/web_socket_channel.dart';
 import 'package:analysis_server/src/get_handler.dart';
 import 'package:analysis_server/src/socket_server.dart';
 
 /**
  * Instances of the class [HttpServer] implement a simple HTTP server. The
  * primary responsibility of this server is to listen for an UPGRADE request and
  * to start an analysis server.
  */
 class HttpAnalysisServer {
   /**
+   * Number of lines of print output to capture.
+   */
+  static const int PRINT_BUFFER_LENGTH = 1000;

[danrubel, 2014/10/28 21:01:02]

MAX_PRINT_BUFFER_MAX_LENGTH ?

[Paul Berry, 2014/10/28 23:29:13]

Done.

+
+  /**
    * An object that can handle either a WebSocket connection or a connection
    * to the client over stdio.
    */
   SocketServer socketServer;
 
   /**
    * An object that can handle GET requests.
    */
   GetHandler getHandler;
 
   /**
    * Initialize a newly created HTTP server.
    */
   HttpAnalysisServer(this.socketServer);
 
   /**
    * Future that is completed with the HTTP server once it is running.
    */
   Future<HttpServer> _server;
 
   /**
+   * Last PRINT_BUFFER_LENGTH lines printed.
+   */
+  List<String> _printBuffer = <String>[];
+
+  /**
    * Attach a listener to a newly created HTTP server.
    */
   void _handleServer(HttpServer httServer) {
     httServer.listen((HttpRequest request) {
       List<String> updateValues = request.headers[HttpHeaders.UPGRADE];
       if (updateValues != null && updateValues.indexOf('websocket') >= 0) {
         WebSocketTransformer.upgrade(request).then((WebSocket websocket) {
           _handleWebSocket(websocket);
         });
       } else if (request.method == 'GET') {
         _handleGetRequest(request);
       } else {
         _returnUnknownRequest(request);
       }
     });
   }
 
   /**
    * Handle a GET request received by the HTTP server.
    */
   void _handleGetRequest(HttpRequest request) {
     if (getHandler == null) {
-      getHandler = new GetHandler(socketServer);
+      getHandler = new GetHandler(socketServer, _printBuffer);
     }
     getHandler.handleGetRequest(request);
   }
 
   /**
    * Handle an UPGRADE request received by the HTTP server by creating and
    * running an analysis server on a [WebSocket]-based communication channel.
    */
   void _handleWebSocket(WebSocket socket) {
     socketServer.createAnalysisServer(new WebSocketServerChannel(socket));
@@ skipping 17 matching lines @@
   void serveHttp(int port) {
     _server = HttpServer.bind(InternetAddress.LOOPBACK_IP_V4, port);
     _server.then(_handleServer);
   }
 
   void close() {
     _server.then((HttpServer server) {
       server.close();
     });
   }
+
+  /**
+   * Record that the given line was printed out by the analysis server.
+   */
+  void recordPrint(String line) {
+    _printBuffer.add(line);
+    if (_printBuffer.length > PRINT_BUFFER_LENGTH) {
+      _printBuffer.removeRange(0, _printBuffer.length - PRINT_BUFFER_LENGTH);
+    }
+  }
 }