Initial support for getting fixes from plugins

pkg/analysis_server/lib/src/domain_abstract.dart

+// 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.
+
+import 'dart:async';
+import 'dart:math' as math;
+
+import 'package:analysis_server/src/analysis_server.dart';
+import 'package:analysis_server/src/plugin/plugin_manager.dart';
+import 'package:analysis_server/src/protocol_server.dart' hide Element;
+import 'package:analyzer_plugin/protocol/protocol.dart' as plugin;
+import 'package:analyzer_plugin/protocol/protocol_constants.dart' as plugin;
+import 'package:analyzer_plugin/protocol/protocol_generated.dart' as plugin;
+
+/**
+ * An abstract implementation of a request handler.
+ */
+abstract class AbstractRequestHandler implements RequestHandler {
+  /**
+   * The analysis server that is using this handler to process requests.
+   */
+  final AnalysisServer server;
+
+  /**
+   * Initialize a newly created request handler to be associated with the given
+   * analysis [server].
+   */
+  AbstractRequestHandler(this.server);
+
+  /**
+   * Given a mapping from plugins to futures that will complete when the plugin
+   * has responded to a request, wait for a finite amount of time for each of
+   * the plugins to respond. Return a list of the responses from each of the
+   * plugins. If a plugin fails to return a response, notify the plugin manager
+   * associated with the server so that non-responsive plugins can be killed or
+   * restarted. The [timeout] is the maximum amount of time that will be spent
+   * waiting for plugins to respond.
+   */
+  Future<List<plugin.Response>> waitForResponses(
+      Map<PluginInfo, Future<plugin.Response>> futures,
+      {int timeout: 500}) async {

[scheglov, 2017/04/19 20:19:04]

Replace with Duration and do Duration arithmetic instead?

[Brian Wilkerson, 2017/04/19 20:52:48]

That seems somewhat expensive, and I'm not sure the code would be easier to
read, but I'm happy to make the changes if you think I should.

+    int endTime = new DateTime.now().millisecondsSinceEpoch + timeout;
+    List<plugin.Response> responses = <plugin.Response>[];
+    for (PluginInfo pluginInfo in futures.keys) {
+      Future<plugin.Response> future = futures[pluginInfo];
+      try {
+        int startTime = new DateTime.now().millisecondsSinceEpoch;
+        plugin.Response response = await future.timeout(
+            new Duration(milliseconds: math.max(endTime - startTime, 0)));
+        if (response.error != null) {
+          // TODO(brianwilkerson) Report the error to the plugin manager.
+          server.instrumentationService.logPluginError(
+              pluginInfo.data,
+              response.error.code.name,
+              response.error.message,
+              response.error.stackTrace);
+        } else {
+          responses.add(response);
+        }
+      } on TimeoutException {
+        // TODO(brianwilkerson) Report the timeout to the plugin manager.
+        server.instrumentationService
+            .logPluginTimeout(pluginInfo.data, plugin.EDIT_REQUEST_GET_FIXES);

[scheglov, 2017/04/19 20:19:04]

Why plugin.EDIT_REQUEST_GET_FIXES?

[Brian Wilkerson, 2017/04/19 20:52:48]

That was a bit of hard coded data I missed when abstracting this out into a
utility method. Cleaned up.

+      } catch (exception, stackTrace) {
+        // TODO(brianwilkerson) Report the exception to the plugin manager.
+        server.instrumentationService
+            .logPluginException(pluginInfo.data, exception, stackTrace);
+      }
+    }
+    return responses;
+  }
+}