Add Driver.useSingleContextManager to turn on single context manager.

pkg/analysis_server/lib/src/analysis_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 analysis.server;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:core' hide Resource;
 import 'dart:math' show max;
 
 import 'package:analysis_server/plugin/protocol/protocol.dart'
     hide AnalysisOptions, Element;
 import 'package:analysis_server/src/analysis_logger.dart';
 import 'package:analysis_server/src/channel/channel.dart';
 import 'package:analysis_server/src/context_manager.dart';
 import 'package:analysis_server/src/operation/operation.dart';
 import 'package:analysis_server/src/operation/operation_analysis.dart';
 import 'package:analysis_server/src/operation/operation_queue.dart';
 import 'package:analysis_server/src/plugin/server_plugin.dart';
 import 'package:analysis_server/src/services/correction/namespace.dart';
 import 'package:analysis_server/src/services/index/index.dart';
 import 'package:analysis_server/src/services/search/search_engine.dart';
 import 'package:analysis_server/src/services/search/search_engine_internal.dart';
+import 'package:analysis_server/src/single_context_manager.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/instrumentation/instrumentation.dart';
 import 'package:analyzer/plugin/embedded_resolver_provider.dart';
 import 'package:analyzer/plugin/resolver_provider.dart';
 import 'package:analyzer/source/embedder.dart';
 import 'package:analyzer/source/pub_package_map_provider.dart';
 import 'package:analyzer/src/dart/ast/utilities.dart';
 import 'package:analyzer/src/generated/engine.dart';
@@ skipping 270 matching lines @@
    */
   AnalysisServer(
       this.channel,
       this.resourceProvider,
       PubPackageMapProvider packageMapProvider,
       Index _index,
       this.serverPlugin,
       this.options,
       this.defaultSdkCreator,
       this.instrumentationService,
-      {ResolverProvider packageResolverProvider: null,
-      EmbeddedResolverProvider embeddedResolverProvider: null,
+      {EmbeddedResolverProvider embeddedResolverProvider: null,
+      ResolverProvider packageResolverProvider: null,
+      bool useSingleContextManager: false,
       this.rethrowExceptions: true})
       : index = _index,
         searchEngine = _index != null ? new SearchEngineImpl(_index) : null {
     _performance = performanceDuringStartup;
     defaultContextOptions.incremental = true;
     defaultContextOptions.incrementalApi =
         options.enableIncrementalResolutionApi;
     defaultContextOptions.incrementalValidation =
         options.enableIncrementalResolutionValidation;
     defaultContextOptions.generateImplicitErrors = false;
     operationQueue = new ServerOperationQueue();
     sdkManager = new DartSdkManager(defaultSdkCreator);
-    contextManager = new ContextManagerImpl(
-        resourceProvider,
-        sdkManager,
-        packageResolverProvider,
-        embeddedResolverProvider,
-        packageMapProvider,
-        analyzedFilesGlobs,
-        instrumentationService,
-        defaultContextOptions);
+    if (useSingleContextManager) {
+      contextManager = new SingleContextManager(resourceProvider, sdkManager,
+          () => packageResolverProvider(null), analyzedFilesGlobs);
+    } else {
+      contextManager = new ContextManagerImpl(
+          resourceProvider,
+          sdkManager,
+          packageResolverProvider,
+          embeddedResolverProvider,
+          packageMapProvider,
+          analyzedFilesGlobs,
+          instrumentationService,
+          defaultContextOptions);
+    }
     ServerContextManagerCallbacks contextManagerCallbacks =
         new ServerContextManagerCallbacks(this, resourceProvider);
     contextManager.callbacks = contextManagerCallbacks;
     _noErrorNotification = options.noErrorNotification;
     AnalysisEngine.instance.logger = new AnalysisLogger(this);
     _onAnalysisStartedController = new StreamController.broadcast();
     _onFileAnalyzedController = new StreamController.broadcast();
     _onPriorityChangeController =
         new StreamController<PriorityChangeEvent>.broadcast();
     running = true;
@@ skipping 1410 matching lines @@
   /**
    * The [PerformanceTag] for time spent in server request handlers.
    */
   static PerformanceTag serverRequests = new PerformanceTag('serverRequests');
 
   /**
    * The [PerformanceTag] for time spent in split store microtasks.
    */
   static PerformanceTag splitStore = new PerformanceTag('splitStore');
 }