remove internal streaming of results, remove obsolete test, cleanup unused code

pkg/analysis_server/lib/src/services/completion/completion_manager.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 services.completion.manager;
 
 import 'dart:async';
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:analysis_server/src/provisional/completion/completion_core.dart'
-    show CompletionContributor, CompletionContributorFactory, CompletionRequest, CompletionResult;
+    show
+        CompletionContributor,
+        CompletionContributorFactory,
+        CompletionRequest,
+        CompletionResult;
 import 'package:analysis_server/src/services/completion/dart_completion_manager.dart';
 import 'package:analysis_server/src/services/search/search_engine.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/source.dart';
 
 /**
  * Manages completion contributors for a given completion request.
  */
 abstract class CompletionManager {
   /**
    * The context in which the completion was computed.
    */
   final AnalysisContext context;
 
   /**
    * The source in which the completion was computed.
    */
   final Source source;
 
-  /**
-   * The controller used for returning completion results.
-   */
-  StreamController<CompletionResult> controller;
-
   CompletionManager(this.context, this.source);
 
   /**
    * Create a manager for the given request.
    */
   factory CompletionManager.create(
       AnalysisContext context,
       Source source,
       SearchEngine searchEngine,
       Iterable<CompletionContributor> newContributors) {
@@ skipping 18 matching lines @@
     return new Future.value(true);
   }
 
   /**
    * Compute completion results for the given reqeust and append them to the stream.
    * Clients should not call this method directly as it is automatically called
    * when a client listens to the stream returned by [results].
    * Subclasses should override this method, append at least one result
    * to the [controller], and close the controller stream once complete.
    */
-  void computeSuggestions(CompletionRequest request);
+  Future<CompletionResult> computeSuggestions(CompletionRequest request);
 
   /**
    * Discard any pending operations.
    * Subclasses may override but should call super.dispose
    */
   void dispose() {}
-
-  /**
-   * Generate a stream of code completion results.
-   */
-  Stream<CompletionResult> results(CompletionRequest request) {
-    controller = new StreamController<CompletionResult>(onListen: () {
-      scheduleMicrotask(() {
-        computeSuggestions(request);
-      });
-    });
-    return controller.stream;
-  }
 }
 
 /**
  * Overall performance of a code completion operation.
  */
 class CompletionPerformance {
   final DateTime start = new DateTime.now();
   final Map<String, Duration> _startTimes = new Map<String, Duration>();
   final Stopwatch _stopwatch = new Stopwatch();
   final List<OperationPerformance> operations = <OperationPerformance>[];
@@ skipping 110 matching lines @@
    * portion of an identifier before the original offset. In particular, the
    * replacementOffset will be the offset of the beginning of said identifier.
    */
   final int replacementOffset;
 
   /**
    * The suggested completions.
    */
   final List<CompletionSuggestion> suggestions;
 
-  /**
-   * `true` if this is that last set of results that will be returned
-   * for the indicated completion.
-   */
-  final bool last;
-
-  CompletionResultImpl(this.replacementOffset, this.replacementLength,
-      this.suggestions, this.last);
-
-  /**
-   * Return `true` if this is the last completion result that will be produced.
-   */
-  bool get isLast => last;
+  CompletionResultImpl(
+      this.replacementOffset, this.replacementLength, this.suggestions);
 }
 
 class NoOpCompletionManager extends CompletionManager {
   NoOpCompletionManager(Source source) : super(null, source);
 
   @override
-  void computeSuggestions(CompletionRequest request) {
-    controller.add(new CompletionResultImpl(request.offset, 0, [], true));
+  Future<CompletionResult> computeSuggestions(CompletionRequest request) async {
+    return new CompletionResultImpl(request.offset, 0, []);
   }
 }
 
 /**
  * The performance of an operation when computing code completion.
  */
 class OperationPerformance {
   /**
    * The name of the operation
    */
   final String name;
 
   /**
    * The elapse time or `null` if undefined.
    */
   final Duration elapsed;
 
   OperationPerformance(this.name, this.elapsed);
 }