invoke computeCache when priority sources change

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.computer;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol.dart';
 import 'package:analysis_server/src/services/completion/dart_completion_manager.dart';
@@ skipping 57 matching lines @@
       }
       if (AnalysisEngine.isHtmlFileName(source.shortName)) {
         //TODO (danrubel) implement
 //        return new HtmlCompletionManager(context, searchEngine, source, offset);
       }
     }
     return new NoOpCompletionManager(source);
   }
 
   /**
+   * Compute and cache information in preparation for a possible code
+   * completion request sometime in the future. The default implementation
+   * of this method does nothing. Subclasses may override but should not
+   * count on this method being called before [computeSuggestions].
+   */
+  void computeCache() {
+  }
+
+  /**
    * 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 compute(CompletionRequest request);
+  void computeSuggestions(CompletionRequest request);
 
   /**
    * Generate a stream of code completion results.
    */
   Stream<CompletionResult> results(CompletionRequest request) {
     controller = new StreamController<CompletionResult>(onListen: () {
       scheduleMicrotask(() {
-        compute(request);
+        computeSuggestions(request);
       });
     });
     return controller.stream;
   }
 }
 
 /**
  * Overall performance of a code completion operation.
  */
 class CompletionPerformance {
@@ skipping 88 matching lines @@
 
   CompletionResult(this.replacementOffset, this.replacementLength,
       this.suggestions, this.last);
 }
 
 class NoOpCompletionManager extends CompletionManager {
 
   NoOpCompletionManager(Source source) : super(null, source);
 
   @override
-  void compute(CompletionRequest request) {
+  void computeSuggestions(CompletionRequest request) {
     controller.add(new CompletionResult(request.offset, 0, [], true));
   }
 }
 
 /**
  * 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);
 }