invoke computeCache when priority sources change

pkg/analysis_server/lib/src/domain_completion.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 domain.completion;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/constants.dart';
@@ skipping 35 matching lines @@
   /**
    * Code completion peformance for the last completion operation.
    */
   CompletionPerformance performance;
 
   /**
    * Initialize a new request handler for the given [server].
    */
   CompletionDomainHandler(this.server) {
     server.onContextsChanged.listen(contextsChanged);
+    server.onPriorityChange.listen(priorityChanged);
   }
 
   /**
    * Return the completion manager for most recent [Source] and [AnalysisContext],
    * or `null` if none.
    */
   CompletionManager get manager => _manager;
 
   /**
    * Return the [CompletionManager] for the given [context] and [source],
@@ skipping 41 matching lines @@
       if (requestName == COMPLETION_GET_SUGGESTIONS) {
         return processRequest(request);
       }
     } on RequestFailure catch (exception) {
       return exception.response;
     }
     return null;
   }
 
   /**
+   * If the set the priority files has changed, then pre-cache completion
+   * information related to the first priority file.
+   */
+  void priorityChanged(PriorityChangeEvent event) {
+    Source source = event.firstSource;
+    if (source == null) {
+      return;
+    }
+    AnalysisContext context = server.getAnalysisContextForSource(source);
+    if (context == null) {
+      return;
+    }
+    completionManagerFor(context, source).computeCache();
+  }
+
+  /**
    * Process a `completion.getSuggestions` request.
    */
   Response processRequest(Request request) {
     performance = new CompletionPerformance();
     // extract params
     CompletionGetSuggestionsParams params =
         new CompletionGetSuggestionsParams.fromRequest(request);
     // schedule completion analysis
     String completionId = (_nextCompletionId++).toString();
     CompletionManager manager = completionManagerFor(
@@ skipping 58 matching lines @@
    * Discard the sourcesChanged subscription if any
    */
   void _discardManager() {
     if (_sourcesChangedSubscription != null) {
       _sourcesChangedSubscription.cancel();
       _sourcesChangedSubscription = null;
     }
     _manager = null;
   }
 }