update code completion suggestion relevance based on common usage

pkg/analysis_server/lib/src/services/completion/dart_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.dart;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol.dart';
 import 'package:analysis_server/src/services/completion/arglist_computer.dart';
 import 'package:analysis_server/src/services/completion/combinator_computer.dart';
+import 'package:analysis_server/src/services/completion/common_usage_computer.dart';
 import 'package:analysis_server/src/services/completion/completion_manager.dart';
 import 'package:analysis_server/src/services/completion/completion_target.dart';
 import 'package:analysis_server/src/services/completion/dart_completion_cache.dart';
 import 'package:analysis_server/src/services/completion/imported_computer.dart';
 import 'package:analysis_server/src/services/completion/invocation_computer.dart';
 import 'package:analysis_server/src/services/completion/keyword_computer.dart';
 import 'package:analysis_server/src/services/completion/local_computer.dart';
 import 'package:analysis_server/src/services/completion/optype.dart';
 import 'package:analysis_server/src/services/search/search_engine.dart';
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/engine.dart';
+import 'package:analyzer/src/generated/scanner.dart';
 import 'package:analyzer/src/generated/source.dart';
-import 'package:analyzer/src/generated/scanner.dart';
 
-// Relevance highest to lowest
+const int DART_RELEVANCE_COMMON_USAGE = 1200;
+const int DART_RELEVANCE_DEFAULT = 1000;
 const int DART_RELEVANCE_HIGH = 2000;
+const int DART_RELEVANCE_INHERITED_ACCESSOR = 1057;
+const int DART_RELEVANCE_INHERITED_FIELD = 1058;
+const int DART_RELEVANCE_INHERITED_METHOD = 1057;
+const int DART_RELEVANCE_KEYWORD = 1055;
+const int DART_RELEVANCE_LOCAL_ACCESSOR = 1057;
+const int DART_RELEVANCE_LOCAL_FIELD = 1058;
+const int DART_RELEVANCE_LOCAL_FUNCTION = 1056;
+const int DART_RELEVANCE_LOCAL_METHOD = 1057;
+const int DART_RELEVANCE_LOCAL_TOP_LEVEL_VARIABLE = 1056;
 const int DART_RELEVANCE_LOCAL_VARIABLE = 1059;
+const int DART_RELEVANCE_LOW = 500;
 const int DART_RELEVANCE_PARAMETER = 1059;
-const int DART_RELEVANCE_INHERITED_FIELD = 1058;
-const int DART_RELEVANCE_LOCAL_FIELD = 1058;
-const int DART_RELEVANCE_INHERITED_ACCESSOR = 1057;
-const int DART_RELEVANCE_INHERITED_METHOD = 1057;
-const int DART_RELEVANCE_LOCAL_ACCESSOR = 1057;
-const int DART_RELEVANCE_LOCAL_METHOD = 1057;
-const int DART_RELEVANCE_LOCAL_FUNCTION = 1056;
-const int DART_RELEVANCE_LOCAL_TOP_LEVEL_VARIABLE = 1056;
-const int DART_RELEVANCE_KEYWORD = 1055;
-const int DART_RELEVANCE_DEFAULT = 1000;
-const int DART_RELEVANCE_LOW = 500;
 
 /**
  * The base class for computing code completion suggestions.
  */
 abstract class DartCompletionComputer {
   /**
    * Computes the initial set of [CompletionSuggestion]s based on
    * the given completion context. The compilation unit and completion node
    * in the given completion context may not be resolved.
    * This method should execute quickly and not block waiting for any analysis.
@@ skipping 11 matching lines @@
   Future<bool> computeFull(DartCompletionRequest request);
 }
 
 /**
  * Manages code completion for a given Dart file completion request.
  */
 class DartCompletionManager extends CompletionManager {
   final SearchEngine searchEngine;
   final DartCompletionCache cache;
   List<DartCompletionComputer> computers;
+  CommonUsageComputer commonUsageComputer;
 
   DartCompletionManager(AnalysisContext context, this.searchEngine,
-      Source source, this.cache, [this.computers])
+      Source source, this.cache, [this.computers, this.commonUsageComputer])
       : super(context, source) {
     if (computers == null) {
       computers = [
           new KeywordComputer(),
           new LocalComputer(),
           new ArgListComputer(),
           new CombinatorComputer(),
           new ImportedComputer(),
           new InvocationComputer()];
     }
+    if (commonUsageComputer == null) {
+      commonUsageComputer = new CommonUsageComputer();
+    }
   }
 
   /**
    * Create a new initialized Dart source completion manager
    */
   factory DartCompletionManager.create(AnalysisContext context,
       SearchEngine searchEngine, Source source) {
     return new DartCompletionManager(
         context,
         searchEngine,
@@ skipping 39 matching lines @@
       }
 
       List<DartCompletionComputer> todo = new List.from(computers);
       todo.removeWhere((DartCompletionComputer c) {
         return request.performance.logElapseTime(
             'computeFast ${c.runtimeType}',
             () {
           return c.computeFast(request);
         });
       });
+      commonUsageComputer.computeFast(request);
       sendResults(request, todo.isEmpty);
       return todo;
     });
   }
 
   /**
    * If there is remaining work to be done, then wait for the unit to be
    * resolved and request that each remaining computer finish their work.
    * Return a [Future] that completes when the last notification has been sent.
    */
@@ skipping 18 matching lines @@
         int count = todo.length;
         todo.forEach((DartCompletionComputer c) {
           String name = c.runtimeType.toString();
           String completeTag = 'computeFull $name complete';
           request.performance.logStartTime(completeTag);
           request.performance.logElapseTime('computeFull $name', () {
             c.computeFull(request).then((bool changed) {
               request.performance.logElapseTime(completeTag);
               bool last = --count == 0;
               if (changed || last) {
+                commonUsageComputer.computeFull(request);
                 sendResults(request, last);
               }
             });
           });
         });
       });
     });
   }
 
   @override
@@ skipping 144 matching lines @@
    * Information about the types of suggestions that should be included.
    * The [target] must be set first.
    */
   OpType get optype {
     if (_optype == null) {
       _optype = new OpType.forCompletion(target, offset);
     }
     return _optype;
   }
 }