refactor import caching to exclude suggestions for inherited members

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/completion_manager.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/search/search_engine.dart';
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/source.dart';
 
 /**
- * The `DartCompletionCache` contains cached information from a prior code
- * completion operation.
- */
-class DartCompletionCache extends CompletionCache {
-
-  /**
-   * A hash of the import directives.
-   */
-  String importKey;
-
-  /**
-   * Library prefix suggestions based upon imports,
-   * or `null` if nothing has been cached.
-   */
-  List<CompletionSuggestion> libraryPrefixSuggestions;
-
-  /**
-   * Type suggestions based upon imports,
-   * or `null` if nothing has been cached.
-   */
-  List<CompletionSuggestion> importedTypeSuggestions;
-
-  /**
-   * Suggestions for methods and functions that have void return type,
-   * or `null` if nothing has been cached.
-   */
-  List<CompletionSuggestion> importedVoidReturnSuggestions;
-
-  /**
-   * Other suggestions based upon imports,
-   * or `null` if nothing has been cached.
-   */
-  List<CompletionSuggestion> otherImportedSuggestions;
-
-  DartCompletionCache(AnalysisContext context, Source source)
-      : super(context, source);
-}
-
-/**
  * 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.
    * Returns `true` if the computer's work is complete
    * or `false` if [computeFull] should be called to complete the work.
@@ skipping 232 matching lines @@
   _ReplacementOffsetBuilder(this.request) {
     request.replacementOffset = request.offset;
     request.replacementLength = 0;
   }
 
   visitSimpleIdentifier(SimpleIdentifier node) {
     request.replacementOffset = node.offset;
     request.replacementLength = node.length;
   }
 }