Replace computeNode() with AstProvider in search.

pkg/analysis_server/lib/src/services/search/search_engine_internal.dart

 // Copyright (c) 2016, 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 analysis_server.src.services.search.search_engine_internal;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/services/correction/source_range.dart';
 import 'package:analysis_server/src/services/index/index.dart';
 import 'package:analysis_server/src/services/search/search_engine.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/visitor.dart';
+import 'package:analyzer/src/dart/element/ast_provider.dart';
 import 'package:analyzer/src/dart/element/element.dart';
 import 'package:analyzer/src/dart/element/member.dart';
 import 'package:analyzer/src/generated/engine.dart' show AnalysisContext;
 import 'package:analyzer/src/generated/resolver.dart' show NamespaceBuilder;
 import 'package:analyzer/src/generated/source.dart' show Source, SourceRange;
 import 'package:analyzer/src/generated/utilities_general.dart';
 import 'package:analyzer/src/summary/idl.dart';
 
 /**
+ * The type of a function that returns the [AstProvider] managing the [file].
+ */
+typedef AstProvider GetAstProvider(String file);

[Brian Wilkerson, 2017/02/03 14:43:47]

Is this necessary? It seems like it's just as performant to create the
AstProvider as it is to create the closure to return the AstProvider, and less
indirection through functions would be better.

[scheglov, 2017/02/03 18:31:36]

AstProvider is bound to a single AnalysisDriver or AnalysisContext.

When we create SearchEngineImpl, we don't know which local Element(s) will be
searched. Depending on the specific element, we need to choose AnalysisDriver,
and so AstProvider.

[Brian Wilkerson, 2017/02/03 18:38:25]

That makes sense. It would be good to add that to a comment so it's clear later.

+
+/**
  * A [SearchEngine] implementation.
  */
 class SearchEngineImpl implements SearchEngine {
   final Index _index;
+  final GetAstProvider _getAstProvider;
 
-  SearchEngineImpl(this._index);
+  SearchEngineImpl(this._index, this._getAstProvider);
 
   @override
   Future<Set<ClassElement>> searchAllSubtypes(ClassElement type) async {
     List<SearchMatch> matches = <SearchMatch>[];
     await _addMatches(
         matches, type, IndexRelationKind.IS_ANCESTOR_OF, MatchKind.DECLARATION);
     return matches.map((match) => match.element as ClassElement).toSet();
   }
 
   @override
@@ skipping 206 matching lines @@
               false));
         }
       }
     }
     return matches;
   }
 
   Future<List<SearchMatch>> _searchReferences_Local(
       Element element, bool isRootNode(AstNode n)) async {
     _LocalReferencesVisitor visitor = new _LocalReferencesVisitor(element);
-    AstNode node = element.computeNode();
+    AstProvider astProvider = _getAstProvider(element.source.fullName);
+    AstNode node = await astProvider.getResolvedNodeForElement(element);
     AstNode enclosingNode = node?.getAncestor(isRootNode);
     enclosingNode?.accept(visitor);
     return visitor.matches;
   }
 
   Future<List<SearchMatch>> _searchReferences_Parameter(
       ParameterElement parameter) async {
     List<SearchMatch> matches = <SearchMatch>[];
     matches.addAll(await _searchReferences(parameter));
     matches.addAll(await _searchReferences_Local(parameter, (AstNode node) {
@@ skipping 307 matching lines @@
       _addMatch(node, kind);
     }
   }
 
   void _addMatch(AstNode node, MatchKind kind) {
     bool isQualified = node.parent is Label;
     matches.add(new SearchMatchImpl(context, libraryUri, unitUri, kind,
         rangeNode(node), true, isQualified));
   }
 }