Fix for truncated unlinked summaries in ByteStore.

pkg/analyzer/lib/src/dart/analysis/file_state.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.
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:typed_data';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 98 matching lines @@
 
   bool _exists;
   List<int> _contentBytes;
   String _content;
   String _contentHash;
   LineInfo _lineInfo;
   Set<String> _definedTopLevelNames;
   Set<String> _definedClassMemberNames;
   Set<String> _referencedNames;
   Set<String> _subtypedNames;
+  String _unlinkedKey;
   UnlinkedUnit _unlinked;
   List<int> _apiSignature;
 
   List<FileState> _importedFiles;
   List<FileState> _exportedFiles;
   List<FileState> _partedFiles;
   List<NameFilter> _exportFilters;
 
   Set<FileState> _directReferencedFiles = new Set<FileState>();
   Set<FileState> _transitiveFiles;
@@ skipping 146 matching lines @@
    * The external names referenced by the file.
    */
   Set<String> get referencedNames => _referencedNames;
 
   /**
    * The names which are used in `extends`, `with` or `implements` clauses in
    * the file. Import prefixes and type arguments are not included.
    */
   Set<String> get subtypedNames => _subtypedNames;
 
+  @visibleForTesting
+  FileStateTestView get test => new FileStateTestView(this);
+
   /**
    * Return public top-level declarations declared in the file. The keys to the
    * map are names of declarations.
    */
   Map<String, TopLevelDeclaration> get topLevelDeclarations {
     if (_topLevelDeclarations == null) {
       _topLevelDeclarations = <String, TopLevelDeclaration>{};
 
       void addDeclaration(TopLevelDeclarationKind kind, String name) {
         if (!name.startsWith('_')) {
@@ skipping 122 matching lines @@
     }
 
     // Compute the content hash.
     List<int> contentBytes = UTF8.encode(_content);
     {
       List<int> hashBytes = md5.convert(contentBytes).bytes;
       _contentHash = hex.encode(hashBytes);
     }
 
     // Prepare the unlinked bundle key.
-    String unlinkedKey;
     {
       ApiSignature signature = new ApiSignature();
       signature.addUint32List(_fsState._salt);
       signature.addInt(contentBytes.length);
       signature.addString(_contentHash);
-      unlinkedKey = '${signature.toHex()}.unlinked';
+      _unlinkedKey = '${signature.toHex()}.unlinked';
     }
 
     // Prepare bytes of the unlinked bundle - existing or new.
     List<int> bytes;
     {
-      bytes = _fsState._byteStore.get(unlinkedKey);
-      if (bytes == null) {
+      bytes = _fsState._byteStore.get(_unlinkedKey);
+      if (bytes == null || bytes.isEmpty) {
         CompilationUnit unit = parse(AnalysisErrorListener.NULL_LISTENER);
         _fsState._logger.run('Create unlinked for $path', () {
           UnlinkedUnitBuilder unlinkedUnit = serializeAstUnlinked(unit);
           DefinedNames definedNames = computeDefinedNames(unit);
           List<String> referencedNames = computeReferencedNames(unit).toList();
           List<String> subtypedNames = computeSubtypedNames(unit).toList();
           bytes = new AnalysisDriverUnlinkedUnitBuilder(
                   unit: unlinkedUnit,
                   definedTopLevelNames: definedNames.topLevelNames.toList(),
                   definedClassMemberNames:
                       definedNames.classMemberNames.toList(),
                   referencedNames: referencedNames,
                   subtypedNames: subtypedNames)
               .toBuffer();
-          _fsState._byteStore.put(unlinkedKey, bytes);
+          _fsState._byteStore.put(_unlinkedKey, bytes);
         });
       }
     }
 
     // Read the unlinked bundle.
     var driverUnlinkedUnit = new AnalysisDriverUnlinkedUnit.fromBuffer(bytes);
     _definedTopLevelNames = driverUnlinkedUnit.definedTopLevelNames.toSet();
     _definedClassMemberNames =
         driverUnlinkedUnit.definedClassMemberNames.toSet();
     _referencedNames = driverUnlinkedUnit.referencedNames.toSet();
@@ skipping 168 matching lines @@
     }
     for (int i = 0; i < a.length; i++) {
       if (a[i] != b[i]) {
         return false;
       }
     }
     return true;
   }
 }
 
+@visibleForTesting
+class FileStateTestView {
+  final FileState file;
+
+  FileStateTestView(this.file);
+
+  String get unlinkedKey => file._unlinkedKey;
+}
+
 /**
  * Information about known file system state.
  */
 class FileSystemState {
   final PerformanceLog _logger;
   final ResourceProvider _resourceProvider;
   final ByteStore _byteStore;
   final FileContentOverlay _contentOverlay;
   final SourceFactory _sourceFactory;
   final AnalysisOptions _analysisOptions;
@@ skipping 277 matching lines @@
 
 /**
  * Information about changes to the known file set.
  */
 class KnownFilesSetChange {
   final Set<String> added;
   final Set<String> removed;
 
   KnownFilesSetChange(this.added, this.removed);
 }