Add AnalysisCache.onResultInvalidated, use in DartWorkManager.

pkg/analyzer/lib/src/context/cache.dart

 // Copyright (c) 2015, 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 analyzer.src.context.cache;
 
+import 'dart:async';
 import 'dart:collection';
 
 import 'package:analyzer/src/generated/engine.dart'
     show AnalysisEngine, CacheState, InternalAnalysisContext, RetentionPriority;
 import 'package:analyzer/src/generated/java_engine.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/utilities_collection.dart';
 import 'package:analyzer/src/generated/utilities_general.dart';
 import 'package:analyzer/src/task/model.dart';
 import 'package:analyzer/task/model.dart';
@@ skipping 12 matching lines @@
    * the content of the cache is modified.
    */
   static bool _TRACE_CHANGES = false;
 
   /**
    * An array containing the partitions of which this cache is comprised.
    */
   final List<CachePartition> _partitions;
 
   /**
+   * The [StreamController] reporting [InvalidatedResult]s.
+   */
+  final StreamController<InvalidatedResult> _onResultInvalidated =
+      new StreamController<InvalidatedResult>.broadcast(sync: true);
+
+  /**
    * Initialize a newly created cache to have the given [partitions]. The
    * partitions will be searched in the order in which they appear in the array,
    * so the most specific partition (usually an [SdkCachePartition]) should be
    * first and the most general (usually a [UniversalCachePartition]) last.
    */
-  AnalysisCache(this._partitions);
+  AnalysisCache(this._partitions) {
+    for (CachePartition partition in _partitions) {
+      partition.onResultInvalidated.listen((InvalidatedResult event) {
+        _onResultInvalidated.add(event);
+      });
+    }
+  }
+
+  /**
+   * Return the stream that is notified when a value is invalidated.
+   */
+  Stream<InvalidatedResult> get onResultInvalidated =>
+      _onResultInvalidated.stream;
 
   // TODO(brianwilkerson) Implement or delete this.
 //  /**
 //   * Return information about each of the partitions in this cache.
 //   */
 //  List<AnalysisContextStatistics_PartitionData> get partitionData {
 //    int count = _partitions.length;
 //    List<AnalysisContextStatistics_PartitionData> data =
 //        new List<AnalysisContextStatistics_PartitionData>(count);
 //    for (int i = 0; i < count; i++) {
@@ skipping 438 matching lines @@
       CacheEntry entry = _partition.get(dependentResult.target);
       if (entry != null) {
         entry._invalidate(dependentResult.result);
       }
     });
     // If empty, remove the entry altogether.
     if (_resultMap.isEmpty) {
       _partition._targetMap.remove(target);
       _partition._removeIfSource(target);
     }
+    // Notify controller.
+    _partition._onResultInvalidated
+        .add(new InvalidatedResult(this, descriptor));
   }
 
   /**
    * Invalidates all the results of this entry, with propagation.
    */
   void _invalidateAll() {
     List<ResultDescriptor> results = _resultMap.keys.toList();
     for (ResultDescriptor result in results) {
       _invalidate(result);
     }
@@ skipping 224 matching lines @@
    */
   final InternalAnalysisContext context;
 
   /**
    * A table mapping caching policies to the cache flush managers.
    */
   final HashMap<ResultCachingPolicy, CacheFlushManager> _flushManagerMap =
       new HashMap<ResultCachingPolicy, CacheFlushManager>();
 
   /**
+   * The [StreamController] reporting [InvalidatedResult]s.
+   */
+  final StreamController<InvalidatedResult> _onResultInvalidated =
+      new StreamController<InvalidatedResult>.broadcast(sync: true);
+
+  /**
    * A table mapping the targets belonging to this partition to the information
    * known about those targets.
    */
   HashMap<AnalysisTarget, CacheEntry> _targetMap =
       new HashMap<AnalysisTarget, CacheEntry>();
 
   /**
    * A set of the [Source] targets.
    */
   final HashSet<Source> _sources = new HashSet<Source>();
@@ skipping 12 matching lines @@
   /**
    * Return a table mapping the targets known to the context to the information
    * known about the target.
    *
    * <b>Note:</b> This method is only visible for use by [AnalysisCache] and
    * should not be used for any other purpose.
    */
   Map<AnalysisTarget, CacheEntry> get map => _targetMap;
 
   /**
+   * Return the stream that is notified when a value is invalidated.
+   */
+  Stream<InvalidatedResult> get onResultInvalidated =>
+      _onResultInvalidated.stream;
+
+  /**
    * Return the entry associated with the given [target].
    */
   CacheEntry get(AnalysisTarget target) => _targetMap[target];
 
   /**
    * Return [Source]s whose full path is equal to the given [path].
    * Maybe empty, but not `null`.
    */
   List<Source> getSourcesWithFullName(String path) {
     List<Source> sources = _pathToSources[path];
@@ skipping 130 matching lines @@
           if (sources.isEmpty) {
             _pathToSources.remove(fullName);
           }
         }
       }
     }
   }
 }
 
 /**
+ * [InvalidatedResult] describes an invalidated result.
+ */
+class InvalidatedResult {
+  /**
+   * The target in which the result was invalidated.
+   */
+  final CacheEntry entry;
+
+  /**
+   * The descriptor of the result which was invalidated.
+   */
+  final ResultDescriptor descriptor;
+
+  InvalidatedResult(this.entry, this.descriptor);
+
+  @override
+  String toString() => '$descriptor of ${entry.target}';
+}
+
+/**
  * The data about a single analysis result that is stored in a [CacheEntry].
  */
 // TODO(brianwilkerson) Consider making this a generic class so that the value
 // can be typed.
 class ResultData {
   /**
    * The [ResultDescriptor] this result is for.
    */
   final ResultDescriptor descriptor;
 
@@ skipping 122 matching lines @@
   void resultAccessed(TargetedResult result) {}
 
   @override
   List<TargetedResult> resultStored(TargetedResult newResult, newValue) {
     return TargetedResult.EMPTY_LIST;
   }
 
   @override
   void targetRemoved(AnalysisTarget target) {}
 }