Heap snapshot visualizations

runtime/observatory/lib/src/service/object.dart

Index: runtime/observatory/lib/src/service/object.dart
diff --git a/runtime/observatory/lib/src/service/object.dart b/runtime/observatory/lib/src/service/object.dart
index 98a128b06ed86ea9a92b296de83aa854877c4fc4..b60526e0c8283b91e5cb6ef258eb0b9119eac8ef 100644
--- a/runtime/observatory/lib/src/service/object.dart
+++ b/runtime/observatory/lib/src/service/object.dart
@@ -779,10 +779,9 @@ class HeapSnapshot {
   final DateTime timeStamp;
   final Isolate isolate;
 
-  HeapSnapshot(this.isolate, ByteData data) :
-      graph = new ObjectGraph(new ReadStream(data)),
-      timeStamp = new DateTime.now() {
-  }
+  HeapSnapshot(this.isolate, chunks, nodeCount) :
+      graph = new ObjectGraph(chunks, nodeCount),
+      timeStamp = new DateTime.now();
 
   List<Future<ServiceObject>> getMostRetained({int classId, int limit}) {
     var result = [];
@@ -795,8 +794,6 @@ class HeapSnapshot {
     }
     return result;
   }
-
-
 }
 
 /// State for a running isolate.
@@ -857,6 +854,20 @@ class Isolate extends ServiceObjectOwner with Coverage {
         .then(_buildClassHierarchy);
   }
 
+  Future<List<Class>> getClassRefs() async {
+    ServiceMap classList = await invokeRpc('getClassList', {});
+    assert(classList.type == 'ClassList');
+    var classRefs = [];
+    for (var cls in classList['classes']) {
+      // Skip over non-class classes.
+      if (cls is Class) {
+        _classesByCid[cls.vmCid] = cls;
+        classRefs.add(cls);
+      }
+    }
+    return classRefs;
+  }
+
   /// Given the class list, loads each class.
   Future<List<Class>> _loadClasses(ServiceMap classList) {

[koda, 2015/05/19 20:12:35]

Is this one still needed?

[rmacnak, 2015/05/19 22:16:08]

Used by getClassHierarchy.

     assert(classList.type == 'ClassList');
@@ -864,6 +875,7 @@ class Isolate extends ServiceObjectOwner with Coverage {
     for (var cls in classList['classes']) {
       // Skip over non-class classes.
       if (cls is Class) {
+        _classesByCid[cls.vmCid] = cls;
         futureClasses.add(cls.load());
       }
     }
@@ -886,6 +898,8 @@ class Isolate extends ServiceObjectOwner with Coverage {
     return new Future.value(objectClass);
   }
 
+  Class getClassByCid(int cid) => _classesByCid[cid];
+
   ServiceObject getFromMap(ObservableMap map) {
     if (map == null) {
       return null;
@@ -938,6 +952,7 @@ class Isolate extends ServiceObjectOwner with Coverage {
 
   @observable Class objectClass;
   @observable final rootClasses = new ObservableList<Class>();
+  Map<int, Class> _classesByCid = new Map<int, Class>();
 
   @observable Library rootLibrary;
   @observable ObservableList<Library> libraries =
@@ -958,21 +973,42 @@ class Isolate extends ServiceObjectOwner with Coverage {
 
   @observable DartError error;
   @observable HeapSnapshot latestSnapshot;
-  Completer<HeapSnapshot> _snapshotFetch;
+  StreamController _snapshotFetch;
+
+  var chunksInProgress;
 
   void _loadHeapSnapshot(ServiceEvent event) {
-    latestSnapshot = new HeapSnapshot(this, event.data);
+    // Occasionally these actually arrive out of order.
+    var i = event.i;
+    var n = event.n;
+    if (chunksInProgress == null) {
+      chunksInProgress = new List(n);
+    }
+    chunksInProgress[i] = event.data;
+    _snapshotFetch.add("Receiving snapshot chunk ${i + 1} of $n...");
+
+    for (i = 0; i < n; i++) {
+      if (chunksInProgress[i] == null) return;
+    }
+
+    var chunks = chunksInProgress;
+    chunksInProgress = null;
+
+    latestSnapshot = new HeapSnapshot(this, chunks, event.nodeCount);
     if (_snapshotFetch != null) {
-      _snapshotFetch.complete(latestSnapshot);
+      latestSnapshot.graph.process(_snapshotFetch).then((graph) {
+        _snapshotFetch.add(latestSnapshot);
+        _snapshotFetch.close();
+      });
     }
   }
 
-  Future<HeapSnapshot> fetchHeapSnapshot() {
-    if (_snapshotFetch == null || _snapshotFetch.isCompleted) {
-      _snapshotFetch = new Completer<HeapSnapshot>();
+  Stream fetchHeapSnapshot() {
+    if (_snapshotFetch == null || _snapshotFetch.isClosed) {
+      _snapshotFetch = new StreamController();
       isolate.invokeRpcNoUpgrade('requestHeapSnapshot', {});
     }
-    return _snapshotFetch.future;
+    return _snapshotFetch.stream;
   }
 
   void updateHeapsFromMap(ObservableMap map) {
@@ -1424,6 +1460,7 @@ class ServiceEvent extends ServiceObject {
   @observable ByteData data;
   @observable int count;
   @observable String reason;
+  int i, n, nodeCount;

[koda, 2015/05/19 20:12:35]

Consider more descriptive names.

 
   @observable bool get isPauseEvent {
     return (eventType == kPauseStart ||
@@ -1456,6 +1493,15 @@ class ServiceEvent extends ServiceObject {
     if (map['_data'] != null) {
       data = map['_data'];
     }
+    if (map['i'] != null) {
+      i = map['i'];
+    }
+    if (map['n'] != null) {
+      n = map['n'];
+    }
+    if (map['nodeCount'] != null) {
+      nodeCount = map['nodeCount'];
+    }
     if (map['count'] != null) {
       count = map['count'];
     }