Support filtering heapdomstats by types, to support attribution of ta…

…rgeted sets of objects

Summary:
Now that we want to push higher attribution for specific features, it's helpful to be able to list unattributed objects that float to the top of the dominator tree, and that need more reference classifiers.

Note that this is not sufficient to ensure complete attribution, as matching objects could still be descendants of other top-level objects, or float to non-meaningful intermediate nodes.

Differential Revision: D54563606

fbshipit-source-id: 26d3ae58017fdcc70947ef29083903731e5c8d9b

Commands/HeapDomStatsCommand.cs

@@ -5,6 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+using MemorySnapshotAnalyzer.AbstractMemorySnapshot;
 using MemorySnapshotAnalyzer.CommandInfrastructure;
 using System;
 using System.Collections.Generic;
@@ -19,6 +20,12 @@ public HeapDomStatsCommand(Repl repl) : base(repl) {}
 #pragma warning disable CS0649 // Field '...' is never assigned to, and will always have its default value
         [FlagArgument("bysize")]
         public bool OrderBySize;
+
+        [NamedArgument("type")]
+        public CommandLineArgument? TypeIndexOrPattern;
+
+        [FlagArgument("includederived")]
+        public bool IncludeDerived;
 #pragma warning restore CS0649 // Field '...' is never assigned to, and will always have its default value
 
         public override void Run()
@@ -28,6 +35,16 @@ public override void Run()
 
         void DumpStats()
         {
+            TypeSet? typeSet;
+            if (TypeIndexOrPattern != null)
+            {
+                typeSet = TypeIndexOrPattern.ResolveTypeIndexOrPattern(Context, IncludeDerived);
+            }
+            else
+            {
+                typeSet = null;
+            }
+
             List<int>? children = CurrentHeapDom.GetChildren(CurrentHeapDom.RootNodeIndex);
 
             var stats = new Dictionary<int, (int Count, long Size)>();
@@ -43,12 +60,17 @@ void DumpStats()
                     int nodeIndex = children[i];
                     if (CurrentBacktracer.IsLiveObjectNode(nodeIndex))
                     {
+                        int postorderIndex = CurrentBacktracer.NodeIndexToPostorderIndex(nodeIndex);
+                        int typeIndex = CurrentTracedHeap.PostorderTypeIndexOrSentinel(postorderIndex);
+                        if (typeSet != null && !typeSet.Contains(typeIndex))
+                        {
+                            continue;
+                        }
+
                         long treeSize = CurrentHeapDom.TreeSize(nodeIndex);
                         totalSize += treeSize;
                         totalObjectCount++;
 
-                        int postorderIndex = CurrentBacktracer.NodeIndexToPostorderIndex(nodeIndex);
-                        int typeIndex = CurrentTracedHeap.PostorderTypeIndexOrSentinel(postorderIndex);
                         if (stats.TryGetValue(typeIndex, out (int Count, long Size) data))
                         {
                             stats[typeIndex] = (data.Count + 1, data.Size + CurrentHeapDom.TreeSize(nodeIndex));
@@ -101,6 +123,6 @@ void DumpStats()
             Output.EndArray();
         }
 
-        public override string HelpText => "heapdomstats ['bysize]";
+        public override string HelpText => "heapdomstats ['bysize] ['type [<type index or pattern>] ['includederived]]";
     }
 }