Add RPC and UI for reachable size of an object / all instances of a class.

runtime/vm/service.cc

Index: runtime/vm/service.cc
diff --git a/runtime/vm/service.cc b/runtime/vm/service.cc
index 70ca2e305fdbbafe1eebd3bb66ff0206469932b1..5cd668054612952130d4c7adaf1260ca79fae9b9 100644
--- a/runtime/vm/service.cc
+++ b/runtime/vm/service.cc
@@ -1806,6 +1806,50 @@ static bool GetRetainedSize(Thread* thread, JSONStream* js) {
 }
 
 
+static const MethodParameter* get_reachable_size_params[] = {
+  ISOLATE_PARAMETER,
+  NULL,

[Cutch, 2015/11/18 15:00:20]

new IdParameter("targetId", true),

[rmacnak, 2015/11/18 18:07:29]

Done, here and retained_size

+};
+
+
+static bool GetReachableSize(Thread* thread, JSONStream* js) {
+  const char* target_id = js->LookupParam("targetId");
+  if (target_id == NULL) {

[Cutch, 2015/11/18 15:00:20]

ASSERT(target_id != NULL);

[rmacnak, 2015/11/18 18:07:29]

Done.

+    PrintMissingParamError(js, "targetId");
+    return true;
+  }
+  ObjectIdRing::LookupResult lookup_result;
+  Object& obj = Object::Handle(LookupHeapObject(thread, target_id,
+                                                &lookup_result));
+  if (obj.raw() == Object::sentinel().raw()) {
+    if (lookup_result == ObjectIdRing::kCollected) {
+      PrintSentinel(js, kCollectedSentinel);

[Cutch, 2015/11/18 15:00:20]

Should GetReachableSize for a collected object be collected? Shouldn't it be 0?

[rmacnak, 2015/11/18 18:07:29]

Asking any question about an object that got collected should be fail-stop.

+    } else if (lookup_result == ObjectIdRing::kExpired) {
+      PrintSentinel(js, kExpiredSentinel);
+    } else {
+      PrintInvalidParamError(js, "targetId");
+    }
+    return true;
+  }
+  // TODO(rmacnak): There is no way to get the size retained by a class object.
+  // SizeRetainedByClass should be a separate RPC.
+  if (obj.IsClass()) {
+    const Class& cls = Class::Cast(obj);
+    ObjectGraph graph(thread);
+    intptr_t retained_size = graph.SizeReachableByClass(cls.id());
+    const Object& result = Object::Handle(Integer::New(retained_size));
+    result.PrintJSON(js, true);
+    return true;
+  }
+
+  ObjectGraph graph(thread);
+  intptr_t retained_size = graph.SizeReachableByInstance(obj);
+  const Object& result = Object::Handle(Integer::New(retained_size));
+  result.PrintJSON(js, true);
+  return true;
+}
+
+
 static const MethodParameter* evaluate_params[] = {
   ISOLATE_PARAMETER,
   NULL,
@@ -3455,6 +3499,8 @@ static ServiceMethodDescriptor service_methods_[] = {
     get_object_by_address_params },
   { "_getPorts", GetPorts,
     get_ports_params },
+  { "_getReachableSize", GetReachableSize,
+    get_reachable_size_params },
   { "_getRetainedSize", GetRetainedSize,
     get_retained_size_params },
   { "_getRetainingPath", GetRetainingPath,