Provide a logical view of VM-internal maps in Observatory.

runtime/vm/object.cc

 // Copyright (c) 2012, 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.
 
 #include "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 19339 matching lines @@
                                                    old_tags);
     tags = CompareAndSwapTags(old_tags, new_tags);
   } while (tags != old_tags);
 }
 
 
 const char* Array::ToCString() const {
   if (IsNull()) {
     return IsImmutable() ? "_ImmutableList NULL" : "_List NULL";
   }
-  const char* format = IsImmutable() ?
-      "_ImmutableList len:%" Pd : "_List len:%" Pd;
-  intptr_t len = OS::SNPrint(NULL, 0, format, Length()) + 1;
-  char* chars = Isolate::Current()->current_zone()->Alloc<char>(len);
-  OS::SNPrint(chars, len, format, Length());
-  return chars;
+  Zone* zone = Isolate::Current()->current_zone();
+  const char* format = IsImmutable() ? "_ImmutableList len:%" Pd
+                                     : "_List len:%" Pd;
+  return zone->PrintToString(format, Length());
 }
 
 
 void Array::PrintJSONImpl(JSONStream* stream, bool ref) const {
   JSONObject jsobj(stream);
   PrintSharedInstanceJSON(&jsobj, ref);
   jsobj.AddProperty("kind", "List");
   jsobj.AddServiceId(*this);
   jsobj.AddProperty("length", Length());
   if (ref) {
     return;
   }
   {
     JSONArray jsarr(&jsobj, "elements");
+    Object& element = Object::Handle();
     for (intptr_t index = 0; index < Length(); index++) {
       JSONObject jselement(&jsarr);
       jselement.AddProperty("index", index);
 
-      Object& element = Object::Handle(At(index));
+      element = At(index);
       jselement.AddProperty("value", element);
     }
   }
 }
 
 
 RawArray* Array::Grow(const Array& source,
                       intptr_t new_length,
                       Heap::Space space) {
   Isolate* isolate = Isolate::Current();
@@ skipping 221 matching lines @@
   JSONObject jsobj(stream);
   PrintSharedInstanceJSON(&jsobj, ref);
   jsobj.AddProperty("kind", "List");
   jsobj.AddServiceId(*this);
   jsobj.AddProperty("length", Length());
   if (ref) {
     return;
   }
   {
     JSONArray jsarr(&jsobj, "elements");
+    Object& element = Object::Handle();
     for (intptr_t index = 0; index < Length(); index++) {
       JSONObject jselement(&jsarr);
       jselement.AddProperty("index", index);
 
-      Object& element = Object::Handle(At(index));
+      element = At(index);
       jselement.AddProperty("value", element);
     }
   }
 }
 
 
 // Equivalent to Dart's operator "==" and hashCode.
 class DefaultHashTraits {
  public:
   static bool IsMatch(const Object& a, const Object& b) {
@@ skipping 67 matching lines @@
                                       LinkedHashMap::InstanceSize(),
                                       space);
     NoSafepointScope no_safepoint;
     result ^= raw;
   }
   return result.raw();
 }
 
 
 const char* LinkedHashMap::ToCString() const {
-  // TODO(koda): Print key/value pairs.
-  return "_LinkedHashMap";
+  Zone* zone = Isolate::Current()->current_zone();
+  return zone->PrintToString("_LinkedHashMap len:%" Pd, Length());
 }
 
 
 void LinkedHashMap::PrintJSONImpl(JSONStream* stream, bool ref) const {
   JSONObject jsobj(stream);
   PrintSharedInstanceJSON(&jsobj, ref);
   jsobj.AddProperty("kind", "Map");
   jsobj.AddServiceId(*this);
-  // TODO(koda): Print length.
+  jsobj.AddProperty("length", Length());
   if (ref) {
     return;
   }
-  // TODO(koda): Print key/value pairs.
+  {
+    JSONArray jsarr(&jsobj, "associations");
+    Object& object = Object::Handle();
+    LinkedHashMap::Iterator iterator(*this);
+    while (iterator.MoveNext()) {
+      JSONObject jsassoc(&jsarr);
+      object = iterator.CurrentKey();
+      jsassoc.AddProperty("key", object);
+      object = iterator.CurrentValue();
+      jsassoc.AddProperty("value", object);
+    }
+  }
 }
 
 
 RawFloat32x4* Float32x4::New(float v0, float v1, float v2, float v3,
                              Heap::Space space) {
   ASSERT(Isolate::Current()->object_store()->float32x4_class() !=
          Class::null());
   Float32x4& result = Float32x4::Handle();
   {
     RawObject* raw = Object::Allocate(Float32x4::kClassId,
@@ skipping 1072 matching lines @@
   return tag_label.ToCString();
 }
 
 
 void UserTag::PrintJSONImpl(JSONStream* stream, bool ref) const {
   Instance::PrintJSONImpl(stream, ref);
 }
 
 
 }  // namespace dart