Dramatically speed up detailed heap snapshot generation.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 3d88568882350628c8f4895c41c0265c9f502f8f..e50c1c4f32810483d3368d474b27c73dbf58bd71 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -1121,6 +1121,9 @@ class HeapObject: public Object {
   // object is overflowed (ie, partially restore the map pointer).
   inline void ClearOverflow();
 
+  // Returns address of the field at offset in obj.
+  inline Address GetFieldAddress(int offset);

[Vitaly Repeshko, 2011/03/17 16:52:00]

This is "obj->address() + offset". If a helper for this is really need, please
move it to the profiler code.

[mnaganov (inactive), 2011/03/17 17:37:18]

Removed.

+
   // Returns the field at offset in obj, as a read/write Object* reference.
   // Does no checking, and is safe to use during GC, while maps are invalid.
   // Does not invoke write barrier, so should only be assigned to
@@ -1587,6 +1590,7 @@ class JSObject: public HeapObject {
   inline int GetHeaderSize();
 
   inline int GetInternalFieldCount();
+  inline Address GetInternalFieldOffset(int index);

[Vitaly Repeshko, 2011/03/17 16:52:00]

Since it's called "...Offset" it should return an offset. Then a generic helper
can turn it into an address.

[mnaganov (inactive), 2011/03/17 17:37:18]

Fixed.

   inline Object* GetInternalField(int index);
   inline void SetInternalField(int index, Object* value);
 
@@ -1700,6 +1704,7 @@ class JSObject: public HeapObject {
       int unused_property_fields);
 
   // Access fast-case object properties at index.
+  inline Address GetFastPropertyAddress(int index);

[Vitaly Repeshko, 2011/03/17 16:52:00]

I think this also should return an offset.

[mnaganov (inactive), 2011/03/17 17:37:18]

Done.

   inline Object* FastPropertyAt(int index);
   inline Object* FastPropertyAtPut(int index, Object* value);