use bit fields for class state and field type values. This shrinks the snapshot

vm/object.h

 // 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.
 
 #ifndef VM_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 619 matching lines @@
 
   RawLibraryPrefix* LookupLibraryPrefix(const String& name) const;
 
   void InsertCanonicalConstant(intptr_t index, const Instance& constant) const;
 
   static intptr_t InstanceSize() {
     return RoundedAllocationSize(sizeof(RawClass));
   }
 
   bool is_interface() const {
-    return raw_ptr()->is_interface_;
+    return InterfaceBit::decode(raw_ptr()->state_bits_);
   }
   void set_is_interface() const;
-  static intptr_t is_interface_offset() {
-    return OFFSET_OF(RawClass, is_interface_);
-  }
 
   bool is_finalized() const {
-    return raw_ptr()->class_state_ == RawClass::kFinalized;
+    return StateBits::decode(raw_ptr()->state_bits_) == RawClass::kFinalized;
   }
   void set_is_finalized() const;
 
   bool is_prefinalized() const {
-    return raw_ptr()->class_state_ == RawClass::kPreFinalized;
+    return StateBits::decode(raw_ptr()->state_bits_) == RawClass::kPreFinalized;
   }
 
   void set_is_prefinalized() const;
 
-  bool is_const() const {
-    return raw_ptr()->is_const_;
-  }
+  bool is_const() const { return ConstBit::decode(raw_ptr()->state_bits_); }
   void set_is_const() const;
 
   int num_native_fields() const {
     return raw_ptr()->num_native_fields_;
   }
   void set_num_native_fields(int value) const {
     raw_ptr()->num_native_fields_ = value;
   }
   static intptr_t num_native_fields_offset() {
     return OFFSET_OF(RawClass, num_native_fields_);
@@ skipping 33 matching lines @@
   static RawClass* NewSignatureClass(const String& name,
                                      const Function& signature_function,
                                      const Script& script);
 
   // Return a class object corresponding to the specified kind. If
   // a canonicalized version of it exists then that object is returned
   // otherwise a new object is allocated and returned.
   static RawClass* GetClass(intptr_t class_id, bool is_signature_class);
 
  private:
+  enum {
+    kConstBit = 1,
+    kInterfaceBit,

[srdjan, 2012/08/14 22:40:44]

The partial numeration is confusing. I would numerate them all, especially since
it is not consecutive.

[siva, 2012/08/15 00:17:16]

Done.

+    kStateTagBit,
+    kStateTagSize = 2,
+  };
+  class ConstBit : public BitField<bool, kConstBit, 1> {};
+  class InterfaceBit : public BitField<bool, kInterfaceBit, 1> {};
+  class StateBits : public BitField<RawClass::ClassState,
+                                    kStateTagBit, kStateTagSize> {}; // NOLINT

[cshapiro, 2012/08/14 22:05:13]

This seems to be generating a lint error.  2 spaces should be deposited between
the ; and the //

[siva, 2012/08/14 22:40:18]

Done.

+
   void set_name(const String& value) const;
   void set_token_pos(intptr_t value) const;
   void set_signature_function(const Function& value) const;
   void set_signature_type(const AbstractType& value) const;
-  void set_class_state(int8_t state) const;
+  void set_class_state(RawClass::ClassState state) const;
+  void set_state_bits(uint8_t bits) const;
 
   void set_constants(const Array& value) const;
 
   void set_canonical_types(const Array& value) const;
   RawArray* canonical_types() const;
 
   void CalculateFieldOffsets() const;
 
   // Assigns empty array to all raw class array fields.
   void InitEmptyFields();
@@ skipping 946 matching lines @@
   HEAP_OBJECT_IMPLEMENTATION(Function, Object);
   friend class Class;
 };
 
 
 class Field : public Object {
  public:
   RawString* name() const { return raw_ptr()->name_; }
   RawString* UserVisibleName() const;
 
-  bool is_static() const { return raw_ptr()->is_static_; }
-  bool is_final() const { return raw_ptr()->is_final_; }
-  bool is_const() const { return raw_ptr()->is_const_; }
+  bool is_static() const { return StaticBit::decode(raw_ptr()->kind_bits_); }
+  bool is_final() const { return FinalBit::decode(raw_ptr()->kind_bits_); }
+  bool is_const() const { return ConstBit::decode(raw_ptr()->kind_bits_); }
 
   inline intptr_t Offset() const;
   inline void SetOffset(intptr_t value) const;
 
   RawInstance* value() const;
   void set_value(const Instance& value) const;
 
   RawClass* owner() const { return raw_ptr()->owner_; }
 
   RawAbstractType* type() const  { return raw_ptr()->type_; }
   void set_type(const AbstractType& value) const;
 
   static intptr_t InstanceSize() {
     return RoundedAllocationSize(sizeof(RawField));
   }
 
   static RawField* New(const String& name,
                        bool is_static,
                        bool is_final,
                        bool is_const,
                        const Class& owner,
                        intptr_t token_pos);
 
   static intptr_t value_offset() { return OFFSET_OF(RawField, value_); }
 
   intptr_t token_pos() const { return raw_ptr()->token_pos_; }
 
-  bool has_initializer() const { return raw_ptr()->has_initializer_; }
+  bool has_initializer() const {
+    return HasInitializerBit::decode(raw_ptr()->kind_bits_);
+  }
   void set_has_initializer(bool has_initializer) const {
-    raw_ptr()->has_initializer_ = has_initializer;
+    uword bits = raw_ptr()->kind_bits_;
+    raw_ptr()->kind_bits_ = HasInitializerBit::update(has_initializer, bits);
   }
 
   // Constructs getter and setter names for fields and vice versa.
   static RawString* GetterName(const String& field_name);
   static RawString* GetterSymbol(const String& field_name);
   static RawString* SetterName(const String& field_name);
   static RawString* SetterSymbol(const String& field_name);
   static RawString* NameFromGetter(const String& getter_name);
   static RawString* NameFromSetter(const String& setter_name);
   static bool IsGetterName(const String& function_name);
   static bool IsSetterName(const String& function_name);
 
  private:
+  enum {
+    kConstBit = 1,
+    kStaticBit,
+    kFinalBit,
+    kHasInitializerBit,
+  };
+  class ConstBit : public BitField<bool, kConstBit, 1> {};
+  class StaticBit : public BitField<bool, kStaticBit, 1> {};
+  class FinalBit : public BitField<bool, kFinalBit, 1> {};
+  class HasInitializerBit : public BitField<bool, kHasInitializerBit, 1> {};
+
   void set_name(const String& value) const;
   void set_is_static(bool is_static) const {
-    raw_ptr()->is_static_ = is_static;
+    uword bits = raw_ptr()->kind_bits_;
+    raw_ptr()->kind_bits_ = StaticBit::update(is_static, bits);
   }
   void set_is_final(bool is_final) const {
-    raw_ptr()->is_final_ = is_final;
+    uword bits = raw_ptr()->kind_bits_;
+    raw_ptr()->kind_bits_ = FinalBit::update(is_final, bits);
   }
   void set_is_const(bool value) const {
-    raw_ptr()->is_const_ = value;
+    uword bits = raw_ptr()->kind_bits_;
+    raw_ptr()->kind_bits_ = ConstBit::update(value, bits);
   }
   void set_owner(const Class& value) const {
     StorePointer(&raw_ptr()->owner_, value.raw());
   }
   void set_token_pos(intptr_t token_pos) const {
     raw_ptr()->token_pos_ = token_pos;
   }
+  void set_kind_bits(intptr_t value) const {
+    raw_ptr()->kind_bits_ = value;
+  }
   static RawField* New();
 
   HEAP_OBJECT_IMPLEMENTATION(Field, Object);
   friend class Class;
+  friend class HeapProfiler;
 };
 
 
 class LiteralToken : public Object {
  public:
   Token::Kind kind() const { return raw_ptr()->kind_; }
   RawString* literal() const { return raw_ptr()->literal_; }
   RawObject* value() const { return raw_ptr()->value_; }
 
   static intptr_t InstanceSize() {
@@ skipping 3725 matching lines @@
     if (this->CharAt(i) != str.CharAt(begin_index + i)) {
       return false;
     }
   }
   return true;
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_