Add Dart_IsExternalString and Dart_ExternalStringGetPeer to the dart

runtime/vm/object.h

 // Copyright (c) 2011, 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 "vm/assert.h"
 #include "vm/dart.h"
 #include "vm/globals.h"
@@ skipping 2457 matching lines @@
   virtual bool Equals(const Instance& other) const;
 
   intptr_t CompareTo(const String& other) const;
 
   bool StartsWith(const String& other) const;
 
   virtual RawInstance* Canonicalize() const;
 
   bool IsSymbol() const;
 
+  virtual bool IsExternal() const { return false; }
+  virtual void* GetPeer() const {
+    UNREACHABLE();
+    return NULL;
+  }
+
   static RawString* New(const char* str, Heap::Space space = Heap::kNew);
   static RawString* New(const uint8_t* characters,
                         intptr_t len,
                         Heap::Space space = Heap::kNew);
   static RawString* New(const uint16_t* characters,
                         intptr_t len,
                         Heap::Space space = Heap::kNew);
   static RawString* New(const uint32_t* characters,
                         intptr_t len,
                         Heap::Space space = Heap::kNew);
@@ skipping 256 matching lines @@
 class ExternalOneByteString : public String {
  public:
   virtual int32_t CharAt(intptr_t index) const {
     return *CharAddr(index);
   }
 
   virtual intptr_t CharSize() const {
     return kOneByteChar;
   }
 
+  virtual bool IsExternal() const { return true; }
+  virtual void* GetPeer() const {
+    return raw_ptr()->external_data_->peer_;
+  }
+
   static intptr_t InstanceSize() {
     return RoundedAllocationSize(sizeof(RawExternalOneByteString));
   }
 
   static RawExternalOneByteString* New(const uint8_t* characters,
                                        intptr_t len,
                                        void* peer,
                                        PeerFinalizer callback,
                                        Heap::Space space);
 
@@ skipping 17 matching lines @@
 class ExternalTwoByteString : public String {
  public:
   virtual int32_t CharAt(intptr_t index) const {
     return *CharAddr(index);
   }
 
   virtual intptr_t CharSize() const {
     return kTwoByteChar;
   }
 
+  virtual bool IsExternal() const { return true; }
+  virtual void* GetPeer() const {
+    return raw_ptr()->external_data_->peer_;
+  }
+
   static intptr_t InstanceSize() {
     return RoundedAllocationSize(sizeof(RawExternalTwoByteString));
   }
 
   static RawExternalTwoByteString* New(const uint16_t* characters,
                                        intptr_t len,
                                        void* peer,
                                        PeerFinalizer callback,
                                        Heap::Space space = Heap::kNew);
 
@@ skipping 17 matching lines @@
 class ExternalFourByteString : public String {
  public:
   virtual int32_t CharAt(intptr_t index) const {
     return *CharAddr(index);
   }
 
   virtual intptr_t CharSize() const {
     return kFourByteChar;
   }
 
+  virtual bool IsExternal() const { return true; }
+  virtual void* GetPeer() const {
+    return raw_ptr()->external_data_->peer_;
+  }
+
   static intptr_t InstanceSize() {
     return RoundedAllocationSize(sizeof(RawExternalFourByteString));
   }
 
   static RawExternalFourByteString* New(const uint32_t* characters,
                                         intptr_t len,
                                         void* peer,
                                         PeerFinalizer callback,
                                         Heap::Space space = Heap::kNew);
 
@@ skipping 409 matching lines @@
 }
 
 
 void Context::SetAt(intptr_t index, const Instance& value) const {
   StorePointer(InstanceAddr(index), value.raw());
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_