Add an API to control the disposal of external string resources...

include/v8.h

 // Copyright 2007-2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1104 matching lines @@
   static Local<String> NewSymbol(const char* data, int length = -1);
 
   /**
    * Creates a new string by concatenating the left and the right strings
    * passed in as parameters.
    */
   static Local<String> Concat(Handle<String> left, Handle<String>right);
 
   /**
    * Creates a new external string using the data defined in the given
-   * resource. The resource is deleted when the external string is no
-   * longer live on V8's heap. The caller of this function should not
-   * delete or modify the resource. Neither should the underlying buffer be
-   * deallocated or modified except through the destructor of the
-   * external string resource.
+   * resource. When the external string is no longer live on V8's heap the
+   * resource will be disposed. If a disposal callback has been set using
+   * SetExternalStringDiposeCallback this callback will be called to dispose
+   * the resource. Otherwise, V8 will dispose the resource using the C++ delete
+   * operator. The caller of this function should not otherwise delete or
+   * modify the resource. Neither should the underlying buffer be deallocated
+   * or modified except through the destructor of the external string resource.
    */
   static Local<String> NewExternal(ExternalStringResource* resource);
 
   /**
    * Associate an external string resource with this string by transforming it
    * in place so that existing references to this string in the JavaScript heap
    * will use the external string resource. The external string resource's
    * character contents needs to be equivalent to this string.
    * Returns true if the string has been changed to be an external string.
-   * The string is not modified if the operation fails.
+   * The string is not modified if the operation fails. See NewExternal for
+   * information on the lifetime of the resource.
    */
   bool MakeExternal(ExternalStringResource* resource);
 
   /**
    * Creates a new external string using the ascii data defined in the given
-   * resource. The resource is deleted when the external string is no
-   * longer live on V8's heap. The caller of this function should not
-   * delete or modify the resource. Neither should the underlying buffer be
-   * deallocated or modified except through the destructor of the
-   * external string resource.
+   * resource. When the external string is no longer live on V8's heap the
+   * resource will be disposed. If a disposal callback has been set using
+   * SetExternalStringDiposeCallback this callback will be called to dispose
+   * the resource. Otherwise, V8 will dispose the resource using the C++ delete
+   * operator. The caller of this function should not otherwise delete or
+   * modify the resource. Neither should the underlying buffer be deallocated
+   * or modified except through the destructor of the external string resource.
    */
   static Local<String> NewExternal(ExternalAsciiStringResource* resource);
 
   /**
    * Associate an external string resource with this string by transforming it
    * in place so that existing references to this string in the JavaScript heap
    * will use the external string resource. The external string resource's
    * character contents needs to be equivalent to this string.
    * Returns true if the string has been changed to be an external string.
-   * The string is not modified if the operation fails.
+   * The string is not modified if the operation fails. See NewExternal for
+   * information on the lifetime of the resource.
    */
   bool MakeExternal(ExternalAsciiStringResource* resource);
 
   /**
    * Returns true if this string can be made external.
    */
   bool CanMakeExternal();
 
   /** Creates an undetectable string from the supplied ascii or utf-8 data.*/
   static Local<String> NewUndetectable(const char* data, int length = -1);
@@ skipping 68 matching lines @@
     Value(const Value&);
     void operator=(const Value&);
   };
 
  private:
   void VerifyExternalStringResource(ExternalStringResource* val) const;
   static void CheckCast(v8::Value* obj);
 };
 
 
+typedef void (*ExternalStringDiposeCallback)
+    (String::ExternalStringResourceBase* resource);
+
+
 /**
  * A JavaScript number value (ECMA-262, 4.3.20)
  */
 class V8EXPORT Number : public Primitive {
  public:
   double Value() const;
   static Local<Number> New(double value);
   static inline Number* Cast(v8::Value* obj);
  private:
   Number();
@@ skipping 1197 matching lines @@
    */
   static bool AddMessageListener(MessageCallback that,
                                  Handle<Value> data = Handle<Value>());
 
   /**
    * Remove all message listeners from the specified callback function.
    */
   static void RemoveMessageListeners(MessageCallback that);
 
   /**
+   * Set a callback to be called when an external string is no longer live on
+   * V8's heap. The resource will no longer be needed by V8 and the embedder
+   * can dispose of if. If this callback is not set V8 will free the resource
+   * using the C++ delete operator.
+   */
+  static void SetExternalStringDiposeCallback(
+      ExternalStringDiposeCallback that);
+
+  /**
    * Sets V8 flags from a string.
    */
   static void SetFlagsFromString(const char* str, int length);
 
   /**
    * Sets V8 flags from the command line.
    */
   static void SetFlagsFromCommandLine(int* argc,
                                       char** argv,
                                       bool remove_flags);
@@ skipping 1108 matching lines @@
 
 }  // namespace v8
 
 
 #undef V8EXPORT
 #undef V8EXPORT_INLINE
 #undef TYPE_CHECK
 
 
 #endif  // V8_H_