therubyracer/ext/v8/v8_weakref.cpp

#include "v8.h"
#include "v8_weakref.h"

using namespace v8;

v8_weakref::v8_weakref(VALUE object) {
  this->external = Persistent<External>::New(External::New((void *)this));
  this->external.MakeWeak(this, v8_weakref_dispose);
  this->set(object);
}

void v8_weakref::set(VALUE value) {
  this->object_id = rb_obj_id(value);
  VALUE data = Data_Wrap_Struct(rb_cObject, 0, 0, this);
  VALUE finalizer = rb_proc_new((VALUE (*)(...))v8_weakref_finalize, data);
  rb_funcall(v8_weakref_objectspace(), rb_intern("define_finalizer"), 2, value, finalizer);
}

VALUE v8_weakref::get() {
  if (this->object_id) {
    return rb_rescue((VALUE (*)(...))v8_weakref_id2ref, this->object_id, (VALUE (*)(...))v8_weakref_nil, Qnil);
  } else {
    return Qnil;
  }
}

VALUE v8_weakref_finalize(VALUE object_id, VALUE data) {
  v8_weakref* weakref = 0;
  Data_Get_Struct(data, struct v8_weakref, weakref);
  weakref->object_id = Qnil;
  return Qnil;
}

void v8_weakref_dispose(Persistent<Value> value, void* weakref) {
  value.Dispose();
  value.Clear();
  delete (v8_weakref*)weakref;
}

VALUE v8_weakref_nil(VALUE nil, VALUE exception) {
  return nil;
}

VALUE v8_weakref_objectspace() {
  return rb_const_get(rb_cObject, rb_intern("ObjectSpace"));
}

VALUE v8_weakref_id2ref(VALUE id) {
  return rb_funcall(v8_weakref_objectspace(), rb_intern("_id2ref"), 1, id);
}