gecko-dev/dom/base/StructuredCloneTester.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "StructuredCloneTester.h"

#include "js/StructuredClone.h"
#include "mozilla/RefPtr.h"
#include "mozilla/dom/StructuredCloneTags.h"
#include "mozilla/dom/StructuredCloneTesterBinding.h"
#include "xpcpublic.h"

namespace mozilla {

class ErrorResult;

namespace dom {

NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_0(StructuredCloneTester)
NS_IMPL_CYCLE_COLLECTING_ADDREF(StructuredCloneTester)
NS_IMPL_CYCLE_COLLECTING_RELEASE(StructuredCloneTester)
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(StructuredCloneTester)
  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END

StructuredCloneTester::StructuredCloneTester(nsISupports* aParent,
                                             const bool aSerializable,
                                             const bool aDeserializable)
  : mParent(aParent),
    mSerializable(aSerializable),
    mDeserializable(aDeserializable)
{
}

/* static */ already_AddRefed<StructuredCloneTester>
StructuredCloneTester::Constructor(const GlobalObject& aGlobal,
                                   const bool aSerializable,
                                   const bool aDeserializable,
                                   ErrorResult& aRv)
{
  RefPtr<StructuredCloneTester> sct = new StructuredCloneTester(aGlobal.GetAsSupports(),
                                                                aSerializable,
                                                                aDeserializable);
  return sct.forget();
}

bool
StructuredCloneTester::Serializable() const
{
  return mSerializable;
}

bool
StructuredCloneTester::Deserializable() const
{
  return mDeserializable;
}

/* static */ JSObject*
StructuredCloneTester::ReadStructuredClone(JSContext* aCx,
                                           JSStructuredCloneReader* aReader)
{
  uint32_t serializable = 0;
  uint32_t deserializable = 0;

  if (!JS_ReadUint32Pair(aReader, &serializable, &deserializable)) {
    return nullptr;
  }

  nsIGlobalObject* global = xpc::CurrentNativeGlobal(aCx);

  if (NS_WARN_IF(!global)) {
    return nullptr;
  }

  // Prevent the return value from being trashed by a GC during ~nsRefPtr
  JS::RootedObject result(aCx);

  RefPtr<StructuredCloneTester> sct = new StructuredCloneTester(
    global,
    static_cast<bool>(serializable),
    static_cast<bool>(deserializable)
  );

  // "Fail" deserialization
  if (!sct->Deserializable()) {
    xpc::Throw(aCx, NS_ERROR_DOM_DATA_CLONE_ERR);
    return nullptr;
  }

  result = sct->WrapObject(aCx, nullptr);

  return result;
}

bool
StructuredCloneTester::WriteStructuredClone(JSStructuredCloneWriter* aWriter) const
{
  return JS_WriteUint32Pair(aWriter, SCTAG_DOM_STRUCTURED_CLONE_TESTER, 0) &&
         JS_WriteUint32Pair(aWriter, static_cast<uint32_t>(Serializable()),
                            static_cast<uint32_t>(Deserializable()));
}

nsISupports*
StructuredCloneTester::GetParentObject() const
{
  return mParent;
}

JSObject*
StructuredCloneTester::WrapObject(JSContext* aCx,
                                  JS::Handle<JSObject*> aGivenProto)
{
  return StructuredCloneTester_Binding::Wrap(aCx, this, aGivenProto);
}

} // namespace dom
} // namespace mozilla