/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=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/. */

#ifndef mozilla_net_AutoClose_h

#define mozilla_net_AutoClose_h

#include "nsCOMPtr.h"

#include "mozilla/Mutex.h"

namespace mozilla { namespace net {

// Like an nsAutoPtr for XPCOM streams (e.g. nsIAsyncInputStream) and other

// refcounted classes that need to have the Close() method called explicitly

// before they are destroyed.

template <typename T>

class AutoClose

{

public:

  AutoClose() : mMutex("net::AutoClose.mMutex") { }

  ~AutoClose(){

    CloseAndRelease();

  }

  explicit operator bool()

  {

    MutexAutoLock lock(mMutex);

    return mPtr;

  }

  already_AddRefed<T> forget()

  {

    MutexAutoLock lock(mMutex);

    return mPtr.forget();

  }

  void takeOver(nsCOMPtr<T> & rhs)

  {

    TakeOverInternal(rhs.forget());

  }

  void CloseAndRelease()

  {

    TakeOverInternal(nullptr);

  }

private:

  void TakeOverInternal(already_AddRefed<T>&& aOther)

  {

    nsCOMPtr<T> ptr(std::move(aOther));

    {

      MutexAutoLock lock(mMutex);

      ptr.swap(mPtr);

    }

    if (ptr) {

      ptr->Close();

    }

  }

  void operator=(const AutoClose<T> &) = delete;

  AutoClose(const AutoClose<T> &) = delete;

  nsCOMPtr<T> mPtr;

  Mutex mMutex;

};

} // namespace net

} // namespace mozilla

#endif // mozilla_net_AutoClose_h