/*
   Copyright (c) 2014, 2021, Oracle and/or its affiliates.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License, version 2.0, for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
*/

#ifndef INSTANCE_CALLBACK_INCLUDED
#define INSTANCE_CALLBACK_INCLUDED

#include "i_callable.h"
#include <cstddef> // NULL

namespace Mysql{

/**
  Instance method based callback.
*/
template<typename T_result, typename T_arg, typename T_class>
  class Instance_callback : public I_callable<T_result, T_arg>
{

  typedef T_result (T_class::*Method)(T_arg);

public:
  /**
    Creates new instance method callback.
  */
  Instance_callback(T_class* instance, Method method);

  /**
    Invokes callback method on instance specified in constructor.
  */
  T_result operator()(T_arg argument) const;

protected:
  T_class* m_instance;
private:
  Method m_method;
};

/**
  Instance method based callback. Owns T_class instance and destroys it when it
  dies.
*/
template<typename T_result, typename T_arg, typename T_class>
  class Instance_callback_own
    : public Instance_callback<T_result, T_arg, T_class>
{
  typedef T_result (T_class::*Method)(T_arg);

public:
  /**
    Creates new instance method callback.
  */
  Instance_callback_own(T_class* instance, Method method);

  ~Instance_callback_own();
};

template<typename T_result, typename T_arg, typename T_class>
  Instance_callback<T_result, T_arg, T_class>::
    Instance_callback(T_class* instance, Method method)
  : m_instance(instance), m_method(method)
{}

template<typename T_result, typename T_arg, typename T_class>
  T_result Instance_callback<T_result, T_arg, T_class>::operator()
    (T_arg argument) const
{
  return (this->m_instance->*this->m_method)(argument);
}

template<typename T_result, typename T_arg, typename T_class>
  Instance_callback_own<T_result, T_arg, T_class>::
    Instance_callback_own(T_class* instance, Method method)
  : Instance_callback<T_result, T_arg, T_class>(instance, method)
{}

template<typename T_result, typename T_arg, typename T_class>
  Instance_callback_own<T_result, T_arg, T_class>::
    ~Instance_callback_own()
{
  delete this->m_instance;
  this->m_instance= NULL;
}

}

#endif
