objectstack.cpp

"More for C++" is a class library that provides some features that are usually common for object ori

//
//  This file is part of the "More for C++" library
//
//  Copyright (c) 1999-2003 by Thorsten Goertz ([e-mail])
//
//  The "More for C++" library is free software; you can redistribute it and/or
//  modify it under the terms of the license that comes with this package.
//
//  Read "license.txt" for more details.
//
//  THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
//  WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES
//  OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.

////////////////////////////////////////////////////////////////////////////////

#include <cstddef>
#include "objectstack.hpp"

using namespace more::core;

////////////////////////////////////////////////////////////////////////////////

const size_t SIZE_OF_STACKED_OBJECTS = 1000;

////////////////////////////////////////////////////////////////////////////////

struct ObjectStack::StackedObjects
{
  StackedObjects*   m_pPrevObjects;
  size_t            m_nNoOfObjects;
  void*             m_pObjects[SIZE_OF_STACKED_OBJECTS];
};

////////////////////////////////////////////////////////////////////////////////

ObjectStack::ObjectStack( ): m_pStackedObjects( 0 )
{
}

////////////////////////////////////////////////////////////////////////////////

ObjectStack::~ObjectStack( )
{
  while( m_pStackedObjects != 0 )
  {
    StackedObjects* pObjects = m_pStackedObjects;

    m_pStackedObjects = pObjects -> m_pPrevObjects;
    delete pObjects;
  }
}

////////////////////////////////////////////////////////////////////////////////

bool ObjectStack::isEmpty( ) const
{
  return m_pStackedObjects == 0;
}

////////////////////////////////////////////////////////////////////////////////

void ObjectStack::pushObject
(
  void* pObject
)
{
  if( m_pStackedObjects == 0 || m_pStackedObjects -> m_nNoOfObjects == SIZE_OF_STACKED_OBJECTS )
  {
    StackedObjects* pObjects;

    pObjects = new StackedObjects;
    pObjects -> m_pPrevObjects = m_pStackedObjects;
    pObjects -> m_nNoOfObjects = 0;
    m_pStackedObjects = pObjects;
  }

  size_t& rnNoOfObjects = m_pStackedObjects -> m_nNoOfObjects;
  m_pStackedObjects -> m_pObjects[rnNoOfObjects++] = pObject;
}

////////////////////////////////////////////////////////////////////////////////

void* ObjectStack::popObject( )
{
  void* pResult = 0;

  if( m_pStackedObjects != 0 )
  {
    size_t& rnNoOfObjects = m_pStackedObjects -> m_nNoOfObjects;

    pResult = m_pStackedObjects -> m_pObjects[--rnNoOfObjects];

    if( rnNoOfObjects == 0 )
    {
      StackedObjects* pObjects = m_pStackedObjects;

      m_pStackedObjects = pObjects -> m_pPrevObjects;
      delete pObjects;
    }
  }

  return pResult;
}

////////////////////////////////////////////////////////////////////////////////