tpl_nodePool.H

/* Aleph-w

     / \  | | ___ _ __ | |__      __      __
    / _ \ | |/ _ \ '_ \| '_ \ ____\ \ /\ / / Data structures & Algorithms
   / ___ \| |  __/ |_) | | | |_____\ V  V /  version 1.9b
  /_/   \_\_|\___| .__/|_| |_|      \_/\_/   https://github.com/lrleon/Aleph-w
                 |_|         

  This file is part of Aleph-w library

  Copyright (c) 2002-2018 Leandro Rabindranath Leon & Alejandro Mujica

  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  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 for more details.

  You should have received a copy of the GNU General Public License
  along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
# ifndef TPL_NODEPOOL_H
# define TPL_NODEPOOL_H

# include <tpl_arrayStack.H>

    template <class Node>
class Node_Pool
{

  FixedStack<Node*> node_pool;
  const size_t n;

public:

  Node_Pool(size_t __n = 100) noexcept : node_pool(__n), n(__n) { /* empty */ }

  Node * allocate()
  {
    return node_pool.is_empty() ? new Node : node_pool.pop();
  }

  Node * allocate(const typename Node::key_type & key)
  {
    return new (allocate()) Node (key);
  }

  Node * allocate(typename Node::key_type && key)
  {
    return new (allocate()) Node (std::forward<typename Node::key_type>(key));
  }  

  void deallocate(Node * p) noexcept
  {
    if (node_pool.size() == n)
      delete p;
    else
      node_pool.push(p);
  }

  ~Node_Pool()
  {
    while (not node_pool.is_empty())
      delete node_pool.pop();
  }
};

# endif // TPL_NODEPOOL_H