/* Copyright 2003-2005 Joaquín M López Muñoz.

 * Distributed under the Boost Software License, Version 1.0.

 * (See accompanying file LICENSE_1_0.txt or copy at

 * http://www.boost.org/LICENSE_1_0.txt)

 *

 * See http://www.boost.org/libs/multi_index for library home page.

 */

#ifndef BOOST_MULTI_INDEX_DETAIL_COPY_MAP_HPP

#define BOOST_MULTI_INDEX_DETAIL_COPY_MAP_HPP

#if defined(_MSC_VER)&&(_MSC_VER>=1200)

#pragma once

#endif

#include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */

#include <algorithm>

#include <boost/detail/no_exceptions_support.hpp>

#include <boost/multi_index/detail/auto_space.hpp>

#include <boost/noncopyable.hpp>

#include <cstddef>

#include <functional>

namespace boost{

namespace multi_index{

namespace detail{

/* copy_map is used as an auxiliary structure during copy_() operations.

 * When a container with n nodes is replicated, node_map holds the pairings

 * between original and copied nodes, and provides a fast way to find a

 * copied node from an original one.

 * The semantics of the class are not simple, and no attempt has been made

 * to enforce it: multi_index_container handles it right. On the other hand,

 * the const interface, which is the one provided to index implementations,

 * only allows for:

 *   - Enumeration of pairs of (original,copied) nodes (excluding the headers),

 *   - fast retrieval of copied nodes (including the headers.)

 */

template <typename Node>

struct copy_map_entry

{

  copy_map_entry(Node* f,Node* s):first(f),second(s){}

  Node* first;

  Node* second;

  bool operator<(const copy_map_entry<Node>& x)const

  {

    return std::less<Node*>()(first,x.first);

  }

};

template <typename Node,typename Allocator>

class copy_map:private noncopyable

{

public:

  typedef const copy_map_entry<Node>* const_iterator;

  copy_map(

    const Allocator& al,std::size_t size,Node* header_org,Node* header_cpy):

    al_(al),size_(size),spc(al_,size_),n(0),

    header_org_(header_org),header_cpy_(header_cpy),released(false)

  {}

  ~copy_map()

  {

    if(!released){

      for(std::size_t i=0;i<n;++i){

        boost::detail::allocator::destroy(&spc.data()[i].second->value());

        deallocate(spc.data()[i].second);

      }

    }

  }

  const_iterator begin()const{return spc.data();}

  const_iterator end()const{return spc.data()+n;}

  void clone(Node* node)

  {

    spc.data()[n].first=node;

    spc.data()[n].second=al_.allocate(1);

    BOOST_TRY{

      boost::detail::allocator::construct(

        &spc.data()[n].second->value(),node->value());

    }

    BOOST_CATCH(...){

      deallocate(spc.data()[n].second);

      BOOST_RETHROW;

    }

    BOOST_CATCH_END

    ++n;

    if(n==size_)std::sort(spc.data(),spc.data()+size_);

  }

  Node* find(Node* node)const

  {

    if(node==header_org_)return header_cpy_;

    return std::lower_bound(

      begin(),end(),copy_map_entry<Node>(node,0))->second;

  }

  void release()

  {

    released=true;

  }

private:

  typename boost::detail::allocator::rebind_to<

    Allocator,Node>::type                       al_;

  std::size_t                                   size_;

  auto_space<copy_map_entry<Node>,Allocator>    spc;

  std::size_t                                   n;

  Node*                                         header_org_;

  Node*                                         header_cpy_;

  bool                                          released;

  void deallocate(Node* node)

  {

    al_.deallocate(node,1);

  }

};

} /* namespace multi_index::detail */

} /* namespace multi_index */

} /* namespace boost */

#endif