/* Copyright 2003-2022 Joaquin M Lopez Munoz.

 * 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)

#pragma once

#endif

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

#include <algorithm>

#include <boost/core/addressof.hpp>

#include <boost/core/no_exceptions_support.hpp>

#include <boost/core/noncopyable.hpp>

#include <boost/move/core.hpp>

#include <boost/move/utility_core.hpp>

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

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

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

#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);

  }

};

struct copy_map_value_copier

{

  template<typename Value>

  const Value& operator()(Value& x)const{return x;}

};

struct copy_map_value_mover

{

  template<typename Value>

  BOOST_RV_REF(Value) operator()(Value& x)const{return boost::move(x);}

};

template <typename Node,typename Allocator>

class copy_map:private noncopyable

{

  typedef typename rebind_alloc_for<

    Allocator,Node

  >::type                                  allocator_type;

  typedef allocator_traits<allocator_type> alloc_traits;

  typedef typename alloc_traits::pointer   pointer;

public:

  typedef const copy_map_entry<Node>*      const_iterator;

  typedef typename alloc_traits::size_type size_type;

  copy_map(

    const Allocator& al,size_type 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(size_type i=0;i<n;++i){

        alloc_traits::destroy(

          al_,boost::addressof((spc.data()+i)->second->value()));

        deallocate((spc.data()+i)->second);

      }

    }

  }

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

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

  void copy_clone(Node* node){clone(node,copy_map_value_copier());}

  void move_clone(Node* node){clone(node,copy_map_value_mover());}

  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:

  allocator_type                             al_;

  size_type                                  size_;

  auto_space<copy_map_entry<Node>,Allocator> spc;

  size_type                                  n;

  Node*                                      header_org_;

  Node*                                      header_cpy_;

  bool                                       released;

  pointer allocate()

  {

    return alloc_traits::allocate(al_,1);

  }

  void deallocate(Node* node)

  {

    alloc_traits::deallocate(al_,static_cast<pointer>(node),1);

  }

  template<typename ValueAccess>

  void clone(Node* node,ValueAccess access)

  {

    (spc.data()+n)->first=node;

    (spc.data()+n)->second=raw_ptr<Node*>(allocate());

    BOOST_TRY{

      alloc_traits::construct(

        al_,boost::addressof((spc.data()+n)->second->value()),

        access(node->value()));

    }

    BOOST_CATCH(...){

      deallocate((spc.data()+n)->second);

      BOOST_RETHROW;

    }

    BOOST_CATCH_END

    ++n;

    if(n==size_){

      std::sort(

        raw_ptr<copy_map_entry<Node>*>(spc.data()),

        raw_ptr<copy_map_entry<Node>*>(spc.data())+size_);

    }

  }

};

} /* namespace multi_index::detail */

} /* namespace multi_index */

} /* namespace boost */

#endif