1/* Copyright 2003-2013 Joaquin M Lopez Munoz.
2 * Distributed under the Boost Software License, Version 1.0.
3 * (See accompanying file LICENSE_1_0.txt or copy at
4 * http://www.boost.org/LICENSE_1_0.txt)
5 *
6 * See http://www.boost.org/libs/multi_index for library home page.
7 */
8
9#ifndef BOOST_MULTI_INDEX_DETAIL_COPY_MAP_HPP
10#define BOOST_MULTI_INDEX_DETAIL_COPY_MAP_HPP
11
12#if defined(_MSC_VER)
13#pragma once
14#endif
15
16#include <boost/config.hpp> /* keep it first to prevent nasty warns in MSVC */
17#include <algorithm>
18#include <boost/detail/no_exceptions_support.hpp>
19#include <boost/multi_index/detail/auto_space.hpp>
20#include <boost/noncopyable.hpp>
21#include <cstddef>
22#include <functional>
23
24namespace boost{
25
26namespace multi_index{
27
28namespace detail{
29
30/* copy_map is used as an auxiliary structure during copy_() operations.
31 * When a container with n nodes is replicated, node_map holds the pairings
32 * between original and copied nodes, and provides a fast way to find a
33 * copied node from an original one.
34 * The semantics of the class are not simple, and no attempt has been made
35 * to enforce it: multi_index_container handles it right. On the other hand,
36 * the const interface, which is the one provided to index implementations,
37 * only allows for:
38 * - Enumeration of pairs of (original,copied) nodes (excluding the headers),
39 * - fast retrieval of copied nodes (including the headers.)
40 */
41
42template <typename Node>
43struct copy_map_entry
44{
45 copy_map_entry(Node* f,Node* s):first(f),second(s){}
46
47 Node* first;
48 Node* second;
49
50 bool operator<(const copy_map_entry<Node>& x)const
51 {
52 return std::less<Node*>()(first,x.first);
53 }
54};
55
56template <typename Node,typename Allocator>
57class copy_map:private noncopyable
58{
59public:
60 typedef const copy_map_entry<Node>* const_iterator;
61
62 copy_map(
63 const Allocator& al,std::size_t size,Node* header_org,Node* header_cpy):
64 al_(al),size_(size),spc(al_,size_),n(0),
65 header_org_(header_org),header_cpy_(header_cpy),released(false)
66 {}
67
68 ~copy_map()
69 {
70 if(!released){
71 for(std::size_t i=0;i<n;++i){
72 boost::detail::allocator::destroy(&(spc.data()+i)->second->value());
73 deallocate((spc.data()+i)->second);
74 }
75 }
76 }
77
78 const_iterator begin()const{return &*spc.data();}
79 const_iterator end()const{return &*(spc.data()+n);}
80
81 void clone(Node* node)
82 {
83 (spc.data()+n)->first=node;
84 (spc.data()+n)->second=&*al_.allocate(1);
85 BOOST_TRY{
86 boost::detail::allocator::construct(
87 &(spc.data()+n)->second->value(),node->value());
88 }
89 BOOST_CATCH(...){
90 deallocate((spc.data()+n)->second);
91 BOOST_RETHROW;
92 }
93 BOOST_CATCH_END
94 ++n;
95
96 if(n==size_)std::sort(&*spc.data(),&*spc.data()+size_);
97 }
98
99 Node* find(Node* node)const
100 {
101 if(node==header_org_)return header_cpy_;
102 return std::lower_bound(
103 begin(),end(),copy_map_entry<Node>(node,0))->second;
104 }
105
106 void release()
107 {
108 released=true;
109 }
110
111private:
112 typedef typename boost::detail::allocator::rebind_to<
113 Allocator,Node
114 >::type allocator_type;
115 typedef typename allocator_type::pointer allocator_pointer;
116
117 allocator_type al_;
118 std::size_t size_;
119 auto_space<copy_map_entry<Node>,Allocator> spc;
120 std::size_t n;
121 Node* header_org_;
122 Node* header_cpy_;
123 bool released;
124
125 void deallocate(Node* node)
126 {
127 al_.deallocate(static_cast<allocator_pointer>(node),1);
128 }
129};
130
131} /* namespace multi_index::detail */
132
133} /* namespace multi_index */
134
135} /* namespace boost */
136
137#endif
138