1 /* Copyright 2003-2015 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_SEQ_INDEX_OPS_HPP
10 #define BOOST_MULTI_INDEX_DETAIL_SEQ_INDEX_OPS_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 <boost/detail/no_exceptions_support.hpp>
18 #include <boost/multi_index/detail/seq_index_node.hpp>
19 #include <boost/limits.hpp>
20 #include <boost/type_traits/aligned_storage.hpp>
21 #include <boost/type_traits/alignment_of.hpp>
22 #include <cstddef>
23
24 namespace boost{
25
26 namespace multi_index{
27
28 namespace detail{
29
30 /* Common code for sequenced_index memfuns having templatized and
31 * non-templatized versions.
32 */
33
34 template <typename SequencedIndex,typename Predicate>
sequenced_index_remove(SequencedIndex & x,Predicate pred)35 void sequenced_index_remove(SequencedIndex& x,Predicate pred)
36 {
37 typedef typename SequencedIndex::iterator iterator;
38 iterator first=x.begin(),last=x.end();
39 while(first!=last){
40 if(pred(*first))x.erase(first++);
41 else ++first;
42 }
43 }
44
45 template <typename SequencedIndex,class BinaryPredicate>
sequenced_index_unique(SequencedIndex & x,BinaryPredicate binary_pred)46 void sequenced_index_unique(SequencedIndex& x,BinaryPredicate binary_pred)
47 {
48 typedef typename SequencedIndex::iterator iterator;
49 iterator first=x.begin();
50 iterator last=x.end();
51 if(first!=last){
52 for(iterator middle=first;++middle!=last;middle=first){
53 if(binary_pred(*middle,*first))x.erase(middle);
54 else first=middle;
55 }
56 }
57 }
58
59 template <typename SequencedIndex,typename Compare>
sequenced_index_merge(SequencedIndex & x,SequencedIndex & y,Compare comp)60 void sequenced_index_merge(SequencedIndex& x,SequencedIndex& y,Compare comp)
61 {
62 typedef typename SequencedIndex::iterator iterator;
63 if(&x!=&y){
64 iterator first0=x.begin(),last0=x.end();
65 iterator first1=y.begin(),last1=y.end();
66 while(first0!=last0&&first1!=last1){
67 if(comp(*first1,*first0))x.splice(first0,y,first1++);
68 else ++first0;
69 }
70 x.splice(last0,y,first1,last1);
71 }
72 }
73
74 /* sorting */
75
76 /* auxiliary stuff */
77
78 template<typename Node,typename Compare>
sequenced_index_collate(BOOST_DEDUCED_TYPENAME Node::impl_type * x,BOOST_DEDUCED_TYPENAME Node::impl_type * y,Compare comp)79 void sequenced_index_collate(
80 BOOST_DEDUCED_TYPENAME Node::impl_type* x,
81 BOOST_DEDUCED_TYPENAME Node::impl_type* y,
82 Compare comp)
83 {
84 typedef typename Node::impl_type impl_type;
85 typedef typename Node::impl_pointer impl_pointer;
86
87 impl_pointer first0=x->next();
88 impl_pointer last0=x;
89 impl_pointer first1=y->next();
90 impl_pointer last1=y;
91 while(first0!=last0&&first1!=last1){
92 if(comp(
93 Node::from_impl(first1)->value(),Node::from_impl(first0)->value())){
94 impl_pointer tmp=first1->next();
95 impl_type::relink(first0,first1);
96 first1=tmp;
97 }
98 else first0=first0->next();
99 }
100 impl_type::relink(last0,first1,last1);
101 }
102
103 /* Some versions of CGG require a bogus typename in counter_spc
104 * inside sequenced_index_sort if the following is defined
105 * also inside sequenced_index_sort.
106 */
107
108 BOOST_STATIC_CONSTANT(
109 std::size_t,
110 sequenced_index_sort_max_fill=
111 (std::size_t)std::numeric_limits<std::size_t>::digits+1);
112
113 template<typename Node,typename Compare>
sequenced_index_sort(Node * header,Compare comp)114 void sequenced_index_sort(Node* header,Compare comp)
115 {
116 /* Musser's mergesort, see http://www.cs.rpi.edu/~musser/gp/List/lists1.html.
117 * The implementation is a little convoluted: in the original code
118 * counter elements and carry are std::lists: here we do not want
119 * to use multi_index instead, so we do things at a lower level, managing
120 * directly the internal node representation.
121 * Incidentally, the implementations I've seen of this algorithm (SGI,
122 * Dinkumware, STLPort) are not exception-safe: this is. Moreover, we do not
123 * use any dynamic storage.
124 */
125
126 if(header->next()==header->impl()||
127 header->next()->next()==header->impl())return;
128
129 typedef typename Node::impl_type impl_type;
130 typedef typename Node::impl_pointer impl_pointer;
131
132 typedef typename aligned_storage<
133 sizeof(impl_type),
134 alignment_of<impl_type>::value
135 >::type carry_spc_type;
136 carry_spc_type carry_spc;
137 impl_type& carry=
138 *reinterpret_cast<impl_type*>(&carry_spc);
139 typedef typename aligned_storage<
140 sizeof(
141 impl_type
142 [sequenced_index_sort_max_fill]),
143 alignment_of<
144 impl_type
145 [sequenced_index_sort_max_fill]
146 >::value
147 >::type counter_spc_type;
148 counter_spc_type counter_spc;
149 impl_type* counter=
150 reinterpret_cast<impl_type*>(&counter_spc);
151 std::size_t fill=0;
152
153 carry.prior()=carry.next()=static_cast<impl_pointer>(&carry);
154 counter[0].prior()=counter[0].next()=static_cast<impl_pointer>(&counter[0]);
155
156 BOOST_TRY{
157 while(header->next()!=header->impl()){
158 impl_type::relink(carry.next(),header->next());
159 std::size_t i=0;
160 while(i<fill&&counter[i].next()!=static_cast<impl_pointer>(&counter[i])){
161 sequenced_index_collate<Node>(&carry,&counter[i++],comp);
162 }
163 impl_type::swap(
164 static_cast<impl_pointer>(&carry),
165 static_cast<impl_pointer>(&counter[i]));
166 if(i==fill){
167 ++fill;
168 counter[fill].prior()=counter[fill].next()=
169 static_cast<impl_pointer>(&counter[fill]);
170 }
171 }
172
173 for(std::size_t i=1;i<fill;++i){
174 sequenced_index_collate<Node>(&counter[i],&counter[i-1],comp);
175 }
176 impl_type::swap(
177 header->impl(),static_cast<impl_pointer>(&counter[fill-1]));
178 }
179 BOOST_CATCH(...)
180 {
181 impl_type::relink(
182 header->impl(),carry.next(),static_cast<impl_pointer>(&carry));
183 for(std::size_t i=0;i<=fill;++i){
184 impl_type::relink(
185 header->impl(),counter[i].next(),
186 static_cast<impl_pointer>(&counter[i]));
187 }
188 BOOST_RETHROW;
189 }
190 BOOST_CATCH_END
191 }
192
193 } /* namespace multi_index::detail */
194
195 } /* namespace multi_index */
196
197 } /* namespace boost */
198
199 #endif
200