libstdc++: split_join_fn_imps.hpp Source File

libstdc++

rb_tree_map_/split_join_fn_imps.hpp
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1// -*- C++ -*-
2
3// Copyright (C) 2005-2026 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the terms
7// of the GNU General Public License as published by the Free Software
8// Foundation; either version 3, or (at your option) any later
9// version.
10
11// This library is distributed in the hope that it will be useful, but
12// WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14// General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
24
25// Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
26
27// Permission to use, copy, modify, sell, and distribute this software
28// is hereby granted without fee, provided that the above copyright
29// notice appears in all copies, and that both that copyright notice
30// and this permission notice appear in supporting documentation. None
31// of the above authors, nor IBM Haifa Research Laboratories, make any
32// representation about the suitability of this software for any
33// purpose. It is provided "as is" without express or implied
34// warranty.
35
36/**
37 * @file rb_tree_map_/split_join_fn_imps.hpp
38 * Contains an implementation for rb_tree_.
39 */
40
41#ifdef PB_DS_CLASS_C_DEC
42
43PB_DS_CLASS_T_DEC
44inline void
45PB_DS_CLASS_C_DEC::
46join(PB_DS_CLASS_C_DEC& other)
47{
48 PB_DS_ASSERT_VALID((*this))
49 PB_DS_ASSERT_VALID(other)
50 if (base_type::join_prep(other) == false)
51 {
52 PB_DS_ASSERT_VALID((*this))
53 PB_DS_ASSERT_VALID(other)
54 return;
55 }
56
57 const node_pointer p_x = other.split_min();
58 join_imp(p_x, other.m_p_head->m_p_parent);
59 base_type::join_finish(other);
60 PB_DS_ASSERT_VALID((*this))
61 PB_DS_ASSERT_VALID(other)
62 }
63
64PB_DS_CLASS_T_DEC
65void
66PB_DS_CLASS_C_DEC::
67join_imp(node_pointer p_x, node_pointer p_r)
68{
69 _GLIBCXX_DEBUG_ASSERT(p_x != 0);
70 if (p_r != 0)
71 p_r->m_red = false;
72
73 const size_type h = black_height(base_type::m_p_head->m_p_parent);
74 const size_type other_h = black_height(p_r);
75 node_pointer p_x_l;
76 node_pointer p_x_r;
77 std::pair<node_pointer, node_pointer> join_pos;
78 const bool right_join = h >= other_h;
79 if (right_join)
80 {
81 join_pos = find_join_pos_right(base_type::m_p_head->m_p_parent,
82 h, other_h);
83 p_x_l = join_pos.first;
84 p_x_r = p_r;
85 }
86 else
87 {
88 p_x_l = base_type::m_p_head->m_p_parent;
89 base_type::m_p_head->m_p_parent = p_r;
90 if (p_r != 0)
91 p_r->m_p_parent = base_type::m_p_head;
92
93 join_pos = find_join_pos_left(base_type::m_p_head->m_p_parent,
94 h, other_h);
95 p_x_r = join_pos.first;
96 }
97
98 node_pointer p_parent = join_pos.second;
99 if (p_parent == base_type::m_p_head)
100 {
101 base_type::m_p_head->m_p_parent = p_x;
102 p_x->m_p_parent = base_type::m_p_head;
103 }
104 else
105 {
106 p_x->m_p_parent = p_parent;
107 if (right_join)
108 p_x->m_p_parent->m_p_right = p_x;
109 else
110 p_x->m_p_parent->m_p_left = p_x;
111 }
112
113 p_x->m_p_left = p_x_l;
114 if (p_x_l != 0)
115 p_x_l->m_p_parent = p_x;
116
117 p_x->m_p_right = p_x_r;
118 if (p_x_r != 0)
119 p_x_r->m_p_parent = p_x;
120
121 p_x->m_red = true;
122
123 base_type::initialize_min_max();
124 PB_DS_STRUCT_ONLY_ASSERT_VALID((*this))
125 base_type::update_to_top(p_x, (node_update* )this);
126 insert_fixup(p_x);
127 PB_DS_STRUCT_ONLY_ASSERT_VALID((*this))
128}
129
130PB_DS_CLASS_T_DEC
131inline typename PB_DS_CLASS_C_DEC::node_pointer
132PB_DS_CLASS_C_DEC::
133split_min()
134{
135 node_pointer p_min = base_type::m_p_head->m_p_left;
136
137#ifdef _GLIBCXX_DEBUG
138 const node_pointer p_head = base_type::m_p_head;
139 _GLIBCXX_DEBUG_ASSERT(p_min != p_head);
140#endif
141
142 remove_node(p_min);
143 return p_min;
144}
145
146PB_DS_CLASS_T_DEC
147 std::pair<
148 typename PB_DS_CLASS_C_DEC::node_pointer,
149 typename PB_DS_CLASS_C_DEC::node_pointer>
150PB_DS_CLASS_C_DEC::
151find_join_pos_right(node_pointer p_l, size_type h_l, size_type h_r)
152{
153 _GLIBCXX_DEBUG_ASSERT(h_l >= h_r);
154
155 if (base_type::m_p_head->m_p_parent == 0)
156 return (std::make_pair((node_pointer)0, base_type::m_p_head));
157
158 node_pointer p_l_parent = base_type::m_p_head;
159 while (h_l > h_r)
160 {
161 if (p_l->m_red == false)
162 {
163 _GLIBCXX_DEBUG_ASSERT(h_l > 0);
164 --h_l;
165 }
166
167 p_l_parent = p_l;
168 p_l = p_l->m_p_right;
169 }
170
171 if (!is_effectively_black(p_l))
172 {
173 p_l_parent = p_l;
174 p_l = p_l->m_p_right;
175 }
176
177 _GLIBCXX_DEBUG_ASSERT(is_effectively_black(p_l));
178 _GLIBCXX_DEBUG_ASSERT(black_height(p_l) == h_r);
179 _GLIBCXX_DEBUG_ASSERT(p_l == 0 || p_l->m_p_parent == p_l_parent);
180 return std::make_pair(p_l, p_l_parent);
181}
182
183PB_DS_CLASS_T_DEC
184 std::pair<
185 typename PB_DS_CLASS_C_DEC::node_pointer,
186 typename PB_DS_CLASS_C_DEC::node_pointer>
187PB_DS_CLASS_C_DEC::
188find_join_pos_left(node_pointer p_r, size_type h_l, size_type h_r)
189{
190 _GLIBCXX_DEBUG_ASSERT(h_r > h_l);
191 if (base_type::m_p_head->m_p_parent == 0)
192 return (std::make_pair((node_pointer)0,
193 base_type::m_p_head));
194 node_pointer p_r_parent = base_type::m_p_head;
195 while (h_r > h_l)
196 {
197 if (p_r->m_red == false)
198 {
199 _GLIBCXX_DEBUG_ASSERT(h_r > 0);
200 --h_r;
201 }
202
203 p_r_parent = p_r;
204 p_r = p_r->m_p_left;
205 }
206
207 if (!is_effectively_black(p_r))
208 {
209 p_r_parent = p_r;
210 p_r = p_r->m_p_left;
211 }
212
213 _GLIBCXX_DEBUG_ASSERT(is_effectively_black(p_r));
214 _GLIBCXX_DEBUG_ASSERT(black_height(p_r) == h_l);
215 _GLIBCXX_DEBUG_ASSERT(p_r == 0 || p_r->m_p_parent == p_r_parent);
216 return std::make_pair(p_r, p_r_parent);
217}
218
219PB_DS_CLASS_T_DEC
220inline typename PB_DS_CLASS_C_DEC::size_type
221PB_DS_CLASS_C_DEC::
222black_height(node_pointer p_nd)
223{
224 size_type h = 1;
225 while (p_nd != 0)
226 {
227 if (p_nd->m_red == false)
228 ++h;
229 p_nd = p_nd->m_p_left;
230 }
231 return h;
232}
233
234PB_DS_CLASS_T_DEC
235void
236PB_DS_CLASS_C_DEC::
237split(key_const_reference r_key, PB_DS_CLASS_C_DEC& other)
238{
239 PB_DS_ASSERT_VALID((*this))
240 PB_DS_ASSERT_VALID(other)
241
242 if (base_type::split_prep(r_key, other) == false)
243 {
244 PB_DS_ASSERT_VALID((*this))
245 PB_DS_ASSERT_VALID(other)
246 return;
247 }
248
249 PB_DS_STRUCT_ONLY_ASSERT_VALID((*this))
250 PB_DS_STRUCT_ONLY_ASSERT_VALID(other)
251 node_pointer p_nd = this->upper_bound(r_key).m_p_nd;
252 do
253 {
254 node_pointer p_next_nd = p_nd->m_p_parent;
255 if (Cmp_Fn::operator()(r_key, PB_DS_V2F(p_nd->m_value)))
256 split_at_node(p_nd, other);
257
258 PB_DS_STRUCT_ONLY_ASSERT_VALID((*this))
259 PB_DS_STRUCT_ONLY_ASSERT_VALID(other)
260 p_nd = p_next_nd;
261 }
262 while (p_nd != base_type::m_p_head);
263
264 base_type::split_finish(other);
265 PB_DS_ASSERT_VALID((*this))
266}
267
268PB_DS_CLASS_T_DEC
269void
270PB_DS_CLASS_C_DEC::
271split_at_node(node_pointer p_nd, PB_DS_CLASS_C_DEC& other)
272{
273 _GLIBCXX_DEBUG_ASSERT(p_nd != 0);
274
275 node_pointer p_l = p_nd->m_p_left;
276 node_pointer p_r = p_nd->m_p_right;
277 node_pointer p_parent = p_nd->m_p_parent;
278 if (p_parent == base_type::m_p_head)
279 {
280 base_type::m_p_head->m_p_parent = p_l;
281 if (p_l != 0)
282 {
283 p_l->m_p_parent = base_type::m_p_head;
284 p_l->m_red = false;
285 }
286 }
287 else
288 {
289 if (p_parent->m_p_left == p_nd)
290 p_parent->m_p_left = p_l;
291 else
292 p_parent->m_p_right = p_l;
293
294 if (p_l != 0)
295 p_l->m_p_parent = p_parent;
296
297 this->update_to_top(p_parent, (node_update* )this);
298
299 if (!p_nd->m_red)
300 remove_fixup(p_l, p_parent);
301 }
302
303 base_type::initialize_min_max();
304 other.join_imp(p_nd, p_r);
305 PB_DS_STRUCT_ONLY_ASSERT_VALID((*this))
306 PB_DS_STRUCT_ONLY_ASSERT_VALID(other)
307}
308
309#endif
std::make_pair
constexpr pair< typename __decay_and_strip< _T1 >::__type, typename __decay_and_strip< _T2 >::__type > make_pair(_T1 &&__x, _T2 &&__y)
A convenience wrapper for creating a pair from two objects.
Definition stl_pair.h:1169
std::pair
Struct holding two objects (or references) of arbitrary type.
Definition stl_pair.h:307
std::pair::first
_T1 first
The first member.
Definition stl_pair.h:311
std::pair::second
_T2 second
The second member.
Definition stl_pair.h:312