1 // -*- C++ -*-
2
3 // Copyright (C) 2005, 2006 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 2, 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 // You should have received a copy of the GNU General Public License
17 // along with this library; see the file COPYING. If not, write to
18 // the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
19 // MA 02111-1307, USA.
20
21 // As a special exception, you may use this file as part of a free
22 // software library without restriction. Specifically, if other files
23 // instantiate templates or use macros or inline functions from this
24 // file, or you compile this file and link it with other files to
25 // produce an executable, this file does not by itself cause the
26 // resulting executable to be covered by the GNU General Public
27 // License. This exception does not however invalidate any other
28 // reasons why the executable file might be covered by the GNU General
29 // Public License.
30
31 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
32
33 // Permission to use, copy, modify, sell, and distribute this software
34 // is hereby granted without fee, provided that the above copyright
35 // notice appears in all copies, and that both that copyright notice
36 // and this permission notice appear in supporting documentation. None
37 // of the above authors, nor IBM Haifa Research Laboratories, make any
38 // representation about the suitability of this software for any
39 // purpose. It is provided "as is" without express or implied
40 // warranty.
41
42 /**
43 * @file erase_fn_imps.hpp
44 * Contains an implementation for rb_tree_.
45 */
46
47 PB_DS_CLASS_T_DEC
48 inline bool
49 PB_DS_CLASS_C_DEC::
erase(const_key_reference r_key)50 erase(const_key_reference r_key)
51 {
52 point_iterator it = find(r_key);
53 if (it == base_type::end())
54 return false;
55 erase(it);
56 return true;
57 }
58
59 PB_DS_CLASS_T_DEC
60 inline typename PB_DS_CLASS_C_DEC::iterator
61 PB_DS_CLASS_C_DEC::
erase(iterator it)62 erase(iterator it)
63 {
64 _GLIBCXX_DEBUG_ONLY(assert_valid());
65 if (it == base_type::end())
66 return it;
67
68 iterator ret_it = it;
69 ++ret_it;
70 erase_node(it.m_p_nd);
71 _GLIBCXX_DEBUG_ONLY(assert_valid());
72 return ret_it;
73 }
74
75 PB_DS_CLASS_T_DEC
76 inline typename PB_DS_CLASS_C_DEC::reverse_iterator
77 PB_DS_CLASS_C_DEC::
erase(reverse_iterator it)78 erase(reverse_iterator it)
79 {
80 _GLIBCXX_DEBUG_ONLY(assert_valid());
81 if (it.m_p_nd == base_type::m_p_head)
82 return it;
83
84 reverse_iterator ret_it = it;
85 ++ret_it;
86 erase_node(it.m_p_nd);
87 _GLIBCXX_DEBUG_ONLY(assert_valid());
88 return ret_it;
89 }
90
91 PB_DS_CLASS_T_DEC
92 template<typename Pred>
93 inline typename PB_DS_CLASS_C_DEC::size_type
94 PB_DS_CLASS_C_DEC::
erase_if(Pred pred)95 erase_if(Pred pred)
96 {
97 _GLIBCXX_DEBUG_ONLY(assert_valid();)
98 size_type num_ersd = 0;
99 iterator it = base_type::begin();
100 while (it != base_type::end())
101 {
102 if (pred(*it))
103 {
104 ++num_ersd;
105 it = erase(it);
106 }
107 else
108 ++it;
109 }
110
111 _GLIBCXX_DEBUG_ONLY(assert_valid();)
112 return num_ersd;
113 }
114
115 PB_DS_CLASS_T_DEC
116 void
117 PB_DS_CLASS_C_DEC::
erase_node(node_pointer p_nd)118 erase_node(node_pointer p_nd)
119 {
120 remove_node(p_nd);
121 base_type::actual_erase_node(p_nd);
122 _GLIBCXX_DEBUG_ONLY(assert_valid());
123 }
124
125 PB_DS_CLASS_T_DEC
126 void
127 PB_DS_CLASS_C_DEC::
remove_node(node_pointer p_z)128 remove_node(node_pointer p_z)
129 {
130 update_min_max_for_erased_node(p_z);
131 node_pointer p_y = p_z;
132 node_pointer p_x = NULL;
133 node_pointer p_new_x_parent = NULL;
134
135 if (p_y->m_p_left == NULL)
136 p_x = p_y->m_p_right;
137 else if (p_y->m_p_right == NULL)
138 p_x = p_y->m_p_left;
139 else
140 {
141 p_y = p_y->m_p_right;
142 while (p_y->m_p_left != NULL)
143 p_y = p_y->m_p_left;
144 p_x = p_y->m_p_right;
145 }
146
147 if (p_y == p_z)
148 {
149 p_new_x_parent = p_y->m_p_parent;
150 if (p_x != NULL)
151 p_x->m_p_parent = p_y->m_p_parent;
152
153 if (base_type::m_p_head->m_p_parent == p_z)
154 base_type::m_p_head->m_p_parent = p_x;
155 else if (p_z->m_p_parent->m_p_left == p_z)
156 {
157 p_y->m_p_left = p_z->m_p_parent;
158 p_z->m_p_parent->m_p_left = p_x;
159 }
160 else
161 {
162 p_y->m_p_left = NULL;
163 p_z->m_p_parent->m_p_right = p_x;
164 }
165 }
166 else
167 {
168 p_z->m_p_left->m_p_parent = p_y;
169 p_y->m_p_left = p_z->m_p_left;
170 if (p_y != p_z->m_p_right)
171 {
172 p_new_x_parent = p_y->m_p_parent;
173 if (p_x != NULL)
174 p_x->m_p_parent = p_y->m_p_parent;
175 p_y->m_p_parent->m_p_left = p_x;
176 p_y->m_p_right = p_z->m_p_right;
177 p_z->m_p_right->m_p_parent = p_y;
178 }
179 else
180 p_new_x_parent = p_y;
181
182 if (base_type::m_p_head->m_p_parent == p_z)
183 base_type::m_p_head->m_p_parent = p_y;
184 else if (p_z->m_p_parent->m_p_left == p_z)
185 p_z->m_p_parent->m_p_left = p_y;
186 else
187 p_z->m_p_parent->m_p_right = p_y;
188
189 p_y->m_p_parent = p_z->m_p_parent;
190 std::swap(p_y->m_red, p_z->m_red);
191 p_y = p_z;
192 }
193
194 update_to_top(p_new_x_parent, (node_update* )this);
195
196 if (p_y->m_red)
197 return;
198
199 remove_fixup(p_x, p_new_x_parent);
200 }
201
202 PB_DS_CLASS_T_DEC
203 void
204 PB_DS_CLASS_C_DEC::
remove_fixup(node_pointer p_x,node_pointer p_new_x_parent)205 remove_fixup(node_pointer p_x, node_pointer p_new_x_parent)
206 {
207 _GLIBCXX_DEBUG_ASSERT(p_x == NULL || p_x->m_p_parent == p_new_x_parent);
208
209 while (p_x != base_type::m_p_head->m_p_parent && is_effectively_black(p_x))
210 if (p_x == p_new_x_parent->m_p_left)
211 {
212 node_pointer p_w = p_new_x_parent->m_p_right;
213 if (p_w->m_red)
214 {
215 p_w->m_red = false;
216 p_new_x_parent->m_red = true;
217 base_type::rotate_left(p_new_x_parent);
218 p_w = p_new_x_parent->m_p_right;
219 }
220
221 if (is_effectively_black(p_w->m_p_left)
222 && is_effectively_black(p_w->m_p_right))
223 {
224 p_w->m_red = true;
225 p_x = p_new_x_parent;
226 p_new_x_parent = p_new_x_parent->m_p_parent;
227 }
228 else
229 {
230 if (is_effectively_black(p_w->m_p_right))
231 {
232 if (p_w->m_p_left != NULL)
233 p_w->m_p_left->m_red = false;
234
235 p_w->m_red = true;
236 base_type::rotate_right(p_w);
237 p_w = p_new_x_parent->m_p_right;
238 }
239
240 p_w->m_red = p_new_x_parent->m_red;
241 p_new_x_parent->m_red = false;
242
243 if (p_w->m_p_right != NULL)
244 p_w->m_p_right->m_red = false;
245
246 base_type::rotate_left(p_new_x_parent);
247 update_to_top(p_new_x_parent, (node_update* )this);
248 break;
249 }
250 }
251 else
252 {
253 node_pointer p_w = p_new_x_parent->m_p_left;
254 if (p_w->m_red == true)
255 {
256 p_w->m_red = false;
257 p_new_x_parent->m_red = true;
258 base_type::rotate_right(p_new_x_parent);
259 p_w = p_new_x_parent->m_p_left;
260 }
261
262 if (is_effectively_black(p_w->m_p_right)
263 && is_effectively_black(p_w->m_p_left))
264 {
265 p_w->m_red = true;
266 p_x = p_new_x_parent;
267 p_new_x_parent = p_new_x_parent->m_p_parent;
268 }
269 else
270 {
271 if (is_effectively_black(p_w->m_p_left))
272 {
273 if (p_w->m_p_right != NULL)
274 p_w->m_p_right->m_red = false;
275
276 p_w->m_red = true;
277 base_type::rotate_left(p_w);
278 p_w = p_new_x_parent->m_p_left;
279 }
280
281 p_w->m_red = p_new_x_parent->m_red;
282 p_new_x_parent->m_red = false;
283
284 if (p_w->m_p_left != NULL)
285 p_w->m_p_left->m_red = false;
286
287 base_type::rotate_right(p_new_x_parent);
288 update_to_top(p_new_x_parent, (node_update* )this);
289 break;
290 }
291 }
292
293 if (p_x != NULL)
294 p_x->m_red = false;
295 }
296