1 // -*- C++ -*-
2 
3 // Copyright (C) 2005-2022 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 pat_trie_/erase_fn_imps.hpp
38  * Contains an implementation class for pat_trie.
39  */
40 
41 #ifdef PB_DS_CLASS_C_DEC
42 
43 PB_DS_CLASS_T_DEC
44 inline bool
45 PB_DS_CLASS_C_DEC::
erase(key_const_reference r_key)46 erase(key_const_reference r_key)
47 {
48   node_pointer p_nd = find_imp(r_key);
49   if (p_nd == 0 || p_nd->m_type == i_node)
50     {
51       PB_DS_CHECK_KEY_DOES_NOT_EXIST(r_key)
52       return false;
53     }
54 
55   _GLIBCXX_DEBUG_ASSERT(p_nd->m_type == leaf_node);
56   if (!synth_access_traits::equal_keys(PB_DS_V2F(reinterpret_cast<leaf_pointer>(p_nd)->value()), r_key))
57     {
58       PB_DS_CHECK_KEY_DOES_NOT_EXIST(r_key)
59       return false;
60     }
61 
62   PB_DS_CHECK_KEY_EXISTS(r_key)
63   erase_leaf(static_cast<leaf_pointer>(p_nd));
64   PB_DS_ASSERT_VALID((*this))
65   return true;
66 }
67 
68 PB_DS_CLASS_T_DEC
69 void
70 PB_DS_CLASS_C_DEC::
erase_fixup(inode_pointer p_nd)71 erase_fixup(inode_pointer p_nd)
72 {
73   _GLIBCXX_DEBUG_ASSERT(std::distance(p_nd->begin(), p_nd->end()) >= 1);
74   if (std::distance(p_nd->begin(), p_nd->end()) == 1)
75     {
76       node_pointer p_parent = p_nd->m_p_parent;
77       if (p_parent == m_p_head)
78           m_p_head->m_p_parent = *p_nd->begin();
79       else
80           {
81             _GLIBCXX_DEBUG_ASSERT(p_parent->m_type == i_node);
82             node_pointer p_new_child = *p_nd->begin();
83 
84             typedef inode_pointer inode_ptr;
85             inode_ptr p_internal = static_cast<inode_ptr>(p_parent);
86             p_internal->replace_child(p_new_child, pref_begin(p_new_child),
87                                             pref_end(p_new_child), this);
88           }
89       (*p_nd->begin())->m_p_parent = p_nd->m_p_parent;
90       p_nd->~inode();
91       s_inode_allocator.deallocate(p_nd, 1);
92 
93       if (p_parent == m_p_head)
94           return;
95 
96       _GLIBCXX_DEBUG_ASSERT(p_parent->m_type == i_node);
97       p_nd = static_cast<inode_pointer>(p_parent);
98     }
99 
100   while (true)
101     {
102       _GLIBCXX_DEBUG_ASSERT(std::distance(p_nd->begin(), p_nd->end()) > 1);
103       p_nd->update_prefixes(this);
104       apply_update(p_nd, (node_update*)this);
105       PB_DS_ASSERT_NODE_VALID(p_nd)
106       if (p_nd->m_p_parent->m_type == head_node)
107           return;
108 
109       _GLIBCXX_DEBUG_ASSERT(p_nd->m_p_parent->m_type == i_node);
110 
111       p_nd = static_cast<inode_pointer>(p_nd->m_p_parent);
112     }
113 }
114 
115 PB_DS_CLASS_T_DEC
116 inline void
117 PB_DS_CLASS_C_DEC::
actual_erase_leaf(leaf_pointer p_l)118 actual_erase_leaf(leaf_pointer p_l)
119 {
120   _GLIBCXX_DEBUG_ASSERT(m_size > 0);
121   --m_size;
122   _GLIBCXX_DEBUG_ONLY(debug_base::erase_existing(PB_DS_V2F(p_l->value())));
123   p_l->~leaf();
124   s_leaf_allocator.deallocate(p_l, 1);
125 }
126 
127 PB_DS_CLASS_T_DEC
128 void
129 PB_DS_CLASS_C_DEC::
clear()130 clear()
131 {
132   if (!empty())
133     {
134       clear_imp(m_p_head->m_p_parent);
135       m_size = 0;
136       initialize();
137       _GLIBCXX_DEBUG_ONLY(debug_base::clear();)
138       PB_DS_ASSERT_VALID((*this))
139     }
140 }
141 
142 PB_DS_CLASS_T_DEC
143 void
144 PB_DS_CLASS_C_DEC::
clear_imp(node_pointer p_nd)145 clear_imp(node_pointer p_nd)
146 {
147   if (p_nd->m_type == i_node)
148     {
149       _GLIBCXX_DEBUG_ASSERT(p_nd->m_type == i_node);
150       for (typename inode::iterator it =
151                static_cast<inode_pointer>(p_nd)->begin();
152              it != static_cast<inode_pointer>(p_nd)->end();
153              ++it)
154           {
155             node_pointer p_child =* it;
156             clear_imp(p_child);
157           }
158       s_inode_allocator.deallocate(static_cast<inode_pointer>(p_nd), 1);
159       return;
160     }
161 
162   _GLIBCXX_DEBUG_ASSERT(p_nd->m_type == leaf_node);
163   static_cast<leaf_pointer>(p_nd)->~leaf();
164   s_leaf_allocator.deallocate(static_cast<leaf_pointer>(p_nd), 1);
165 }
166 
167 PB_DS_CLASS_T_DEC
168 inline typename PB_DS_CLASS_C_DEC::const_iterator
169 PB_DS_CLASS_C_DEC::
erase(const_iterator it)170 erase(const_iterator it)
171 {
172   PB_DS_ASSERT_VALID((*this))
173 
174   if (it == end())
175     return it;
176 
177   const_iterator ret_it = it;
178   ++ret_it;
179   _GLIBCXX_DEBUG_ASSERT(it.m_p_nd->m_type == leaf_node);
180   erase_leaf(static_cast<leaf_pointer>(it.m_p_nd));
181   PB_DS_ASSERT_VALID((*this))
182   return ret_it;
183 }
184 
185 #ifdef PB_DS_DATA_TRUE_INDICATOR
186 PB_DS_CLASS_T_DEC
187 inline typename PB_DS_CLASS_C_DEC::iterator
188 PB_DS_CLASS_C_DEC::
erase(iterator it)189 erase(iterator it)
190 {
191   PB_DS_ASSERT_VALID((*this))
192 
193   if (it == end())
194     return it;
195   iterator ret_it = it;
196   ++ret_it;
197   _GLIBCXX_DEBUG_ASSERT(it.m_p_nd->m_type == leaf_node);
198   erase_leaf(static_cast<leaf_pointer>(it.m_p_nd));
199   PB_DS_ASSERT_VALID((*this))
200   return ret_it;
201 }
202 #endif // #ifdef PB_DS_DATA_TRUE_INDICATOR
203 
204 PB_DS_CLASS_T_DEC
205 inline typename PB_DS_CLASS_C_DEC::const_reverse_iterator
206 PB_DS_CLASS_C_DEC::
erase(const_reverse_iterator it)207 erase(const_reverse_iterator it)
208 {
209   PB_DS_ASSERT_VALID((*this))
210 
211   if (it.m_p_nd == m_p_head)
212     return it;
213   const_reverse_iterator ret_it = it;
214   ++ret_it;
215 
216   _GLIBCXX_DEBUG_ASSERT(it.m_p_nd->m_type == leaf_node);
217   erase_leaf(static_cast<leaf_pointer>(it.m_p_nd));
218   PB_DS_ASSERT_VALID((*this))
219   return ret_it;
220 }
221 
222 #ifdef PB_DS_DATA_TRUE_INDICATOR
223 PB_DS_CLASS_T_DEC
224 inline typename PB_DS_CLASS_C_DEC::reverse_iterator
225 PB_DS_CLASS_C_DEC::
erase(reverse_iterator it)226 erase(reverse_iterator it)
227 {
228   PB_DS_ASSERT_VALID((*this))
229 
230   if (it.m_p_nd == m_p_head)
231     return it;
232   reverse_iterator ret_it = it;
233   ++ret_it;
234 
235   _GLIBCXX_DEBUG_ASSERT(it.m_p_nd->m_type == leaf_node);
236   erase_leaf(static_cast<leaf_pointer>(it.m_p_nd));
237   PB_DS_ASSERT_VALID((*this))
238   return ret_it;
239 }
240 #endif // #ifdef PB_DS_DATA_TRUE_INDICATOR
241 
242 PB_DS_CLASS_T_DEC
243 template<typename Pred>
244 inline typename PB_DS_CLASS_C_DEC::size_type
245 PB_DS_CLASS_C_DEC::
erase_if(Pred pred)246 erase_if(Pred pred)
247 {
248   size_type num_ersd = 0;
249   PB_DS_ASSERT_VALID((*this))
250 
251   iterator it = begin();
252   while (it != end())
253     {
254       PB_DS_ASSERT_VALID((*this))
255       if (pred(*it))
256           {
257             ++num_ersd;
258             it = erase(it);
259           }
260       else
261           ++it;
262     }
263 
264   PB_DS_ASSERT_VALID((*this))
265   return num_ersd;
266 }
267 
268 PB_DS_CLASS_T_DEC
269 void
270 PB_DS_CLASS_C_DEC::
erase_leaf(leaf_pointer p_l)271 erase_leaf(leaf_pointer p_l)
272 {
273   update_min_max_for_erased_leaf(p_l);
274   if (p_l->m_p_parent->m_type == head_node)
275     {
276       _GLIBCXX_DEBUG_ASSERT(size() == 1);
277       clear();
278       return;
279     }
280 
281   _GLIBCXX_DEBUG_ASSERT(size() > 1);
282   _GLIBCXX_DEBUG_ASSERT(p_l->m_p_parent->m_type == i_node);
283 
284   inode_pointer p_parent = static_cast<inode_pointer>(p_l->m_p_parent);
285 
286   p_parent->remove_child(p_l);
287   erase_fixup(p_parent);
288   actual_erase_leaf(p_l);
289 }
290 
291 PB_DS_CLASS_T_DEC
292 void
293 PB_DS_CLASS_C_DEC::
update_min_max_for_erased_leaf(leaf_pointer p_l)294 update_min_max_for_erased_leaf(leaf_pointer p_l)
295 {
296   if (m_size == 1)
297     {
298       m_p_head->m_p_min = m_p_head;
299       m_p_head->m_p_max = m_p_head;
300       return;
301     }
302 
303   if (p_l == static_cast<leaf_const_pointer>(m_p_head->m_p_min))
304     {
305       iterator it(p_l);
306       ++it;
307       m_p_head->m_p_min = it.m_p_nd;
308       return;
309     }
310 
311   if (p_l == static_cast<leaf_const_pointer>(m_p_head->m_p_max))
312     {
313       iterator it(p_l);
314       --it;
315       m_p_head->m_p_max = it.m_p_nd;
316     }
317 }
318 #endif
319