libstdc++

split_fn_imps.hpp
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1 // -*- C++ -*-
2
3 // Copyright (C) 2005-2013 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_/split_fn_imps.hpp
38 * Contains an implementation class for pat_trie.
39 */
40
41 PB_DS_CLASS_T_DEC
42 void
43 PB_DS_CLASS_C_DEC::
44 split(key_const_reference r_key, PB_DS_CLASS_C_DEC& other)
45 {
46 PB_DS_ASSERT_VALID((*this))
47 PB_DS_ASSERT_VALID(other)
48 branch_bag bag;
49 leaf_pointer p_split_lf = split_prep(r_key, other, bag);
50 if (p_split_lf == 0)
51 {
52 _GLIBCXX_DEBUG_ASSERT(bag.empty());
53 PB_DS_ASSERT_VALID((*this))
54 PB_DS_ASSERT_VALID(other)
55 return;
56 }
57
58 _GLIBCXX_DEBUG_ASSERT(!bag.empty());
59 other.clear();
60
61 m_p_head->m_p_parent = rec_split(m_p_head->m_p_parent, pref_begin(p_split_lf),
62 pref_end(p_split_lf), other, bag);
63
64 m_p_head->m_p_parent->m_p_parent = m_p_head;
65
66 head_pointer __ohead = other.m_p_head;
67 __ohead->m_p_max = m_p_head->m_p_max;
68 m_p_head->m_p_max = rightmost_descendant(m_p_head->m_p_parent);
69 __ohead->m_p_min = other.leftmost_descendant(__ohead->m_p_parent);
70
71 other.m_size = std::distance(other.PB_DS_CLASS_C_DEC::begin(),
72 other.PB_DS_CLASS_C_DEC::end());
73 m_size -= other.m_size;
74 PB_DS_ASSERT_VALID((*this))
75 PB_DS_ASSERT_VALID(other)
76 }
77
78 PB_DS_CLASS_T_DEC
79 typename PB_DS_CLASS_C_DEC::leaf_pointer
80 PB_DS_CLASS_C_DEC::
81 split_prep(key_const_reference r_key, PB_DS_CLASS_C_DEC& other,
82 branch_bag& r_bag)
83 {
84 _GLIBCXX_DEBUG_ASSERT(r_bag.empty());
85 if (m_size == 0)
86 {
87 other.clear();
88 PB_DS_ASSERT_VALID((*this))
89 PB_DS_ASSERT_VALID(other)
90 return 0;
91 }
92
93 if (synth_access_traits::cmp_keys(r_key,
94 PB_DS_V2F(static_cast<leaf_const_pointer>(m_p_head->m_p_min)->value())))
95 {
96 other.clear();
97 value_swap(other);
98 PB_DS_ASSERT_VALID((*this))
99 PB_DS_ASSERT_VALID(other)
100 return 0;
101 }
102
103 if (!synth_access_traits::cmp_keys(r_key,
104 PB_DS_V2F(static_cast<leaf_const_pointer>(m_p_head->m_p_max)->value())))
105 {
106 PB_DS_ASSERT_VALID((*this))
107 PB_DS_ASSERT_VALID(other)
108 return 0;
109 }
110
111 iterator it = lower_bound(r_key);
112
113 if (!synth_access_traits::equal_keys(PB_DS_V2F(*it), r_key))
114 --it;
115
116 node_pointer p_nd = it.m_p_nd;
117 _GLIBCXX_DEBUG_ASSERT(p_nd->m_type == leaf_node);
118 leaf_pointer p_ret_l = static_cast<leaf_pointer>(p_nd);
119 while (p_nd->m_type != head_node)
120 {
121 r_bag.add_branch();
122 p_nd = p_nd->m_p_parent;
123 }
124 _GLIBCXX_DEBUG_ONLY(debug_base::split(r_key,(synth_access_traits&)(*this), other);)
125
126 return p_ret_l;
127 }
128
129 PB_DS_CLASS_T_DEC
130 typename PB_DS_CLASS_C_DEC::node_pointer
131 PB_DS_CLASS_C_DEC::
132 rec_split(node_pointer p_nd, a_const_iterator b_it, a_const_iterator e_it,
133 PB_DS_CLASS_C_DEC& other, branch_bag& r_bag)
134 {
135 if (p_nd->m_type == leaf_node)
136 {
137 _GLIBCXX_DEBUG_ASSERT(other.m_p_head->m_p_parent == 0);
138 return p_nd;
139 }
140
141 _GLIBCXX_DEBUG_ASSERT(p_nd->m_type == i_node);
142 inode_pointer p_ind = static_cast<inode_pointer>(p_nd);
143
144 node_pointer pfirst = p_ind->get_child_node(b_it, e_it, this);
145 node_pointer p_child_ret = rec_split(pfirst, b_it, e_it, other, r_bag);
146 PB_DS_ASSERT_NODE_VALID(p_child_ret)
147 p_ind->replace_child(p_child_ret, b_it, e_it, this);
148 apply_update(p_ind, (node_update*)this);
149
150 inode_iterator child_it = p_ind->get_child_it(b_it, e_it, this);
151 const size_type lhs_dist = std::distance(p_ind->begin(), child_it);
152 const size_type lhs_num_children = lhs_dist + 1;
153 _GLIBCXX_DEBUG_ASSERT(lhs_num_children > 0);
154
155 const size_type rhs_dist = std::distance(p_ind->begin(), p_ind->end());
156 size_type rhs_num_children = rhs_dist - lhs_num_children;
157 if (rhs_num_children == 0)
158 {
159 apply_update(p_ind, (node_update*)this);
160 return p_ind;
161 }
162
163 other.split_insert_branch(p_ind->get_e_ind(), b_it, child_it,
164 rhs_num_children, r_bag);
165
166 child_it = p_ind->get_child_it(b_it, e_it, this);
167 while (rhs_num_children != 0)
168 {
169 ++child_it;
170 p_ind->remove_child(child_it);
171 --rhs_num_children;
172 }
173 apply_update(p_ind, (node_update*)this);
174
175 const size_type int_dist = std::distance(p_ind->begin(), p_ind->end());
176 _GLIBCXX_DEBUG_ASSERT(int_dist >= 1);
177 if (int_dist > 1)
178 {
179 p_ind->update_prefixes(this);
180 PB_DS_ASSERT_NODE_VALID(p_ind)
181 apply_update(p_ind, (node_update*)this);
182 return p_ind;
183 }
184
185 node_pointer p_ret = *p_ind->begin();
186 p_ind->~inode();
187 s_inode_allocator.deallocate(p_ind, 1);
188 apply_update(p_ret, (node_update*)this);
189 return p_ret;
190 }
191
192 PB_DS_CLASS_T_DEC
193 void
194 PB_DS_CLASS_C_DEC::
195 split_insert_branch(size_type e_ind, a_const_iterator b_it,
196 inode_iterator child_b_it,
197 size_type num_children, branch_bag& r_bag)
198 {
199 #ifdef _GLIBCXX_DEBUG
200 if (m_p_head->m_p_parent != 0)
201 PB_DS_ASSERT_NODE_VALID(m_p_head->m_p_parent)
202 #endif
203
204 const size_type start = m_p_head->m_p_parent == 0 ? 0 : 1;
205 const size_type total_num_children = start + num_children;
206 if (total_num_children == 0)
207 {
208 _GLIBCXX_DEBUG_ASSERT(m_p_head->m_p_parent == 0);
209 return;
210 }
211
212 if (total_num_children == 1)
213 {
214 if (m_p_head->m_p_parent != 0)
215 {
216 PB_DS_ASSERT_NODE_VALID(m_p_head->m_p_parent)
217 return;
218 }
219
220 _GLIBCXX_DEBUG_ASSERT(m_p_head->m_p_parent == 0);
221 ++child_b_it;
222 m_p_head->m_p_parent = *child_b_it;
223 m_p_head->m_p_parent->m_p_parent = m_p_head;
224 apply_update(m_p_head->m_p_parent, (node_update*)this);
225 PB_DS_ASSERT_NODE_VALID(m_p_head->m_p_parent)
226 return;
227 }
228
229 _GLIBCXX_DEBUG_ASSERT(total_num_children > 1);
230 inode_pointer p_new_root = r_bag.get_branch();
231 new (p_new_root) inode(e_ind, b_it);
232 size_type num_inserted = 0;
233 while (num_inserted++ < num_children)
234 {
235 ++child_b_it;
236 PB_DS_ASSERT_NODE_VALID((*child_b_it))
237 p_new_root->add_child(*child_b_it, pref_begin(*child_b_it),
238 pref_end(*child_b_it), this);
239 }
240
241 if (m_p_head->m_p_parent != 0)
242 p_new_root->add_child(m_p_head->m_p_parent,
243 pref_begin(m_p_head->m_p_parent),
244 pref_end(m_p_head->m_p_parent), this);
245
246 m_p_head->m_p_parent = p_new_root;
247 p_new_root->m_p_parent = m_p_head;
248 apply_update(m_p_head->m_p_parent, (node_update*)this);
249 PB_DS_ASSERT_NODE_VALID(m_p_head->m_p_parent)
250 }