1// -*- C++ -*-
2
3// Copyright (C) 2005-2015 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
41PB_DS_CLASS_T_DEC
42void
43PB_DS_CLASS_C_DEC::
44split(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
78PB_DS_CLASS_T_DEC
79typename PB_DS_CLASS_C_DEC::leaf_pointer
80PB_DS_CLASS_C_DEC::
81split_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
129PB_DS_CLASS_T_DEC
130typename PB_DS_CLASS_C_DEC::node_pointer
131PB_DS_CLASS_C_DEC::
132rec_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
192PB_DS_CLASS_T_DEC
193void
194PB_DS_CLASS_C_DEC::
195split_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}
251