libstdc++-v3/include/ext/pb_ds/detail/pat_trie_/split_fn_imps.hpp

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005-2023 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 #ifdef PB_DS_CLASS_C_DEC
  42
  43 PB_DS_CLASS_T_DEC
  44 void
  45 PB_DS_CLASS_C_DEC::
  46 split(key_const_reference r_key, PB_DS_CLASS_C_DEC& other)
  47 {
  48   PB_DS_ASSERT_VALID((*this))
  49   PB_DS_ASSERT_VALID(other)
  50   branch_bag bag;
  51   leaf_pointer p_split_lf = split_prep(r_key, other, bag);
  52   if (p_split_lf == 0)
  53     {
  54       _GLIBCXX_DEBUG_ASSERT(bag.empty());
  55       PB_DS_ASSERT_VALID((*this))
  56       PB_DS_ASSERT_VALID(other)
  57       return;
  58     }
  59
  60   _GLIBCXX_DEBUG_ASSERT(!bag.empty());
  61   other.clear();
  62
  63   m_p_head->m_p_parent = rec_split(m_p_head->m_p_parent, pref_begin(p_split_lf),
  64                                    pref_end(p_split_lf), other, bag);
  65
  66   m_p_head->m_p_parent->m_p_parent = m_p_head;
  67
  68   head_pointer __ohead = other.m_p_head;
  69   __ohead->m_p_max = m_p_head->m_p_max;
  70   m_p_head->m_p_max = rightmost_descendant(m_p_head->m_p_parent);
  71   __ohead->m_p_min = other.leftmost_descendant(__ohead->m_p_parent);
  72
  73   other.m_size = std::distance(other.PB_DS_CLASS_C_DEC::begin(),
  74                                other.PB_DS_CLASS_C_DEC::end());
  75   m_size -= other.m_size;
  76   PB_DS_ASSERT_VALID((*this))
  77   PB_DS_ASSERT_VALID(other)
  78 }
  79
  80 PB_DS_CLASS_T_DEC
  81 typename PB_DS_CLASS_C_DEC::leaf_pointer
  82 PB_DS_CLASS_C_DEC::
  83 split_prep(key_const_reference r_key, PB_DS_CLASS_C_DEC& other,
  84            branch_bag& r_bag)
  85 {
  86   _GLIBCXX_DEBUG_ASSERT(r_bag.empty());
  87   if (m_size == 0)
  88     {
  89       other.clear();
  90       PB_DS_ASSERT_VALID((*this))
  91       PB_DS_ASSERT_VALID(other)
  92       return 0;
  93     }
  94
  95   if (synth_access_traits::cmp_keys(r_key,
  96                                     PB_DS_V2F(static_cast<leaf_const_pointer>(m_p_head->m_p_min)->value())))
  97     {
  98       other.clear();
  99       value_swap(other);
 100       PB_DS_ASSERT_VALID((*this))
 101       PB_DS_ASSERT_VALID(other)
 102       return 0;
 103     }
 104
 105   if (!synth_access_traits::cmp_keys(r_key,
 106                                        PB_DS_V2F(static_cast<leaf_const_pointer>(m_p_head->m_p_max)->value())))
 107     {
 108       PB_DS_ASSERT_VALID((*this))
 109       PB_DS_ASSERT_VALID(other)
 110       return 0;
 111     }
 112
 113   iterator it = lower_bound(r_key);
 114
 115   if (!synth_access_traits::equal_keys(PB_DS_V2F(*it), r_key))
 116     --it;
 117
 118   node_pointer p_nd = it.m_p_nd;
 119   _GLIBCXX_DEBUG_ASSERT(p_nd->m_type == leaf_node);
 120   leaf_pointer p_ret_l = static_cast<leaf_pointer>(p_nd);
 121   while (p_nd->m_type != head_node)
 122     {
 123       r_bag.add_branch();
 124       p_nd = p_nd->m_p_parent;
 125     }
 126   _GLIBCXX_DEBUG_ONLY(debug_base::split(r_key,(synth_access_traits&)(*this), other);)
 127
 128   return p_ret_l;
 129 }
 130
 131 PB_DS_CLASS_T_DEC
 132 typename PB_DS_CLASS_C_DEC::node_pointer
 133 PB_DS_CLASS_C_DEC::
 134 rec_split(node_pointer p_nd, a_const_iterator b_it, a_const_iterator e_it,
 135           PB_DS_CLASS_C_DEC& other, branch_bag& r_bag)
 136 {
 137   if (p_nd->m_type == leaf_node)
 138     {
 139       _GLIBCXX_DEBUG_ASSERT(other.m_p_head->m_p_parent == 0);
 140       return p_nd;
 141     }
 142
 143   _GLIBCXX_DEBUG_ASSERT(p_nd->m_type == i_node);
 144   inode_pointer p_ind = static_cast<inode_pointer>(p_nd);
 145
 146   node_pointer pfirst = p_ind->get_child_node(b_it, e_it, this);
 147   node_pointer p_child_ret = rec_split(pfirst, b_it, e_it, other, r_bag);
 148   PB_DS_ASSERT_NODE_VALID(p_child_ret)
 149   p_ind->replace_child(p_child_ret, b_it, e_it, this);
 150   apply_update(p_ind, (node_update*)this);
 151
 152   inode_iterator child_it = p_ind->get_child_it(b_it, e_it, this);
 153   const size_type lhs_dist = std::distance(p_ind->begin(), child_it);
 154   const size_type lhs_num_children = lhs_dist + 1;
 155   _GLIBCXX_DEBUG_ASSERT(lhs_num_children > 0);
 156
 157   const size_type rhs_dist =  std::distance(p_ind->begin(), p_ind->end());
 158   size_type rhs_num_children = rhs_dist - lhs_num_children;
 159   if (rhs_num_children == 0)
 160     {
 161       apply_update(p_ind, (node_update*)this);
 162       return p_ind;
 163     }
 164
 165   other.split_insert_branch(p_ind->get_e_ind(), b_it, child_it,
 166                             rhs_num_children, r_bag);
 167
 168   child_it = p_ind->get_child_it(b_it, e_it, this);
 169   while (rhs_num_children != 0)
 170     {
 171       ++child_it;
 172       p_ind->remove_child(child_it);
 173       --rhs_num_children;
 174     }
 175   apply_update(p_ind, (node_update*)this);
 176
 177   const size_type int_dist = std::distance(p_ind->begin(), p_ind->end());
 178   _GLIBCXX_DEBUG_ASSERT(int_dist >= 1);
 179   if (int_dist > 1)
 180     {
 181       p_ind->update_prefixes(this);
 182       PB_DS_ASSERT_NODE_VALID(p_ind)
 183       apply_update(p_ind, (node_update*)this);
 184       return p_ind;
 185     }
 186
 187   node_pointer p_ret = *p_ind->begin();
 188   p_ind->~inode();
 189   s_inode_allocator.deallocate(p_ind, 1);
 190   apply_update(p_ret, (node_update*)this);
 191   return p_ret;
 192 }
 193
 194 PB_DS_CLASS_T_DEC
 195 void
 196 PB_DS_CLASS_C_DEC::
 197 split_insert_branch(size_type e_ind, a_const_iterator b_it,
 198                     inode_iterator child_b_it,
 199                     size_type num_children, branch_bag& r_bag)
 200 {
 201 #ifdef _GLIBCXX_DEBUG
 202   if (m_p_head->m_p_parent != 0)
 203     PB_DS_ASSERT_NODE_VALID(m_p_head->m_p_parent)
 204 #endif
 205
 206   const size_type start = m_p_head->m_p_parent == 0 ? 0 : 1;
 207   const size_type total_num_children = start + num_children;
 208   if (total_num_children == 0)
 209     {
 210       _GLIBCXX_DEBUG_ASSERT(m_p_head->m_p_parent == 0);
 211       return;
 212     }
 213
 214   if (total_num_children == 1)
 215     {
 216       if (m_p_head->m_p_parent != 0)
 217         {
 218           PB_DS_ASSERT_NODE_VALID(m_p_head->m_p_parent)
 219           return;
 220         }
 221
 222       _GLIBCXX_DEBUG_ASSERT(m_p_head->m_p_parent == 0);
 223       ++child_b_it;
 224       m_p_head->m_p_parent = *child_b_it;
 225       m_p_head->m_p_parent->m_p_parent = m_p_head;
 226       apply_update(m_p_head->m_p_parent, (node_update*)this);
 227       PB_DS_ASSERT_NODE_VALID(m_p_head->m_p_parent)
 228       return;
 229     }
 230
 231   _GLIBCXX_DEBUG_ASSERT(total_num_children > 1);
 232   inode_pointer p_new_root = r_bag.get_branch();
 233   new (p_new_root) inode(e_ind, b_it);
 234   size_type num_inserted = 0;
 235   while (num_inserted++ < num_children)
 236     {
 237       ++child_b_it;
 238       PB_DS_ASSERT_NODE_VALID((*child_b_it))
 239       p_new_root->add_child(*child_b_it, pref_begin(*child_b_it),
 240                             pref_end(*child_b_it), this);
 241     }
 242
 243   if (m_p_head->m_p_parent != 0)
 244     p_new_root->add_child(m_p_head->m_p_parent,
 245                           pref_begin(m_p_head->m_p_parent),
 246                           pref_end(m_p_head->m_p_parent), this);
 247
 248   m_p_head->m_p_parent = p_new_root;
 249   p_new_root->m_p_parent = m_p_head;
 250   apply_update(m_p_head->m_p_parent, (node_update*)this);
 251   PB_DS_ASSERT_NODE_VALID(m_p_head->m_p_parent)
 252 }
 253 #endif