libstdc++-v3/include/ext/pb_ds/detail/trie_policy/prefix_search_node_update_imp.hpp

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005, 2006, 2009 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 prefix_search_node_update_imp.hpp
  38  * Contains an implementation of prefix_search_node_update.
  39  */
  40
  41 PB_DS_CLASS_T_DEC
  42 std::pair<
  43   typename PB_DS_CLASS_C_DEC::const_iterator,
  44   typename PB_DS_CLASS_C_DEC::const_iterator>
  45 PB_DS_CLASS_C_DEC::
  46 prefix_range(const_key_reference r_key) const
  47 {
  48   const e_access_traits& r_traits = get_e_access_traits();
  49
  50   return (prefix_range(
  51                        r_traits.begin(r_key),
  52                        r_traits.end(r_key)));
  53 }
  54
  55 PB_DS_CLASS_T_DEC
  56 std::pair<
  57   typename PB_DS_CLASS_C_DEC::iterator,
  58   typename PB_DS_CLASS_C_DEC::iterator>
  59 PB_DS_CLASS_C_DEC::
  60 prefix_range(const_key_reference r_key)
  61 {
  62   return (prefix_range(
  63                        get_e_access_traits().begin(r_key),
  64                        get_e_access_traits().end(r_key)));
  65 }
  66
  67 PB_DS_CLASS_T_DEC
  68 std::pair<
  69   typename PB_DS_CLASS_C_DEC::const_iterator,
  70   typename PB_DS_CLASS_C_DEC::const_iterator>
  71 PB_DS_CLASS_C_DEC::
  72 prefix_range(typename e_access_traits::const_iterator b, typename e_access_traits::const_iterator e) const
  73 {
  74   const std::pair<iterator, iterator> non_const_ret =
  75     const_cast<PB_DS_CLASS_C_DEC* >(this)->prefix_range(b, e);
  76
  77   return (std::make_pair(
  78                          const_iterator(non_const_ret.first),
  79                          const_iterator(non_const_ret.second)));
  80 }
  81
  82 PB_DS_CLASS_T_DEC
  83 std::pair<
  84   typename PB_DS_CLASS_C_DEC::iterator,
  85   typename PB_DS_CLASS_C_DEC::iterator>
  86 PB_DS_CLASS_C_DEC::
  87 prefix_range(typename e_access_traits::const_iterator b, typename e_access_traits::const_iterator e)
  88 {
  89   Node_Iterator nd_it = node_begin();
  90   Node_Iterator end_nd_it = node_end();
  91
  92   const e_access_traits& r_traits =
  93     get_e_access_traits();
  94
  95   const size_type given_range_length = std::distance(b, e);
  96
  97   while (true)
  98     {
  99       if (nd_it == end_nd_it)
 100         return (std::make_pair(end(), end()));
 101
 102       const size_type common_range_length =
 103         PB_DS_BASE_C_DEC::common_prefix_len(nd_it, b, e, r_traits);
 104
 105       if (common_range_length >= given_range_length)
 106         {
 107           iterator ret_b = this->leftmost_it(nd_it);
 108
 109           iterator ret_e = this->rightmost_it(nd_it);
 110
 111           return (std::make_pair(ret_b, ++ret_e));
 112         }
 113
 114       nd_it = next_child(nd_it, b, e, end_nd_it, r_traits);
 115     }
 116 }
 117
 118 PB_DS_CLASS_T_DEC
 119 typename PB_DS_CLASS_C_DEC::node_iterator
 120 PB_DS_CLASS_C_DEC::
 121 next_child(node_iterator nd_it, typename e_access_traits::const_iterator b, typename e_access_traits::const_iterator e, node_iterator end_nd_it, const e_access_traits& r_traits)
 122 {
 123   const size_type num_children = nd_it.num_children();
 124
 125   node_iterator ret = end_nd_it;
 126
 127   size_type max_length = 0;
 128
 129   for (size_type i = 0; i < num_children; ++i)
 130     {
 131       node_iterator pot = nd_it.get_child(i);
 132
 133       const size_type common_range_length =
 134         PB_DS_BASE_C_DEC::common_prefix_len(            pot, b, e, r_traits);
 135
 136       if (common_range_length > max_length)
 137         {
 138           ret = pot;
 139
 140           max_length = common_range_length;
 141         }
 142     }
 143
 144   return (ret);
 145 }
 146
 147 PB_DS_CLASS_T_DEC
 148 inline void
 149 PB_DS_CLASS_C_DEC::
 150 operator()(node_iterator /*nd_it*/, const_node_iterator /*end_nd_it*/) const
 151 { }