libstdc++
prefix_search_node_update_imp.hpp
Go to the documentation of this file.
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 trie_policy/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(key_const_reference r_key) const
47 {
48  const access_traits& r_traits = get_access_traits();
49  return (prefix_range(r_traits.begin(r_key), r_traits.end(r_key)));
50 }
51 
52 PB_DS_CLASS_T_DEC
53 std::pair<
54  typename PB_DS_CLASS_C_DEC::iterator,
55  typename PB_DS_CLASS_C_DEC::iterator>
56 PB_DS_CLASS_C_DEC::
57 prefix_range(key_const_reference r_key)
58 {
59  return (prefix_range(get_access_traits().begin(r_key),
60  get_access_traits().end(r_key)));
61 }
62 
63 PB_DS_CLASS_T_DEC
64 std::pair<
65  typename PB_DS_CLASS_C_DEC::const_iterator,
66  typename PB_DS_CLASS_C_DEC::const_iterator>
67 PB_DS_CLASS_C_DEC::
68 prefix_range(typename access_traits::const_iterator b,
69  typename access_traits::const_iterator e) const
70 {
71  const std::pair<iterator, iterator> non_const_ret =
72  const_cast<PB_DS_CLASS_C_DEC* >(this)->prefix_range(b, e);
73 
74  return (std::make_pair(const_iterator(non_const_ret.first),
75  const_iterator(non_const_ret.second)));
76 }
77 
78 PB_DS_CLASS_T_DEC
79 std::pair<
80  typename PB_DS_CLASS_C_DEC::iterator,
81  typename PB_DS_CLASS_C_DEC::iterator>
82 PB_DS_CLASS_C_DEC::
83 prefix_range(typename access_traits::const_iterator b,
84  typename access_traits::const_iterator e)
85 {
86  Node_Itr nd_it = node_begin();
87  Node_Itr end_nd_it = node_end();
88 
89  const access_traits& r_traits = get_access_traits();
90  const size_type given_range_length = std::distance(b, e);
91 
92  while (true)
93  {
94  if (nd_it == end_nd_it)
95  return (std::make_pair(end(), end()));
96 
97  const size_type common_range_length =
98  base_type::common_prefix_len(nd_it, b, e, r_traits);
99 
100  if (common_range_length >= given_range_length)
101  {
102  iterator ret_b = this->leftmost_it(nd_it);
103  iterator ret_e = this->rightmost_it(nd_it);
104  return (std::make_pair(ret_b, ++ret_e));
105  }
106  nd_it = next_child(nd_it, b, e, end_nd_it, r_traits);
107  }
108 }
109 
110 PB_DS_CLASS_T_DEC
111 typename PB_DS_CLASS_C_DEC::node_iterator
112 PB_DS_CLASS_C_DEC::
113 next_child(node_iterator nd_it, typename access_traits::const_iterator b,
114  typename access_traits::const_iterator e, node_iterator end_nd_it,
115  const access_traits& r_traits)
116 {
117  const size_type num_children = nd_it.num_children();
118  node_iterator ret = end_nd_it;
119  size_type max_length = 0;
120  for (size_type i = 0; i < num_children; ++i)
121  {
122  node_iterator pot = nd_it.get_child(i);
123  const size_type common_range_length =
124  base_type::common_prefix_len(pot, b, e, r_traits);
125 
126  if (common_range_length > max_length)
127  {
128  ret = pot;
129  max_length = common_range_length;
130  }
131  }
132  return (ret);
133 }
134 
135 PB_DS_CLASS_T_DEC
136 inline void
137 PB_DS_CLASS_C_DEC::
138 operator()(node_iterator /*nd_it*/, node_const_iterator /*end_nd_it*/) const
139 { }