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 trie_policy/prefix_search_node_update_imp.hpp
38 * Contains an implementation of prefix_search_node_update.
39 */
40
41PB_DS_CLASS_T_DEC
42std::pair<
43  typename PB_DS_CLASS_C_DEC::const_iterator,
44  typename PB_DS_CLASS_C_DEC::const_iterator>
45PB_DS_CLASS_C_DEC::
46prefix_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
52PB_DS_CLASS_T_DEC
53std::pair<
54  typename PB_DS_CLASS_C_DEC::iterator,
55  typename PB_DS_CLASS_C_DEC::iterator>
56PB_DS_CLASS_C_DEC::
57prefix_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
63PB_DS_CLASS_T_DEC
64std::pair<
65  typename PB_DS_CLASS_C_DEC::const_iterator,
66  typename PB_DS_CLASS_C_DEC::const_iterator>
67PB_DS_CLASS_C_DEC::
68prefix_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
78PB_DS_CLASS_T_DEC
79std::pair<
80  typename PB_DS_CLASS_C_DEC::iterator,
81  typename PB_DS_CLASS_C_DEC::iterator>
82PB_DS_CLASS_C_DEC::
83prefix_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
110PB_DS_CLASS_T_DEC
111typename PB_DS_CLASS_C_DEC::node_iterator
112PB_DS_CLASS_C_DEC::
113next_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
135PB_DS_CLASS_T_DEC
136inline void
137PB_DS_CLASS_C_DEC::
138operator()(node_iterator /*nd_it*/, node_const_iterator /*end_nd_it*/) const
139{ }
140