libstdc++
prefix_search_node_update_imp.hpp
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00001 // -*- C++ -*-
00002 
00003 // Copyright (C) 2005, 2006, 2009 Free Software Foundation, Inc.
00004 //
00005 // This file is part of the GNU ISO C++ Library.  This library is free
00006 // software; you can redistribute it and/or modify it under the terms
00007 // of the GNU General Public License as published by the Free Software
00008 // Foundation; either version 3, or (at your option) any later
00009 // version.
00010 
00011 // This library is distributed in the hope that it will be useful, but
00012 // WITHOUT ANY WARRANTY; without even the implied warranty of
00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014 // General Public License for more details.
00015 
00016 // Under Section 7 of GPL version 3, you are granted additional
00017 // permissions described in the GCC Runtime Library Exception, version
00018 // 3.1, as published by the Free Software Foundation.
00019 
00020 // You should have received a copy of the GNU General Public License and
00021 // a copy of the GCC Runtime Library Exception along with this program;
00022 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
00023 // <http://www.gnu.org/licenses/>.
00024 
00025 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
00026 
00027 // Permission to use, copy, modify, sell, and distribute this software
00028 // is hereby granted without fee, provided that the above copyright
00029 // notice appears in all copies, and that both that copyright notice
00030 // and this permission notice appear in supporting documentation. None
00031 // of the above authors, nor IBM Haifa Research Laboratories, make any
00032 // representation about the suitability of this software for any
00033 // purpose. It is provided "as is" without express or implied
00034 // warranty.
00035 
00036 /**
00037  * @file trie_policy/prefix_search_node_update_imp.hpp
00038  * Contains an implementation of prefix_search_node_update.
00039  */
00040 
00041 PB_DS_CLASS_T_DEC
00042 std::pair<
00043   typename PB_DS_CLASS_C_DEC::const_iterator,
00044   typename PB_DS_CLASS_C_DEC::const_iterator>
00045 PB_DS_CLASS_C_DEC::
00046 prefix_range(key_const_reference r_key) const
00047 {
00048   const access_traits& r_traits = get_access_traits();
00049   return (prefix_range(r_traits.begin(r_key), r_traits.end(r_key)));
00050 }
00051 
00052 PB_DS_CLASS_T_DEC
00053 std::pair<
00054   typename PB_DS_CLASS_C_DEC::iterator,
00055   typename PB_DS_CLASS_C_DEC::iterator>
00056 PB_DS_CLASS_C_DEC::
00057 prefix_range(key_const_reference r_key)
00058 {
00059   return (prefix_range(get_access_traits().begin(r_key),
00060                get_access_traits().end(r_key)));
00061 }
00062 
00063 PB_DS_CLASS_T_DEC
00064 std::pair<
00065   typename PB_DS_CLASS_C_DEC::const_iterator,
00066   typename PB_DS_CLASS_C_DEC::const_iterator>
00067 PB_DS_CLASS_C_DEC::
00068 prefix_range(typename access_traits::const_iterator b,
00069          typename access_traits::const_iterator e) const
00070 {
00071   const std::pair<iterator, iterator> non_const_ret =
00072     const_cast<PB_DS_CLASS_C_DEC* >(this)->prefix_range(b, e);
00073 
00074   return (std::make_pair(const_iterator(non_const_ret.first),
00075              const_iterator(non_const_ret.second)));
00076 }
00077 
00078 PB_DS_CLASS_T_DEC
00079 std::pair<
00080   typename PB_DS_CLASS_C_DEC::iterator,
00081   typename PB_DS_CLASS_C_DEC::iterator>
00082 PB_DS_CLASS_C_DEC::
00083 prefix_range(typename access_traits::const_iterator b,
00084          typename access_traits::const_iterator e)
00085 {
00086   Node_Itr nd_it = node_begin();
00087   Node_Itr end_nd_it = node_end();
00088 
00089   const access_traits& r_traits = get_access_traits();
00090   const size_type given_range_length = std::distance(b, e);
00091 
00092   while (true)
00093     {
00094       if (nd_it == end_nd_it)
00095     return (std::make_pair(end(), end()));
00096 
00097       const size_type common_range_length =
00098     base_type::common_prefix_len(nd_it, b, e, r_traits);
00099 
00100       if (common_range_length >= given_range_length)
00101     {
00102       iterator ret_b = this->leftmost_it(nd_it);
00103       iterator ret_e = this->rightmost_it(nd_it);
00104       return (std::make_pair(ret_b, ++ret_e));
00105     }
00106       nd_it = next_child(nd_it, b, e, end_nd_it, r_traits);
00107     }
00108 }
00109 
00110 PB_DS_CLASS_T_DEC
00111 typename PB_DS_CLASS_C_DEC::node_iterator
00112 PB_DS_CLASS_C_DEC::
00113 next_child(node_iterator nd_it, typename access_traits::const_iterator b,
00114        typename access_traits::const_iterator e, node_iterator end_nd_it,
00115        const access_traits& r_traits)
00116 {
00117   const size_type num_children = nd_it.num_children();
00118   node_iterator ret = end_nd_it;
00119   size_type max_length = 0;
00120   for (size_type i = 0; i < num_children; ++i)
00121     {
00122       node_iterator pot = nd_it.get_child(i);
00123       const size_type common_range_length =
00124     base_type::common_prefix_len(pot, b, e, r_traits);
00125 
00126       if (common_range_length > max_length)
00127     {
00128       ret = pot;
00129       max_length = common_range_length;
00130     }
00131     }
00132   return (ret);
00133 }
00134 
00135 PB_DS_CLASS_T_DEC
00136 inline void
00137 PB_DS_CLASS_C_DEC::
00138 operator()(node_iterator /*nd_it*/, node_const_iterator /*end_nd_it*/) const
00139 { }