3 // Copyright (C) 2005 Free Software Foundation, Inc.
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
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 2, or (at your option)
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // You should have received a copy of the GNU General Public License along
17 // with this library; see the file COPYING. If not, write to the Free
18 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
21 // As a special exception, you may use this file as part of a free software
22 // library without restriction. Specifically, if other files instantiate
23 // templates or use macros or inline functions from this file, or you compile
24 // this file and link it with other files to produce an executable, this
25 // file does not by itself cause the resulting executable to be covered by
26 // the GNU General Public License. This exception does not however
27 // invalidate any other reasons why the executable file might be covered by
28 // the GNU General Public License.
30 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
32 // Permission to use, copy, modify, sell, and distribute this software
33 // is hereby granted without fee, provided that the above copyright
34 // notice appears in all copies, and that both that copyright notice and
35 // this permission notice appear in supporting documentation. None of
36 // the above authors, nor IBM Haifa Research Laboratories, make any
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41 * @file mask_based_range_hashing.hpp
42 * Contains a range hashing policy base.
45 #ifndef MASK_BASED_RANGE_HASHING_HPP
46 #define MASK_BASED_RANGE_HASHING_HPP
54 #define PB_ASSOC_CLASS_T_DEC \
55 template<typename Size_Type>
57 #define PB_ASSOC_CLASS_C_DEC \
58 mask_based_range_hashing< \
61 template<typename Size_Type>
62 class mask_based_range_hashing
65 typedef Size_Type size_type;
69 swap(PB_ASSOC_CLASS_C_DEC& r_other);
72 notify_resized(size_type size);
75 range_hash(size_type hash) const;
80 const static size_type s_num_bits_in_size_type;
82 const static size_type s_highest_bit_1;
86 const typename PB_ASSOC_CLASS_C_DEC::size_type
87 PB_ASSOC_CLASS_C_DEC::s_num_bits_in_size_type =
88 sizeof(typename PB_ASSOC_CLASS_C_DEC::size_type) << 3;
91 const typename PB_ASSOC_CLASS_C_DEC::size_type
92 PB_ASSOC_CLASS_C_DEC::s_highest_bit_1 =
93 (typename PB_ASSOC_CLASS_C_DEC::size_type) 1
94 << (s_num_bits_in_size_type - 1);
98 PB_ASSOC_CLASS_C_DEC::
99 swap(PB_ASSOC_CLASS_C_DEC& r_other)
101 std::swap(m_mask, r_other.m_mask);
106 PB_ASSOC_CLASS_C_DEC::
107 notify_resized(size_type size)
111 while (size ^ s_highest_bit_1)
122 while (i++ < s_num_bits_in_size_type)
123 m_mask = (m_mask << 1) ^ 1;
127 inline typename PB_ASSOC_CLASS_C_DEC::size_type
128 PB_ASSOC_CLASS_C_DEC::
129 range_hash(size_type hash) const
131 return (hash& m_mask);
134 #undef PB_ASSOC_CLASS_T_DEC
135 #undef PB_ASSOC_CLASS_C_DEC
137 } // namespace detail
139 } // namespace pb_assoc
141 #endif // #ifndef MASK_BASED_RANGE_HASHING_HPP