1 // -*- C++ -*- 2 3 // Copyright (C) 2005, 2006, 2009, 2010 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 hash_prime_size_policy_imp.hpp 38 * Contains a resize size policy implementation. 39 */ 40 41 #pragma GCC system_header 42 43 namespace detail 44 { 45 enum 46 { 47 num_distinct_sizes_32_bit = 30, 48 num_distinct_sizes_64_bit = 62, 49 num_distinct_sizes = sizeof(std::size_t) != 8 ? 50 num_distinct_sizes_32_bit : num_distinct_sizes_64_bit, 51 }; 52 53 // Originally taken from the SGI implementation; acknowledged in the docs. 54 // Further modified (for 64 bits) from tr1's hashtable. 55 static const std::size_t g_a_sizes[num_distinct_sizes_64_bit] = 56 { 57 /* 0 */ 5ul, 58 /* 1 */ 11ul, 59 /* 2 */ 23ul, 60 /* 3 */ 47ul, 61 /* 4 */ 97ul, 62 /* 5 */ 199ul, 63 /* 6 */ 409ul, 64 /* 7 */ 823ul, 65 /* 8 */ 1741ul, 66 /* 9 */ 3469ul, 67 /* 10 */ 6949ul, 68 /* 11 */ 14033ul, 69 /* 12 */ 28411ul, 70 /* 13 */ 57557ul, 71 /* 14 */ 116731ul, 72 /* 15 */ 236897ul, 73 /* 16 */ 480881ul, 74 /* 17 */ 976369ul, 75 /* 18 */ 1982627ul, 76 /* 19 */ 4026031ul, 77 /* 20 */ 8175383ul, 78 /* 21 */ 16601593ul, 79 /* 22 */ 33712729ul, 80 /* 23 */ 68460391ul, 81 /* 24 */ 139022417ul, 82 /* 25 */ 282312799ul, 83 /* 26 */ 573292817ul, 84 /* 27 */ 1164186217ul, 85 /* 28 */ 2364114217ul, 86 /* 29 */ 4294967291ul, 87 /* 30 */ (std::size_t)8589934583ull, 88 /* 31 */ (std::size_t)17179869143ull, 89 /* 32 */ (std::size_t)34359738337ull, 90 /* 33 */ (std::size_t)68719476731ull, 91 /* 34 */ (std::size_t)137438953447ull, 92 /* 35 */ (std::size_t)274877906899ull, 93 /* 36 */ (std::size_t)549755813881ull, 94 /* 37 */ (std::size_t)1099511627689ull, 95 /* 38 */ (std::size_t)2199023255531ull, 96 /* 39 */ (std::size_t)4398046511093ull, 97 /* 40 */ (std::size_t)8796093022151ull, 98 /* 41 */ (std::size_t)17592186044399ull, 99 /* 42 */ (std::size_t)35184372088777ull, 100 /* 43 */ (std::size_t)70368744177643ull, 101 /* 44 */ (std::size_t)140737488355213ull, 102 /* 45 */ (std::size_t)281474976710597ull, 103 /* 46 */ (std::size_t)562949953421231ull, 104 /* 47 */ (std::size_t)1125899906842597ull, 105 /* 48 */ (std::size_t)2251799813685119ull, 106 /* 49 */ (std::size_t)4503599627370449ull, 107 /* 50 */ (std::size_t)9007199254740881ull, 108 /* 51 */ (std::size_t)18014398509481951ull, 109 /* 52 */ (std::size_t)36028797018963913ull, 110 /* 53 */ (std::size_t)72057594037927931ull, 111 /* 54 */ (std::size_t)144115188075855859ull, 112 /* 55 */ (std::size_t)288230376151711717ull, 113 /* 56 */ (std::size_t)576460752303423433ull, 114 /* 57 */ (std::size_t)1152921504606846883ull, 115 /* 58 */ (std::size_t)2305843009213693951ull, 116 /* 59 */ (std::size_t)4611686018427387847ull, 117 /* 60 */ (std::size_t)9223372036854775783ull, 118 /* 61 */ (std::size_t)18446744073709551557ull, 119 }; 120 121 } // namespace detail 122 123 PB_DS_CLASS_T_DEC 124 inline 125 PB_DS_CLASS_C_DEC:: 126 hash_prime_size_policy(size_type n) : m_start_size(n) 127 { m_start_size = get_nearest_larger_size(n); } 128 129 PB_DS_CLASS_T_DEC 130 inline void 131 PB_DS_CLASS_C_DEC:: 132 swap(PB_DS_CLASS_C_DEC& other) 133 { std::swap(m_start_size, other.m_start_size); } 134 135 PB_DS_CLASS_T_DEC 136 inline PB_DS_CLASS_C_DEC::size_type 137 PB_DS_CLASS_C_DEC:: 138 get_nearest_larger_size(size_type n) const 139 { 140 const std::size_t* const p_upper = std::upper_bound(detail::g_a_sizes, 141 detail::g_a_sizes + detail::num_distinct_sizes, n); 142 143 if (p_upper == detail::g_a_sizes + detail::num_distinct_sizes) 144 __throw_resize_error(); 145 return *p_upper; 146 } 147 148 PB_DS_CLASS_T_DEC 149 inline PB_DS_CLASS_C_DEC::size_type 150 PB_DS_CLASS_C_DEC:: 151 get_nearest_smaller_size(size_type n) const 152 { 153 const std::size_t* p_lower = std::lower_bound(detail::g_a_sizes, 154 detail::g_a_sizes + detail::num_distinct_sizes, n); 155 156 if (*p_lower >= n && p_lower != detail::g_a_sizes) 157 --p_lower; 158 if (*p_lower < m_start_size) 159 return m_start_size; 160 return *p_lower; 161 } 162
