libstdc++
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00001 // -*- C++ -*- 00002 00003 // Copyright (C) 2005, 2006, 2009, 2010 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 hash_prime_size_policy_imp.hpp 00038 * Contains a resize size policy implementation. 00039 */ 00040 00041 #pragma GCC system_header 00042 00043 namespace detail 00044 { 00045 enum 00046 { 00047 num_distinct_sizes_32_bit = 30, 00048 num_distinct_sizes_64_bit = 62, 00049 num_distinct_sizes = sizeof(std::size_t) != 8 ? 00050 num_distinct_sizes_32_bit : num_distinct_sizes_64_bit, 00051 }; 00052 00053 // Originally taken from the SGI implementation; acknowledged in the docs. 00054 // Further modified (for 64 bits) from tr1's hashtable. 00055 static const std::size_t g_a_sizes[num_distinct_sizes_64_bit] = 00056 { 00057 /* 0 */ 5ul, 00058 /* 1 */ 11ul, 00059 /* 2 */ 23ul, 00060 /* 3 */ 47ul, 00061 /* 4 */ 97ul, 00062 /* 5 */ 199ul, 00063 /* 6 */ 409ul, 00064 /* 7 */ 823ul, 00065 /* 8 */ 1741ul, 00066 /* 9 */ 3469ul, 00067 /* 10 */ 6949ul, 00068 /* 11 */ 14033ul, 00069 /* 12 */ 28411ul, 00070 /* 13 */ 57557ul, 00071 /* 14 */ 116731ul, 00072 /* 15 */ 236897ul, 00073 /* 16 */ 480881ul, 00074 /* 17 */ 976369ul, 00075 /* 18 */ 1982627ul, 00076 /* 19 */ 4026031ul, 00077 /* 20 */ 8175383ul, 00078 /* 21 */ 16601593ul, 00079 /* 22 */ 33712729ul, 00080 /* 23 */ 68460391ul, 00081 /* 24 */ 139022417ul, 00082 /* 25 */ 282312799ul, 00083 /* 26 */ 573292817ul, 00084 /* 27 */ 1164186217ul, 00085 /* 28 */ 2364114217ul, 00086 /* 29 */ 4294967291ul, 00087 /* 30 */ (std::size_t)8589934583ull, 00088 /* 31 */ (std::size_t)17179869143ull, 00089 /* 32 */ (std::size_t)34359738337ull, 00090 /* 33 */ (std::size_t)68719476731ull, 00091 /* 34 */ (std::size_t)137438953447ull, 00092 /* 35 */ (std::size_t)274877906899ull, 00093 /* 36 */ (std::size_t)549755813881ull, 00094 /* 37 */ (std::size_t)1099511627689ull, 00095 /* 38 */ (std::size_t)2199023255531ull, 00096 /* 39 */ (std::size_t)4398046511093ull, 00097 /* 40 */ (std::size_t)8796093022151ull, 00098 /* 41 */ (std::size_t)17592186044399ull, 00099 /* 42 */ (std::size_t)35184372088777ull, 00100 /* 43 */ (std::size_t)70368744177643ull, 00101 /* 44 */ (std::size_t)140737488355213ull, 00102 /* 45 */ (std::size_t)281474976710597ull, 00103 /* 46 */ (std::size_t)562949953421231ull, 00104 /* 47 */ (std::size_t)1125899906842597ull, 00105 /* 48 */ (std::size_t)2251799813685119ull, 00106 /* 49 */ (std::size_t)4503599627370449ull, 00107 /* 50 */ (std::size_t)9007199254740881ull, 00108 /* 51 */ (std::size_t)18014398509481951ull, 00109 /* 52 */ (std::size_t)36028797018963913ull, 00110 /* 53 */ (std::size_t)72057594037927931ull, 00111 /* 54 */ (std::size_t)144115188075855859ull, 00112 /* 55 */ (std::size_t)288230376151711717ull, 00113 /* 56 */ (std::size_t)576460752303423433ull, 00114 /* 57 */ (std::size_t)1152921504606846883ull, 00115 /* 58 */ (std::size_t)2305843009213693951ull, 00116 /* 59 */ (std::size_t)4611686018427387847ull, 00117 /* 60 */ (std::size_t)9223372036854775783ull, 00118 /* 61 */ (std::size_t)18446744073709551557ull, 00119 }; 00120 00121 } // namespace detail 00122 00123 PB_DS_CLASS_T_DEC 00124 inline 00125 PB_DS_CLASS_C_DEC:: 00126 hash_prime_size_policy(size_type n) : m_start_size(n) 00127 { m_start_size = get_nearest_larger_size(n); } 00128 00129 PB_DS_CLASS_T_DEC 00130 inline void 00131 PB_DS_CLASS_C_DEC:: 00132 swap(PB_DS_CLASS_C_DEC& other) 00133 { std::swap(m_start_size, other.m_start_size); } 00134 00135 PB_DS_CLASS_T_DEC 00136 inline PB_DS_CLASS_C_DEC::size_type 00137 PB_DS_CLASS_C_DEC:: 00138 get_nearest_larger_size(size_type n) const 00139 { 00140 const std::size_t* const p_upper = std::upper_bound(detail::g_a_sizes, 00141 detail::g_a_sizes + detail::num_distinct_sizes, n); 00142 00143 if (p_upper == detail::g_a_sizes + detail::num_distinct_sizes) 00144 __throw_resize_error(); 00145 return *p_upper; 00146 } 00147 00148 PB_DS_CLASS_T_DEC 00149 inline PB_DS_CLASS_C_DEC::size_type 00150 PB_DS_CLASS_C_DEC:: 00151 get_nearest_smaller_size(size_type n) const 00152 { 00153 const std::size_t* p_lower = std::lower_bound(detail::g_a_sizes, 00154 detail::g_a_sizes + detail::num_distinct_sizes, n); 00155 00156 if (*p_lower >= n && p_lower != detail::g_a_sizes) 00157 --p_lower; 00158 if (*p_lower < m_start_size) 00159 return m_start_size; 00160 return *p_lower; 00161 }