libstdc++-v3/include/ext/pb_assoc/detail/resize_policy/hash_prime_size_policy_imp.hpp

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005 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
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 2, or (at your option)
   9 // any later version.
  10
  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.
  15
  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,
  19 // USA.
  20
  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.
  29
  30 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
  31
  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
  37 // representation about the suitability of this software for any
  38 // purpose. It is provided "as is" without express or implied warranty.
  39
  40 /*
  41  * @file hash_prime_size_policy_imp.hpp
  42  * Contains an implementation of hash_prime_size_policy.
  43  */
  44
  45 namespace detail
  46 {
  47
  48   enum
  49     {
  50       num_distinct_sizes = 28
  51     };
  52
  53   static const size_t s_a_sizes[num_distinct_sizes] =
  54     {
  55       /* Dealing cards... */
  56       /* 0      */ 53ul,
  57       /* 1      */ 97ul,
  58       /* 2      */ 193ul,
  59       /* 3      */ 389ul,
  60       /* 4      */ 769ul,
  61       /* 5      */ 1543ul,
  62       /* 6      */ 3079ul,
  63       /* 7      */ 6151ul,
  64       /* 8      */ 12289ul,
  65       /* 9      */ 24593ul,
  66       /* 10     */ 49157ul,
  67       /* 11     */ 98317ul,
  68       /* 12     */ 196613ul,
  69       /* 13     */ 393241ul,
  70       /* 14     */ 786433ul,
  71       /* 15     */ 1572869ul,
  72       /* 16     */ 3145739ul,
  73       /* 17     */ 6291469ul,
  74       /* 18     */ 12582917ul,
  75       /* 19     */ 25165843ul,
  76       /* 20     */ 50331653ul,
  77       /* 21     */ 100663319ul,
  78       /* 22     */ 201326611ul,
  79       /* 23     */ 402653189ul,
  80       /* 24     */ 805306457ul,
  81       /* 25     */ 1610612741,
  82       /* 26     */ 3221225473ul,
  83       /* 27     */ 4294967291ul
  84       /* Pot's good, let's play */
  85     };
  86
  87 } // namespace detail
  88
  89 PB_ASSOC_CLASS_T_DEC
  90 inline void
  91 PB_ASSOC_CLASS_C_DEC::
  92 swap(PB_ASSOC_CLASS_C_DEC& /*r_other*/)
  93 { }
  94
  95 PB_ASSOC_CLASS_T_DEC
  96 PB_ASSOC_CLASS_C_DEC::size_type
  97 PB_ASSOC_CLASS_C_DEC::
  98 get_init_size(size_type suggested_size) const
  99 {
 100   return (get_nearest_larger_size_imp(suggested_size));
 101 }
 102
 103 PB_ASSOC_CLASS_T_DEC
 104 inline PB_ASSOC_CLASS_C_DEC::size_type
 105 PB_ASSOC_CLASS_C_DEC::
 106 get_nearest_larger_size(size_type cur_size) const
 107 {
 108   PB_ASSOC_DBG_ONLY(assert_is_one_of_my_sizes(cur_size);)
 109
 110     return (get_nearest_larger_size_imp(cur_size));
 111 }
 112
 113 PB_ASSOC_CLASS_T_DEC
 114 inline PB_ASSOC_CLASS_C_DEC::size_type
 115 PB_ASSOC_CLASS_C_DEC::
 116 get_nearest_smaller_size(size_type cur_size) const
 117 {
 118   PB_ASSOC_DBG_ONLY(assert_is_one_of_my_sizes(cur_size);)
 119
 120     return (*std::lower_bound(detail::s_a_sizes, detail::s_a_sizes + detail::num_distinct_sizes, cur_size - 1));
 121 }
 122
 123 PB_ASSOC_CLASS_T_DEC
 124 inline PB_ASSOC_CLASS_C_DEC::size_type
 125 PB_ASSOC_CLASS_C_DEC::
 126 get_nearest_larger_size_imp(size_type size) const
 127 {
 128   const size_t* const p_upper =
 129     std::upper_bound(detail::s_a_sizes, detail::s_a_sizes + detail::num_distinct_sizes, size);
 130
 131   return ((p_upper == detail::s_a_sizes + detail::num_distinct_sizes)?
 132           size :
 133           *p_upper);
 134 }
 135
 136 #ifdef PB_ASSOC_HT_PRIME_SIZE_POLICY_DEBUG
 137 PB_ASSOC_CLASS_T_DEC
 138 void
 139 PB_ASSOC_CLASS_C_DEC::
 140 assert_is_one_of_my_sizes(size_type size)
 141 {
 142   const size_t* const p_end =
 143     detail::s_a_sizes + detail::num_distinct_sizes;
 144
 145   const size_t* const p_found =
 146     std::find(detail::s_a_sizes, p_end, size)
 147
 148     PB_ASSOC_DBG_ASSERT(p_found != p_end);
 149 }
 150 #endif // #ifdef PB_ASSOC_HT_PRIME_SIZE_POLICY_DEBUG