libstdc++
hash_exponential_size_policy_imp.hpp
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1 // -*- C++ -*-
2 
3 // Copyright (C) 2005-2020 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.
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11 // This library is distributed in the hope that it will be useful, but
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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.
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20 // You should have received a copy of the GNU General Public License and
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24 
25 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
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27 // Permission to use, copy, modify, sell, and distribute this software
28 // is hereby granted without fee, provided that the above copyright
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35 
36 /**
37  * @file hash_exponential_size_policy_imp.hpp
38  * Contains a resize size policy implementation.
39  */
40 
41 #ifdef PB_DS_CLASS_C_DEC
42 
43 PB_DS_CLASS_T_DEC
44 PB_DS_CLASS_C_DEC::
45 hash_exponential_size_policy(size_type start_size, size_type grow_factor) :
46  m_start_size(start_size),
47  m_grow_factor(grow_factor)
48 { }
49 
50 PB_DS_CLASS_T_DEC
51 void
52 PB_DS_CLASS_C_DEC::
53 swap(PB_DS_CLASS_C_DEC& other)
54 {
55  std::swap(m_start_size, other.m_start_size);
56  std::swap(m_grow_factor, other.m_grow_factor);
57 }
58 
59 PB_DS_CLASS_T_DEC
60 typename PB_DS_CLASS_C_DEC::size_type
61 PB_DS_CLASS_C_DEC::
62 get_nearest_larger_size(size_type size) const
63 {
64  size_type ret = m_start_size;
65  while (ret <= size)
66  {
67  const size_type next_ret = ret* m_grow_factor;
68  if (next_ret < ret)
69  __throw_insert_error();
70  ret = next_ret;
71  }
72  return ret;
73 }
74 
75 PB_DS_CLASS_T_DEC
76 typename PB_DS_CLASS_C_DEC::size_type
77 PB_DS_CLASS_C_DEC::
78 get_nearest_smaller_size(size_type size) const
79 {
80  size_type ret = m_start_size;
81  while (true)
82  {
83  const size_type next_ret = ret* m_grow_factor;
84  if (next_ret < ret)
85  __throw_resize_error();
86  if (next_ret >= size)
87  return (ret);
88  ret = next_ret;
89  }
90  return ret;
91 }
92 
93 #endif