libstdc++-v3/include/ext/pb_ds/detail/resize_policy/hash_exponential_size_policy_imp.hpp

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005-2019 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_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