libstdc++
hash_exponential_size_policy_imp.hpp
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00001 // -*- C++ -*-
00002 
00003 // Copyright (C) 2005, 2006, 2009 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_exponential_size_policy_imp.hpp
00038  * Contains a resize size policy implementation.
00039  */
00040 
00041 PB_DS_CLASS_T_DEC
00042 PB_DS_CLASS_C_DEC::
00043 hash_exponential_size_policy(size_type start_size, size_type grow_factor) :
00044   m_start_size(start_size),
00045   m_grow_factor(grow_factor)
00046 { }
00047 
00048 PB_DS_CLASS_T_DEC
00049 void
00050 PB_DS_CLASS_C_DEC::
00051 swap(PB_DS_CLASS_C_DEC& other)
00052 {
00053   std::swap(m_start_size, other.m_start_size);
00054   std::swap(m_grow_factor, other.m_grow_factor);
00055 }
00056 
00057 PB_DS_CLASS_T_DEC
00058 typename PB_DS_CLASS_C_DEC::size_type
00059 PB_DS_CLASS_C_DEC::
00060 get_nearest_larger_size(size_type size) const
00061 {
00062   size_type ret = m_start_size;
00063   while (ret <= size)
00064     {
00065       const size_type next_ret = ret*  m_grow_factor;
00066       if (next_ret < ret)
00067     __throw_insert_error();
00068       ret = next_ret;
00069     }
00070   return ret;
00071 }
00072 
00073 PB_DS_CLASS_T_DEC
00074 typename PB_DS_CLASS_C_DEC::size_type
00075 PB_DS_CLASS_C_DEC::
00076 get_nearest_smaller_size(size_type size) const
00077 {
00078   size_type ret = m_start_size;
00079   while (true)
00080     {
00081       const size_type next_ret = ret*  m_grow_factor;
00082       if (next_ret < ret)
00083     __throw_resize_error();
00084       if (next_ret >= size)
00085     return (ret);
00086       ret = next_ret;
00087     }
00088   return ret;
00089 }
00090