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// -*- C++ -*-

// Copyright (C) 2005, 2006, 2009, 2010 Free Software Foundation, Inc.

//

// This file is part of the GNU ISO C++ Library.  This library is free

// software; you can redistribute it and/or modify it under the terms

// of the GNU General Public License as published by the Free Software

// Foundation; either version 3, or (at your option) any later

// version.

// This library is distributed in the hope that it will be useful, but

// WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

// General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional

// permissions described in the GCC Runtime Library Exception, version

// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and

// a copy of the GCC Runtime Library Exception along with this program;

// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see

// <http://www.gnu.org/licenses/>.

// Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.

// Permission to use, copy, modify, sell, and distribute this software

// is hereby granted without fee, provided that the above copyright

// notice appears in all copies, and that both that copyright notice

// and this permission notice appear in supporting documentation. None

// of the above authors, nor IBM Haifa Research Laboratories, make any

// representation about the suitability of this software for any

// purpose. It is provided "as is" without express or implied

// warranty.

/**

 * @file hash_prime_size_policy_imp.hpp

 * Contains a resize size policy implementation.

 */

#pragma GCC system_header

namespace detail

{

  enum

    {

      num_distinct_sizes_32_bit = 30,

      num_distinct_sizes_64_bit = 62,

      num_distinct_sizes = sizeof(std::size_t) != 8 ?

            num_distinct_sizes_32_bit : num_distinct_sizes_64_bit,

    };

  // Originally taken from the SGI implementation; acknowledged in the docs.

  // Further modified (for 64 bits) from tr1's hashtable.

  static const std::size_t g_a_sizes[num_distinct_sizes_64_bit] =

    {

      /* 0     */              5ul,

      /* 1     */              11ul,

      /* 2     */              23ul,

      /* 3     */              47ul,

      /* 4     */              97ul,

      /* 5     */              199ul,

      /* 6     */              409ul,

      /* 7     */              823ul,

      /* 8     */              1741ul,

      /* 9     */              3469ul,

      /* 10    */              6949ul,

      /* 11    */              14033ul,

      /* 12    */              28411ul,

      /* 13    */              57557ul,

      /* 14    */              116731ul,

      /* 15    */              236897ul,

      /* 16    */              480881ul,

      /* 17    */              976369ul,

      /* 18    */              1982627ul,

      /* 19    */              4026031ul,

      /* 20    */              8175383ul,

      /* 21    */              16601593ul,

      /* 22    */              33712729ul,

      /* 23    */              68460391ul,

      /* 24    */              139022417ul,

      /* 25    */              282312799ul,

      /* 26    */              573292817ul,

      /* 27    */              1164186217ul,

      /* 28    */              2364114217ul,

      /* 29    */              4294967291ul,

      /* 30    */ (std::size_t)8589934583ull,

      /* 31    */ (std::size_t)17179869143ull,

      /* 32    */ (std::size_t)34359738337ull,

      /* 33    */ (std::size_t)68719476731ull,

      /* 34    */ (std::size_t)137438953447ull,

      /* 35    */ (std::size_t)274877906899ull,

      /* 36    */ (std::size_t)549755813881ull,

      /* 37    */ (std::size_t)1099511627689ull,

      /* 38    */ (std::size_t)2199023255531ull,

      /* 39    */ (std::size_t)4398046511093ull,

      /* 40    */ (std::size_t)8796093022151ull,

      /* 41    */ (std::size_t)17592186044399ull,

      /* 42    */ (std::size_t)35184372088777ull,

      /* 43    */ (std::size_t)70368744177643ull,

      /* 44    */ (std::size_t)140737488355213ull,

      /* 45    */ (std::size_t)281474976710597ull,

      /* 46    */ (std::size_t)562949953421231ull,

      /* 47    */ (std::size_t)1125899906842597ull,

      /* 48    */ (std::size_t)2251799813685119ull,

      /* 49    */ (std::size_t)4503599627370449ull,

      /* 50    */ (std::size_t)9007199254740881ull,

      /* 51    */ (std::size_t)18014398509481951ull,

      /* 52    */ (std::size_t)36028797018963913ull,

      /* 53    */ (std::size_t)72057594037927931ull,

      /* 54    */ (std::size_t)144115188075855859ull,

      /* 55    */ (std::size_t)288230376151711717ull,

      /* 56    */ (std::size_t)576460752303423433ull,

      /* 57    */ (std::size_t)1152921504606846883ull,

      /* 58    */ (std::size_t)2305843009213693951ull,

      /* 59    */ (std::size_t)4611686018427387847ull,

      /* 60    */ (std::size_t)9223372036854775783ull,

      /* 61    */ (std::size_t)18446744073709551557ull,

    };

} // namespace detail

PB_DS_CLASS_T_DEC

inline

PB_DS_CLASS_C_DEC::

hash_prime_size_policy(size_type n) : m_start_size(n)

{ m_start_size = get_nearest_larger_size(n); }

PB_DS_CLASS_T_DEC

inline void

PB_DS_CLASS_C_DEC::

swap(PB_DS_CLASS_C_DEC& other)

{ std::swap(m_start_size, other.m_start_size); }

PB_DS_CLASS_T_DEC

inline PB_DS_CLASS_C_DEC::size_type

PB_DS_CLASS_C_DEC::

get_nearest_larger_size(size_type n) const

{

  const std::size_t* const p_upper = std::upper_bound(detail::g_a_sizes,

                     detail::g_a_sizes + detail::num_distinct_sizes, n);

  if (p_upper == detail::g_a_sizes + detail::num_distinct_sizes)

    __throw_resize_error();

  return *p_upper;

}

PB_DS_CLASS_T_DEC

inline PB_DS_CLASS_C_DEC::size_type

PB_DS_CLASS_C_DEC::

get_nearest_smaller_size(size_type n) const

{

  const std::size_t* p_lower = std::lower_bound(detail::g_a_sizes,

                       detail::g_a_sizes + detail::num_distinct_sizes, n);

  if (*p_lower >= n &&  p_lower != detail::g_a_sizes)

    --p_lower;

  if (*p_lower < m_start_size)

    return m_start_size;

  return *p_lower;

}