Chris@102: //////////////////////////////////////////////////////////////////////////////
Chris@102: //
Chris@102: // (C) Copyright Ion Gaztanaga 2014-2015. Distributed under the Boost
Chris@102: // Software License, Version 1.0. (See accompanying file
Chris@102: // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@102: //
Chris@102: // See http://www.boost.org/libs/container for documentation.
Chris@102: //
Chris@102: //////////////////////////////////////////////////////////////////////////////
Chris@102: #ifndef BOOST_CONTAINER_DETAIL_NEXT_CAPACITY_HPP
Chris@102: #define BOOST_CONTAINER_DETAIL_NEXT_CAPACITY_HPP
Chris@102: 
Chris@102: #ifndef BOOST_CONFIG_HPP
Chris@102: #  include <boost/config.hpp>
Chris@102: #endif
Chris@102: 
Chris@102: #if defined(BOOST_HAS_PRAGMA_ONCE)
Chris@102: #  pragma once
Chris@102: #endif
Chris@102: 
Chris@102: // container
Chris@102: #include <boost/container/throw_exception.hpp>
Chris@102: // container/detail
Chris@102: #include <boost/container/detail/min_max.hpp>
Chris@102: 
Chris@102: namespace boost {
Chris@102: namespace container {
Chris@102: namespace container_detail {
Chris@102: 
Chris@102: enum NextCapacityOption { NextCapacityDouble, NextCapacity60Percent };
Chris@102: 
Chris@102: template<class SizeType, NextCapacityOption Option>
Chris@102: struct next_capacity_calculator;
Chris@102: 
Chris@102: template<class SizeType>
Chris@102: struct next_capacity_calculator<SizeType, NextCapacityDouble>
Chris@102: {
Chris@102:    static SizeType get(const SizeType max_size
Chris@102:                       ,const SizeType capacity
Chris@102:                       ,const SizeType n)
Chris@102:    {
Chris@102:       const SizeType remaining = max_size - capacity;
Chris@102:       if ( remaining < n )
Chris@102:          boost::container::throw_length_error("get_next_capacity, allocator's max_size reached");
Chris@102:       const SizeType additional = max_value(n, capacity);
Chris@102:       return ( remaining < additional ) ? max_size : ( capacity + additional );
Chris@102:    }
Chris@102: };
Chris@102: 
Chris@102: template<class SizeType>
Chris@102: struct next_capacity_calculator<SizeType, NextCapacity60Percent>
Chris@102: {
Chris@102:    static SizeType get(const SizeType max_size
Chris@102:                      ,const SizeType capacity
Chris@102:                      ,const SizeType n)
Chris@102:    {
Chris@102:       const SizeType remaining = max_size - capacity;
Chris@102:       if ( remaining < n )
Chris@102:          boost::container::throw_length_error("get_next_capacity, allocator's max_size reached");
Chris@102:       const SizeType m3 = max_size/3;
Chris@102: 
Chris@102:       if (capacity < m3)
Chris@102:          return capacity + max_value(3*(capacity+1)/5, n);
Chris@102: 
Chris@102:       if (capacity < m3*2)
Chris@102:          return capacity + max_value((capacity+1)/2, n);
Chris@102:       return max_size;
Chris@102:    }
Chris@102: };
Chris@102: 
Chris@102: }  //namespace container_detail {
Chris@102: }  //namespace container {
Chris@102: }  //namespace boost {
Chris@102: 
Chris@102: #endif   //#ifndef BOOST_CONTAINER_DETAIL_NEXT_CAPACITY_HPP