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