townforge/contrib/epee/include/misc_language.h
Crypto City d75bedc5c6 use 6th decile instead of median for block size algorithm
this should avoid the block size never growing under pressure
if the totality of PoW hash rate is from a single pool which
only mines empty blocks
2025-08-01 07:02:17 +00:00

130 lines
4.0 KiB
C++

// Copyright (c) 2006-2013, Andrey N. Sabelnikov, www.sabelnikov.net
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// * Neither the name of the Andrey N. Sabelnikov nor the
// names of its contributors may be used to endorse or promote products
// derived from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER BE LIABLE FOR ANY
// DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
#pragma once
#include <boost/utility/value_init.hpp>
#include <boost/shared_ptr.hpp>
#include <vector>
namespace epee
{
#define AUTO_VAL_INIT(v) boost::value_initialized<decltype(v)>()
namespace misc_utils
{
bool sleep_no_w(long ms);
template <typename T>
T get_mid(const T &a, const T &b)
{
//returns the average of two numbers; overflow safe and works with at least all integral and floating point types
//(a+b)/2 = (a/2) + (b/2) + ((a - 2*(a/2)) + (b - 2*(b/2)))/2
return (a/2) + (b/2) + ((a - 2*(a/2)) + (b - 2*(b/2)))/2;
}
template<class type_vec_type>
type_vec_type median(std::vector<type_vec_type> &v)
{
if(v.empty())
return boost::value_initialized<type_vec_type>();
if(v.size() == 1)
return v[0];
size_t n = (v.size()) / 2;
std::sort(v.begin(), v.end());
//nth_element(v.begin(), v.begin()+n-1, v.end());
if(v.size()%2)
{//1, 3, 5...
return v[n];
}else
{//2, 4, 6...
return get_mid<type_vec_type>(v[n-1],v[n]);
}
}
template<class type_vec_type>
static type_vec_type decile(std::vector<type_vec_type> &v, uint32_t d)
{
if(v.empty())
return boost::value_initialized<type_vec_type>();
if(v.size() == 1)
return v[0];
size_t n = (v.size() * d) / 10 - 1;
if (n >= v.size())
n = v.size();
std::sort(v.begin(), v.end());
type_vec_type fraction = (v.size() * d) % 10;
if (fraction == 0 || n == v.size()-1)
return v[n];
else
return v[n] + fraction * (v[n+1] - v[n]) / 10;
}
/************************************************************************/
/* */
/************************************************************************/
struct call_befor_die_base
{
virtual ~call_befor_die_base(){}
};
typedef boost::shared_ptr<call_befor_die_base> auto_scope_leave_caller;
template<class t_scope_leave_handler>
struct call_befor_die: public call_befor_die_base
{
t_scope_leave_handler m_func;
call_befor_die(t_scope_leave_handler f):m_func(f)
{}
~call_befor_die()
{
try { m_func(); }
catch (...) { /* ignore */ }
}
};
template<class t_scope_leave_handler>
auto_scope_leave_caller create_scope_leave_handler(t_scope_leave_handler f)
{
auto_scope_leave_caller slc(new call_befor_die<t_scope_leave_handler>(f));
return slc;
}
template<typename T> struct struct_init: T
{
struct_init(): T{} {}
};
}
}