mirror of
https://github.com/monero-project/monero.git
synced 2024-12-27 13:29:25 -05:00
72 lines
3.0 KiB
C++
72 lines
3.0 KiB
C++
// Copyright (c) 2020-2022, The Monero Project
|
|
|
|
//
|
|
// All rights reserved.
|
|
//
|
|
// Redistribution and use in source and binary forms, with or without modification, are
|
|
// permitted provided that the following conditions are met:
|
|
//
|
|
// 1. Redistributions of source code must retain the above copyright notice, this list of
|
|
// conditions and the following disclaimer.
|
|
//
|
|
// 2. 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.
|
|
//
|
|
// 3. Neither the name of the copyright holder 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 HOLDER OR CONTRIBUTORS 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 <chrono>
|
|
#include "crypto/crypto.h"
|
|
|
|
namespace crypto
|
|
{
|
|
//! Generate poisson distributed values in discrete `D` time units.
|
|
template<typename D>
|
|
struct random_poisson_duration
|
|
{
|
|
using result_type = D; //!< std::chrono::duration time unit precision
|
|
using rep = typename result_type::rep; //!< Type used to represent duration value
|
|
|
|
//! \param average for generated durations
|
|
explicit random_poisson_duration(result_type average)
|
|
: dist(average.count() < 0 ? 0 : average.count())
|
|
{}
|
|
|
|
//! Generate a crypto-secure random duration
|
|
result_type operator()()
|
|
{
|
|
crypto::random_device rand{};
|
|
return result_type{dist(rand)};
|
|
}
|
|
|
|
private:
|
|
std::poisson_distribution<rep> dist;
|
|
};
|
|
|
|
/* A custom duration is used for subsecond precision because of the
|
|
variance. If 5000 milliseconds is given, 95% of the values fall between
|
|
4859ms-5141ms in 1ms increments (not enough time variance). Providing 1/4
|
|
seconds would yield 95% of the values between 3s-7.25s in 1/4s
|
|
increments. */
|
|
|
|
//! Generate random durations with 1 second precision
|
|
using random_poisson_seconds = random_poisson_duration<std::chrono::seconds>;
|
|
//! Generate random duration with 1/4 second precision
|
|
using random_poisson_subseconds =
|
|
random_poisson_duration<std::chrono::duration<std::chrono::milliseconds::rep, std::ratio<1, 4>>>;
|
|
}
|