file_in_use_backoff.h

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/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright The KiCad Developers, see AUTHORS.txt for contributors.
 *
 * This program 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 of the License, or (at your
 * option) any later version.
 *
 * This program 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 
#ifndef KICAD_FILE_IN_USE_BACKOFF_H
#define KICAD_FILE_IN_USE_BACKOFF_H
 
#include <algorithm>
#include <chrono>
#include <random>

inline std::chrono::milliseconds FileInUseBackoff( int aAttempt, std::minstd_rand& aRng )
{
    constexpr long long FIRST_WAIT_MS = 100;
    constexpr int       MAX_DOUBLINGS = 4;
 
    const long long ceiling = FIRST_WAIT_MS << std::clamp( aAttempt, 0, MAX_DOUBLINGS );
 
    std::uniform_int_distribution<long long> spread( ceiling / 2, ceiling );
 
    return std::chrono::milliseconds( spread( aRng ) );
}
 
#endif // KICAD_FILE_IN_USE_BACKOFF_H