Seth Hillbrand
b404b30fb9
Initializing m_last to time_point::min() causes signed integer overflow when computing now - m_last, since the nanosecond difference exceeds int64_t range. Initialize to now - interval instead so the first Ready() call passes naturally.
65 lines
2.0 KiB
C++
65 lines
2.0 KiB
C++
/*
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* This program source code file is part of KiCad, a free EDA CAD application.
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*
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* Copyright The KiCad Developers, see AUTHORS.txt for contributors.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, you may find one here:
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* http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
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* or you may search the http://www.gnu.org website for the version 2 license,
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* or you may write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
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*/
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#pragma once
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#include <chrono>
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/**
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* Rate-limiter that fires at most once per interval.
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*
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* The first call to Ready() always returns true so callers can emit an
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* initial update immediately.
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*/
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class THROTTLE
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{
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public:
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explicit THROTTLE( std::chrono::milliseconds aInterval ) :
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m_interval( aInterval ),
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m_last( std::chrono::steady_clock::now() - aInterval )
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{
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}
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/**
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* @return true when at least \a m_interval has elapsed since the previous
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* true return (or since construction). Resets the internal clock
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* on a true return.
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*/
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bool Ready()
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{
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auto now = std::chrono::steady_clock::now();
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if( now - m_last >= m_interval )
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{
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m_last = now;
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return true;
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}
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return false;
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}
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private:
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std::chrono::milliseconds m_interval;
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std::chrono::steady_clock::time_point m_last;
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};
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