58 lines
2.4 KiB
C++
58 lines
2.4 KiB
C++
/*
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* Copyright (C) 2020 Apple Inc. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
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* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
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* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "config.h"
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#include "FrameRateMonitor.h"
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namespace WebCore {
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static constexpr Seconds MinimumAverageDuration = 1_s;
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static constexpr Seconds MaxQueueDuration = 2_s;
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static constexpr unsigned MaxFrameDelayCount = 3;
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void FrameRateMonitor::update()
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{
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++m_frameCount;
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auto frameTime = MonotonicTime::now().secondsSinceEpoch().value();
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auto lastFrameTime = m_observedFrameTimeStamps.isEmpty() ? frameTime : m_observedFrameTimeStamps.last();
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if (m_observedFrameRate) {
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auto maxDelay = MaxFrameDelayCount / m_observedFrameRate;
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if ((frameTime - lastFrameTime) > maxDelay)
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m_lateFrameCallback({ MonotonicTime::fromRawSeconds(frameTime), MonotonicTime::fromRawSeconds(lastFrameTime) });
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}
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m_observedFrameTimeStamps.append(frameTime);
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m_observedFrameTimeStamps.removeAllMatching([&](auto time) {
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return time <= frameTime - MaxQueueDuration.value();
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});
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auto queueDuration = m_observedFrameTimeStamps.last() - m_observedFrameTimeStamps.first();
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if (queueDuration > MinimumAverageDuration.value())
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m_observedFrameRate = (m_observedFrameTimeStamps.size() / queueDuration);
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}
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}
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