/*
    KWin - the KDE window manager
    This file is part of the KDE project.

    SPDX-FileCopyrightText: 2006 Lubos Lunak <l.lunak@kde.org>
    SPDX-FileCopyrightText: 2009, 2010, 2011 Martin Gräßlin <mgraesslin@kde.org>

    SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "swap_profiler.h"
#include <logging.h>

namespace KWin
{

SwapProfiler::SwapProfiler()
{
    init();
}

void SwapProfiler::init()
{
    m_time = 2 * 1000*1000; // we start with a long time mean of 2ms ...
    m_counter = 0;
}

void SwapProfiler::begin()
{
    m_timer.start();
}

char SwapProfiler::end()
{
    // .. and blend in actual values.
    // this way we prevent extremes from killing our long time mean
    m_time = (10*m_time + m_timer.nsecsElapsed())/11;
    if (++m_counter > 500) {
        const bool blocks = m_time > 1000 * 1000; // 1ms, i get ~250µs and ~7ms w/o triple buffering...
        qCDebug(KWIN_OPENGL) << "Triple buffering detection:" << QString(blocks ? QStringLiteral("NOT available") : QStringLiteral("Available")) <<
                        " - Mean block time:" << m_time/(1000.0*1000.0) << "ms";
        return blocks ? 'd' : 't';
    }
    return 0;
}

}