/****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the Qt Mobility Components.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
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** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
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** rights.  These rights are described in the Digia Qt LGPL Exception
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** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
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****************************************************************************/

#include "performance.h"

/************************** time measurement **************************/

#ifdef Q_OS_WIN32

static double QueryPerformanceFrequency_wrapper()
{
    LARGE_INTEGER freq;

    Q_ASSERT(QueryPerformanceFrequency(&freq));

    return static_cast<double>(freq.QuadPart);
}

double ticksPerSecond = QueryPerformanceFrequency_wrapper();

perf_t perf_currentTime()
{
    LARGE_INTEGER ret;

    Q_ASSERT(QueryPerformanceCounter(&ret));

    return ret;
}

double perf_diffTime(perf_t start, perf_t end)
{
    return (end.QuadPart - start.QuadPart) / ticksPerSecond;
}

quint64 perf_diffTimeNative(perf_t start, perf_t end)
{
    return end.QuadPart - start.QuadPart;
}

#else

perf_t perf_currentTime()
{
    return QTime::currentTime();
}

double perf_diffTime(perf_t start, perf_t end)
{
    return start.msecsTo(end) / 1000.0;
}

quint64 perf_diffTimeNative(perf_t start, perf_t end)
{
    return start.msecsTo(end);
}

#endif

/************************** memory consumption **************************/

#ifdef Q_OS_WIN32

#include <psapi.h>

quint64 perf_currentMemUsage()
{
    PROCESS_MEMORY_COUNTERS pmc;

    BOOL success = GetProcessMemoryInfo(GetCurrentProcess(), &pmc, sizeof(pmc));

    if (!success)
        return -1;

    return pmc.WorkingSetSize;
}

#else
#ifdef Q_OS_LINUX

#include <cstdio>

quint64 perf_currentMemUsage()
{
    FILE * statm = std::fopen("/proc/self/statm", "r");
    long long ret = -1;
    std::fscanf(statm, "%Lu", &ret);
    std::fclose(statm);
    return ret*1024;
}

#else
#ifdef Q_OS_MAC

#include <malloc/malloc.h>

quint64 perf_currentMemUsage()
{
    malloc_statistics_t stats;

    malloc_zone_statistics(NULL, &stats);

    return stats.size_allocated; // maybe t.size_in_use?
}

#else
#if  _BSD_SOURCE || _SVID_SOURCE || (_XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED) && !(_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600)


#include <unistd.h>

static char * sbrk_0_initial = (char*)sbrk(0);

quint64 perf_currentMemUsage()
{
    return (char*)sbrk(0)-sbrk_0_initial;
}

#else
quint64 perf_currentMemUsage()
{
    return 0;
}

#endif
#endif
#endif
#endif

/* TODO:
    mem
        - more platforms!
            - mac: malloc_zone_statistics
            -
    leaks?
        - boehm gc
*/