/****************************************************************************
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** Copyright (C) 2013 Klaralvdalens Datakonsult AB (KDAB)
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****************************************************************************/

#include "kdlockfile.h"
#include "kdlockfile_p.h"

#include <QtCore/QCoreApplication>
#include <QtCore/QFileInfo>

KDLockFile::Private::~Private()
{
    unlock();
}

bool KDLockFile::Private::lock()
{
    const QFileInfo fi(filename);
    handle = CreateFile(filename.toStdWString().data(),
                        GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ,
                        NULL, fi.exists() ? OPEN_EXISTING : CREATE_NEW,
                        FILE_ATTRIBUTE_HIDDEN | FILE_ATTRIBUTE_TEMPORARY | FILE_FLAG_DELETE_ON_CLOSE, NULL);

    if (!handle)
        return false;
    QString pid = QString::number(qApp->applicationPid());
    QByteArray data = pid.toLatin1();
    DWORD bytesWritten;
    const bool wrotePid = WriteFile(handle, data.data(), data.size(), &bytesWritten, NULL);
    if (!wrotePid)
        return false;
    FlushFileBuffers(handle);

    const bool locked = LockFile(handle, 0, 0, fi.size(), 0);

    this->locked = locked;
    return locked;
}

bool KDLockFile::Private::unlock()
{
    const QFileInfo fi(filename);
    if (locked) {
        const bool success = UnlockFile(handle, 0, 0, 0, fi.size());
        this->locked = !success;
        CloseHandle(handle);
        return success;
    }
    return true;
}