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#ifndef QWINDOWSPIPEWRITER_P_H
#define QWINDOWSPIPEWRITER_P_H

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//

#include <QtCore/private/qglobal_p.h>
#include <qelapsedtimer.h>
#include <qobject.h>
#include <qbytearray.h>
#include <qt_windows.h>

QT_BEGIN_NAMESPACE

#define SLEEPMIN 10
#define SLEEPMAX 500

class QIncrementalSleepTimer
{

public:
    QIncrementalSleepTimer(int msecs)
        : totalTimeOut(msecs)
        , nextSleep(qMin(SLEEPMIN, totalTimeOut))
    {
        if (totalTimeOut == -1)
            nextSleep = SLEEPMIN;
        timer.start();
    }

    int nextSleepTime()
    {
        int tmp = nextSleep;
        nextSleep = qMin(nextSleep * 2, qMin(SLEEPMAX, timeLeft()));
        return tmp;
    }

    int timeLeft() const
    {
        if (totalTimeOut == -1)
            return SLEEPMAX;
        return qMax(int(totalTimeOut - timer.elapsed()), 0);
    }

    bool hasTimedOut() const
    {
        if (totalTimeOut == -1)
            return false;
        return timer.elapsed() >= totalTimeOut;
    }

    void resetIncrements()
    {
        nextSleep = qMin(SLEEPMIN, timeLeft());
    }

private:
    QElapsedTimer timer;
    int totalTimeOut;
    int nextSleep;
};

class Q_CORE_EXPORT QWindowsPipeWriter : public QObject
{
    Q_OBJECT
public:
    explicit QWindowsPipeWriter(HANDLE pipeWriteEnd, QObject *parent = nullptr);
    ~QWindowsPipeWriter();

    bool write(const QByteArray &ba);
    void stop();
    bool waitForWrite(int msecs);
    bool isWriteOperationActive() const { return writeSequenceStarted; }
    qint64 bytesToWrite() const;

Q_SIGNALS:
    void canWrite();
    void bytesWritten(qint64 bytes);
    void _q_queueBytesWritten(QPrivateSignal);

private:
    static void CALLBACK writeFileCompleted(DWORD errorCode, DWORD numberOfBytesTransfered,
                                            OVERLAPPED *overlappedBase);
    void notified(DWORD errorCode, DWORD numberOfBytesWritten);
    bool waitForNotification(int timeout);
    void emitPendingBytesWrittenValue();

    class Overlapped : public OVERLAPPED
    {
        Q_DISABLE_COPY_MOVE(Overlapped)
    public:
        explicit Overlapped(QWindowsPipeWriter *pipeWriter);
        void clear();

        QWindowsPipeWriter *pipeWriter;
    };

    HANDLE handle;
    Overlapped overlapped;
    QByteArray buffer;
    qint64 pendingBytesWrittenValue;
    bool stopped;
    bool writeSequenceStarted;
    bool notifiedCalled;
    bool bytesWrittenPending;
    bool inBytesWritten;
};

QT_END_NAMESPACE

#endif // QWINDOWSPIPEWRITER_P_H
