/****************************************************************************

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** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

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** This file contains pre-release code and may not be distributed.

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** contained in the Technology Preview License Agreement accompanying

** this package.

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** 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

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****************************************************************************/

#ifndef QHOSTINFO_P_H

#define QHOSTINFO_P_H

//

//  W A R N I N G

//  -------------

//

// This file is not part of the Qt API.  It exists for the convenience

// of the QHostInfo class.  This header file may change from

// version to version without notice, or even be removed.

//

// We mean it.

//

#include "QtCore/qcoreapplication.h"

#include "private/qcoreapplication_p.h"

#include "QtNetwork/qhostinfo.h"

#include "QtCore/qmutex.h"

#include "QtCore/qwaitcondition.h"

#include "QtCore/qobject.h"

#include "QtCore/qpointer.h"

#if !defined QT_NO_THREAD

#include "QtCore/qthread.h"

#    define QHostInfoAgentBase QThread

#else

#    define QHostInfoAgentBase QObject

#endif

QT_BEGIN_NAMESPACE

static const int QHOSTINFO_THREAD_WAIT = 250; // ms

class QHostInfoResult : public QObject

{

    Q_OBJECT

public Q_SLOTS:

    inline void emitResultsReady(const QHostInfo &info)

    {

        emit resultsReady(info);

        if (autoDelete)

            delete this;

    }

Q_SIGNALS:

    void resultsReady(const QHostInfo &info);

public:

    int lookupId;

    bool autoDelete;

};

struct QHostInfoQuery

{

    inline QHostInfoQuery() : object(0) {}

    inline ~QHostInfoQuery() { delete object; }

    inline QHostInfoQuery(const QString &name, QHostInfoResult *result)

        : hostName(name), object(result) {}

    QString hostName;

    QHostInfoResult *object;

};

class QHostInfoAgent : public QHostInfoAgentBase

{

    Q_OBJECT

public:

    inline QHostInfoAgent()

    {

        // There is a chance that there will be two instances of

        // QHostInfoAgent if two threads try to get Q_GLOBAL_STATIC

        // object at the same time. The second object will be deleted

        // immediately before anyone uses it, but we need to be

        // careful about what we do in the constructor.

        static QBasicAtomicInt done = Q_BASIC_ATOMIC_INITIALIZER(0);

        if (done.testAndSetRelaxed(0, 1))

            qAddPostRoutine(staticCleanup);

        moveToThread(QCoreApplicationPrivate::mainThread());

        quit = false;

        pendingQueryId = -1;

    }

    inline ~QHostInfoAgent()

    { cleanup(); }

    void run();

    static QHostInfo fromName(const QString &hostName);

    inline void addHostName(const QString &name, QHostInfoResult *result)

    {

        QMutexLocker locker(&mutex);

        queries << new QHostInfoQuery(name, result);

        cond.wakeOne();

    }

    inline void abortLookup(int id)

    {

        QMutexLocker locker(&mutex);

        for (int i = 0; i < queries.size(); ++i) {

            QHostInfoResult *result = queries.at(i)->object;

            if (result->lookupId == id) {

                result->disconnect();

                delete queries.takeAt(i);

                return;

            }

        }

        if (pendingQueryId == id)

            pendingQueryId = -1;

    }

    static void staticCleanup();

public Q_SLOTS:

    inline void cleanup()

    {

        {

            QMutexLocker locker(&mutex);

            qDeleteAll(queries);

            queries.clear();

            quit = true;

            cond.wakeOne();

        }

#ifndef QT_NO_THREAD

        if (!wait(QHOSTINFO_THREAD_WAIT))

            terminate();

        wait();

#endif

    }

private:

    QList<QHostInfoQuery *> queries;

    QMutex mutex;

    QWaitCondition cond;

    volatile bool quit;

    int pendingQueryId;

};

class QHostInfoPrivate

{

public:

    inline QHostInfoPrivate()

        : err(QHostInfo::NoError),

          errorStr(QLatin1String(QT_TRANSLATE_NOOP("QHostInfo", "Unknown error"))),

          lookupId(0)

    {

    }

    QHostInfo::HostInfoError err;

    QString errorStr;

    QList<QHostAddress> addrs;

    QString hostName;

    int lookupId;

};

QT_END_NAMESPACE

#endif // QHOSTINFO_P_H