/*

* Copyright (c) 2006 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:   The header file of DevTokenNullStream

*

*/

#ifndef __DEVTOKENNULLSTREAM_H__

#define __DEVTOKENNULLSTREAM_H__

#include <s32strm.h>

#include <s32buf.h>

/**

 * Implementation of the MStreamBuf interface that throws away all data written

 * to it.  It does not support reading

 *

 *  @lib DevTokenShared.dll

 *  @since S60 v3.2.

 */

class TNullBuf : public MStreamBuf

    {

    public:

        TNullBuf();

        TUint BytesWritten();

    private:

        virtual void DoWriteL(const TAny* aPtr,TInt aLength);

    private:

        TUint iBytesWritten;

    }; 

/**

 * A write stream that throws away all its input, but keeps track of how many

 * bytes have been written to it.  It is used for determining the amount of

 * memory needed to store externalised objects.

 * 

 *  @lib DevTokenShared.dll

 *  @since S60 v3.2.

 */

class RNullWriteStream : public RWriteStream

    {

    public:

        RNullWriteStream();

        TUint BytesWritten();

    private:

        TNullBuf iSink;

    };

#endif //__DEVTOKENNULLSTREAM_H__

//EOF