1 /*

     2 * Copyright (c) 2004-2009 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

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

     6 * which accompanies this distribution, and is available

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

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description: 

    15 *

    16 */

    17 

    18 

    19 

    20 

    21 /**

    22  @file 

    23  @internalTechnology

    24 */

    25  

    26 #ifndef __NullStream_h__

    27 #define __NullStream_h__

    28 

    29 #include <s32strm.h>

    30 #include <s32buf.h>

    31 

    32 /**

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

    34  * to it.  It does not support reading.

    35  */

    36 

    37 class TNullBuf : public MStreamBuf

    38 	{

    39 public:

    40 	TNullBuf();

    41 	TUint BytesWritten();

    42 private:

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

    44 private:

    45 	TUint iBytesWritten;

    46 	}; 

    47 

    48 /**

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

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

    51  * memory needed to store externalised objects.

    52  */

    53 

    54 class RNullWriteStream : public RWriteStream

    55 	{

    56 public:

    57 	RNullWriteStream();

    58 	TUint BytesWritten();

    59 private:

    60 	TNullBuf iSink;

    61 	};

    62 

    63 #endif