sl@0: /*
sl@0: * Copyright (c) 2004-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: * All rights reserved.
sl@0: * This component and the accompanying materials are made available
sl@0: * under the terms of the License "Eclipse Public License v1.0"
sl@0: * which accompanies this distribution, and is available
sl@0: * at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: *
sl@0: * Initial Contributors:
sl@0: * Nokia Corporation - initial contribution.
sl@0: *
sl@0: * Contributors:
sl@0: *
sl@0: * Description: 
sl@0: *
sl@0: */
sl@0: 
sl@0: 
sl@0: /**
sl@0:  @file 
sl@0:  @internalTechnology
sl@0: */
sl@0:  
sl@0: #ifndef __NullStream_h__
sl@0: #define __NullStream_h__
sl@0: 
sl@0: #include <s32strm.h>
sl@0: #include <s32buf.h>
sl@0: 
sl@0: /**
sl@0:  * Implementation of the MStreamBuf interface that throws away all data written
sl@0:  * to it.  It does not support reading.
sl@0:  */
sl@0: 
sl@0: class TNullBuf : public MStreamBuf
sl@0: 	{
sl@0: public:
sl@0: 	TNullBuf();
sl@0: 	TUint BytesWritten();
sl@0: private:
sl@0: 	virtual void DoWriteL(const TAny* aPtr,TInt aLength);
sl@0: private:
sl@0: 	TUint iBytesWritten;
sl@0: 	}; 
sl@0: 
sl@0: /**
sl@0:  * A write stream that throws away all its input, but keeps track of how many
sl@0:  * bytes have been written to it.  It is used for determining the amount of
sl@0:  * memory needed to store externalised objects.
sl@0:  */
sl@0: 
sl@0: class RNullWriteStream : public RWriteStream
sl@0: 	{
sl@0: public:
sl@0: 	RNullWriteStream();
sl@0: 	TUint BytesWritten();
sl@0: private:
sl@0: 	TNullBuf iSink;
sl@0: 	};
sl@0: 
sl@0: #endif