// Copyright (c) 1998-2009 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:

//

#include "US_STD.H"

EXPORT_C RShareBuf::RShareBuf()

	: iHost(NULL)

/** Constructs an empty shared stream buffer object.

Call one of the Open() functions to prepare the stream. */

	{}

EXPORT_C void RShareBuf::Open(TStreamExchange& aHost,TStreamPos aPos,TInt aMode)

/** Prepares the shared stream buffer for streaming.

The function sets the read mark and/or the write mark to the specified position 

within the host stream.

@param aHost The object that manages shared streaming.

@param aPos The position within the host stream.

@param aMode The streaming mode. This can be read and/or write, as indicated 

by the ERead and EWrite bits.

@see MStreamBuf::TRead

@see MStreamBuf::TWrite */

	{

	iHost=&aHost;

	if (aMode&ERead)

		iRMark=aPos;

	else

		iRMark.Clear();

	if (aMode&EWrite)

		iWMark=aPos;

	else

		iWMark.Clear();

	}

EXPORT_C void RShareBuf::DoRelease()

//

// Withdraw this stream buffer's marks.

//

	{

	if (iHost!=NULL)

		{

		TStreamExchange& host=*iHost;

		iRMark.Withdraw(host);

		iWMark.Withdraw(host);

		iHost=NULL;

		}

	}

EXPORT_C TInt RShareBuf::DoReadL(TAny* aPtr,TInt aMaxLength)

//

// Read up to aMaxLength bytes.

//

	{

	return iRMark.ReadL(Host(),aPtr,aMaxLength);

	}

EXPORT_C TInt RShareBuf::DoReadL(TDes8& aDes,TInt aMaxLength,TRequestStatus& aStatus)

//

// Read up to aMaxLength bytes asynchronously.

//

	{

	return iRMark.ReadL(Host(),aDes,aMaxLength,aStatus);

	}

EXPORT_C TStreamTransfer RShareBuf::DoReadL(MStreamInput& anInput,TStreamTransfer aTransfer)

//

// Push up to aTransfer bytes into anInput.

//

	{

	return iRMark.ReadL(Host(),anInput,aTransfer);

	}

EXPORT_C void RShareBuf::DoWriteL(const TAny* aPtr,TInt aLength)

//

// Write aLength bytes.

//

	{

	iWMark.WriteL(Host(),aPtr,aLength);

	}

EXPORT_C TInt RShareBuf::DoWriteL(const TDesC8& aDes,TInt aMaxLength,TRequestStatus& aStatus)

//

// Write up to aMaxLength bytes asynchronously.

//

	{

	return iWMark.WriteL(Host(),aDes,aMaxLength,aStatus);

	}

EXPORT_C TStreamTransfer RShareBuf::DoWriteL(MStreamOutput& anOutput,TStreamTransfer aTransfer)

//

// Pull up to aTransfer bytes from anOutput.

//

	{

	return iWMark.WriteL(Host(),anOutput,aTransfer);

	}

EXPORT_C TStreamPos RShareBuf::DoSeekL(TMark aMark,TStreamLocation aLocation,TInt anOffset)

//

// Position the mark(s) indicated by aMark at anOffset from aLocation.

//

	{

	TStreamExchange& host=Host();

	if (!aMark)

		{

		TStreamMark mark;

		return mark.SeekL(host,aLocation,anOffset);

		}

//

	__ASSERT_ALWAYS(!(aMark&~(ERead|EWrite)),Panic(EStreamMarkInvalid));

	TStreamPos pos(0);

	if (aMark&ERead)

		{

		__ASSERT_ALWAYS(aLocation!=EStreamMark||aMark==ERead,Panic(EStreamMarkInvalid));

		if (!iRMark.RelatesTo(host))

			__LEAVE(KErrNotReady);

//

		pos=iRMark.SeekL(host,aLocation,anOffset);

		}

	if (aMark&EWrite)

		{

		if (!iWMark.RelatesTo(host))

			__LEAVE(KErrNotReady);

//

		TStreamPos p=iWMark.SeekL(host,aLocation,anOffset);

		__ASSERT_DEBUG(aMark==EWrite||p==pos,User::Invariant());

		return p;

		}

//

	return pos;

	}

EXPORT_C RShareReadStream::RShareReadStream(TStreamExchange& aHost,TStreamPos aPos)

/** Constructs the shared read stream object and prepares the shared stream for 

reading.

@param aHost The object that manages shared streaming.

@param aPos The position of the stream within the host stream. Defaults to 

the beginning of the host stream, if not explicitly specified.

@see KStreamBeginning */

	{

	Open(aHost,aPos);

	}

EXPORT_C void RShareReadStream::Open(TStreamExchange& aHost,TStreamPos aPos)

/** Prepares the shared stream for reading.

@param aHost The object that manages shared streaming.

@param aPos The position of the stream within the host stream. Defaults to 

the beginning of the host stream, if not explicitly specified. */

	{

	iSource.Open(aHost,aPos,iSource.ERead);

	RReadStream::Attach(&iSource);

	}

EXPORT_C RShareWriteStream::RShareWriteStream(TStreamExchange& aHost,TStreamPos aPos)

/** Constructs the shared write stream object and prepares the shared stream for 

writing.

@param aHost The object that manages shared streaming.

@param aPos The position of the stream within the host stream. Defaults to 

the beginning of the host stream, if not explicitly specified.

@see KStreamBeginning */

	{

	Open(aHost,aPos);

	}

EXPORT_C void RShareWriteStream::Open(TStreamExchange& aHost,TStreamPos aPos)

/** Prepares the shared stream for writing.

@param aHost The object that manages shared streaming.

@param aPos The position of the stream within the host stream. Defaults to 

the beginning of the host stream, if not explicitly specified. */

	{

	iSink.Open(aHost,aPos,iSink.EWrite);

	RWriteStream::Attach(&iSink);

	}