// Copyright (c) 1997-2009 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:

// MBuf Stream Queue

// 

//

#include <nifmbuf.h>

//

// MBuf Stream Queues

//

EXPORT_C RMBufStreamQ::RMBufStreamQ()

/**

Constructor

*/

 	{

	iPosition = -1; iMBuf = NULL;

	}

EXPORT_C void RMBufStreamQ::CopyOut(TDes8& aDes)

/**

Copies a data from the chain to a TDes8 buffer

@param aDes the buffer where the data is copied to

*/

 	{

	AsRMBufChain().CopyOut(aDes);

	}

EXPORT_C void RMBufStreamQ::TrimStart(TInt aOffset)

/**

Trims the data upto offset 

@param aOffset the offset

*/

	{

	AsRMBufChain().TrimStart(aOffset);

	if (iNext==NULL)

		{

		iLast = NULL;

		iPosition = -1;

		}

	else

		{

		iPosition -= aOffset;

		}

	}

EXPORT_C void RMBufStreamQ::Append(RMBufChain& aPacket)

/**

Appends a MBuf chain to this stream

@param aPacket the MBuf chain

*/

 	{

	if (iPosition>=0 && iMBuf==NULL)

		{

		RMBuf* m = iLast;

		RMBufQ::Append(aPacket);

		if (m!=NULL && (m = m->Next(), m!=NULL))

			{

			iMBuf = m;

			iOffset = m->Offset();

			iLength = m->Length();

			}

		}

	else

		RMBufQ::Append(aPacket);

	}

EXPORT_C void RMBufStreamQ::CopySegmentL(RMBufChain& aNewChain, TInt aOffset, TInt aLen/*, const TDesC8* aDes*/)

/**

Copies a segment to a MBuf chain

Functionaly the similar to RMBufChain::CopyL, except that cache pointer

information is updated to optimise the common case of each extraction

following on from the previous call.

@param aNewChain the chain to be created

@param aOffset the offset

@param aLen the length

*/

	{

	TInt n, n1, n2;

	TUint8* p1, *p2;

	RMBuf* m1, *m2;

	// Locate offset into stream queue

	if (aOffset>0)

		{

		if (aOffset!=iPosition || iMBuf==NULL)

			{

			TInt o = aOffset;

			RMBuf* m = iNext;

			while (m!=NULL && o>=m->Length())

				{

				o -= m->Length();

				m = m->Next();

				}

			if (!m)

				{

				User::Leave(KErrOverflow);

				}

			iPosition = aOffset;

			iMBuf = m;

			iOffset = o + m->Offset();

			iLength = m->Length() - o;

			}

		m1 = iMBuf;		

		n = iOffset;		

		n1 = iLength;

		p1 = m1->Buffer()+n;

		}

	else

		{

		m1 = iNext;

		p1 = m1->Ptr();

		n1 = m1->Length();

		}

	TInt len = aLen;

	aNewChain.AllocL(len);

	m2 = aNewChain.First();

	p2 = m2->Ptr();

	n2 = m2->Length();

	while (len>0)

		{

		n = n1 < n2 ? n1 : n2;

		Mem::Copy(p2, p1, n);

		if (n1 -= n, n1 == 0)

			{

			if (m1 = m1->Next(), m1==NULL)

				break;

			p1 = m1->Ptr();

			n1 = m1->Length();

			}

		else

			p1 += n;

		if (n2 -= n, n2 == 0)

			{

			if (m2 = m2->Next(), m2==NULL)

				break;

			p2 = m2->Ptr();

			n2 = m2->Length();

			}

		else

			p2 += n;

		len -= n;

		}

	if (m1)

		{

		iPosition = aOffset+aLen;	

		iMBuf = m1;

		iOffset = p1-m1->Buffer();

		iLength = n1;

		}

	else

		{

		iPosition = aOffset+aLen;	

		iMBuf = NULL;	

		}

	}