// Copyright (c) 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: Chain of shared buffers

//

// Description:

//

#ifndef __COMMSBUFCHAIN_H__

#define __COMMSBUFCHAIN_H__

#include <e32base.h>

class TCommsBufAllocator;

class RCommsBuf;

/*

Chain of RCommsBufs. 

@publishedPartner

**/

class RCommsBufChain

	{

	friend class TCommsBufIter;

	friend class RCommsBufQ;

	public:

	inline RCommsBufChain();

	inline RCommsBufChain(RCommsBuf* aHeadBuf);

	inline TBool IsEmpty() const;

	IMPORT_C TInt Length() const;

	IMPORT_C void Assign(RCommsBufChain& aChain);

	IMPORT_C void Append(RCommsBufChain& aChain);

	IMPORT_C void Append(RCommsBuf* aBuf);

	IMPORT_C TInt Append(TInt aLen);

	IMPORT_C void Prepend(RCommsBufChain& aChain);

	IMPORT_C void Prepend(RCommsBuf* aBuf);

	IMPORT_C TInt Prepend(TInt aLen);

	IMPORT_C TInt Alloc(TInt aSize, TCommsBufAllocator& aAccessor);

	IMPORT_C TInt Alloc(TInt aSize, TInt aMinBufSize, TCommsBufAllocator& aAccessor);

	IMPORT_C TInt Alloc(TInt aSize, TInt aMinBufSize, TInt aMaxBufSize, TCommsBufAllocator& aAccessor);

	IMPORT_C TInt Split(TInt aOffset, RCommsBufChain& aNewChain);

	IMPORT_C TInt Align(TInt aSize);

	IMPORT_C void Write(const TDesC8& aDes, TInt aOffset =0);

	IMPORT_C void Read(TDes8& aDes, TInt aOffset =0) const;

	IMPORT_C void Free(); // Free the chain.

	IMPORT_C void TrimStart(TInt nBytes);

	IMPORT_C void TrimEnd(TInt anOffset);

	protected:

	IMPORT_C RCommsBuf* Goto(TInt aDataOffset, TInt& aBufDataOffset, TInt& aBufDataLen, RCommsBuf* &resPrevBuf) const;

	inline RCommsBuf* Goto(TInt aDataOffset, TInt& aBufDataOffset, TInt& aBufDataLen) const;

	IMPORT_C RCommsBuf* Last() const;

	private:

	inline RCommsBuf* First();

	inline const RCommsBuf* First() const;

	RCommsBuf* Last();

	protected:

	RCommsBuf*	iNext;

	};

#include <comms-infras/commsbufchain.inl>

#endif // __COMMSBUFCHAIN_H__