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

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of the License "Symbian Foundation License v1.0" to Symbian Foundation members and "Symbian Foundation End User License Agreement v1.0" to non-members

// which accompanies this distribution, and is available

// at the URL "http://www.symbianfoundation.org/legal/licencesv10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

// tcpseq.h - TCP sequence numbers

// This module defines a TCP sequence number with mod32 arithmetic.

//

/**

 @file tcpseq.h

 @publishedAll

 @released

*/

#ifndef __TCPSEQ_H__

#define __TCPSEQ_H__

#include <e32std.h>

/**  TCP sequence number with mod-32 arithmetic.

@publishedAll

@released

*/

class TTcpSeqNum

	{

public:

  	inline TTcpSeqNum()					  			{ iSeq = 0; }

  	inline TTcpSeqNum(TUint32 aSeq)			  		{ iSeq = aSeq; }

  	inline TTcpSeqNum(const TTcpSeqNum& aSeq)		{ iSeq = aSeq.iSeq; }

  	inline TTcpSeqNum& operator=(TUint32 aSeq)		  { iSeq = aSeq; return *this; }

  	inline TTcpSeqNum& operator=(const TTcpSeqNum& aSeq)	  { iSeq = aSeq.iSeq; return *this; }

  	inline TTcpSeqNum& operator+=(TInt aOff)		  { iSeq += aOff; return *this; }

  	inline TTcpSeqNum& operator-=(TInt aOff)		  { iSeq -= aOff; return *this; }

  	inline TTcpSeqNum& operator++()			{ ++iSeq; return *this; }

  	inline TTcpSeqNum operator++(TInt)		{ return iSeq++; }

  	inline TTcpSeqNum& operator--()			{ --iSeq; return *this; }

  	inline TTcpSeqNum operator--(TInt)		{ return iSeq--; }

  	inline TBool operator==(const TTcpSeqNum& aSeq) const	{ return iSeq == aSeq.iSeq; }

  	inline TBool operator!=(const TTcpSeqNum& aSeq) const	{ return iSeq != aSeq.iSeq; }

  	inline TBool operator<(const TTcpSeqNum& aSeq) const	{ return (TInt32)(iSeq - aSeq.iSeq) < 0; }

  	inline TBool operator<=(const TTcpSeqNum& aSeq) const	{ return (TInt32)(iSeq - aSeq.iSeq) <= 0; }

  	inline TBool operator>(const TTcpSeqNum& aSeq) const	{ return (TInt32)(iSeq - aSeq.iSeq) > 0; }

  	inline TBool operator>=(const TTcpSeqNum& aSeq) const	{ return (TInt32)(iSeq - aSeq.iSeq) >= 0; }

  	inline TTcpSeqNum operator+(TInt aOff) const		  	{ return iSeq + aOff; }

  	inline TTcpSeqNum operator-(TInt aOff) const		  	{ return iSeq - aOff; }

  	inline TInt32 operator-(const TTcpSeqNum& aSeq) const   { return iSeq - aSeq.iSeq; }

  	//

  	// Automatic typecast can lead to ambiguous expressions and

  	// in the worst case to some very hard-to-track errors.

  	// We use the following explicit typecast instead. -ML

  	//

  	inline TUint32 Uint32() const				  { return iSeq; }

	//inline operator TUint32() const			  { return iSeq; }

  	// Methods for checking whether a sequence number is inside or outside a given window.

  	inline TBool Inside(TTcpSeqNum aSeqLo, TTcpSeqNum aSeqHi)

    	{ return (iSeq - aSeqLo.iSeq) <= (aSeqHi.iSeq - aSeqLo.iSeq); }

  	inline TBool Outside(TTcpSeqNum aSeqLo, TTcpSeqNum aSeqHi)

    	{ return (iSeq - aSeqLo.iSeq) > (aSeqHi.iSeq - aSeqLo.iSeq); }

private:

  	TUint32 iSeq;

	};

#endif