/*

* Copyright (c) 2005 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:    

*

*/

#ifndef C_CTRANSACTIONIDGENERATOR_H

#define C_CTRANSACTIONIDGENERATOR_H

// INCLUDES

#include <e32base.h>

#include "natfwunsaftransactionid.h"

// FORWARD DECLARATIONS

// CLASS DECLARATION

/**

 *  This class provides unique UNSAF TransactionID values. 

 */

class CTransactionIDGenerator : public CBase

    {

    public: // Constructors and destructor

        /**

        * Creates a new instance of CTransactionIDGenerator.        

        * @return A new instance of CTransactionIDGenerator, ownership is

        *    transferred.

        */

        static CTransactionIDGenerator* NewL();

        ~CTransactionIDGenerator();

    public: // New functions

        /**

        * Creates a unique UNSAF TransactionID and writes it into

        * aTransactionID.

        *

        * @param aObject IN: Pointer to an object, whose state will be used as a

        *         random input for creating the UNSAF TransactionID.

        *         Ownership is not transferred.

        * @param aObjectSize Size in bytes, of the object pointed by aObject.

        * @param aTransactionID OUT: UNSAF TransactionID

        */

        void GetIDL( TAny* aObject,

                     TInt aObjectSize,

                     TNATFWUNSAFTransactionID& aTransactionID );

    private:

        CTransactionIDGenerator();

        CTransactionIDGenerator(

            const CTransactionIDGenerator& aTransactionIDGenerator );

        HBufC8* BuildInputDataLC( TAny* aObject, TInt aObjectSize );

        void AddClockInfo( TDes8& aBuf ) const;

        void AddSystemInfo( TDes8& aBuf ) const;

        void ComputeChecksum( TDes8& aBuf,

                              const TAny* aPtr,

                              TInt aLength ) const;

    private: // Data

        //Seed value for Math::Rand()

        TInt64 iSeed;

        TUint32 iCounter;

    private: // For testing purposes

#ifdef TEST_EUNIT

        friend class CSTUNClientImplementationTest;

#endif

        __DECLARE_TEST;

    };

#endif // C_CTRANSACTIONIDGENERATOR_H