/*

* 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:

*

* Description: Logic for bufferred publish and subcribe notifier

*

*/

#ifndef C_SPSBUFFEREDPUBLISHER_H

#define C_SPSBUFFEREDPUBLISHER_H

#include <e32base.h>

/**

 *  P&S ringbuffer implementation

 *  

 *  Ringbuffer size is 127 TUint32:s

 *

 *  @code

 *   Publisher:

 *      CSpsBufferedPublisher::SetL( KCategory, KKey, data );

 *   

 *   Subscriber:

 *      - start to fill buffer

 *        iMember = CSpsBufferedPublisher::NewL( KCategory, KKey );

 *        iMember->Start();

 *        

 *      - when changed data is read

 *        RArray<TUint32> array;

 *        iMember->GetL( array );

 *        // Do something with data

 *        array.Close();

 *        

 *  @endcode

 *

 *  @lib serviceprovidersettings.lib

 */

NONSHARABLE_CLASS( CSpsBufferedPublisher ): public CBase

    {

public: // Publisher methods

    /**

     * ?description

     *

     * @param aCategory P&S Category

     * @param aKey P&S key

     * @param aData Data to be published

     */

    static void SetL( TUid aCategory, TUint aKey, TUint32 aData );

public: // Subscriber methods

    /**

     * Creates P&S key if not yet created.

     * 

     * Two-phased constructor.

     * @param aCategory P&S Category

     * @param aKey P&S key

     */

    static CSpsBufferedPublisher* NewL( TUid aCategory, TUint aKey );

    /**

     * Destructor.

     */

    virtual ~CSpsBufferedPublisher();

    /**

     * Start logging of buffer changes

     * Must be stopped before it can start from current position

     */

    void Start();

    /**

     * Stop logging of buffer changes

     */

    void Stop();

    /**

     * Get logged P&S data

     * 

     * @param aData Changed data since last get

     * @leave KErrNotReady if not started

     */

    void GetL( RArray<TUint32>& aData );

private:

    CSpsBufferedPublisher( TUid aCategory, TUint aKey );

    void ConstructL();

private:

    static void SignalAndCloseSemaphore( TAny* aPtr );

    static TUint32& At( TDes8& aData, TInt aIndex );

    static TUint Max( TDesC8& aData );

    static TInt32 Base( TDesC8& aData, TInt aIndex  );

    static TUint32& GlobalIndex( TDes8& aData );

private: // data

    TUid iCategory;

    TUint iKey;

    TInt iIndex;

    };

#endif // C_CSPSBUFFEREDPUBLISHER_H