/*

* Copyright (c) 2002-2009 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 "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:   Declaration of the DataFrameMemMngr class.

*

*/

/*

* %version: 11 %

*/

#ifndef DATAFRAMEMMNGR_H

#define DATAFRAMEMMNGR_H

#include "EthernetFrameMemMngr.h"

class WlanChunk;

/**

*  Memory manager for protocol stack side client frame Rx memory

*

*  @since S60 v3.1

*/

class DataFrameMemMngr : public DEthernetFrameMemMngr

    {

public: 

    /** Ctor */

    DataFrameMemMngr( 

        DWlanLogicalChannel& aParent,

        WlanChunk*& aRxFrameMemoryPool,

        TInt aTxFrameBufAllocationUnit ) : 

        DEthernetFrameMemMngr( aParent, aRxFrameMemoryPool ),

        iFrameXferBlockProtoStack( NULL ),

        iTxDataChunk( NULL ),

        iTxFrameMemoryPool( NULL ),

        iTxFrameBufAllocationUnit ( aTxFrameBufAllocationUnit )

        {};

    /** Dtor */

    virtual ~DataFrameMemMngr() 

        {

        iFrameXferBlockProtoStack = NULL;

        iTxDataChunk = NULL;

        iTxFrameMemoryPool = NULL;

        };

protected: 

    /**

    * From DEthernetFrameMemMngr

    * Opens a handle to the allocated shared memory chunk

    *

    * @since S60 5.0

    * @param aThread

    * @param aSharedChunkInfo

    * @param aSharedMemoryChunk The shared memory chunk

    * @return system wide error code, KErrNone upon success

    */

    virtual TInt DoOpenHandle(

        DThread& aThread,

        TSharedChunkInfo& aSharedChunkInfo,

        DChunk* aSharedMemoryChunk );

    /**

    * From DEthernetFrameMemMngr

    * Gets called when rx frame read cycle has ended.

    *

    * @since S60 3.1

    * @param aBufferStart first element of the array that holds pointers to

    *        Rx frame meta headers

    * @param aNumOfBuffers number of meta header pointers in the array

    * @return ETrue if a pending user mode frame read request exists 

    *         and callee should complete it, 

    *         EFalse otherwise

    */

    virtual TBool DoEthernetFrameRxComplete( 

        const TDataBuffer*& aBufferStart, 

        TUint32 aNumOfBuffers );

    /**

    * From DEthernetFrameMemMngr

    * Gets start address of Rx buffers (their offset addresses)

    * that are waiting for completion to user mode

    *

    * @since S60 3.1

    * @return see above

    */

    virtual TUint32* DoGetTobeCompletedBuffersStart();

    /**

    * From DEthernetFrameMemMngr

    * Gets start address of Rx buffers (their offset addresses)

    * that have been completed to user mode

    *

    * @since S60 3.1

    * @return see above

    */

    virtual TUint32* DoGetCompletedBuffersStart();

    /**

    * From DEthernetFrameMemMngr

    * Gets called when user mode client issues a frame receive request 

    * and Rx buffers have been completed to it. The completed Rx frame 

    * buffers are freed.

    *

    * @since S60 3.1

    */

    virtual void DoFreeRxBuffers();

    /**

     * From DEthernetFrameMemMngr

     * Allocates a Tx packet from the shared memory.

     * 

     * @param aLength Length of the requested Tx buffer in bytes

     * @return Pointer to the meta header attached to the allocated packet, on

     *         success.

     *         NULL, in case of failure.

     */

    virtual TDataBuffer* AllocTxBuffer( TUint aLength );

    /**

     * From DEthernetFrameMemMngr

     * Deallocates a Tx packet.

     * 

     * All Tx packets allocated with AllocTxBuffer() must be deallocated using

     * this method.

     * 

     * @param aPacket Meta header of the packet to the deallocated

     */ 

    virtual void FreeTxPacket( TDataBuffer*& aPacket );    

private:

    /**

    * From DEthernetFrameMemMngr

    * Memory finalization method.

    */

    virtual void OnReleaseMemory();

    // Prohibit copy constructor.

    DataFrameMemMngr( const DataFrameMemMngr& );

    // Prohibit assigment operator.

    DataFrameMemMngr& operator= ( const DataFrameMemMngr& );  

private:    // Data

    /** 

    * array of TDataBuffer offset addresses, denoting Rx buffers,

    * which are waiting here in kernel mode to be completed 

    * to user mode, when the next frame receive request arrives

    */

    TUint32 iTobeCompletedBuffers[KMaxToBeCompletedRxBufs];

    /** 

    * array of TDataBuffer offset addresses, denoting Rx buffers, that are

    * currently under processing in user mode

    */

    TUint32 iCompletedBuffers[KMaxCompletedRxBufs];

    RFrameXferBlockProtocolStack* iFrameXferBlockProtoStack;

    /** 

    * pointer to protocol stack side Tx area start in the kernel address 

    * space 

    */

    TUint8* iTxDataChunk;

    /** 

    * Tx frame memory pool manager

    * Own.

    */

    WlanChunk* iTxFrameMemoryPool;

    /**

    * size of the Tx frame buffer allocation unit in bytes

    */

    TInt iTxFrameBufAllocationUnit;

    };

#endif // DATAFRAMEMMNGR_H