/*

* Copyright (c) 2007-2009 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:   WlanChunk declaration

*

*/

/*

* %version: 6 %

*/

#ifndef WLANCHUNK_H

#define WLANCHUNK_H

#include "wlanobject.h"

#include "osalist.h"

#include "osachunkbase.h"

class RWlanHeap;

/**

 *  Memory chunk allocation management object.

 *

 *  Management of memory is based on buddy system, where righ hand side (rhs)

 *  and left hand side (lhs) memory links are coalesced (if they are free) to

 *  the current link to be freed. Allocation size is always alinged to

 *  allocation unit, which equals to the size of cache line. The pointer

 *  returned to the caller is also aligned to the allocation unit.

 *

 */

class WlanChunk : 

    public DBase, public WlanObject, public MWlanOsaChunkBase

    {

public:

    /**

     * ctor

     * NOTE: call IsValid() member from super class 

     * to validate object after ctor

     *

     * @since S60 v3.2

     * @param aStartOfBuf start of buffer

     * @param aEndOfBuf 1 past end of buffer

     * @param aAllocationUnit allocation unit size in bytes

     */

    WlanChunk( TUint8* aStartOfBuf, TUint8* aEndOfBuf, TInt aAllocationUnit );

    /**

	 * Destructor.

	 *

	 * @since S60 v3.2

	 */

    virtual ~WlanChunk();

// from base class MWlanOsaChunkBase

    /**

     * From MWlanOsaChunkBase.

     * Memory allocation. Correct alignment guaranteed

     *

     * @since S60 v3.2

     * @param aSize size of the buffer to be allocated in bytes. 

     *              Must be positive otherwise the allocation fails

     * @param aZeroStamp zero stamp memory or not

     * @return begin of the allocated memory, NULL upon failure

     */

    virtual void* Alloc( TInt aSize, TBool aZeroStamp );

    /**

     * From MWlanOsaChunkBase.

     * Releases memory allocated by the Alloc method

     *

     * @since S60 v3.2

     * @param aPtr begin of the buffer to be freed

     */

    virtual void Free( void* aPtr );

    /**

     * From MWlanOsaChunkBase.

     * Returns the maximum free link size

     *

     * @since S60 v3.2

     * @return maximum free link size

     */

    virtual TInt MaxFreeLinkSize() const;

    /**

     * From MWlanOsaChunkBase.

     * Evaluates is chunk in use or not, 

     * meaning is memory allocated from there or not

     *

     * @since S60 v3.2

     * @return ETrue for unused chunk any other for used chunk

     */

    virtual TBool IsInUse() const;

    /**

     * From MWlanOsaChunkBase.

     * Returns the size of the memory chunk meta header in bytes

     *

     * @since S60 v3.2

     * @return size of the memory chunk meta header

     */

    virtual TInt HeaderSize() const;

    // Prohibit copy constructor.

    WlanChunk( const WlanChunk& );

    // Prohibit assigment operator.

    WlanChunk& operator= ( const WlanChunk& );

private: // data

    RWlanHeap* iHeap;

    };

#endif // WLANCHUNK_H