/*

* Copyright (c) 2002-2005 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:  Declaration of DIscBufferQueue class

*

*/

#ifndef ISCBUFFERQUEUE_H

#define ISCBUFFERQUEUE_H

//  INCLUDES

#include <kernel.h>

// CONSTANTS

// MACROS

// DATA TYPES

// FUNCTION PROTOTYPES

// FORWARD DECLARATIONS

class DIscQueue;

// CLASS DECLARATION

/**

*  Queue class for buffer allocation and management

*

*  @lib IscDataTransmissionBase.LIB

*  @since 2.8

*/

class DIscBufferQueue 

    {

    public:  // Constructors and destructor

        /**

        * C++ default constructor.

        */

        DIscBufferQueue();

        /**

        * Construct a new queue

        * @since 2.8

        * @param  TUint16 aSize size of element in queue

        * @param TUint16 aCount amount of elements in queue

        * @param TUint8* &aCurrentAddress start address of queue

        * @return DIscBufferQueue* pointer to queue

        */

        static DIscBufferQueue* New( TUint16 aSize, TUint16 aCount, TUint8* &aCurrentAddress );

        /**

        * Destructor.

        */

        ~DIscBufferQueue();

    public: // New functions

        /**

        * Checks if queue is empty

        * @since 2.8

        * @return TBool ETrue if empty, otherwise EFalse

        */

        inline TBool Empty(){return iCount ? EFalse : ETrue;};

        /**

        * Reserves first element from the queue

        * @since 2.8

        * @return TDes8* pointer to element if succesful, otherwise NULL

        */

        TDes8* Reserve();

        /**

        * Releases element from the queue

        * @since 2.8

        * @param TDes8* aPtr pointer to element

        * @return void 

        */

        void Release( TDes8* aPtr );

    protected:  // New functions

        /**

        * Function to disable interrupts

        * @since 2.8

        * @return TInt KErrNone if succesful

        */

        TInt DisableIrqs();

        /**

        * Function to restore interrupts

        * @since 2.8

        * @param TInt aLevel level where interrupts should be restored

        * @return void 

        */

        void RestoreIrqs( TInt aLevel );

    protected:  // Functions from base classes

    private:

        /**

        * 2nd phase constructor

        * @since 2.8

        * @param  TUint16 aSize size of element in queue

        * @param TUint16 aCount amount of elements in queue

        * @param TUint8* &aCurrentAddress start address of queue

        * @return TInt 

        */

        TInt Construct( TUint16 aSize, TUint16 aCount, TUint8* &aCurrentAddress );

    public:     // Data

    protected:  // Data

    private:    // Data

        volatile TUint32 iCount;

        TUint32**       iBuffers;

        DIscQueue*      iBuffersQueue;  

    };

#endif      // ISCBUFFERQUEUE_H   

// End of File