/*

* 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:  Low disk space observer for harvester server

*

*/

#ifndef MDSHARVESTERDISKSPACEOBSERVERAO_H

#define MDSHARVESTERDISKSPACEOBSERVERAO_H

// INCLUDE FILES

#include <e32base.h>

#include <f32file.h>

/**

* MMdSHarvesterDiskSpaceObserver

* Observer interface for a disk space notifier.

*/

class MMdSHarvesterDiskSpaceObserver

    {

    public :

        enum TDiskSpaceDirection

            {

            /** Disk space is larger than threshold level */

            EMore,

            /** Disk space is smaller than threshold level */

            ELess

            };

        /**

         * Called to notify the observer that disk space has crossed the specified threshold value.

         *

         * @param aCrossDirection threshold cross direction

         */

        virtual void HandleDiskSpaceNotificationL(TDiskSpaceDirection aDiskSpaceDirection) = 0;

    };

/**

* CMSDiskSpaceNotifierAO.

* A disk space notifier class

*/

class CMdSHarvesterDiskspaceObserverAO : public CActive

    {

    public:

        enum TDiskSpaceNotifierState

            {

            ENormal,

            EIterate

            };

    public : // Constructors and destructors

        /**

         * Constructs a disk space notifier implementation.

         *

         * @param aThreshold minimum free disk space threshold level in bytes

         * @param aFilename filename which defines monitored drive's number

         * @return  metadata server implementation

         */

        static CMdSHarvesterDiskspaceObserverAO* NewL(

            MMdSHarvesterDiskSpaceObserver& aObserver, 

            TInt64 aThreshold, const TDesC& aFilename);

        /**

         * Constructs a disk space notifier implementation and leaves it

         * in the cleanup stack.

         *

         * @param aThreshold minimum free disk space threshold level in bytes

         * @param aFilename filename which defines monitored drive's number

         * @return  metadata server implementation

         */

        static CMdSHarvesterDiskspaceObserverAO* NewLC(        

            MMdSHarvesterDiskSpaceObserver& aObserver, 

            TInt64 aThreshold, const TDesC& aFilename);

        /**

        * Destructor.

        */

        virtual ~CMdSHarvesterDiskspaceObserverAO();

    protected: // Functions from base classes

        /**

         * From CActive

         * Callback function.

         * Invoked to handle responses from the server.

         */

        void RunL();

        /**

         * From CActive

         * Handles errors that occur during notifying the observer.

         */

        TInt RunError(TInt aError);

        /**

         * From CActive

         * Cancels any outstanding operation.

         */

        void DoCancel();

    private: // Constructors and destructors

        /**

         * constructor

         */

        CMdSHarvesterDiskspaceObserverAO(

            MMdSHarvesterDiskSpaceObserver& aObserver,

            TInt64 aThreshold, TDriveNumber aDrive);

        /**

         * 2nd phase constructor

         * @param aThreshold minimum free disk space threshold level in bytes

         * @param aDrive monitored drive's number

         */

        void ConstructL();

    private: // New methods

        void StartNotifier();

        static TDriveNumber GetDriveNumberL( const TDesC& aFilename );

    private: // Data

        MMdSHarvesterDiskSpaceObserver& iObserver;

        RFs iFileServerSession;

        const TInt64 iThreshold;

        const TDriveNumber iDrive;

        TDiskSpaceNotifierState iState;

        TInt iIterationCount;

    };

#endif // MDSHARVESTERDISKSPACEOBSERVERAO_H

// End of File