/*

* 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 "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:  This is disk space notifier for Metadata server.*

*/

#ifndef __MDSDISKSPACENOTIFIER_H__

#define __MDSDISKSPACENOTIFIER_H__

// INCLUDE FILES

#include <e32base.h>

#include <f32file.h>

/**

* MMdSDiskSpaceNotifierObserver

* Observer interface for a disk space notifier.

*/

class MMdSDiskSpaceNotifierObserver

	{

	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;

		/**

		 * Called to if disk space notifier has an error situation.

		 *

		 * @param aError error code

		 */

		virtual void HandleDiskSpaceError(TInt aError) = 0;

	};

/**

* CMSDiskSpaceNotifierAO.

* A disk space notifier class

*/

class CMdSDiskSpaceNotifierAO : 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 CMdSDiskSpaceNotifierAO* NewL(

        	MMdSDiskSpaceNotifierObserver& 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 CMdSDiskSpaceNotifierAO* NewLC(        

        	MMdSDiskSpaceNotifierObserver& aObserver, 

        	TInt64 aThreshold, const TDesC& aFilename);

	    /**

	    * Destructor.

	    */

        virtual ~CMdSDiskSpaceNotifierAO();

        TBool DiskFull() const;

    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

         */

        CMdSDiskSpaceNotifierAO(

        	MMdSDiskSpaceNotifierObserver& 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

        MMdSDiskSpaceNotifierObserver& iObserver;

        RFs iFileServerSession;

        const TInt64 iThreshold;

        const TDriveNumber iDrive;

        TDiskSpaceNotifierState iState;

        TInt iIterationCount;

        TBool iDiskFull;

    };

#endif // __CMDSSERVER_H__

// End of File