/*

* 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 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: 

*

*/

#ifndef __CIPTVEPGFILESWAPPER_H

#define __CIPTVEPGFILESWAPPER_H

// System includes

#include <e32base.h>		// For CActive

#include <f32file.h>		// For RFs

//#include <babackup.h>		// F

// Forward declarations

class CBaBackupSessionWrapper;

class MIptvEpgFileSwapObserver;

/**

*	Class to replace given old file with given new file.

*	This class takes care of requesting to close affected files by

*	using CBaBackupSessionWrapper and monitors the state of those two files.

*	When both files are not open by any other instance anymore this class

*	performs the file switching in it's RunL method and after that signalizes

*	the observers via CBaBackupSessionWrapper that they are allowed to re-open

*	the files for reading and writing.

*/

class CIptvEpgFileSwapper : public CActive

	{

	public:

		/**

		*	Symbian two phace constructor.

		*	@param	aOldFileName	Name of the file to be replaced

		*	@param	aNewFileName	Name of the file to be used to replace aOldFileName

		*	@return	Pointer to newly created instance of CIptvEpgFileSwapper object

		*/

		IMPORT_C static CIptvEpgFileSwapper* NewL( const TFileName& aOldFileName,

												   const TFileName& aNewFileName,

											       MIptvEpgFileSwapObserver& aSwapObserver );

		/**

		*	Destructor

		*/

		virtual ~CIptvEpgFileSwapper();

	public:

		/**

		*	Method to initiate file swapping process. This method signalizes the

		*	backupwrapper to ask all the backup observers for aOldFileName and aNewFilename

		*	to release their handles to the files and sets this object to active state.

		*	@param	None

		*	@return	None

		*/

		IMPORT_C void SwapFilesL();

	private:

		/**

		*	Default constructor

		*	@param	aOldFileName	Name of the file to be replaced

		*	@param	aNewFileName	Name of the file to be used to replace aOldFileName

		*	@param	aSwapObserver	Reference to a class that observes the file swapping

		*	@return	None

		*/

		CIptvEpgFileSwapper( const TFileName& aOldFileName,

							 const TFileName& aNewFileName,

							 MIptvEpgFileSwapObserver& aSwapObserver );

		/**

		*	Symbian second phase constructor containing the code that might leave

		*	during instantiation of this class.

		*	@param	None

		*	@return	None

		*/

		void ConstructL();

		/**

		*	Method that calls RestartFile method of CBaBackupSessionWrapper to allow

		*	observers to re-establish the connections to the files.

		*	@param	None

		*	@return	None

		*/

		void ReleaseFileLocks();

	private: // From CActive

		/**

		*	Overwritten error handling method to get called when active scheduler catches

		*	leave in this active object.

		*	@param	aError	Symbian error code for the occured error

		*	@return	KErrNone if error was handled by this method. If return value is

		*					something else but KErrNone, active scheduler will panic.

		*/

		TInt RunError( TInt aError );

		/**

		*	Method to get called when active object request has been completed.

		*	@param	None

		*	@return	None

		*/

		void RunL();

		/**

		*	Method to handle actual actions required after Cancel-method has been called.

		*/

		void DoCancel();

	private: // instance variables

		/**

		*	Handle to the file server session

		*/

		RFs iFs;

		/**

		*	Timer to use when monitoring open files

		*/

		RTimer iTimeWaster;

		/**

		*	Name of the old file that is to be replaced

		*/

		TFileName iOldFileName;

		/**

		*	Name of the file to be used to replace iOldFileName

		*/

		TFileName iNewFileName;

		/**

		*	Backup session to signalize all observers to release handle to

		*	iOldFileName and iNewFileName

		*/

		CBaBackupSessionWrapper* iBackupWrapper;

		/**

		*	Reference to the class that observes the file swapping

		*/

		MIptvEpgFileSwapObserver& iSwapObserver;

		TInt iSwapTriesAmount;

	};

#endif // __CIPTVEPGFILESWAPPER_H