/*

* Copyright (c) 2004-2009 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: 

* Definition of the Swi::Sis::CCompressed

*

*/

/**

 @file 

 @released

 @internalTechnology

*/

#ifndef __SISCOMPRESSED_H__

#define __SISCOMPRESSED_H__

#include "sisfield.h"

namespace Swi

{

namespace Sis

 {

/**

 * This class represents a SisCompressed entity. This is an <i>envelope</i> which

 * wraps up data encoded with a given compression scheme. Currently we support

 * two compression schemes: 

 * 

 * <ul> 

 *      <li> <b>ECompressDeflate.</b> Data compressed using the zip algorithm

 *      <li> <b>ECompressNone.</b> Denotes uncompressed data

 * </ul>

 *

 * A full description can be found in SGL.GT0188.251.

 *

 * @released

 * @internalTechnology

 */

class CCompressed : public CField

	{

public:

	/**

	 * This creates a new CCompressed object.

	 *

	 * @param aDataProvider 	  An instance of a MSisDataProvider to read the entity from.

	 * @param aTypeReadBehaviour  Whether we need to check the sis type or not.

	 *

	 * @return An instance of CCompressed representing the data read.	 	 

	 */

	static CCompressed* NewLC(MSisDataProvider& aDataProvider, TInt64& aBytesRead, TReadTypeBehaviour aTypeReadBehaviour = EReadType);

	/**

	 * This creates a new CController object.

	 *

	 * @param aDataProvider		 An instance of a MSisDataProvider to read the entity from.

	 * @param aTypeReadBehaviour Whether we need to check the sis type or not.

	 *

	 * @return An instance of CCompressed representing the data read.

	 */

	static CCompressed* NewL(MSisDataProvider& aDataProvider, TInt64& aBytesRead, TReadTypeBehaviour aTypeReadBehaviour = EReadType);

	virtual ~CCompressed();

public: // Business methods

	/**

	 * This function reads and returns the <b>uncompressed</b> SISX controller

	 * data. This raw data can be fed into Swi::Sis::CController for parsing.

	 *

	 * @return A buffer containing the raw, uncompressed, SISX controller data.

	 */	

	HBufC8* ReadControllerDataL();

	/**

	 * Extracts the enveloped data into the given file.

	 *

	 * @param aFile A file handle open for writing. It will store the

	 *              enveloped data into this file.

	 */

	void ExtractDataFieldL(RFile& aFile);

	/**

	 * Extracts some of the enveloped data into the given file. This may be called

	 * multiple times in order to extract all of the data

	 *

	 * @param aFile	A file handle open for writing. It will store the

	 *              	enveloped data into this file.

	 * @param aLength The length of the data to extract.

	 */

	void ExtractDataFieldL(RFile& aFile, TInt64 aLength);

	void ExtractDataFieldL(MSisDataProvider& aDataProvider, RFile& aFile, TInt64 aLength);

	/** the Crc of this CCompressed field

	*/

	TUint16 Crc() const;

private: // Helper methods

	/**

	 * This method instantiate a proper MSisDataProvider instance to handle the

	 * enveloped data. This abstracts us away from the compressed/uncompressed 

	 * storage of data.

	 *

	 * @return An instance of MSisDataProvider which can be used to 

	 *     extract the enveloped file data.

	 */

	MSisDataProvider& DataProviderL();

private: // Life cycle methods

	/**

	 * The constructor.

	 *

	 * @param aDataProvider A instance of MSisDataProvider used to access the raw data.

	 */

	CCompressed(MSisDataProvider& aDataProvider);

	/**

	 * The second-phase constructor.

	 *

	 * @param aTypeReadBehaviour Whether to check the field code or take it for granted.

	 */

	void ConstructL(TInt64& aBytesRead, TReadTypeBehaviour aTypeReadBehaviour);

private:

	MSisDataProvider& iDataProvider;

	MSisDataProvider* iCompressedReader;

	TFieldLength iUncompressedLength;

	TFieldLength iOffset;

	MSisDataProvider* iCurrentDataProvider; ///< Used to keep current data provider pointer across calls to ExtractDataFieldL

	TInt32 iBytesExtracted;

	TUint16 iCrc;

	};

inline TUint16 CCompressed::Crc() const

	{

	return iCrc;

	};

 } // namespace Sis

} // namespace Swi

#endif // __SISCOMPRESSED_H__