/*

* 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: 

* Interface for CCompressedDataProvider

*

*/

/**

 @file 

 @internalTechnology

*/

#ifndef __COMPRESSEDDATAPROVIDER_H__

#define __COMPRESSEDDATAPROVIDER_H__

#include <e32std.h>

#include <ezbufman.h>

#include "sisdataprovider.h"

class CEZDecompressor;

namespace Swi

{

  const TInt KDeflateBufferMaxSize = 0x8000;

  /**

   * This class is decorator over an MSisDataProvider. It adds 

   * an decompression layer so that users can access a compressed 

   * data stream transparently.

   *

   * @released

   * @internalTechnology

   */

  class CCompressedDataProvider : public CBase, public MSisDataProvider, public MEZBufferManager

  {

  public:

  	/**

  	 * Creates a new compressed data provider wrapping up the given data provider.

  	 *

  	 * @param aDataProvider The data provider from which we read the actual data.

  	 * @param abufferSize 	The size of the in-memory buffer used during the decompression.

  	 *

  	 * @return And instance of CCompressedDataProvider decorating the given data provider.

  	 */

    static CCompressedDataProvider* NewL(MSisDataProvider& aDataProvider, TInt abufferSize = KDeflateBufferMaxSize);

  	/**

  	 * Creates a new compressed data provider wrapping up the given data provider and 

  	 * leaves it on the cleanup stack.

  	 *

  	 * @param aDataProvider The data provider from which we read the actual data.

  	 * @param abufferSize 	The size of the in-memory buffer used during the decompression.

  	 *

  	 * @return And instance of CCompressedDataProvider decorating the given data provider.

  	 */

    static CCompressedDataProvider* NewLC(MSisDataProvider& aDataProvider, TInt abufferSize = KDeflateBufferMaxSize);

    ~CCompressedDataProvider();

  public: // from MSisDataProvider

    TInt Read(TDes8& aDes);

    TInt Read(TDes8& aDes, TInt aLength);

    TInt Seek(TSeek aMode, TInt64& aPos);    

  public: // from MEZBufferManager

    void InitializeL(CEZZStream &aZStream);

    void NeedInputL(CEZZStream &aZStream);

    void NeedOutputL(CEZZStream &aZStream);

    void FinalizeL(CEZZStream &aZStream);    

  protected:

  	/**

  	 * The constructor.

  	 *

  	 * @param aDataProvider The underlying data provider object.

  	 */

    CCompressedDataProvider(MSisDataProvider& aDataProvider);

	/**

	 * The second phase contructor.

	 *

	 * @param aBufferSize The size of the in-memory buffer used during decompression.

	 */

    void ConstructL(TInt aBufferSize);

  private:

    MSisDataProvider& iDataProvider;

    CEZDecompressor*  iDecompressor;

    HBufC8* iInputBuffer;

    HBufC8* iOutputBuffer;

    TPtr8   iInputDescriptor;

    TPtr8   iOutputDescriptor;

    TBool   iMore;

    CBufFlat* iBuffer;

  };

} // namespace Swi

#endif // __COMPRESSEDDATAPROVIDER_H__