/*
* 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__