// Copyright (c) 1995-2009 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:

// f32\sfile\sf_pgcompr.h

// 

//

#ifndef __SF_PGCOMPR_H__

#define __SF_PGCOMPR_H__

#include <e32base.h>

#include<f32file.h>

//#include "sf_std.h"

#include <f32image.h>

#include "sf_image.h"

#include <e32uid.h>

#include <e32rom.h>

#include "sf_cache.h"

const TUint KBytePairPageSize = 4096;

// Buffer sized for at least 8 compressed pages - a noncompressible page is one byte larger

const TUint KReadNumberOfPages = 8;

const TUint KPagesBufferSize = (KBytePairPageSize + 1) * KReadNumberOfPages;

typedef TUint8* (*TMemoryMoveFunction)(TAny* aTrg,const TAny* aSrc,TInt aLength); 

struct IndexTableHeader

	{

	TInt	iSizeOfData;					// Includes the index and compressed pages

	TInt	iDecompressedSize;

	TUint16	iNumberOfPages;

	};

// sizeof(IndexTableHeader) returns the wrong value due to rounding/padding, so calculate it

const TUint KIndexTableHeaderSize = sizeof(TInt) + sizeof(TInt) + sizeof(TUint16);

NONSHARABLE_CLASS(CBytePairReader) : public CBase

	{

public:

	static CBytePairReader* NewLC(TUint8* aBuffer, TUint32 aLength);

	CBytePairReader(TUint8* aBuffer, TUint32 aLength);

	virtual TUint DecompressPagesL(TUint8* aTarget, TInt aLength, TMemoryMoveFunction aMemMoveFn);

	void GetPageOffsetsL(TInt32 aInitialOffset, TInt& aPageCount, TInt32*& aPageStarts);

	TUint GetPageL(TUint aPageNum, TUint8* aTarget, TInt aLength, TMemoryMoveFunction aMemMoveFn);		

	virtual void SeekForwardL(TUint aBytes);

protected:

	virtual void ReadInTableL();

	void ReleaseTable();

	IndexTableHeader iHeader;

	TUint16* iIndexTable;

	TUint8* iNextPage;

	TUint iBytesLeft;

	TUint8 iPageBuf[KBytePairPageSize];

	};

NONSHARABLE_CLASS(CBytePairFileReader) : public CBytePairReader

	{

public:

	static CBytePairFileReader* NewLC(RFile& aFile);

	CBytePairFileReader(RFile& aFile);

	~CBytePairFileReader();

	virtual TUint DecompressPagesL(TUint8* aTarget, TInt aLength, TMemoryMoveFunction aMemMovefn);

	virtual void SeekForwardL(TUint aBytes);

protected:

	virtual void ReadInTableL();

	RFile& iFile;

	TUint8 iBuffer[KPagesBufferSize];

	};

#endif // __SF_PGCOMPR_H__