// 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 "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:

// This file holds the class declarations for the CFbTopMBMCache 

// The cache is used to store the stream ids of bitmaps in a MBM file

// 

//

#ifndef __FBSMBMC_H__

#define __FBSMBMC_H__

#include <e32std.h>

#include <e32base.h>

#include <s32std.h>

#include "ShiftedFileStore.h"

//This class holds the TStreamIds of the bitmaps stored in an MBM file

//and the filestore of the last loaded bitmap file. The idea of the cache

//is to speed up loading of bitmaps from a mbm file by skipping the file

//opening process and mapping the MBM id directly to the Stream ids stored

//in the cache

//

NONSHARABLE_CLASS(CFbTopStreamIdCache): public CBase

	{

public:

	CFbTopStreamIdCache(TInt aForwardSize, TInt aBackwardSize, TInt aMaxFilestores);

	~CFbTopStreamIdCache();

	TStreamId GetStreamIdL(RFile& aFile,const TDesC& aFilename,TInt32 aId,TUint aFileOffset, TInt aSessionHandle);

	TStreamId GetStreamIdL(RFs& aFs,const TDesC& aFilename,TInt32 aId,TUint aFileOffset, TInt aSessionHandle);

	CShiftedFileStore* MruFileStore();

	void FlushCache();

	void CloseFileStores(TInt aSessionHandle=0);	// If aSessionHandle is not passed, all file stores will be closed

private:

	class RCacheEntry;

	RCacheEntry* AddCacheEntryL(const TDesC& aFilename, TUint aFileOffset);

	RCacheEntry* FindCacheEntry(const TDesC& aFilename, TUint aFileOffset);

private:

	RPointerArray<RCacheEntry> iEntries;	// Array of pointers to the cache entries in least-recently-used order

	TUint8* iBuffer;						// Buffer for storage of the cache entries

	const TInt iForwardCacheSize;			// Max number of cached bitmap ids after the last requested bitmap id

	const TInt iBackwardCacheSize;			// Max number of cached bitmap ids before the last requested bitmap id

	const TInt iMaxCacheFilestores;			// Max number of filestores in the cache

	friend class CTStreamIdCache;			// This is used for testing purposes

	};

class CFbTopStreamIdCache::RCacheEntry

	{

public:

	RCacheEntry(const TDesC& aFilename, TUint aFileOffset);

	TBool SameFile(const TDesC& aFilename, TUint aFileOffset);

	TStreamId GetStreamIdL(TInt32 aId, TInt aForwardSize, TInt aBackwardSize);

	CShiftedFileStore* FileStore();

	void CloseFileStore();

	TInt SessionHandle() const;

	void CreateFileStoreL(RFile& aFile, TInt aSessionHandle);

	void CreateFileStoreL(RFs& aFs, const TDesC& aFilename, TInt aSessionHandle);

public:

	static const TInt KBaseSize;		// Size of the class excluding array iStreamIdCache

private:

	TBufC<KMaxFileName>	iFilename;		// Name of the mbm file

	TUint iFileOffset;					// Offset into the mbm file

	CShiftedFileStore *iFilestore;		// File store for the mbm file

	TInt iLastId;						// Last requested bitmap id from the mbm file

	TInt iStreamIdCount;				// Number of stream ids from the mbm file

	TInt iSessionHandle;				// Handle to the associated client session

	// Keep always iStreamIdCache as the last data member

	// Memory for it is allocated in CFbTopStreamIdCache::AddCacheEntryL()

	TStreamId iStreamIdCache[1];		// Array of stream ids from the mbm file

	friend class CTStreamIdCache;		// This is used for testing purposes

	};

#endif