// 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