// Copyright (c) 2008-2009 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\sfat32\inc\sl_dir_cache.h

// 

//

/**

 @file

 @internalTechnology

*/

//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

//!!

//!! WARNING!! DO NOT edit this file !! '\sfat' component is obsolete and is not being used. '\sfat32'replaces it

//!!

//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

#ifndef SL_DIR_CACHE_H

#define SL_DIR_CACHE_H

#include "sf_memory_man.h"

#include "sf_memory_client.h"

#include "sl_cache.h"

#include <e32hashtab.h>

//---------------------------------------------------------------------------------------------------------------------------------

class   CDynamicDirCache;

/**

The dynamic directory cache page class

*/

class TDynamicDirCachePage

    {

public:

    enum TPageType

        {

        EUnknown,

        ELocked,

        EUnlocked,

        EActivePage,

        };

public:

    ~TDynamicDirCachePage();

    static TDynamicDirCachePage* NewL(CDynamicDirCache* aOwnerCache, TInt64 aStartMedPos, TUint8* aStartRamAddr);

    inline void SetLocked(TBool);

    inline TBool    IsLocked() const;

    inline TUint8*  StartPtr()  const;

    inline void     SetStartPtr(TUint8* aPtr);

    inline void SetValid(TBool aIsValid);

    inline TBool    IsValid()   const;

    inline void SetPageType(TPageType aType);

    inline TPageType PageType();

    inline TUint32  PageSizeInBytes() const;

    inline TUint32  PageSizeInSegs() const;

    inline void SetPos(TInt64 aPos);

    inline void ResetPos();

    inline TInt64   StartPos()  const;

    inline TUint8*  PtrInPage(TInt64 aPos) const;

    inline TBool    PosCachedInPage(TInt64 aPos) const;

    inline void Deque();

private:

    // declared to disable copying and assignment

    TDynamicDirCachePage& operator=(const TDynamicDirCachePage&);

    TDynamicDirCachePage(const TDynamicDirCachePage&);

    // private constructor, as this class is not supposed to be created on stack

    TDynamicDirCachePage(CDynamicDirCache* aOwnerCache, TInt64 aStartMedPos, TUint8* aStartRamAddr);

public:

    TDblQueLink         iLink;          ///< the embedded link object, see TCachePageList

    TInt64              iStartMedPos;   ///< the starting media address that this page caches

    TUint8*             iStartRamAddr;  ///< the starting ram address that thsi page lives

    CDynamicDirCache*   iOwnerCache;    ///< pointer to the cache that owns this page

    TBool               iValid  :1;     ///< flag to indicate the validity of the page content

    TBool               iLocked :1;     ///< flag to indicate if the page is locked or not

    TPageType           iType;          ///< page type, see TPageType

    };

/**

The lookup table entry class

@see    CDynamicDirCache

*/

class TLookupEntry

    {

    public:

        TLookupEntry(): iPos(0), iRange(0), iPage(NULL) {};

        TLookupEntry(TInt64 aPos, TUint32 aRange, TDynamicDirCachePage* aPage): iPos(aPos), iRange(aRange), iPage(aPage) {};

    public:

        TInt64                  iPos;

        TUint32                 iRange;

        TDynamicDirCachePage*   iPage;

    };

//---------------------------------------------------------------------------------------------------------------------------------

typedef TDblQue<TDynamicDirCachePage> TCachePageList;

/**

Dynamic directory cache.

For now it is directly derived from MWTCacheInterface.

Provides caching FAT directory data.

*/

class CDynamicDirCache : public CBase, public MWTCacheInterface

    {

public:

    ~CDynamicDirCache();

    static CDynamicDirCache* NewL(TFatDriveInterface& aDrive, TUint32 aMinPageNum, TUint32 aMaxPageNum, TUint32 aPageSizeLog2, const TDesC& aClientName);

    //-- overloads from the base class

    void    ReadL (TInt64 aPos, TInt aLength, TDes8& aDes);

    void    WriteL(TInt64 aPos, const TDesC8& aDes);

    void    InvalidateCache(void);

    void    InvalidateCachePage(TUint64 aPos);

    TUint32 PosCached(const TInt64& aPosToSearch, TInt64& aCachedPosStart);

    TUint32 CacheSizeInBytes()  const;

    TInt    Control(TUint32 aFunction, TUint32 aParam1, TAny* aParam2);

    void    SetCacheBasePos(TInt64 aBasePos);

    void    MakePageMRU(TInt64 aPos);

    TUint32 PageSizeInBytesLog2() const;

    TUint32 PageSizeInSegs() const;

    // Debugging functions

    void Dump();

    void Info() const;

protected:

    CDynamicDirCache(TFatDriveInterface& aDrive, TUint32 aMinSizeInBytes, TUint32 aMaxSizeInBytes, TUint32 aPageSizeInBytesLog2);

    void ConstructL(const TDesC& aClientName);

    void ReadDataFromSinglePageL(TInt64 aPos, TInt aLength, TDes8& aDes);

    void WriteDataOntoSinglePageL(TInt64 aPos, const TUint8* aData, TUint32 aDataLen);

    TDynamicDirCachePage* FindPageByPos(TInt64 aPos);

    TDynamicDirCachePage* UpdateActivePageL(TInt64 aPos);

    TDynamicDirCachePage* AllocateAndLockNewPageL(TInt64 aStartMedPos);

    TUint8* LockPage(TDynamicDirCachePage* aPage);

    TInt    UnlockPage(TDynamicDirCachePage* aPage);

    TInt    DecommitPage(TDynamicDirCachePage* aPage);

    inline TInt64  CalcPageStartPos(TInt64 aPos) const;

    void CheckThresholds();

    inline TBool CacheIsFull() const;

    inline TUint32 MaxCacheSizeInPages() const;

    TInt DeQueue(TDynamicDirCachePage* aPage);

    TInt AddFirstOntoQueue(TDynamicDirCachePage* aPage, TDynamicDirCachePage::TPageType aType);

    TInt LookupTblRemove(TInt64 aPagePos);

    TInt LookupTblAdd(TDynamicDirCachePage* aPage);

    TDynamicDirCachePage* LookupTblFind(TInt64 aPos);

    TInt ResetPagePos(TDynamicDirCachePage* aPage);

    void MakePageLastLocked(TDynamicDirCachePage* aPage);

private:

    TUint32             iPageSizeLog2;      ///< log2 value of cache pages size in bytes

    TUint32             iMinCacheSizeInBytes;   ///< minimum cache data size

    TUint32             iMaxCacheSizeInBytes;   ///< maximum cache data size

    TUint32             iMinSizeInPages;    ///< minimum cache page number

    TUint32             iMaxSizeInPages;    ///< maximum cache page number

    TUint32             iPageSizeInBytes;   ///< cache page size in bytes

    TInt64              iCacheBasePos;      ///< cache pages base position, used to align them at cluster size

    TFatDriveInterface& iDrive;             ///< reference to the driver for media access

    TUint32             iCacheDisabled : 1; ///< if not 0 the cache is disabled totally and all reads and writes go via TFatDriveInterface directly

    TDynamicDirCachePage*   iActivePage;    ///< a unique page in cache, used to read new page before make it MRU or have it replaced

    // data structures for LRU page list    

    TCachePageList  iLockedQ;               ///< the locked queue that manages all locked pages, limited by minimum page number

    TCachePageList  iUnlockedQ;             ///< the unlocked queue that manages all locked pages, limited by maximum page number - minimum page number

    TUint32         iLockedQCount;

    TUint32         iUnlockedQCount;

    // data structures for look up table

    THashFunction32<TLookupEntry>   iHashFunction;

    TIdentityRelation<TLookupEntry> iIdentityFunction;

    RHashSet<TLookupEntry>          iLookupTable;   ///< a lookup table that used to speed up page look up

    CCacheMemoryClient* iCacheMemoryClient; ///< interface to cache memory manager

    };

#include"sl_dir_cache.inl"

#endif //SL_DIR_CACHE_H