sl@0: // Copyright (c) 1998-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: // All rights reserved.
sl@0: // This component and the accompanying materials are made available
sl@0: // under the terms of the License "Eclipse Public License v1.0"
sl@0: // which accompanies this distribution, and is available
sl@0: // at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: //
sl@0: // Initial Contributors:
sl@0: // Nokia Corporation - initial contribution.
sl@0: //
sl@0: // Contributors:
sl@0: //
sl@0: // Description:
sl@0: // f32\sfat\sl_facache.h
sl@0: // FAT cache base classes definition
sl@0: // FAT12 and FAT16 cache classes definition
sl@0: // 
sl@0: //
sl@0: 
sl@0: /**
sl@0:  @file
sl@0:  @internalTechnology
sl@0: */
sl@0: 
sl@0: //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
sl@0: //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
sl@0: //!!
sl@0: //!! WARNING!! DO NOT edit this file !! '\sfat' component is obsolete and is not being used. '\sfat32'replaces it
sl@0: //!!
sl@0: //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
sl@0: //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
sl@0: 
sl@0: 
sl@0: #ifndef SL_FAT_CACHE_H
sl@0: #define SL_FAT_CACHE_H
sl@0: 
sl@0: 
sl@0: //-----------------------------------------------------------------------------
sl@0: 
sl@0: /**
sl@0:     A simple abstraction of the 32 bit flags
sl@0: */
sl@0: class T32Bits
sl@0: {
sl@0:  public:
sl@0:     T32Bits() : iData(0) {}
sl@0: 
sl@0:     inline void  Clear();
sl@0:     inline TBool HasBitsSet() const;
sl@0:     inline void SetBit(TUint32 aIndex);
sl@0:     inline TBool operator[](TUint32 aIndex) const;
sl@0: 
sl@0:  private:
sl@0:     TUint32 iData; ///< 32 bits data
sl@0: };
sl@0: 
sl@0: //-----------------------------------------------------------------------------
sl@0: 
sl@0: class CFatBitCache;
sl@0: 
sl@0: /**
sl@0:     An abstract base class for all types of FAT caches.
sl@0:     Provides user interface and some common for all types of FAT caches functionality.
sl@0: */
sl@0: class CFatCacheBase : public CBase
sl@0: {
sl@0:  public:
sl@0: 
sl@0:     virtual ~CFatCacheBase();
sl@0: 
sl@0:     //-- public interface
sl@0:     virtual void Close(TBool /*aDiscardDirtyData*/) {};
sl@0:     virtual void FlushL() = 0;
sl@0: 
sl@0:     virtual TUint32 ReadEntryL(TUint32 aIndex) = 0;
sl@0:     virtual void WriteEntryL(TUint32 aIndex, TUint32 aEntry) = 0;
sl@0:     
sl@0:     virtual TInt Invalidate() = 0;
sl@0:     virtual TInt InvalidateRegion(TUint32 aStartEntry, TUint32 aNumEntries) = 0;
sl@0: 
sl@0:     TInt ReadFatData(TUint32 aPos, TUint32 aLen, TDes8& aData) const;
sl@0:     TInt WriteFatData(TUint32 aPos, const TDesC8& aData) const;
sl@0: 
sl@0:     inline TUint32  FatStartPos() const;
sl@0:     inline TUint32  FatSize() const;
sl@0:     inline TFatType FatType() const;
sl@0: 
sl@0:  public:
sl@0:     
sl@0:     //-- auxilary interface to additional bit supercache (it may exist only in FAT32 cache implementation)
sl@0:     virtual CFatBitCache* BitCacheInterface();
sl@0: 
sl@0: 
sl@0:  protected:
sl@0:     CFatCacheBase();
sl@0: 
sl@0:     virtual void InitialiseL(CFatMountCB* aOwner);
sl@0: 
sl@0:     inline TBool IsDirty() const;
sl@0:     inline void SetDirty(TBool aDirty);
sl@0:     inline TUint NumFATs() const;
sl@0: 
sl@0:     TBool CheckInvalidatingDirtyCache() const;
sl@0: 
sl@0:     inline TUint FAT_SectorSzLog2() const;
sl@0:     inline TUint FAT_SectorSz() const; 
sl@0:     inline TUint FAT_ClusterSzLog2() const;
sl@0: 
sl@0:  protected:
sl@0:     
sl@0:     enum {KInvalidFatNo = 0xFF}; ///< used to invalidate current FAT no.
sl@0:     TUint   iCurrentFatNo;       ///< current FAT number WriteFatData will write to.
sl@0: 
sl@0:  private:    
sl@0:     //-- values cached from owning mount.
sl@0:     TUint32     iFatStartPos;   ///< media position of FAT1 start 
sl@0:     TUint32     iFatSize;       ///< size of FAT in bytes
sl@0:     TUint16     iNumFATs;       ///< number of FATs on the volume
sl@0:     TUint16     iFatSecSzLog2;  ///< Log2(FAT Sector size)
sl@0:     TUint16     iFatClustSzLog2;///< Log2(FAT cluster size)
sl@0:     TFatType    iFatType;       ///< FAT type
sl@0:     TFatDriveInterface* ipDrive;///< interface to the media driver
sl@0:     //---
sl@0: 
sl@0:     TBool       iDirty;         ///< ETrue if the cache is dirty
sl@0: };
sl@0: 
sl@0: 
sl@0: //-----------------------------------------------------------------------------
sl@0: 
sl@0: /**
sl@0:     Fixed FAT12 cache. This is a contiguous cache that caches whole FAT12.
sl@0:     This cache is logically divided to sectors, maximal number of sectors in this cache is KMaxSectorsInCache (32).
sl@0:     
sl@0:     Read granularity: whole cache; anyway it can't be larger than 6126 bytes.
sl@0:     Write granularity: cache sector size, which is always "FAT Sector Size" and non-configurable.
sl@0: */
sl@0: class CFat12Cache : public CFatCacheBase
sl@0: {
sl@0:  public:
sl@0:     static CFat12Cache* NewL(CFatMountCB* aOwner, TUint32 aFatSize);
sl@0: 
sl@0:     //-- overrides from base class
sl@0:     virtual void Close(TBool aDiscardDirtyData);
sl@0:     virtual void FlushL();
sl@0: 
sl@0:     virtual TUint32 ReadEntryL(TUint32 aIndex);
sl@0:     virtual void WriteEntryL(TUint32 aIndex, TUint32 aEntry);
sl@0: 
sl@0:     virtual TInt Invalidate();
sl@0:     virtual TInt InvalidateRegion(TUint32 aStartEntry, TUint32 aNumEntries);
sl@0:     //------------------------------------
sl@0: 
sl@0:  private:
sl@0:     
sl@0:     void InitialiseL(CFatMountCB* aOwner, TUint32 aFatSize); 
sl@0: 
sl@0:     CFat12Cache();
sl@0:     CFat12Cache(const CFat12Cache&);
sl@0:     CFat12Cache& operator=(const CFat12Cache&);
sl@0: 
sl@0: 
sl@0:     inline TUint32 NumSectors() const;
sl@0:     void AssertCacheReallyClean() const;
sl@0: 
sl@0:  private:
sl@0: 
sl@0:     enum {KMaxSectorsInCache = 32};  ///< maximal number sectors in FAT12 cache
sl@0:     enum {KFat12EntryMask = 0x0FFF}; ///< FAT12 entry mask
sl@0: 
sl@0:     TUint32 iSectorsInCache;    ///< total number sectors in the cache, KMaxSectorsInCache max.
sl@0:     T32Bits iDirtySectors;      ///< dirty sectors bitmap. '1' bit corresponds to the dirty sector;
sl@0:     RBuf8   iData;              ///< Whole FAT12 cache data.
sl@0: };
sl@0: 
sl@0: 
sl@0: //-----------------------------------------------------------------------------
sl@0: 
sl@0: /**
sl@0:     Abstract base class for paged caches, i.e. those that consist of some number of cache pages.
sl@0:     In this case the most of the functionality is implemented in page classes and this is just a page container.
sl@0:     Each cache page in turn is logically divided to sectors. The sector is a logical unit of write granularity
sl@0:     See also CFatCachePageBase et al.
sl@0: */
sl@0: class CFatPagedCacheBase : public CFatCacheBase
sl@0: {
sl@0:  public:
sl@0: 
sl@0:     inline TUint PageSizeLog2()  const;
sl@0:     inline TUint PageSize()      const;
sl@0:     
sl@0:     inline TUint SectorSizeLog2() const;
sl@0:     inline TUint SectorsInPage()  const;
sl@0: 
sl@0:  protected:
sl@0:     CFatPagedCacheBase();
sl@0: 
sl@0:  protected:
sl@0:     
sl@0:     enum {KMaxSectorsInPage = 32}; ///< maximal number sectors in FAT cache page
sl@0: 
sl@0:     TUint iPageSizeLog2;    ///< Log2(page size)
sl@0:     TUint iSectorSizeLog2;  ///< Log2(page sector size)
sl@0:  
sl@0: };
sl@0: 
sl@0: //-----------------------------------------------------------------------------
sl@0: 
sl@0: class CFat16FixedCachePage;
sl@0: 
sl@0: /**
sl@0:     FAT16 fixed paged cache. Used for FAT16 only and caches whole FAT16 (its max size is 131048 bytes).
sl@0:     Consists of the fixed array of cache pages; Pages are allocated on demand and never get evicted.
sl@0:     Each page is logically divided to page sectors. The number of pages depends on the FAT16 size.
sl@0: 
sl@0:     Read granularity: One page, which size is 2^aRdGranularityLog2
sl@0:     Write granularity: cache's page sector; its size is 2^aWrGranularityLog2
sl@0: */
sl@0: class CFat16FixedCache : public CFatPagedCacheBase
sl@0: {
sl@0:  public:
sl@0: 
sl@0:     static CFat16FixedCache* NewL(CFatMountCB* aOwner, TUint32 aFatSize, TUint32 aRdGranularityLog2, TUint32 aWrGranularityLog2);
sl@0: 
sl@0:     //-- overrides from base class
sl@0:     virtual void Close(TBool aDiscardDirtyData);
sl@0:     virtual void FlushL();
sl@0: 
sl@0:     virtual TUint32 ReadEntryL(TUint32 aIndex);
sl@0:     virtual void WriteEntryL(TUint32 aIndex, TUint32 aEntry);
sl@0:     
sl@0: 
sl@0:     virtual TInt Invalidate();
sl@0:     virtual TInt InvalidateRegion(TUint32 aStartEntry, TUint32 aNumEntries);
sl@0:     //------------------------------------
sl@0: 
sl@0:  private:
sl@0: 
sl@0:     void InitialiseL(CFatMountCB* aOwner, TUint32 aFatSize, TUint32 aRdGranularityLog2, TUint32 aWrGranularityLog2); 
sl@0:     
sl@0:     CFat16FixedCache();
sl@0:     CFat16FixedCache(const CFat16FixedCache&);
sl@0:     CFat16FixedCache& operator=(const CFat16FixedCache&);
sl@0: 
sl@0:     inline TUint NumPages() const;
sl@0:     void AssertCacheReallyClean() const;
sl@0: 
sl@0:  private:    
sl@0:     RPointerArray<CFat16FixedCachePage> iPages;  ///< array of pointer to the cahe pages; if the entry is NULL, it means that the page isn't allocated yet.
sl@0: 
sl@0: };
sl@0: 
sl@0: 
sl@0: //-----------------------------------------------------------------------------
sl@0: 
sl@0: 
sl@0: /**
sl@0:     An abstract base class for the cache page. Paged caches, i.e derived form CFatPagedCacheBase uses this functionality.
sl@0:     Provides an interface and common functionality for all types of cache pages.
sl@0: 
sl@0:     The FAT cache page contains a number of FAT16 or FAT32 entries, their number is always the power of 2.
sl@0:     The page is logically divided into sectors, the maximal number of sectors in the page is KMaxSectorsInPage (32).
sl@0:     The page read granularity is whole page and the write granularity is the sector  (see aRdGranularityLog2, aWrGranularityLog2 from the cache)
sl@0: 
sl@0:     The caching is write-back, i.e WriteCachedEntryL() modifies data in the cache and marks corresponding page sector as dirty.
sl@0:     FlushL() shall be called to flust all dirty sectors in page to the media
sl@0: 
sl@0: */
sl@0: class CFatCachePageBase : public CBase
sl@0: {
sl@0: public:
sl@0:     
sl@0:     ~CFatCachePageBase();
sl@0: 
sl@0:     //----------------
sl@0:     virtual TBool ReadCachedEntryL (TUint32 aFatIndex, TUint32& aResult) = 0;
sl@0:     virtual TBool WriteCachedEntryL(TUint32 aFatIndex, TUint32 aFatEntry) = 0; 
sl@0:     virtual TUint32 ReadFromMediaL(TUint32 aFatIndex) = 0;
sl@0:     virtual void FlushL(TBool aKeepDirty);
sl@0:     
sl@0:     //----------------
sl@0:     inline TBool IsEntryCached(TUint32 aFatIndex) const ;
sl@0:     void Invalidate(TBool aIgnoreDirtyData = EFalse);
sl@0:     
sl@0:     inline TBool IsDirty() const;
sl@0:     inline TBool IsValid() const;
sl@0:     
sl@0:     inline TUint32 StartFatIndex() const;
sl@0: 
sl@0: protected:
sl@0:     CFatCachePageBase(CFatPagedCacheBase& aCache);
sl@0: 
sl@0:     /** possible states of the page */
sl@0:     enum TState
sl@0:         {
sl@0:         EInvalid, ///< the page's data are invalid
sl@0:         EClean,   ///< the page is clean, data valid and the same as on the media  
sl@0:         EDirty    ///< the page is dirty, there are data eventually to be flushed to the media, iDirtySectors contains dirty sectors bitmap.
sl@0:         };
sl@0: 
sl@0:     inline void SetState(TState aState);
sl@0:     inline TState State() const;
sl@0:     inline void SetClean();
sl@0:     inline TUint32 PageSize() const; 
sl@0:     inline TUint32 NumSectors() const; 
sl@0:     
sl@0:     virtual void DoWriteSectorL(TUint32 aSector)=0;
sl@0:     inline TUint32 EntriesInPage() const;
sl@0: 
sl@0: protected:
sl@0:     TUint32 iStartIndexInFAT;   ///< FAT index this page starts from
sl@0:     T32Bits iDirtySectors;      ///< dirty sectors bitmap. '1' bit corresponds to the dirty sector;
sl@0:     CFatPagedCacheBase& iCache; ///< reference to the owher cache
sl@0:     RBuf8   iData;              ///< page Data
sl@0: 
sl@0: private:
sl@0:     TState  iState;             ///< page state
sl@0:     TUint32 iFatEntriesInPage;  ///< number of FAT entries in the page. 
sl@0: 
sl@0: };
sl@0: 
sl@0: 
sl@0: //---------------------------------------------------------------------------------------------------------------------------------
sl@0: 
sl@0: /**
sl@0:     FAT16 cache page. Used only by CFat16FixedCache.
sl@0: */
sl@0: class CFat16FixedCachePage : public CFatCachePageBase
sl@0: {
sl@0:  public:
sl@0:     ~CFat16FixedCachePage() {}
sl@0:     
sl@0:     static CFat16FixedCachePage* NewL(CFatPagedCacheBase& aCache);
sl@0: 
sl@0:     //-- overrides
sl@0:     virtual TBool ReadCachedEntryL (TUint32 aFatIndex, TUint32& aResult);
sl@0:     virtual TBool WriteCachedEntryL(TUint32 aFatIndex, TUint32 aFatEntry); 
sl@0:     virtual TUint32 ReadFromMediaL(TUint32 aFatIndex);
sl@0:     //----
sl@0: 
sl@0:  private:
sl@0:     CFat16FixedCachePage(CFatPagedCacheBase& aCache);
sl@0: 
sl@0:     //-- outlaws here
sl@0:     CFat16FixedCachePage();
sl@0:     CFat16FixedCachePage(const CFat16FixedCachePage&);
sl@0:     CFat16FixedCachePage& operator=(const CFat16FixedCachePage&);
sl@0: 
sl@0:     virtual void DoWriteSectorL(TUint32 aSector);
sl@0: 
sl@0:     inline TFat16Entry* GetEntryPtr(TUint32 aFatIndex) const;
sl@0: 
sl@0:  private:
sl@0:     enum {KFat16EntryMask = 0xFFFF}; ///< FAT16 entry mask
sl@0: };
sl@0: 
sl@0: 
sl@0: 
sl@0: //---------------------------------------------------------------------------------------------------------------------------------
sl@0: 
sl@0: 
sl@0: 
sl@0: #include "sl_fatcache.inl"
sl@0: 
sl@0: 
sl@0: #endif //SL_FAT_CACHE_H
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