--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/userlibandfileserver/fileserver/sfat/sl_cache.h Mon Oct 19 15:55:17 2009 +0100
@@ -0,0 +1,202 @@
+// Copyright (c) 1996-2009 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_cache.h
+//
+//
+
+/**
+ @file
+ @internalTechnology
+*/
+
+#ifndef SL_CACHE_H
+#define SL_CACHE_H
+
+
+//---------------------------------------------------------------------------------------------------------------------------------
+//-- dedicated FAT directory cache related stuff
+
+//-- if defined, a dedicated cache will be used for FAT directories
+#define ENABLE_DEDICATED_DIR_CACHE
+
+//---------------------------------------------------------------------------------------------------------------------------------
+
+
+/**
+ An abstract interface to the media Write-Through cache
+*/
+class MWTCacheInterface
+ {
+public:
+
+ /** Enums for control functions. See Control() */
+ enum TControl
+ {
+ EDisableCache = 0, ///< disable/enable cache, can be used for debug purposes
+ EDumpCache = 1, ///< print full cache content, can be used for debug purposes
+ ECacheInfo = 2, ///< print cache info, can be used for debug purposes
+ };
+
+ virtual ~MWTCacheInterface() {}
+
+ /** the same meaning and parameters as in CRawDisk::ReadL */
+ virtual void ReadL(TInt64 aPos, TInt aLength, TDes8& aDes)=0;
+
+ /** the same meaning and parameters as in CRawDisk::WriteL */
+ virtual void WriteL(TInt64 aPos,const TDesC8& aDes)=0;
+
+ /** Invalidates whole directory cache*/
+ virtual void InvalidateCache(void)=0;
+
+ /** invalidate a single cache page if the aPos is cached*/
+ virtual void InvalidateCachePage(TUint64 aPos)=0;
+
+ /**
+ Finds out if the media position "aPosToSearch" is in the cache and returns cache page information in this case.
+
+ @param aPosToSearch linear media position to lookup in the cache
+ @param aCachedPosStart if "aPosToSearch" is cached, here will be media position of this page start
+
+ @return 0 if aPosToSearch isn't cached, otherwise cache page size in bytes (see also aCachedPosStart).
+ */
+ virtual TUint32 PosCached(const TInt64& aPosToSearch, TInt64& aCachedPosStart) = 0;
+
+ /**
+ @return size of the cache in bytes. Can be 0.
+ */
+ virtual TUint32 CacheSizeInBytes() const = 0;
+
+ /**
+ Make the page indexed by aPos the MRU page in the cache.
+ Assumes cache evicts pages according to LRU algorithm.
+ */
+ virtual void MakePageMRU(TInt64 aPos) = 0;
+
+ /**
+ @return log2 number of the size of the cache in bytes.
+ */
+ virtual TUint32 PageSizeInBytesLog2() const = 0;
+
+ /**
+ Control method.
+
+ @param aFunction control function
+ @param aParam1 just arbitrary parameter
+ @param aParam2 just arbitrary parameter
+ @return Standard error code.
+ */
+ virtual TInt Control(TUint32 aFunction, TUint32 aParam1, TAny* aParam2)=0;
+
+ /**
+ Set cache base position at aBasePos
+ @param aBasePos base position of the cache pages. Affects pages alignment.
+ */
+ virtual void SetCacheBasePos(TInt64 aBasePos)=0;
+
+ };
+
+//---------------------------------------------------------------------------------------------------------------------------------
+
+/**
+This class represents the media Write-Through cache page
+*/
+class CWTCachePage
+ {
+public:
+
+ static CWTCachePage* NewL(TUint32 aPageSizeLog2);
+ void ConstructL(TUint32 aPageSizeLog2);
+
+ ~CWTCachePage();
+
+ inline TBool PosCached(TInt64 aPos) const;
+ inline TUint32 PosInCachePage(TInt64 aPos) const;
+ inline TUint8* PtrInCachePage(TInt64 aPos) const;
+ inline TUint32 PageSize() const;
+
+protected:
+
+ CWTCachePage();
+ CWTCachePage(const CWTCachePage&);
+ CWTCachePage& operator=(const CWTCachePage&);
+
+public:
+
+ TInt32 iValid; ///< 0 if the page doesn't contain valid data
+ TInt64 iStartPos; ///< cache page base media position
+ RBuf8 iData; ///< page Data
+ };
+
+//---------------------------------------------------------------------------------------------------------------------------------
+
+/**
+ Media Write-through cache.
+*/
+class CMediaWTCache : public CBase, public MWTCacheInterface
+ {
+public:
+ ~CMediaWTCache();
+
+ static CMediaWTCache* NewL(TFatDriveInterface& aDrive, TUint32 aNumPages, TUint32 aPageSizeLog2);
+
+ void ConstructL(TUint32 aNumPages, TUint32 aPageSizeLog2);
+
+ //-- 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;
+ void MakePageMRU(TInt64 aPos);
+ TUint32 PageSizeInBytesLog2() const;
+ TInt Control(TUint32 aFunction, TUint32 aParam1, TAny* aParam2);
+ inline void SetCacheBasePos(TInt64 aBasePos);
+ //--
+
+protected:
+ CMediaWTCache();
+ CMediaWTCache(TFatDriveInterface& aDrive);
+
+ inline TInt64 CalcPageStartPos(TInt64 aPos) const;
+ inline TUint32 PageSize() const;
+
+ void MakePageLRU(TInt aPageNo);
+
+ TInt FindPageByPos(TInt64 aPos) const;
+ TUint32 GrabPage() const;
+ TUint32 GrabReadPageL(TInt64 aPos);
+ TUint32 FindOrGrabReadPageL(TInt64 aPos);
+
+protected:
+ TFatDriveInterface& iDrive; ///< reference to the driver for media access
+ TUint32 iPageSizeLog2; ///< Log2 (cache page size)
+ mutable TBool iAllPagesValid;///< ETrue if all cache pages have valid data
+ TInt64 iCacheBasePos; ///< Cache pages base position, used to align them at cluster size
+ RPointerArray<CWTCachePage> iPages; ///< array of pointers to the cache pages. Used for organising LRU list
+ TUint32 iCacheDisabled :1; ///< if not 0 the cache is disabled totally and all reads and writes go via TFatDriveInterface directly
+ };
+
+
+
+
+#include"sl_cache.inl"
+
+#endif //SL_CACHE_H
+
+
+
+