1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/os/kernelhwsrv/userlibandfileserver/fileserver/sfat32/sl_cache.h Fri Jun 15 03:10:57 2012 +0200
1.3 @@ -0,0 +1,202 @@
1.4 +// Copyright (c) 1996-2009 Nokia Corporation and/or its subsidiary(-ies).
1.5 +// All rights reserved.
1.6 +// This component and the accompanying materials are made available
1.7 +// under the terms of the License "Eclipse Public License v1.0"
1.8 +// which accompanies this distribution, and is available
1.9 +// at the URL "http://www.eclipse.org/legal/epl-v10.html".
1.10 +//
1.11 +// Initial Contributors:
1.12 +// Nokia Corporation - initial contribution.
1.13 +//
1.14 +// Contributors:
1.15 +//
1.16 +// Description:
1.17 +// f32\sfat32\inc\sl_cache.h
1.18 +//
1.19 +//
1.20 +
1.21 +/**
1.22 + @file
1.23 + @internalTechnology
1.24 +*/
1.25 +
1.26 +#ifndef SL_CACHE_H
1.27 +#define SL_CACHE_H
1.28 +
1.29 +
1.30 +//---------------------------------------------------------------------------------------------------------------------------------
1.31 +//-- dedicated FAT directory cache related stuff
1.32 +
1.33 +//-- if defined, a dedicated cache will be used for FAT directories
1.34 +#define ENABLE_DEDICATED_DIR_CACHE
1.35 +
1.36 +//---------------------------------------------------------------------------------------------------------------------------------
1.37 +
1.38 +
1.39 +/**
1.40 + An abstract interface to the media Write-Through cache
1.41 +*/
1.42 +class MWTCacheInterface
1.43 + {
1.44 +public:
1.45 +
1.46 + /** Enums for control functions. See Control() */
1.47 + enum TControl
1.48 + {
1.49 + EDisableCache = 0, ///< disable/enable cache, can be used for debug purposes
1.50 + EDumpCache = 1, ///< print full cache content, can be used for debug purposes
1.51 + ECacheInfo = 2, ///< print cache info, can be used for debug purposes
1.52 + };
1.53 +
1.54 + virtual ~MWTCacheInterface() {}
1.55 +
1.56 + /** the same meaning and parameters as in CRawDisk::ReadL */
1.57 + virtual void ReadL(TInt64 aPos, TInt aLength, TDes8& aDes)=0;
1.58 +
1.59 + /** the same meaning and parameters as in CRawDisk::WriteL */
1.60 + virtual void WriteL(TInt64 aPos,const TDesC8& aDes)=0;
1.61 +
1.62 + /** Invalidates whole directory cache*/
1.63 + virtual void InvalidateCache(void)=0;
1.64 +
1.65 + /** invalidate a single cache page if the aPos is cached*/
1.66 + virtual void InvalidateCachePage(TUint64 aPos)=0;
1.67 +
1.68 + /**
1.69 + Finds out if the media position "aPosToSearch" is in the cache and returns cache page information in this case.
1.70 +
1.71 + @param aPosToSearch linear media position to lookup in the cache
1.72 + @param aCachedPosStart if "aPosToSearch" is cached, here will be media position of this page start
1.73 +
1.74 + @return 0 if aPosToSearch isn't cached, otherwise cache page size in bytes (see also aCachedPosStart).
1.75 + */
1.76 + virtual TUint32 PosCached(const TInt64& aPosToSearch, TInt64& aCachedPosStart) = 0;
1.77 +
1.78 + /**
1.79 + @return size of the cache in bytes. Can be 0.
1.80 + */
1.81 + virtual TUint32 CacheSizeInBytes() const = 0;
1.82 +
1.83 + /**
1.84 + Make the page indexed by aPos the MRU page in the cache.
1.85 + Assumes cache evicts pages according to LRU algorithm.
1.86 + */
1.87 + virtual void MakePageMRU(TInt64 aPos) = 0;
1.88 +
1.89 + /**
1.90 + @return log2 number of the size of the cache in bytes.
1.91 + */
1.92 + virtual TUint32 PageSizeInBytesLog2() const = 0;
1.93 +
1.94 + /**
1.95 + Control method.
1.96 +
1.97 + @param aFunction control function
1.98 + @param aParam1 just arbitrary parameter
1.99 + @param aParam2 just arbitrary parameter
1.100 + @return Standard error code.
1.101 + */
1.102 + virtual TInt Control(TUint32 aFunction, TUint32 aParam1, TAny* aParam2)=0;
1.103 +
1.104 + /**
1.105 + Set cache base position at aBasePos
1.106 + @param aBasePos base position of the cache pages. Affects pages alignment.
1.107 + */
1.108 + virtual void SetCacheBasePos(TInt64 aBasePos)=0;
1.109 +
1.110 + };
1.111 +
1.112 +//---------------------------------------------------------------------------------------------------------------------------------
1.113 +
1.114 +/**
1.115 +This class represents the media Write-Through cache page
1.116 +*/
1.117 +class CWTCachePage
1.118 + {
1.119 +public:
1.120 +
1.121 + static CWTCachePage* NewL(TUint32 aPageSizeLog2);
1.122 + void ConstructL(TUint32 aPageSizeLog2);
1.123 +
1.124 + ~CWTCachePage();
1.125 +
1.126 + inline TBool PosCached(TInt64 aPos) const;
1.127 + inline TUint32 PosInCachePage(TInt64 aPos) const;
1.128 + inline TUint8* PtrInCachePage(TInt64 aPos) const;
1.129 + inline TUint32 PageSize() const;
1.130 +
1.131 +protected:
1.132 +
1.133 + CWTCachePage();
1.134 + CWTCachePage(const CWTCachePage&);
1.135 + CWTCachePage& operator=(const CWTCachePage&);
1.136 +
1.137 +public:
1.138 +
1.139 + TInt32 iValid; ///< 0 if the page doesn't contain valid data
1.140 + TInt64 iStartPos; ///< cache page base media position
1.141 + RBuf8 iData; ///< page Data
1.142 + };
1.143 +
1.144 +//---------------------------------------------------------------------------------------------------------------------------------
1.145 +
1.146 +/**
1.147 + Media Write-through cache.
1.148 +*/
1.149 +class CMediaWTCache : public CBase, public MWTCacheInterface
1.150 + {
1.151 +public:
1.152 + ~CMediaWTCache();
1.153 +
1.154 + static CMediaWTCache* NewL(TDriveInterface& aDrive, TUint32 aNumPages, TUint32 aPageSizeLog2);
1.155 +
1.156 + void ConstructL(TUint32 aNumPages, TUint32 aPageSizeLog2);
1.157 +
1.158 + //-- overloads from the base class
1.159 + void ReadL (TInt64 aPos,TInt aLength,TDes8& aDes);
1.160 + void WriteL(TInt64 aPos,const TDesC8& aDes);
1.161 + void InvalidateCache(void);
1.162 + void InvalidateCachePage(TUint64 aPos);
1.163 +
1.164 +
1.165 + TUint32 PosCached(const TInt64& aPosToSearch, TInt64& aCachedPosStart);
1.166 + TUint32 CacheSizeInBytes() const;
1.167 + void MakePageMRU(TInt64 aPos);
1.168 + TUint32 PageSizeInBytesLog2() const;
1.169 + TInt Control(TUint32 aFunction, TUint32 aParam1, TAny* aParam2);
1.170 + inline void SetCacheBasePos(TInt64 aBasePos);
1.171 + //--
1.172 +
1.173 +protected:
1.174 + CMediaWTCache();
1.175 + CMediaWTCache(TDriveInterface& aDrive);
1.176 +
1.177 + inline TInt64 CalcPageStartPos(TInt64 aPos) const;
1.178 + inline TUint32 PageSize() const;
1.179 +
1.180 + void MakePageLRU(TInt aPageNo);
1.181 +
1.182 + TInt FindPageByPos(TInt64 aPos) const;
1.183 + TUint32 GrabPage() const;
1.184 + TUint32 GrabReadPageL(TInt64 aPos);
1.185 + TUint32 FindOrGrabReadPageL(TInt64 aPos);
1.186 +
1.187 +protected:
1.188 + TDriveInterface& iDrive; ///< reference to the driver for media access
1.189 + TUint32 iPageSizeLog2; ///< Log2 (cache page size)
1.190 + mutable TBool iAllPagesValid;///< ETrue if all cache pages have valid data
1.191 + TInt64 iCacheBasePos; ///< Cache pages base position, used to align them at cluster size
1.192 + RPointerArray<CWTCachePage> iPages; ///< array of pointers to the cache pages. Used for organising LRU list
1.193 + TUint32 iCacheDisabled :1; ///< if not 0 the cache is disabled totally and all reads and writes go via TDriveInterface directly
1.194 + };
1.195 +
1.196 +
1.197 +
1.198 +
1.199 +#include"sl_cache.inl"
1.200 +
1.201 +#endif //SL_CACHE_H
1.202 +
1.203 +
1.204 +
1.205 +