userlibandfileserver/fileserver/sfat/sl_dir_cache.h
changeset 43 96e5fb8b040d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/userlibandfileserver/fileserver/sfat/sl_dir_cache.h	Thu Dec 17 09:24:54 2009 +0200
@@ -0,0 +1,206 @@
+// 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 '\sfat' component is obsolete and is not being used.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
+
+
+
+