//+--------------------------------------------------------------------------- // // Microsoft Windows // Copyright (C) Microsoft Corporation, 1992 - 1992. // // File: cache.hxx // // Contents: Stream cache code // // Classes: CStreamCache // // Functions: // // History: 26-May-93 PhilipLa Created // //---------------------------------------------------------------------------- #ifndef __CACHE_HXX__ #define __CACHE_HXX__ class CDirectStream; class CDirectory; class CFat; #define CACHESIZE 9 struct SCacheEntry { ULONG ulOffset; SECT sect; ULONG ulRunLength; inline SCacheEntry(); }; inline SCacheEntry::SCacheEntry() { ulOffset = MAX_ULONG; sect = ENDOFCHAIN; ulRunLength = 0; } SAFE_DFBASED_PTR(CBasedDirectStreamPtr, CDirectStream); //+--------------------------------------------------------------------------- // // Class: CStreamCache (stmc) // // Purpose: Cache for stream optimization // // Interface: See below. // // History: 14-Dec-92 PhilipLa Created // //---------------------------------------------------------------------------- class CStreamCache { public: CStreamCache(); ~CStreamCache(); void Init(CMStream *pmsParent, SID sid, CDirectStream *pds); void Empty(void); SCODE GetSect(ULONG ulOffset, SECT *psect); SCODE GetESect(ULONG ulOffset, SECT *psect); SCODE EmptyRegion(ULONG oStart, ULONG oEnd); SCODE Allocate(CFat *pfat, ULONG cSect, SECT *psectStart); SCODE Contig( ULONG ulOffset, BOOL fWrite, SSegment STACKBASED *aseg, ULONG ulLength, ULONG *pcSeg); private: inline CDirectory *GetDir(void); inline CFat * GetFat(void); inline CFat * GetMiniFat(void); inline ULONG GetSize(void); inline SID GetSid(void); inline CFat * SelectFat(void); SCODE GetStart(SECT *psectStart); inline BOOL CheckSegment(ULONG ulOffset, SCacheEntry sce, ULONG *pulCount, SECT *psectCache, ULONG *pulCacheOffset); void CacheSegment(SSegment *pseg); SCacheEntry _ase[CACHESIZE]; CBasedDirectStreamPtr _pds; CBasedMStreamPtr _pmsParent; SID _sid; USHORT _uHighCacheIndex; USHORT _uNextCacheIndex; USHORT _uCacheState; }; #endif // #ifndef __CACHE_HXX__