windows-nt/Source/XPSP1/NT/com/ole32/stg/h/cache.hxx

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2020-09-26 03:20:57 -05:00
//+---------------------------------------------------------------------------
//
// 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);
#ifdef LARGE_STREAMS
inline ULONGLONG GetSize(void);
#else
inline ULONG GetSize(void);
#endif
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__