111 lines
2.4 KiB
C++
111 lines
2.4 KiB
C++
//+---------------------------------------------------------------------------
|
|
//
|
|
// 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__
|