Source code of Windows XP (NT5)
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//+---------------------------------------------------------------------------
//
// Microsoft Windows
// Copyright (C) Microsoft Corporation, 1992 - 1998
//
// File: PhyStr.hxx
//
// Contents: Buffer/Index package
//
// Classes:
//
// History: 09-Jan-96 KyleP Lifted from CIndex directory
//
//----------------------------------------------------------------------------
#pragma once
#include <pstore.hxx>
#include <pmmstrm.hxx>
class PStorageObject;
class PStorage;
class PSaveProgressTracker;
//+-------------------------------------------------------------------------
//
// Class: CPhysBuffer
//
// Purpose: Encapsulates a reference counted 'buffer'.
//
// History: 07-Mar-92 KyleP Created
// 21-Apr-93 BartoszM Rewrote to use memory mapped files
//
// Notes: Physical buffers are managed objects. They are created
// by physical indexes and property caches.
//
//--------------------------------------------------------------------------
class CPhysBuffer
{
public:
CPhysBuffer( PMmStream& stream,
ULONG PageNo,
BOOL fWrite,
BOOL fIntentToWrite,
BOOL fMap );
~CPhysBuffer();
CPhysBuffer *Next() { return _pphysNext; }
void Link( CPhysBuffer * pphysbuf ) { _pphysNext = pphysbuf; }
void SetIntentToWrite()
{
Win4Assert( _fWrite );
_fNeedToFlush = TRUE;
}
BOOL RequiresFlush() const { return _fNeedToFlush; }
void Reference()
{
InterlockedIncrement( &_cRef );
}
void DeReference( unsigned usn )
{
Win4Assert( 0 != _cRef );
InterlockedDecrement( &_cRef );
_usn = usn;
}
BOOL IsReferenced()
{
return ( 0 != InterlockedCompareExchange( &_cRef,
0,
0 ) );
}
BOOL IsRefCountOne()
{
return ( 1 == _cRef );
}
ULONG PageNumber() { return _PageNo; }
unsigned GetUSN() { return _usn; }
ULONG * GetPage( ULONG nPage )
{
ULONG cpageIntoBuf = nPage & ( PAGES_PER_COMMON_PAGE - 1 );
Win4Assert( ( nPage % PAGES_PER_COMMON_PAGE ) ==
( nPage & ( PAGES_PER_COMMON_PAGE - 1 ) ) );
BYTE * pbBase = (BYTE *) ( _fMap ? _strmBuf.Get() : _xBuffer.Get() );
return (ULONG*)( pbBase + CI_PAGE_SIZE * cpageIntoBuf );
}
void Flush( BOOL fFailFlush );
BOOL IsWritable() { return _fWrite; }
#ifdef CIEXTMODE
void CiExtDump(void *ciExtSelf);
#endif
private:
ULONG _PageNo;
CMmStreamBuf _strmBuf;
PMmStream & _stream;
long _cRef;
unsigned _usn;
CPhysBuffer * _pphysNext;
BOOL _fNeedToFlush; // Is flush required for writable buffers?
BOOL _fWrite;
BOOL _fMap; // TRUE if mapped, FALSE if Read/WriteFile
XArrayVirtual<BYTE> _xBuffer; // buffer to use if not mapped
};
//+-------------------------------------------------------------------------
//
// Class: CBufferCache
//
// Purpose: A cache of buffers
//
// History: 17-Mar-93 BartoszM Created
//
//--------------------------------------------------------------------------
class CBufferCache
{
friend class CBufferCacheIter;
public:
CBufferCache( unsigned cHash );
~CBufferCache();
void Free( BOOL fFailFlush = TRUE );
void Add( CPhysBuffer * pphysBuf, ULONG hash );
CPhysBuffer * Search( ULONG hash, ULONG commonPage );
void Destroy ( ULONG ulPage, BOOL fFailFlush = TRUE );
void Flush( ULONG nHighPage, BOOL fLeaveFlushFlagAlone = FALSE );
void TryToRemoveBuffers( unsigned cLimit );
BOOL MinPageInUse( ULONG & minPage );
unsigned Count() { return _cBuffers; }
#ifdef CIEXTMODE
void CiExtDump(void *ciExtSelf);
#endif
ULONG hash(ULONG nPage)
{
return (nPage/PAGES_PER_COMMON_PAGE) % _cHash;
}
private:
unsigned _cBuffers;
unsigned _cHash;
XArray<CPhysBuffer *> _aPhysBuf;
#if CIDBG == 1
unsigned _cCacheHits;
unsigned _cCacheMisses;
#endif // DBG==1 || CIDBG==1
};
//+-------------------------------------------------------------------------
//
// Class: CBufferCacheIterator
//
// Purpose: Iterates over the cache of buffers
//
// History: 17-Mar-93 BartoszM Created
//
//--------------------------------------------------------------------------
class CBufferCacheIter
{
public:
CBufferCacheIter ( CBufferCache& cache );
BOOL AtEnd() { return _pBuf == 0; }
void operator++();
CPhysBuffer* Get() { return _pBuf; }
private:
CPhysBuffer** _pPhysBuf;
unsigned _idx;
CPhysBuffer* _pBuf;
unsigned _cHash;
};
//+-------------------------------------------------------------------------
//
// Class: CPhysStorage
//
// Purpose: Provides physical access to index pages
//
// History: 07-Mar-92 KyleP Created
// 21-Apr-93 BartoszM Rewrote to use memory mapped files
// 17-Feb-94 KyleP Subclass for PhysIndex / PhysHash
// 10-Apr-94 SrikantS Added the ability to reopen for write
// from read and also to provide support
// for restarting a master merge.
//
//--------------------------------------------------------------------------
const LONGLONG eSigPhysStorage = 0x45524f5453594850i64; // "PHYSTORE"
class CPhysStorage
{
public:
virtual ~CPhysStorage();
void Close();
void Reopen( BOOL fWritable = FALSE );
ULONG * BorrowNewBuffer(ULONG nPage);
ULONG * BorrowBuffer( ULONG nPage,
BOOL fWritable=FALSE,
BOOL fWriteIntent = FALSE );
void ReturnBuffer( ULONG nPage,
BOOL fFlush = FALSE,
BOOL fFailFlush = TRUE );
BOOL RequiresFlush( ULONG nPage );
inline ULONG * BorrowNewLargeBuffer( ULONG nLargePage );
inline ULONG * BorrowLargeBuffer( ULONG nLargePage,
BOOL fWritable = TRUE,
BOOL fWriteIntent = TRUE );
inline void ReturnLargeBuffer( ULONG nLargePage );
ULONG PageSize() const { return _cpageFileSize; }
ULONG PagesInUse() const { return _cpageUsedFileSize; }
WORKID ObjectId() const { return _objectId; }
void Flush( BOOL fLeaveFlushFlagAlone = FALSE );
void SetUsedPagesCount(ULONG cPage)
{
Win4Assert( cPage <= _cpageFileSize );
_cpageUsedFileSize = cPage;
}
BOOL MinPageInUse( ULONG &minPage );
ULONG ShrinkFromFront( ULONG ulFirstPage, ULONG ulNumPages );
void ShrinkToFit();
void UpdatePageCount( CPhysStorage & storage )
{
_cpageFileSize = storage._cpageFileSize;
_cpageUsedFileSize = storage._cpageUsedFileSize;
}
void SetPageGrowth( ULONG cpageGrowth )
{
Win4Assert( cpageGrowth > 0 );
_cpageGrowth = cpageGrowth;
}
void * GetLargePagePointer( ULONG nLargePage );
BOOL WouldLargePageGrowMapping( ULONG nLargePage );
void MakeBackupCopy( CPhysStorage & dst,
PSaveProgressTracker & progressTracker );
WCHAR const * GetPath() { return _stream->GetPath(); }
BOOL IsWritable() const { return _fWritable; }
PStorage & GetStorage() { return _storage; }
#ifdef CIEXTMODE
void CiExtDump(void *ciExtSelf);
#endif
protected:
CPhysStorage( PStorage & storage,
PStorageObject& obj,
WORKID objectId,
unsigned cpageReqSize,
PMmStream * stream,
BOOL fThrowCorruptErrorOnFailures,
unsigned cCachedItems = 0,
BOOL fAllowReadAhead = TRUE );
CPhysStorage( PStorage & storage,
PStorageObject& obj,
WORKID objectId,
PMmStream * stream,
PStorage::EOpenMode mode,
BOOL fThrowCorruptErrorOnFailures,
unsigned cCachedItems = 0,
BOOL fAllowReadAhead = FALSE );
virtual void ReOpenStream() = 0;
const LONGLONG _sigPhysStorage;
PStorage& _storage;
PStorageObject& _obj;
XPtr<PMmStream> _stream;
BOOL _fWritable;
private:
ULONG * LokBorrowOrAddBuffer( ULONG hash,
ULONG commonPage,
ULONG nPage,
BOOL fAdd,
BOOL fWritable,
BOOL fIntentToWrite );
ULONG * LokBorrowNewBuffer( ULONG hash,
ULONG commonPage,
ULONG nPage );
void _GrowFile( ULONG cpageSize );
unsigned _usnGen; // usns for pages
unsigned _cMaxCachedBuffers; // # pages to cache
ULONG _cpageFileSize; // File size on disk
ULONG _cpageUsedFileSize; // # pages in use in file
ULONG _cpageGrowth; // # pages to grow file size
ULONG _iFirstNonShrunkPage; // first page not shrunk
BOOL _fAllowReadAhead; // TRUE if non-mapped IO ok
WORKID _objectId;
BOOL _fThrowCorruptErrorOnFailures; // Should errors during opening
// be marked as catalog corruption ?
XPtr<CMutexSem> _xMutex;
XPtr<CReadWriteAccess> _xRWAccess;
CBufferCache _cache;
};
inline ULONG * CPhysStorage::BorrowNewLargeBuffer( ULONG nLargePage )
{
ULONG *pBuffer = BorrowNewBuffer( nLargePage * PAGES_PER_COMMON_PAGE );
RtlZeroMemory( pBuffer, COMMON_PAGE_SIZE );
return pBuffer;
}
inline ULONG * CPhysStorage::BorrowLargeBuffer(
ULONG nLargePage,
BOOL fWritable,
BOOL fWriteIntent )
{
return BorrowBuffer( nLargePage * PAGES_PER_COMMON_PAGE,
fWritable,
fWriteIntent );
}
inline void CPhysStorage::ReturnLargeBuffer( ULONG nLargePage )
{
ReturnBuffer( nLargePage * PAGES_PER_COMMON_PAGE );
}