Leaked source code of windows server 2003
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250 lines
7.6 KiB

//
//------ Page Structure ---------------------------------------------------
//
#define cbPage 4096 // database logical page size
#define ctagMax 256 // default limit on number of tags
typedef BYTE PGTYP;
// the pragma is bad for efficiency, but we need it here so that the
// THREEBYTES will not be aligned on 4-byte boundary
#pragma pack(1)
typedef struct _pghdr
{
ULONG ulChecksum; // checksum of page, always 1st byte
ULONG ulDBTimeLow; // database time page dirtied
PGNO pgnoFDP; // pgno of FDP which owns this page
SHORT cbFree; // count free bytes
SHORT ibMic; // minimum used byte
SHORT ctagMac; // count tags used
SHORT itagFree; // itag of first free tag
SHORT cbUncommittedFreed; // bytes freed from this page, but *possibly*
// uncommitted (this number will always be
// a subset of cbFree)
THREEBYTES pgnoPrev; // pgno of previous page
THREEBYTES pgnoNext; // pgno of next page
} PGHDR;
typedef struct _pgtrlr
{
PGTYP pgtyp:3;
BYTE bDBTimeHigh:4;
BYTE bitModified:1;
THREEBYTES pgnoThisPage;
} PGTRLR;
typedef struct _tag
{
SHORT cb;
SHORT ib;
} TAG;
/* tag status
/**/
typedef enum { tsLine, tsVacant, tsLink } TS;
typedef struct _page
{
PGHDR;
TAG rgtag[1];
BYTE rgbFiller[ cbPage -
sizeof(PGHDR) - // pghdr
sizeof(TAG) - // rgtag[1]
sizeof(BYTE) - // rgbData[1]
sizeof(PGTRLR) ]; // pgtyp and pgnoThisPage
BYTE rgbData[1];
PGTRLR;
} PAGE;
#pragma pack()
STATIC INLINE VOID PMSetDBTime( PAGE *ppage, QWORD qwDBTime )
{
QWORDX qwx;
qwx.qw = qwDBTime;
ppage->bDBTimeHigh = (BYTE) qwx.h;
ppage->ulDBTimeLow = qwx.l;
}
STATIC INLINE QWORD QwPMDBTime( PAGE *ppage )
{
QWORDX qwx;
qwx.l = ppage->ulDBTimeLow;
qwx.h = (ULONG) ppage->bDBTimeHigh;
return qwx.qw;
}
STATIC INLINE VOID PMIncDBTime( PAGE *ppage )
{
QWORDX qwx;
qwx.qw = QwPMDBTime( ppage );
qwx.qw++;
PMSetDBTime( ppage, qwx.qw );
}
#define bitLink (1L<<31)
#define pgtypFDP ((PGTYP) 0)
#define pgtypRecord ((PGTYP) 1)
#define pgtypIndexNC ((PGTYP) 2)
#define pgtypSort ((PGTYP) 4)
#define PMSetPageType( ppage, pgtypT ) ( (ppage)->pgtyp = pgtypT )
#define PMPageTypeOfPage( ppage ) ( (PGTYP)( (ppage)->pgtyp) )
#ifdef DEBUG
VOID PMSetModified( SSIB *ssib );
VOID PMResetModified( SSIB *pssib );
VOID CheckPgno( PAGE *ppage, PN pn );
#else
#define CheckPgno( ppage, pn )
#define PMSetModified( pssib ) ( (pssib)->pbf->ppage->bitModified = 1 )
#define PMResetModified( pssib ) ( (pssib)->pbf->ppage->bitModified = 0 )
#endif
#define PMPageSetModified( ppage ) ( (ppage)->bitModified = 1 )
#define PMPageResetModified( ppage ) ( (ppage)->bitModified = 0 )
#define FPMPageModified( ppage ) ( (ppage)->bitModified )
#define PMSetPgnoFDP( ppage, pgnoT ) ( (ppage)->pgnoFDP = pgnoT )
#define PgnoPMPgnoFDPOfPage( ppage ) ( (ppage)->pgnoFDP )
#define SetPgno( ppage, pgno ) \
ThreeBytesFromL( &(ppage)->pgnoThisPage, (pgno) )
#define SetPgnoNext( ppage, pgno ) \
ThreeBytesFromL( &(ppage)->pgnoNext, (pgno) )
#define SetPgnoPrev( ppage, pgno ) \
ThreeBytesFromL( &(ppage)->pgnoPrev, (pgno) )
#define PgnoFromPage( ppage, ppgno ) \
LFromThreeBytes( ppgno, &(ppage)->pgnoThisPage )
#ifdef DEBUG
#define PgnoNextFromPage( pssib, ppgno ) \
{ CheckSSIB( pssib ); LFromThreeBytes( ppgno, &(pssib)->pbf->ppage->pgnoNext ); }
#define PgnoPrevFromPage( pssib, ppgno ) \
{ CheckSSIB( (pssib) ); LFromThreeBytes( ppgno, &(pssib)->pbf->ppage->pgnoPrev ); }
#else
#define PgnoNextFromPage( pssib, ppgno ) \
LFromThreeBytes( ppgno, &(pssib)->pbf->ppage->pgnoNext )
#define PgnoPrevFromPage( pssib, ppgno ) \
LFromThreeBytes( ppgno, &(pssib)->pbf->ppage->pgnoPrev )
#endif
#define absdiff( x, y ) ( (x) > (y) ? (x)-(y) : (y)-(x) )
#define pgdiscont( pgno1, pgno2 ) \
( ( (pgno1) == 0 ) || ( (pgno2) == 0 ) ? 0 \
: absdiff( (pgno1), (pgno2) ) / cpgDiscont )
#define ibPgnoPrevPage ( (INT) (ULONG_PTR)&((PAGE *)0)->pgnoPrev )
#define ibPgnoNextPage ( (INT) (ULONG_PTR)&((PAGE *)0)->pgnoNext )
#define ibCbFreeTotal ( (INT) (ULONG_PTR)&((PAGE *)0)->cbFree )
#define ibCtagMac ( (INT) (ULONG_PTR)&((PAGE *)0)->ctagMac )
#define ibPgtyp ( (INT) (ULONG_PTR)&((PAGE *)0)->pgtyp )
#define CbLastFreeSpace(ppage) \
( (ppage)->ibMic \
- sizeof(PGHDR) \
- ( sizeof(TAG) * (ppage)->ctagMac ) )
#define IbCbFromPtag( ibP, cbP, ptagP ) \
{ TAG *_ptagT = ptagP; \
(ibP) = _ptagT->ib; \
(cbP) = _ptagT->cb; \
}
#define PtagFromIbCb( ptagP, ibP, cbP ) \
{ TAG *_ptagT = ptagP; \
_ptagT->ib = (SHORT)(ibP); \
_ptagT->cb = (SHORT)(cbP); \
}
#ifdef DEBUG
#define PMGet( pssib, itagT ) CallS( ErrPMGet( pssib, itagT ) )
#else
#define PMGet( pssib, itagT ) \
{ \
PAGE *ppageT_ = (pssib)->pbf->ppage; \
TAG *ptagT_ = &(ppageT_->rgtag[itagT]); \
Assert( itagT >= 0 ); \
Assert( itagT < (pssib)->pbf->ppage->ctagMac ); \
(pssib)->line.pb = (BYTE *)ppageT_ + ptagT_->ib; \
(pssib)->line.cb = ptagT_->cb; \
}
#endif
#define ItagPMMost( ppage ) ((ppage)->ctagMac - 1)
BOOL FPMFreeTag( SSIB *pssib, INT citagReq );
#ifdef DEBUG
// This call does not guarantee the accuracy of cbUncommittedFree.
// If accuracy is needed, call CbNDFreePageSpace() instead.
#define CbPMFreeSpace( pssib ) ( CheckSSIB(pssib), \
((INT)( (pssib)->pbf->ppage->cbFree - (pssib)->pbf->ppage->cbUncommittedFreed ) ) )
#else
#define CbPMFreeSpace( pssib ) \
((INT)( (pssib)->pbf->ppage->cbFree - (pssib)->pbf->ppage->cbUncommittedFreed ) )
#endif
#if 0 // No longer needed with uncommitted freed page space count
#define PMAllocFreeSpace( pssib, cb ) \
{ \
Assert( (INT)(pssib)->pbf->ppage->cbFree >= cb ); \
(pssib)->pbf->ppage->cbFree -= cb; \
}
#define PMFreeFreeSpace( pssib, cb ) \
{ \
Assert( (INT)(pssib)->pbf->ppage->cbFree >= 0 ); \
(pssib)->pbf->ppage->cbFree += cb; \
Assert( (INT)(pssib)->pbf->ppage->cbFree < cbPage ); \
}
#endif
#ifdef DEBUG
#define AssertBTFOP(pssib) \
Assert( PMPageTypeOfPage((pssib)->pbf->ppage) == pgtypSort || \
PMPageTypeOfPage((pssib)->pbf->ppage) == pgtypFDP || \
(pssib)->itag != 0 || \
( CbNDKey( (pssib)->line.pb ) == 0 && \
!FNDBackLink( *(pssib)->line.pb ) ) \
)
#else
#define AssertBTFOP( pssib )
#endif
#define PbPMGetChunk(pssib, ib) &(((BYTE *)((pssib)->pbf->ppage))[ib])
INT CbPMLinkSpace( SSIB *pssib );
TS TsPMTagstatus( PAGE *ppage, INT itag );
VOID PMInitPage( PAGE *ppage, PGNO pgno, PGTYP pgtyp, PGNO pgnoFDP );
INT ItagPMQueryNextItag( SSIB *pssib );
ERR ErrPMInsert( SSIB *pssib, LINE *rgline, INT cline );
VOID PMDelete( SSIB *ssib );
ERR ErrPMReplace( SSIB *pssib, LINE *rgline, INT cline );
ERR ErrPMGet( SSIB *pssib, INT itag );
VOID PMGetLink( SSIB *pssib, INT itag, LINK *plink );
VOID PMExpungeLink( SSIB *pssib );
VOID PMReplaceWithLink( SSIB *pssib, SRID srid );
VOID PMReplaceLink( SSIB *pssib, SRID srid );
INT CPMIFreeTag( PAGE *ppage );
BOOL FPMEmptyPage( SSIB *pssib );
BOOL FPMLastNode( SSIB *pssib );
BOOL FPMLastNodeWithLinks( SSIB *pssib );
VOID PMDirty( SSIB *pssib );
VOID PMReadAsync( PIB *ppib, PN pn );
ERR ErrPMAccessPage( FUCB *pfucb, PGNO pgno );
#ifdef DEBUG
VOID PageConsistent( PAGE *ppage );
#endif