Leaked source code of windows server 2003
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#ifndef _SCB_H
#define _SCB_H
// Redirect Asserts in inline code to seem to fire from this file
#define szAssertFilename __FILE__
// includes
#include <stddef.h>
// tune these constants for optimal performance
// maximum amount of fast memory (cache) to use for sorting
#define cbSortMemFast ( 16 * ( 4088 + 1 ) )
// maximum amount of normal memory to use for sorting
#define cbSortMemNorm ( 1024 * 1024L )
// maximum size for memory resident Temp Table
#define cbResidentTTMax ( 64 * 1024L )
// minimum count of sort pairs effectively sorted by Quicksort
// NOTE: must be greater than 2!
#define cspairQSortMin ( 32 )
// maximum partition stack depth for Quicksort
#define cpartQSortMax ( 16 )
// maximum count of runs to merge at once (fan-in)
#define crunFanInMax ( 16 )
// I/O cluster size (in pages)
#define cpgClusterSize ( 2 )
// define to use predictive preread instead of prereading all runs
//#define PRED_PREREAD
// Sort Page structure
//
// This is a custom page layout for use in the temporary database by sorting
// only. Sufficient structure still remains so that other page reading code
// can recognize that they do not know this format and can continue on their
// merry way.
#pragma pack(1)
typedef struct _spage
{
ULONG ulChecksum; // page checksum
#ifdef PRED_PREREAD
USHORT ibLastSREC; // offset to last unbroken SREC
#endif // PRED_PREREAD
BYTE rgbData[ // free data space =
cbPage // page size
- sizeof( ULONG ) // - ulChecksum
#ifdef PRED_PREREAD
- sizeof( USHORT ) // - ibLastSREC
#endif // PRED_PREREAD
- sizeof( PGTYP ) // - pgtyp
- sizeof( THREEBYTES ) // - pgnoThisPage
];
PGTYP pgtyp; // page type (== pgtypSort)
THREEBYTES pgnoThisPage; // this page's page number
} SPAGE;
#pragma pack()
// returns start of free data area in a sort page
STATIC INLINE BYTE *PbDataStartPspage( SPAGE *pspage )
{
return (BYTE *)( &pspage->rgbData);
}
// returns end of free data area in a sort page + 1
STATIC INLINE BYTE *PbDataEndPspage( SPAGE *pspage )
{
return (BYTE *)( &pspage->pgtyp );
}
// free data space per SPAGE
#define cbFreeSPAGE ( offsetof( SPAGE, pgtyp ) - offsetof( SPAGE, rgbData ) )
// maximum count of SPAGEs' data that can be stored in normal sort memory
#define cspageSortMax ( cbSortMemNorm / cbFreeSPAGE )
// amount of normal memory actually used for sorting
// (designed to make original runs fill pages exactly)
#define cbSortMemNormUsed ( cspageSortMax * cbFreeSPAGE )
// Sort Pair in fast sort memory
//
// (key prefix, index) pairs are sorted so that most of the data that needs
// to be examined during a sort will be loaded into cache memory, allowing
// the sort to run very fast. If two key prefixes are equal, we must go out
// to slower memory to compare the remainder of the keys (if any) to determine
// the proper sort order. This makes it important for the prefixes to be as
// discriminatory as possible for each record.
//
// CONSIDER: adding a flag to indicate that the entire key is present
//
// Indexes are compressed pointers that describe the record's position in
// the slow memory sort buffer. Each record's position can only be known to
// a granularity designated by the size of the normal sort memory. For
// example, if you specify 128KB of normal memory, the granularity is 2
// because the index can only take on 65536 values:
// ceil( ( 128 * 1024 ) / 65536 ) = 2.
// size of key prefix (in bytes)
#define cbKeyPrefix ( 14 )
#pragma pack(1)
// NOTE: sizeof(SPAIR) must be a power of 2 >= 8
typedef struct _spair
{
USHORT irec; // record index
BYTE rgbKey[cbKeyPrefix]; // key prefix
} SPAIR;
#pragma pack()
// addressing granularity of record indexes (fit indexes into USHORT)
// (run disk usage is optimal for cbIndexGran == 1)
#define cbIndexGran ( ( cbSortMemNormUsed + 0xFFFFL ) / 0x10000L )
// maximum index of records that can be stored in normal memory
#define irecSortMax ( cbSortMemNormUsed / cbIndexGran )
// maximum count of SPAIRs' data that can be stored in fast sort memory
// NOTE: we are reserving one for temporary sort key storage (at cspairSortMax)
#define cspairSortMax ( cbSortMemFast / sizeof( SPAIR ) - 1 )
// amount of fast memory actually used for sorting (counting reserve SPAIR)
#define cbSortMemFastUsed ( ( cspairSortMax + 1 ) * sizeof( SPAIR ) )
// count of "Sort Record indexes" required to store count bytes of data
// (This is fast if numbers are chosen to make cbIndexGran a power of 2
// (especially 1) due to compiler optimizations)
STATIC INLINE LONG CirecToStoreCb( LONG cb )
{
return ( cb + cbIndexGran - 1 ) / cbIndexGran;
}
// generalized Sort Record type (encompasses all types)
// NOTE: using void blocks illegal declarations, pointer math, etc
typedef VOID SREC;
// Unique run identifier (first page of run = run id)
typedef PGNO RUN;
#define runNull ( (RUN) pgnoNull )
#define crunAll ( 0x7FFFFFFFL )
// Run Information structure
typedef struct _runinfo
{
RUN run; // this run
CPG cpg; // count of pages in run
LONG cb; // count of bytes of data in run
LONG crec; // count of records in each run
CPG cpgUsed; // count of pages actually used
} RUNINFO;
// Run Link structure (used in RUNLIST)
typedef struct _runlink
{
struct _runlink *prunlinkNext; // next run
RUNINFO runinfo; // runinfo for this run
} RUNLINK;
#define prunlinkNil ( (RUNLINK *) 0 )
// RUNLINK allocation operators
#define PrunlinkRUNLINKAlloc() ( (RUNLINK *) LAlloc( 1, sizeof( RUNLINK ) ) )
#ifdef DEBUG /* Debug check for illegal use of freed runlink */
#define RUNLINKReleasePrcb(prunlink) { LFree( prunlink ); prunlink = prunlinkNil; }
#else
#define RUNLINKReleasePrcb(prunlink) { LFree( prunlink ); }
#endif
// Run List structure
typedef struct _runlist
{
RUNLINK *prunlinkHead; // head of runlist
LONG crun; // count of runs in list
} RUNLIST;
// Merge Tree Node
//
// These nodes are used in the replacement-selection sort tree that merges
// the incoming runs into one large run. Due to the way the tree is set up,
// each node acts as both an internal (loser) node and as an external (input)
// node, with the exception of node 0, which keeps the last winner instead
// of a loser.
typedef struct _mtnode
{
// external node
struct _rcb *prcb; // input run
struct _mtnode *pmtnodeExtUp; // pointer to father node
// internal node
SREC *psrec; // current record
struct _mtnode *pmtnodeSrc; // record's source node
struct _mtnode *pmtnodeIntUp; // pointer to father node
} MTNODE;
// Special values for psrec for replacement-selection sort. psrecNegInf is a
// sentinel value less than any possible key and is used for merge tree
// initialization. psrecInf is a sentinel value greater than any possible key
// and is used to indicate the end of the input stream.
#define psrecNegInf ( (SREC *) -1L )
#define psrecInf ( (SREC *) NULL )
// Optimized Tree Merge Node
//
// These nodes are used to build the merge plan for the depth first merge of
// an optimized tree merge. This tree is built so that we perform the merges
// from the smaller side of the tree to the larger side of the tree, all in
// the interest of increasing our cache locality during the merge process.
typedef struct _otnode
{
RUNLIST runlist; // list of runs for this node
struct _otnode *rgpotnode[crunFanInMax]; // subtrees for this node
struct _otnode *potnodeAllocNext; // next node (allocation)
struct _otnode *potnodeLevelNext; // next node (level)
} OTNODE;
#define potnodeNil ( (OTNODE *) 0 )
// Special value for potnode for the optimized tree merge tree build routine.
// potnodeLevel0 means that the current level is comprised of original runs,
// not of other merge nodes.
#define potnodeLevel0 ( (OTNODE *) -1L )
// OTNODE allocation operators
#define PotnodeOTNODEAlloc() ( (OTNODE *) LAlloc( 1, sizeof( OTNODE ) ) )
#ifdef DEBUG /* Debug check for illegal use of freed otnode */
#define OTNODEReleasePotnode(potnode) { LFree( potnode ); potnode = potnodeNil; }
#else
#define OTNODEReleasePotnode(potnode) { LFree( potnode ); }
#endif
// Sort Control Block (SCB)
typedef struct _scb
{
FCB fcb; // FCB MUST BE FIRST FIELD IN STRUCTURE
JET_GRBIT grbit; // sort grbit
INT fFlags; // sort flags
LONG cRecords; // count of records in sort
// memory-resident sorting
SPAIR *rgspair; // sort pair buffer
LONG ispairMac; // next available sort pair
BYTE *rgbRec; // record buffer
LONG cbCommit; // amount of committed buffer space
LONG irecMac; // next available record index
LONG crecBuf; // count of records in buffer
LONG cbData; // total record data size (actual)
// disk-resident sorting
LONG crun; // count of original runs generated
RUNLIST runlist; // list of runs to be merged
// sort/merge run output
PGNO pgnoNext; // next page in output run
struct _bf *pbfOut; // current output buffer
BYTE *pbOutMac; // next available byte in page
BYTE *pbOutMax; // end of available page
// merge (replacement-selection sort)
LONG crunMerge; // count of runs being read/merged
MTNODE rgmtnode[crunFanInMax]; // merge tree
// merge duplicate removal
BOOL fUnique; // remove duplicates during merge
struct _bf *pbfLast; // last used read ahead buffer
struct _bf *pbfAssyLast; // last used assembly buffer
#ifdef PCACHE_OPTIMIZATION
/* pad to multiple of 32 bytes
/**/
BYTE rgbFiller[12];
#endif
} SCB;
// SCB allocation operators
#define PscbMEMAlloc() (SCB *)PbMEMAlloc( iresSCB )
#ifdef DEBUG /* Debug check for illegal use of freed scb */
#define MEMReleasePscb(pscb) { MEMRelease( iresSCB, (BYTE *) ( pscb ) ); pscb = pscbNil; }
#else
#define MEMReleasePscb(pscb) { MEMRelease( iresSCB, (BYTE *) ( pscb ) ); }
#endif
// SCB fFlags
#define fSCBInsert (1<<0)
#define fSCBIndex (1<<1)
#define fSCBUnique (1<<2)
// SCB fFlags operators
STATIC INLINE VOID SCBSetInsert( SCB *pscb ) { pscb->fFlags |= fSCBInsert; }
STATIC INLINE VOID SCBResetInsert( SCB *pscb ) { pscb->fFlags &= ~fSCBInsert; }
STATIC INLINE BOOL FSCBInsert( SCB *pscb ) { return pscb->fFlags & fSCBInsert; }
STATIC INLINE VOID SCBSetIndex( SCB *pscb ) { pscb->fFlags |= fSCBIndex; }
STATIC INLINE VOID SCBResetIndex( SCB *pscb ) { pscb->fFlags &= ~fSCBIndex; }
STATIC INLINE BOOL FSCBIndex( SCB *pscb ) { return pscb->fFlags & fSCBIndex; }
STATIC INLINE VOID SCBSetUnique( SCB *pscb ) { pscb->fFlags |= fSCBUnique; }
STATIC INLINE VOID SCBResetUnique( SCB *pscb ) { pscb->fFlags &= ~fSCBUnique; }
STATIC INLINE BOOL FSCBUnique( SCB *pscb ) { return pscb->fFlags & fSCBUnique; }
// Sort Record in normal sort memory
//
// There are two types of Sort Records. One type, SRECD, is used for general
// sort records and can have an abitrary record data field. The second type,
// SRECI, is used when we know we are sorting Key/SRID records during index
// creation. SRECI is more compact and therefore allows more records to fit
// in each run in this special (and common) case.
#pragma pack(1)
typedef struct _srecd
{
USHORT cbRec; // record size
BYTE cbKey; // key size
BYTE rgbKey[]; // key
// BYTE rgbData[]; // data (just for illustration)
} UNALIGNED SRECD;
typedef struct _sreci
{
BYTE cbKey; // key size
BYTE rgbKey[]; // key
// SRID srid; // srid (just for illistration)
} UNALIGNED SRECI;
#pragma pack()
// minimum amount of record that must be read in order to retrieve its size
#define cbSRECReadMin ( offsetof( SRECD, cbKey ) )
// the following functions abstract different operations on a sort record pointer
// to perform the appropriate operations, depending on the flags set in the SCB
// returns size of an existing sort record
STATIC INLINE LONG CbSRECSizePscbPsrec( SCB *pscb, SREC *psrec )
{
if ( FSCBIndex( pscb ) )
return sizeof( SRECI ) + ( (SRECI *) psrec )->cbKey + sizeof( SRID );
return ( (SRECD * ) psrec )->cbRec;
}
// calculates size of a potential sort record
STATIC INLINE LONG CbSRECSizePscbCbCb( SCB *pscb, LONG cbKey, LONG cbData )
{
if ( FSCBIndex( pscb ) )
return sizeof( SRECI ) + cbKey + sizeof( SRID );
return sizeof( SRECD ) + cbKey + cbData;
}
// sets size of sort record
STATIC INLINE VOID SRECSizePscbPsrecCb( SCB *pscb, SREC *psrec, LONG cb )
{
if ( !FSCBIndex( pscb ) )
( (SRECD * ) psrec )->cbRec = (USHORT) cb;
}
// returns size of sort record key
STATIC INLINE LONG CbSRECKeyPscbPsrec( SCB *pscb, SREC *psrec )
{
if ( FSCBIndex( pscb ) )
return ( (SRECI *) psrec )->cbKey;
return ( (SRECD * ) psrec )->cbKey;
}
// sets size of sort record key
STATIC INLINE VOID SRECKeySizePscbPsrecCb( SCB *pscb, SREC *psrec, LONG cb )
{
if ( FSCBIndex( pscb ) )
( (SRECI *) psrec )->cbKey = (BYTE) cb;
else
( (SRECD *) psrec )->cbKey = (BYTE) cb;
}
// returns sort record key buffer pointer
STATIC INLINE BYTE *PbSRECKeyPscbPsrec( SCB *pscb, SREC *psrec )
{
if ( FSCBIndex( pscb ) )
return ( (SRECI *) psrec )->rgbKey;
return ( (SRECD *) psrec )->rgbKey;
}
// returns sort record key as a Pascal string
STATIC INLINE BYTE *StSRECKeyPscbPsrec( SCB *pscb, SREC *psrec )
{
if ( FSCBIndex( pscb ) )
return &( (SRECI *) psrec )->cbKey;
return &( (SRECD *) psrec )->cbKey;
}
// returns size of sort record data
STATIC INLINE LONG CbSRECDataPscbPsrec( SCB *pscb, SREC *psrec )
{
if ( FSCBIndex( pscb ) )
return sizeof( SRID );
return ( (SRECD *) psrec )->cbRec - ( (SRECD *) psrec )->cbKey - sizeof( SRECD );
}
// returns sort record data buffer pointer
STATIC INLINE BYTE *PbSRECDataPscbPsrec( SCB *pscb, SREC *psrec )
{
if ( FSCBIndex( pscb ) )
return ( (SRECI *) psrec )->rgbKey + ( (SRECI *) psrec )->cbKey;
return ( (SRECD * ) psrec )->rgbKey + ( (SRECD * ) psrec )->cbKey;
}
// returns pointer to a sort record given a base address and a Sort Record Index
STATIC INLINE SREC *PsrecFromPbIrec( BYTE *pb, LONG irec )
{
return (SREC *) ( pb + irec * cbIndexGran );
}
// Run Control Block
//
// This control block is used for multiple instance use of the run input
// functions ErrSORTIRunOpen, ErrSORTIRunNext, and ErrSORTIRunClose.
typedef struct _rcb
{
SCB *pscb; // associated SCB
RUNINFO runinfo; // run information
struct _bf *rgpbf[cpgClusterSize]; // pinned read ahead buffers
LONG ipbf; // current buffer
BYTE *pbInMac; // next byte in page data
BYTE *pbInMax; // end of page data
LONG cbRemaining; // remaining bytes of data in run
#ifdef PRED_PREREAD
SREC *psrecPred; // SREC used for predictive preread
#endif // PRED_PREREAD
struct _bf *pbfAssy; // record assembly buffer
} RCB;
#define prcbNil ( (RCB *) 0 )
// RCB allocation operators
#define PrcbRCBAlloc() ( (RCB *) LAlloc( 1, sizeof( RCB ) ) )
#ifdef DEBUG /* Debug check for illegal use of freed rcb */
#define RCBReleasePrcb(prcb) { LFree( prcb ); prcb = prcbNil; }
#else
#define RCBReleasePrcb(prcb) { LFree( prcb ); }
#endif
//#define UtilPerfDumpStats( a ) ( 0 )
// End Assert redirection
#undef szAssertFilename
#endif // _SCB_H