Windows-Server-2003/inetsrv/query/cindex/pcomp.hxx

616 lines
15 KiB
C++

//+---------------------------------------------------------------------------
//
// Microsoft Windows
// Copyright (C) Microsoft Corporation, 1991 - 2000.
//
// File: PComp.hxx
//
// Contents: Persistent index compressor, and decompressor
//
// Classes: CCoder, CKeyComp, CPersComp
//
// History: 03-Jul-91 KyleP Created
// 05-Nov-91 BartoszM Restructured to use CCoder
// 05-Dec-93 w-PatG Restructured to use CKeyComp
//
// Notes: The CKeyComp class is under development, testing phase.
// Several revisions must be made to increase the amount of
// inheritence, and improve the coding algorithm used by CKeyComp.
//
//----------------------------------------------------------------------------
#pragma once
#include <keycur.hxx>
#include <misc.hxx>
#include <pdir.hxx>
#include "bitstm.hxx"
#define LINK_MAX_BITS (CI_PAGE_SHIFT + 8) // The max. value of "link" of the persistent index
#define LINK_MAX_VALUE ( 1 << LINK_MAX_BITS ) //
const unsigned OccDeltaBits = 7; // Bits to initially store an
// occurrence delta.
class CPageBuffer;
//+---------------------------------------------------------------------------
//
// Class: CCoder
//
// Purpose: Common class for encoding/decoding of compressed data
//
// Interface:
//
// History: 05-Nov-91 BartoszM Created
//
//----------------------------------------------------------------------------
class CCoder
{
public:
CCoder(WORKID widMax);
CCoder(WORKID widMax, const CKeyBuf& keyInit);
CCoder(CCoder& orig);
virtual ~CCoder();
#if DEVL == 1
void Dump();
#endif
#ifdef CIEXTMODE
void CiExtDump(void *ciExtSelf);
#endif
protected:
UINT AverageWidBits ( UINT cWid );
void SetAverageBits ( UINT cWid )
{ _cbitAverageWid = AverageWidBits ( cWid ); }
const WORKID _widMaximum; // Maximum workid in current index
CKeyBuf _key;
WORKID _wid;
OCCURRENCE _occ;
UINT _cbitAverageWid; // Log of the average WorkId delta.
};
__forceinline UINT CCoder::AverageWidBits ( UINT cWid )
{
ciAssert ( cWid != 0 );
ciAssert ( _widMaximum / cWid != 0 );
UINT x = Log2(_widMaximum / cWid);
ciAssert ( x <= ULONG_BITS );
ciAssert ( x > 0 );
return x;
}
//+---------------------------------------------------------------------------
//
// Class: CKeyComp (kcomp)
//
// Purpose: Key compressor
//
// Interface: (Under development)
//
// History: 12-Nov-93 w-PatG Created.
//
// Notes: Derived class that lies between base class CCoder and further
// derived class CPersCoder.
//----------------------------------------------------------------------------
const LONGLONG eSigKeyComp = 0x20504d4f4359454bi64; // "KEYCOMP"
class CKeyComp: public CCoder
{
public:
CKeyComp(CPhysIndex& phIndex, WORKID widMax, BOOL fUseLinks = TRUE);
CKeyComp(CPhysIndex& phIndex,
WORKID widMax,
const BitOffset & bitOffRestart,
const BitOffset & bitOffSplitKey,
const CKeyBuf & splitKey,
BOOL fUseLinks = TRUE);
~CKeyComp();
void PutKey(const CKeyBuf * pkey, BitOffset & bitOffCurKey);
__forceinline void GetOffset( BitOffset & bitOff )
{
_bitStream.GetOffset( bitOff );
}
__forceinline BOOL IsAtSentinel()
{
return _key.IsMaxKey();
}
#if DEVL == 1
void Dump();
#endif
void ZeroToEndOfPage()
{
_bitStream.ZeroToEndOfPage();
}
void InitSignature()
{
_bitStream.InitSignature();
}
void WriteFirstKeyFull() { _fWriteFirstKeyFull = TRUE; }
#ifdef CIEXTMODE
void CiExtDump(void *ciExtSelf);
#endif
void FreeStream()
{
_bitStream.FreeStream();
_bitStreamLink.FreeStream();
}
protected:
void BitCompress(ULONG ul, unsigned cbitAverage);
void IBitCompress(ULONG ul, unsigned cbitAverage, unsigned bitSize);
void PutPSSize ( unsigned cPrefix, unsigned cSuffix );
void PutPid ( PROPID pid );
const LONGLONG _sigKeyComp; //
CPhysIndex & _phIndex; // The Physical Index for the bitstream
CWBitStream _bitStream; // must be created first
BOOL _fUseLinks;
CPBitStream _bitStreamLink;
BitOffset _bitOffCurKey; // These two bitOffsets are used to rewind
BitOffset _bitOffLastKey; // the compressor to the previous key.
BOOL _fWriteFirstKeyFull; // Write first key on each page fully
};
//+---------------------------------------------------------------------------
//
// Class: CKeyDeComp (kdcomp)
//
// Purpose: Persistent key de-compressor
//
// Interface:
//
// History: 09-Jul-91 KyleP Created.
// 22-Nov-93 w-PatG Converted from CPersDeComp
//
// Notes: One of the key requirements for using de-compressors is
// that if an operation fails because the end of page was
// reached, that *same* operation must be the first one
// performed on the following compressor.
//
//----------------------------------------------------------------------------
const LONGLONG eSigKeyDeComp = 0x504d4f434459454bi64; // "KEYDCOMP"
class CKeyDeComp: public CCoder, public CKeyCursor
{
public:
CKeyDeComp( PDirectory& pDir,
INDEXID iid,
CPhysIndex& phIndex,
WORKID widMax,
BOOL fUseLinks = TRUE,
BOOL fUseDir = TRUE );
CKeyDeComp( PDirectory& pDir,
INDEXID iid,
CPhysIndex& phIndex,
BitOffset& posKey,
const CKeyBuf& keyInit,
const CKey* pKey,
WORKID widMax,
BOOL fUseLinks = TRUE,
BOOL fUseDir = TRUE );
CKeyDeComp( CKeyDeComp & decomp );
~CKeyDeComp();
const CKeyBuf * GetKey();
const CKeyBuf * GetNextKey();
virtual const CKeyBuf * GetNextKey( BitOffset * pBitOff );
virtual const CKeyBuf * GetKey( BitOffset * pBitOff );
PROPID Pid();
void GetOffset( BitOffset & bitOff );
void FreeStream() { _bitStream.FreeStream(); }
void RefillStream() { _bitStream.RefillStream(); }
//
// Unused. Required for inheritance.
//
OCCURRENCE Occurrence();
OCCURRENCE NextOccurrence();
ULONG OccurrenceCount();
OCCURRENCE MaxOccurrence();
WORKID WorkId();
WORKID NextWorkId();
ULONG HitCount();
#if DEVL == 1
void Dump();
#endif
#ifdef CIEXTMODE
void CiExtDump(void *ciExtSelf);
#endif
protected:
const CKeyBuf* SeekKey(const CKey* pKey);
ULONG BitUnCompress(unsigned cbitAverage);
ULONG IBitUnCompress(unsigned cbitAverage, ULONG ulPartial);
void LoadKey();
void LoadPSSize ( unsigned& cPrefix, unsigned& cSuffix );
void LoadPid ();
BOOL IsAtSentinel() const { return _fAtSentinel; }
const LONGLONG _sigKeyDeComp;
CRBitStream _bitStream;
BOOL _fUseLinks;
BitOffset _bitOffNextKey;
PDirectory& _pDir;
BOOL _fUseDir;
BOOL _fAtSentinel; // TRUE if at sentinel (end) key.
CPhysIndex & _physIndex;
#if (CIDBG == 1)
BOOL _fLastKeyFromDir; // TRUE if last key looked up in directory
#else
BOOL _fDummy; // to keep chk/free size the same
#endif
};
//+---------------------------------------------------------------------------
//
// Class: CPersComp (pcomp)
//
// Purpose: Persistent index compressor
//
// Interface:
//
// History: 03-Jul-91 KyleP Created.
// 02-Dec-93 w-PatG Altered to use CKeyComp.
//
//----------------------------------------------------------------------------
const LONGLONG eSigPersComp = 0x504d4f4353524550i64; // "PERSCOMP"
class CPersComp: public CKeyComp
{
public:
CPersComp(CPhysIndex& phIndex, WORKID widMax);
CPersComp(CPhysIndex& phIndex, WORKID widMax,
const BitOffset & bitOffRestart,
const BitOffset & bitoffSplitKey,
const CKeyBuf & splitKey );
~CPersComp();
void PutKey(const CKeyBuf * pkey,
ULONG cWorkId,
BitOffset & bitOffCurKey);
void PutWorkId(WORKID wid, OCCURRENCE maxOcc, ULONG cOccurrence);
inline void PutOccurrence(OCCURRENCE occ);
#if DEVL == 1
void Dump();
#endif
#ifdef CIEXTMODE
void CiExtDump(void *ciExtSelf);
#endif
void FreeStream()
{
_bitStreamPatch.FreeStream();
CKeyComp::FreeStream();
}
protected:
inline void BackSpace();
void SetCWIDAccuracy();
void PatchWidCount ();
void PutWidCount ( ULONG cWorkId );
void SkipWidCount ();
void PutMaxOccurrence( OCCURRENCE maxOcc );
const LONGLONG _sigPersComp;
unsigned _cWidActual; // Used to decide if the originally
unsigned _cWidProposed; // Original WorkId count. Used to
// allocate space for the count.
CPBitStream _bitStreamPatch; // Used to back patch wid count
// created after main _bitStream
#if DEVL == 1
unsigned _cOccLeft; // ciVerify the specified number of
#endif
};
//+---------------------------------------------------------------------------
//----------------------------------------------------------------------------
inline void CPersComp::BackSpace()
{
_bitStream.Seek(_bitOffCurKey);
if ( _fUseLinks ) _bitStreamLink.Seek(_bitOffLastKey);
ZeroToEndOfPage();
_phIndex.SetUsedPagesCount( _bitOffCurKey.Page() + 1 );
_cWidProposed = _cWidActual;
_key.SetCount( 0 );
}
//+---------------------------------------------------------------------------
//
// Class: CPersDeComp (pdcomp)
//
// Purpose: Persistent index de-compressor
//
// Interface:
//
// History: 09-Jul-91 KyleP Created.
// 02-Dec-93 w-PatG Altered to use CKeyComp.
//
// Notes: One of the key requirements for using de-compressors is
// that if an operation fails because the end of page was
// reached, that *same* operation must be the first one
// performed on the following compressor.
//
//
//----------------------------------------------------------------------------
const LONGLONG eSigPersDeComp = 0x504d434453524550i64; // "PERSDCMP"
class CPersDeComp: public CKeyDeComp
{
public:
CPersDeComp(
PDirectory& pDir,
INDEXID iid,
CPhysIndex& phIndex,
WORKID widMax,
BOOL fUseLinks = TRUE,
BOOL fUseDir = TRUE );
CPersDeComp(
PDirectory& pDir,
INDEXID iid,
CPhysIndex& phIndex,
BitOffset& posKey,
const CKeyBuf& keyInit,
const CKey* pKey,
WORKID widMax,
BOOL fUseLinks = TRUE,
BOOL fUseDir = TRUE);
CPersDeComp(CPersDeComp& orig);
~CPersDeComp();
const CKeyBuf * GetNextKey();
const CKeyBuf * GetNextKey( BitOffset * pbitOff );
WORKID WorkId();
WORKID NextWorkId();
ULONG WorkIdCount();
OCCURRENCE Occurrence();
OCCURRENCE NextOccurrence();
OCCURRENCE MaxOccurrence() { return _maxOcc; }
ULONG OccurrenceCount();
ULONG HitCount() {
return OccurrenceCount();
}
void RatioFinished ( ULONG& denom, ULONG& num );
#if DEVL == 1
void Dump();
#endif
#ifdef CIEXTMODE
void CiExtDump(void *ciExtSelf);
#endif
private:
void LoadKey();
void FinishKeyLoad();
void LoadWorkId();
void LoadOccurrence();
void LoadFirstOccurrence();
void LoadWidCount ();
void LoadMaxOccurrence();
const LONGLONG _sigPersDeComp;
//
// 'Current' state of the decompressor. These values are always
// valid and are returned by the various Get functions.
//
ULONG _cWid;
ULONG _cOcc;
OCCURRENCE _maxOcc;
//
// 'Transient' state. Helps the decompressor figure out what/where
// its decompressing.
//
BOOL _fcwidAccurate;
ULONG _cWidLeft;
ULONG _cOccLeft;
};
//+---------------------------------------------------------------------------
//
// Member: CPersComp::PutOccurrence, public
//
// Synopsis: Store an occurrence for the current WorkId.
//
// Arguments: [occ] -- The occurrence to store.
//
// Modifies: [occ] is added to the persistent index.
//
// History: 08-Jul-91 KyleP Created.
//
//----------------------------------------------------------------------------
__forceinline void CPersComp::PutOccurrence(OCCURRENCE occ)
{
ciAssert(occ != OCC_INVALID);
ciAssert(occ > _occ);
ciAssert(_cOccLeft > 0);
ciDebugOut (( DEB_PCOMP | DEB_NOCOMPNAME,"%d ", occ ));
BitCompress(occ - _occ, OccDeltaBits);
_occ = occ;
#if CIDBG == 1
_cOccLeft--;
#endif
}
//+---------------------------------------------------------------------------
//
// Member: CKeyComp::BitCompress, private
//
// Synopsis: Compress and store a number.
//
// Arguments: [ul] -- Number to store.
//
// [cbitAverage] -- Minimum number of bits to store.
//
// Algorithm: First, store the bottom cbitAverage bits.
// while there are more bits to store
// store a 1 bit indicating more to follow
// store the next n bits, where n = 2, 3, 4, ...
// store a 0 bit indicating end of sequence
//
// History: 08-Jul-91 KyleP Created.
// 06-Dec-93 w-PatG Moved from CPersComp.
//
//----------------------------------------------------------------------------
__forceinline void CKeyComp::BitCompress(ULONG ul, unsigned cbitAverage)
{
ciAssert(cbitAverage > 0);
ciAssert(cbitAverage <= ULONG_BITS );
unsigned bitSize = Log2(ul);
//
// If bitSize < cbitAverage then rightshift
// to make it cbitAverage and store cbitAverage bits
// plus the signal bit (0 = done, 1 = more)
//
if (bitSize <= cbitAverage)
{
//
// Store cbitAverage bits of ul
// plus a trailing 0 bit for end-of-sequence
// cbitAverage == ULONG_BITS (maximum!) is a special case,
// no trailing bit is used.
if (cbitAverage < ULONG_BITS)
_bitStream.PutBits(ul << 1, cbitAverage + 1);
else
{
ciAssert(cbitAverage == ULONG_BITS);
_bitStream.PutBits(ul, ULONG_BITS);
}
}
else
IBitCompress(ul, cbitAverage, bitSize);
}
__forceinline PROPID CKeyDeComp::Pid()
{
return GetKey()?
_key.Pid():
pidInvalid;
}