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//+---------------------------------------------------------------------------
//
// Copyright (C) 1995-1995, Microsoft Corporation.
//
// File: rowseek.hxx
//
// Contents: Declarations of classes for row seek descriptions,
// used with the IRowset implementations.
//
// Classes: CRowSeekDescription - base class
// CRowSeekNext - for GetNextRows
// CRowSeekAt - for GetRowsAt
// CRowSeekAtRatio - for GetRowsAtRatio
// CRowSeekByBookmark - for GetRowsByBookmark
// CRowSeekByValues - for GetRowsByValues (maybe someday)
//
// History: 03 Apr 1995 AlanW Created
//
//----------------------------------------------------------------------------
#pragma once
#include <bigtable.hxx>
//+-------------------------------------------------------------------------
//
// Class: CRowSeekDescription
//
// Purpose: Describes row positioning operation for a GetRows call
//
// Notes: This is a base class for one of several derived classes
// that give row positioning parameters for various types of
// GetRows operations.
//
//--------------------------------------------------------------------------
enum RowSeekMethod{ eRowSeekNull = 0, eRowSeekCurrent = 1, eRowSeekAt = 2, eRowSeekAtRatio = 3, eRowSeekByBookmark = 4,};
class CRowSeekDescription{public: CRowSeekDescription( DWORD eType, CI_TBL_CHAPT chapt ) : _chapt( chapt ) { }
virtual ~CRowSeekDescription( ) { }
virtual void Marshall( PSerStream & stm ) const = 0;
virtual unsigned MarshalledSize( void ) const;
virtual BOOL IsCurrentRowSeek(void) const { return FALSE; }
virtual BOOL IsByBmkRowSeek(void) const { return FALSE; }
virtual SCODE GetRows( CTableCursor & rCursor, CTableSource & rTable, CGetRowsParams& rFetchParams, XPtr<CRowSeekDescription>& pSeekDescOut) const = 0;
virtual void MergeResults( CRowSeekDescription * pRowSeek );
virtual BOOL IsDone(void) const { return FALSE; }
CI_TBL_CHAPT GetChapter() const { return _chapt; }
protected: void MarshallBase( PSerStream & stm, DWORD eType ) const;
void SetChapter(CI_TBL_CHAPT Chapter) { _chapt = Chapter; }
private:
CI_TBL_CHAPT _chapt;};
//+-------------------------------------------------------------------------
//
// Class: CRowSeekNext
//
// Purpose: Describes row positioning operation for a GetNextRows call.
// The only parameter is the number of rows to be skipped prior
// to the transfer operation.
//
//--------------------------------------------------------------------------
class CRowSeekNext: public CRowSeekDescription{public: CRowSeekNext( CI_TBL_CHAPT chapt, LONG cRowsToSkip ) : CRowSeekDescription( eRowSeekCurrent, chapt ) { SetSkip( cRowsToSkip ); }
CRowSeekNext( PDeSerStream & stm, int iVersion );
BOOL IsCurrentRowSeek(void) const { return TRUE; }
void Marshall( PSerStream & stm ) const;
SCODE GetRows( CTableCursor & rCursor, CTableSource & rTable, CGetRowsParams& rFetchParams, XPtr<CRowSeekDescription>& pSeekDescOut) const;
LONG GetSkip() const { return _cSkip; }
void SetSkip(LONG cRowsToSkip) { _cSkip = cRowsToSkip; }
private: LONG _cSkip; // rows to skip
};
//+-------------------------------------------------------------------------
//
// Class: CRowSeekAt
//
// Purpose: Describes row positioning operation for a GetRowsAt call.
// The parameters are the bookmark for the desired position,
// and the offset from that position.
//
//--------------------------------------------------------------------------
class CRowSeekAt: public CRowSeekDescription{public: CRowSeekAt( HWATCHREGION hRegion, CI_TBL_CHAPT chapt, LONG lRowOffset, CI_TBL_BMK bmk ) : CRowSeekDescription( eRowSeekAt, chapt ), _hRegion (hRegion), _cRowsOffset ( lRowOffset ), _bmkOffset ( bmk ) { }
CRowSeekAt( PDeSerStream & stm, int iVersion );
void Marshall( PSerStream & stm ) const;
SCODE GetRows( CTableCursor & rCursor, CTableSource & rTable, CGetRowsParams& rFetchParams, XPtr<CRowSeekDescription>& pSeekDescOut) const;
WORKID Bmk() const { return (WORKID)_bmkOffset; }
LONG Offset() const { return _cRowsOffset; }
private: HWATCHREGION _hRegion; LONG _cRowsOffset; CI_TBL_BMK _bmkOffset;};
//+-------------------------------------------------------------------------
//
// Class: CRowSeekAtRatio
//
// Purpose: Describes row positioning operation for a GetRowsAtRatio
// call. The parameters are the numerator and denominator
// of the ratio. If this operation is restarted, the class
// is transformed into a CRowSeekAt for the restart wid
// and a skip of one.
//
//--------------------------------------------------------------------------
class CRowSeekAtRatio: public CRowSeekDescription{public: CRowSeekAtRatio( HWATCHREGION hRegion, CI_TBL_CHAPT chapt, ULONG ulNum, ULONG ulDen ) : CRowSeekDescription( eRowSeekAtRatio, chapt ), _hRegion (hRegion), _ulNumerator( ulNum ), _ulDenominator( ulDen ) { }
CRowSeekAtRatio( PDeSerStream & stm, int iVersion );
void Marshall( PSerStream & stm ) const;
SCODE GetRows( CTableCursor & rCursor, CTableSource & rTable, CGetRowsParams& rFetchParams, XPtr<CRowSeekDescription>& pSeekDescOut) const;
ULONG RatioNumerator() const { return _ulNumerator; }
ULONG RatioDenominator() const { return _ulDenominator; }
private: HWATCHREGION _hRegion; ULONG _ulNumerator; ULONG _ulDenominator;};
//+-------------------------------------------------------------------------
//
// Class: CRowSeekByBookmark
//
// Purpose: Describes row positioning operation for a GetRowsByBookmark
// call. The parameter is an array of bookmarks.
// This class also contains an array of SCODEs to record
// the status of bookmark lookups.
//
//--------------------------------------------------------------------------
class CRowSeekByBookmark: public CRowSeekDescription{public: //
// NOTE: For this constructor, the CRowSeekDescription will now
// own the memory pointed to by pBookmarks.
CRowSeekByBookmark( CI_TBL_CHAPT chapt, ULONG cBookmarks, CI_TBL_BMK * pBookmarks = 0 ) : CRowSeekDescription( eRowSeekByBookmark, chapt ), _cBookmarks ( cBookmarks ), _maxRet ( cBookmarks ), _aBookmarks ( pBookmarks ), _cValidRet ( 0 ), _ascRet ( 0 ) { if (0 == pBookmarks) _cBookmarks = 0; }
CRowSeekByBookmark( PDeSerStream & stm, int iVersion );
virtual ~CRowSeekByBookmark( );
virtual BOOL IsByBmkRowSeek(void) const { return TRUE; }
void Marshall( PSerStream & stm ) const;
SCODE GetRows( CTableCursor & rCursor, CTableSource & rTable, CGetRowsParams& rFetchParams, XPtr<CRowSeekDescription>& pSeekDescOut) const;
void MergeResults( CRowSeekDescription * pRowSeek );
BOOL IsDone(void) const { return _cBookmarks == 0; }
ULONG GetValidStatuses(void) { return _cValidRet; }
SCODE GetStatus(unsigned i) { return _ascRet[i]; }
private: void _SetStatus( unsigned i, SCODE sc);
ULONG _cBookmarks; // size of _aBookmarks
ULONG _maxRet; // size of _ascRet
ULONG _cValidRet; // number of valid entries in _ascRet
CI_TBL_BMK* _aBookmarks; // array of bookmarks
SCODE* _ascRet; // array of returned statuses
};
//+-------------------------------------------------------------------------
//
// Function: MarshallRowSeekDescription, public inline
//
// Synopsis: Marshall a row seek description and assign to a smart
// pointer.
//
// Arguments: [stmSer] - Deserialization stream
// [iVersion] - output stream version
// [pRowSeek] - pointer to row seek description
//
// Returns: Nothing. Throws if error.
//
// History: 02 May 1995 AlanW Created
//
//+-------------------------------------------------------------------------
inline void MarshallRowSeekDescription( PSerStream &stmSer, int iVersion, CRowSeekDescription* pRowSeek){ if (0 == pRowSeek) { stmSer.PutULong(eRowSeekNull); } else { pRowSeek->Marshall(stmSer); }}
//+-------------------------------------------------------------------------
//
// Function: UnmarshallRowSeekDescription, public inline
//
// Synopsis: Unmarshall a row seek description and assign to a smart
// pointer.
//
// Arguments: [stmDeser] - Deserialization stream
// [iVersion] - input stream version
// [xpRowSeek] - smart pointer to row seek description
//
// Returns: Nothing. Throws if error.
//
// History: 02 May 1995 AlanW Created
//
//+-------------------------------------------------------------------------
inline void UnmarshallRowSeekDescription( PDeSerStream & stmDeser, int iVersion, XPtr<CRowSeekDescription> & xpRowSeek, BOOL fAllowNull ){ //
// Deserialize the row seek description
//
ULONG eMethod = stmDeser.GetULong();
switch (eMethod) { case eRowSeekNull: if ( !fAllowNull ) THROW( CException( STATUS_INVALID_PARAMETER ) ); break;
case eRowSeekCurrent: xpRowSeek.Set( new CRowSeekNext( stmDeser, iVersion ) ); break;
case eRowSeekAt: xpRowSeek.Set( new CRowSeekAt( stmDeser, iVersion ) ); break;
case eRowSeekAtRatio: xpRowSeek.Set( new CRowSeekAtRatio( stmDeser, iVersion ) ); break;
case eRowSeekByBookmark: xpRowSeek.Set( new CRowSeekByBookmark( stmDeser, iVersion ) ); break;
default: // Don't assert or the pipe hacking test will stop
// Win4Assert( eMethod <= eRowSeekByBookmark );
ciDebugOut(( DEB_ERROR, "UnmarshallRowSeekDescription, invalid eMethod: %d\n", eMethod ));
THROW( CException( STATUS_INVALID_PARAMETER ) ); }}
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