Leaked source code of windows server 2003
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//+---------------------------------------------------------------------------
//
// Microsoft Windows
// Copyright (C) Microsoft Corporation, 1995 - 2000.
//
// File: QOptimiz.hxx
//
// Contents: Query optimizer. Chooses indexes and table implementations.
//
// Classes: CQueryOptimizer
//
// History: 21-Jun-95 KyleP Created
//
//----------------------------------------------------------------------------
#pragma once
#include <coldesc.hxx>
#include <xpr.hxx>
#include <cqueue.hxx>
#include <strategy.hxx>
#include <qiterate.hxx>
#include <rstprop.hxx>
#include <timlimit.hxx>
#include <ciintf.h>
#include <frmutils.hxx>
class CPidRemapper;
DECLARE_SMARTP( Columns );
DECLARE_SMARTP( Sort );
class CGenericCursor;
class CSingletonCursor;
const MAX_HITS_FOR_FAST_SORT_BY_RANK_OPT = 2000; // Internal cutoff on # results for
// sorted-by-rank optimization
//+---------------------------------------------------------------------------
//
// Class: CQueryOptimizer
//
// Purpose: Chooses indexes and table strategies.
//
// History: 21-Jun-95 KyleP Created.
//
//----------------------------------------------------------------------------
class CQueryOptimizer
{
public:
CQueryOptimizer( XInterface<ICiCQuerySession>& xQuerySession,
ICiCDocStore *pDocStore,
XRestriction & rst,
CColumnSet const & cols,
CSortSet const * psort,
CPidRemapper const & pidmap,
CRowsetProperties const & rProps,
DWORD dwQueryStatus
);
~CQueryOptimizer();
//
// Table choices.
//
inline BOOL IsMultiCursor() const;
inline BOOL IsFullySorted() const;
inline BOOL IsPositionable() const;
//
// Cursor retrieval
//
inline BOOL RequiresCI() const;
inline void GetCurrentComponentIndex( unsigned & iCurrent,
unsigned & cTotal ) const;
inline BOOL CQueryOptimizer::IsWorkidUnique()
{
//
// If we have a null catalog, we do not have wids in a
// persistent store. So we have to return FALSE here to cause
// the bigtable to associate wids with the matching docs and
// use them wherever wids are needed.
//
return !_fNullCatalog;
}
CGenericCursor * QueryNextCursor( ULONG & status, BOOL& fAbort );
CSingletonCursor * QuerySingletonCursor( BOOL& fAbort );
CTimeLimit & GetTimeLimit();
//
// Singleton support
//
inline void EnableSingletonCursors();
# ifdef CIEXTMODE
void CiExtDump(void *ciExtSelf);
# endif
ULONG MaxResults() const { return _cMaxResults; }
ULONG FirstRows() const { return _cFirstRows; }
BOOL FetchDeferredValue( WORKID wid,
CFullPropSpec const & ps,
PROPVARIANT & var );
BOOL CanPartialDefer()
{
// We cannot partial defer if:
// We have a null catalog OR
// enumOption == CI_ENUM_MUST_NEVER_DEFER
if ( _fNullCatalog )
{
return FALSE;
}
CI_ENUM_OPTIONS enumOption;
SCODE sc = _xQuerySession->GetEnumOption( &enumOption );
if ( FAILED( sc ) )
{
vqDebugOut(( DEB_ERROR, "CanPartialDefer - GetEnumOption returned 0x%x\n", sc ));
return FALSE;
}
return ( enumOption != CI_ENUM_MUST_NEVER_DEFER );
}
private:
//
// Validation
//
BOOL Validate();
//
// Query optimization
//
void ChooseIndexStrategy( CSortSet const * psort, CColumnSet const & cols );
CGenericCursor * ApplyIndexStrategy( ULONG & status, BOOL& fAbort );
ACCESS_MASK _AccessMask() const;
BOOL _fMulti; // TRUE if query requires > 1 cursor.
BOOL _fAtEnd; // TRUE if out of cursors.
BOOL _fFullySorted; // TRUE if current component will iterate
// in sorted order.
DWORD _dwQueryStatus; // The original status
XInterface<ICiCQuerySession> _xQuerySession; // Query session object
XInterface<ICiCDeferredPropRetriever> _xDefPropRetriever; // Deferred property retriever
XInterface<ICiManager> _xCiManager; // Content index
CCiFrameworkParams _frameworkParams; // Admin parameters
BOOL _fSortedByRankOpt; // TRUE if can use CSortedByRankCursor
BOOL _fRankVectorProp; // TRUE if rank vector is in the output column
ULONG _cMaxResults; // Limit on # query results
ULONG _cFirstRows; // only sort and return the first _cFristRows rows
# if CIDBG == 1
XRestriction _xrstOriginal; // For debugging only.
# endif
CPidRemapper const & _pidmap; // VPID/PID/PROPSPEC translations
CTimeLimit _TimeLimit; // execution time limit (must precede _xXpr)
XXpr _xXpr; // Expression (test against object)
XRestriction _xFullyResolvableRst; // Content query
// _TimeLimit must be before _qRstIterator
CQueryRstIterator _qRstIterator; // Iterator over various components of OR query
XColumnSet _xcols; // Used for multi-part queries.
XSortSet _xsort; // Used for multi-part queries.
//
// Singleton support.
//
BOOL _fNeedSingleton; // TRUE if QuerySingletonCursor may be called.
XXpr _xxprSingleton; // Copy of current expression for singleton.
//
// Content queries
//
BOOL _fUseCI; // If TRUE, always use CI value index for property queries.
BOOL _fDeferTrimming; // If TRUE, sorted rank cursor will trim results *after* full fetch from CI
BOOL _fCIRequiredGlobal; // Does the any component of query require a CI ?
BOOL _fCIRequired; // Does the current component of OR query require a CI ?
ACCESS_MASK _am;
CMutexSem _mtxSem; // To serialize when creating deferred prop retriever
BOOL _fNullCatalog; // Do we have a null catalog?
};
inline BOOL CQueryOptimizer::IsMultiCursor() const
{
return _fMulti;
}
inline BOOL CQueryOptimizer::IsFullySorted() const
{
return _fFullySorted || _fSortedByRankOpt;
}
inline BOOL CQueryOptimizer::IsPositionable() const
{
return FALSE;
}
inline void CQueryOptimizer::EnableSingletonCursors()
{
_fNeedSingleton = TRUE;
}
inline BOOL CQueryOptimizer::RequiresCI() const
{
return _fCIRequiredGlobal || _fUseCI;
}
inline void CQueryOptimizer::GetCurrentComponentIndex( unsigned & iCurrent,
unsigned & cTotal ) const
{
_qRstIterator.GetCurComponentIndex( iCurrent, cTotal );
//
// If we're not done, then there is a component waiting inside CQueryOptimizer.
//
if ( !_fAtEnd )
{
Win4Assert( iCurrent >= 2 );
iCurrent--;
}
}
//+-------------------------------------------------------------------------
//
// Member: CQueryOptimizer::_AccessMask, private
//
// Returns: Access mask appropriate given properties in query
//
// History: 23-Oct-95 dlee Created
//
//--------------------------------------------------------------------------
inline ACCESS_MASK CQueryOptimizer::_AccessMask() const
{
return _am;
}
inline CTimeLimit & CQueryOptimizer::GetTimeLimit()
{
return _TimeLimit;
}
DECLARE_SMARTP( QueryOptimizer )