Leaked source code of windows server 2003
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//+---------------------------------------------------------------------------
//
// Microsoft Windows
// Copyright (C) Microsoft Corporation, 1995 - 1998.
//
// File: SeqSort.cxx
//
// Contents: Sequential cursor for sorted results.
//
// Classes: CSequentialSerial
//
// History: 05-Jun-95 KyleP Created
// 14-Jan-97 KrishnaN Undefined CI_INETSRV and
// related changes
//
//----------------------------------------------------------------------------
#include <pch.cxx>
#pragma hdrstop
#include "seqsort.hxx"
#include "rowman.hxx"
#include "rowcache.hxx"
// Rowset object Interfaces that support Ole DB error objects
static const IID * apRowsetErrorIFs[] =
{
&IID_IAccessor,
&IID_IColumnsInfo,
&IID_IConvertType,
&IID_IRowset,
&IID_IRowsetInfo,
//&IID_IRowsetWatchRegion,
//&IID_IRowsetAsynch,
&IID_IRowsetQueryStatus,
//&IID_IColumnsRowset,
&IID_IConnectionPointContainer,
&IID_IRowsetIdentity,
//&IID_IRowsetLocate,
//&IID_IRowsetResynch,
//&IID_IRowsetScroll,
//&IID_IRowsetUpdate,
//&IID_ISupportErrorInfo
};
static const ULONG cRowsetErrorIFs = sizeof(apRowsetErrorIFs)/sizeof(apRowsetErrorIFs[0]);
//+---------------------------------------------------------------------------
//
// Member: CSequentialSorted::CSequentialSorted, public
//
// Synopsis: Constructor.
//
// Arguments: [pUnkOuter] -- outer unknown
// [ppMyUnk] -- OUT: on return, filled with pointer to my
// non-delegating IUnknown
// [aChild] -- Child rowset(s).
// [cChild] -- Count of rowsets in [aChild].
// [Props] -- Rowset properties.
// [cCol] -- Number of original columns.
// [Sort] -- Sort specification.
//
// History: 05-Jun-95 KyleP Created.
//
//----------------------------------------------------------------------------
CSequentialSorted::CSequentialSorted( IUnknown * pUnkOuter,
IUnknown ** ppMyUnk,
IRowset ** aChild,
unsigned cChild,
CMRowsetProps const & Props,
unsigned cCol,
CSort const & Sort,
CAccessorBag & aAccessors) :
CDistributedRowset( pUnkOuter, ppMyUnk,
aChild, cChild, Props, cCol,
aAccessors, _DBErrorObj ),
_apCursor( cChild ),
_bindSort( Sort.Count() ),
#pragma warning(disable : 4355) // 'this' in a constructor
_DBErrorObj(* (IUnknown *) (IRowset *)this, _mutex),
#pragma warning(default : 4355) // 'this' in a constructor
_heap( cChild )
{
_DBErrorObj.SetInterfaceArray(cRowsetErrorIFs, apRowsetErrorIFs);
//
// Build binding for sort set.
//
DBORDINAL cColumnInfo;
DBCOLUMNINFO * aColumnInfo;
WCHAR * awchColInfo;
SCODE sc = _GetFullColumnInfo( &cColumnInfo, &aColumnInfo, &awchColInfo );
XCoMem<DBCOLUMNINFO> mem( aColumnInfo );
XCoMem<WCHAR> strings( awchColInfo );
if ( FAILED(sc) )
{
vqDebugOut(( DEB_ERROR, "CSequentialSort: GetColumnInfo returned 0x%x\n", sc ));
THROW( CException( sc ) );
}
_cbSort = _Comparator.Init( Sort,
_bindSort.GetPointer(),
aColumnInfo,
cColumnInfo );
//
// Create accessors
//
for ( unsigned i = 0; i < _cChild; i++ )
{
_apCursor[i] = new CMiniRowCache( i,
_aChild[i],
Sort.Count(),
_bindSort.GetPointer(),
_cbSort );
}
//
// Initialize heap
//
_heap.Init( &_Comparator, _apCursor.GetPointer() );
END_CONSTRUCTION( CSequentialSorted );
}
//+---------------------------------------------------------------------------
//
// Member: CSequentialSorted::~CSequentialSorted, public
//
// Synopsis: Destructor
//
// History: 05-Jun-95 KyleP Created.
//
//----------------------------------------------------------------------------
CSequentialSorted::~CSequentialSorted()
{
//
// Release any remaining cursors.
//
for ( int i = _cChild - 1; i >= 0; i-- )
{
delete _apCursor[i];
}
}
//+---------------------------------------------------------------------------
//
// Member: CSequentialSort::_GetNextRows, protected
//
// Synopsis: Sequentially fetch rows
//
// Arguments: [hChapter] -- Chapter
// [cRowsToSkip] -- Skip this many rows before beginning.
// [cRows] -- Try to fetch this many rows.
// [pcRowsObtained] -- Actually fetched this many.
// [pphRows] -- Store HROWs here. Allocate memory if
// [pphRows] is zero.
//
// History: 07-Apr-95 KyleP Created.
//
// Notes: Need to have Ole DB error handling here because we are translating
// errors.
//
//----------------------------------------------------------------------------
SCODE CSequentialSorted::_GetNextRows( HCHAPTER hChapter,
DBROWOFFSET cRowsToSkip,
DBROWCOUNT cRows,
DBCOUNTITEM * pcRowsObtained,
HROW * * pphRows )
{
_DBErrorObj.ClearErrorInfo();
SCODE sc = S_OK;
BOOL fAllocated = FALSE;
ULONG cTotalRowsObtained = 0;
Win4Assert( 0 == hChapter && "Chapter support not yet implemented" );
if (!pcRowsObtained || !pphRows)
{
vqDebugOut(( DEB_IERROR, "CSequentialSorted::GetNextRows: Invalid parameter(s).\n" ));
return _DBErrorObj.PostHResult(E_INVALIDARG, IID_IRowset);
}
*pcRowsObtained = 0;
if (0 == cRows) // nothing to fetch
return S_OK;
//
// Don't support backwards fetch.
//
if ( cRows < 0 || cRowsToSkip < 0 )
{
return _DBErrorObj.PostHResult(DB_E_CANTSCROLLBACKWARDS, IID_IRowset);
}
TRY
{
//
// We may have to allocate memory, if the caller didn't.
//
if ( 0 == *pphRows )
{
*pphRows = (HROW *)CoTaskMemAlloc( (ULONG) ( cRows * sizeof(HROW) ) );
fAllocated = TRUE;
}
if ( 0 == *pphRows )
{
vqDebugOut(( DEB_ERROR, "CSequentialSerial::GetNextRows: Out of memory.\n" ));
THROW( CException( E_OUTOFMEMORY ) );
}
//
// We may have reached some temporary condition such as
// DB_S_ROWLIMITEXCEEDED on the last pass. Iterate until we
// have a valid heap.
//
_heap.Validate();
//
// Adjust cache size if necessary.
//
if ( !_heap.IsHeapEmpty() )
_heap.AdjustCacheSize( (ULONG) cRows );
//
// Fetch from top of heap.
//
while ( cTotalRowsObtained < (ULONG)cRows )
{
//
// We may be entirely out of rows.
//
if ( _heap.IsHeapEmpty() )
{
sc = DB_S_ENDOFROWSET;
break;
}
if ( cRowsToSkip )
{
cRowsToSkip--;
}
else
{
if ( _RowManager.IsTrackingSiblings() )
(*pphRows)[cTotalRowsObtained] =
_RowManager.Add( _heap.Top()->Index(), _heap.TopHROWs() );
else
(*pphRows)[cTotalRowsObtained] =
_RowManager.Add( _heap.Top()->Index(), _heap.Top()->GetHROW() );
cTotalRowsObtained++;
}
//
// Fetch the next row.
//
PMiniRowCache::ENext next = _heap.Next();
if ( CMiniRowCache::NotNow == next )
{
sc = DB_S_ROWLIMITEXCEEDED;
break;
}
}
*pcRowsObtained = cTotalRowsObtained;
}
CATCH( CException, e )
{
sc = e.GetErrorCode();
vqDebugOut(( DEB_ERROR, "Exception 0x%x calling IRowset::GetNextRows\n", sc ));
//
// If we already have some rows, then we can't 'unfetch' them, so we have
// to mask this error. Presumably it won't be transient and we'll get it
// again later.
//
if ( cTotalRowsObtained > 0 )
{
sc = DB_S_ROWLIMITEXCEEDED;
}
else if ( fAllocated )
{
CoTaskMemFree( *pphRows );
*pphRows = 0;
}
}
END_CATCH
if (FAILED(sc))
_DBErrorObj.PostHResult(sc, IID_IRowset);
return( sc );
}
//+---------------------------------------------------------------------------
//
// Member: CSequentialSorted::RestartPosition, public
//
// Synopsis: Reset cursor for GetNextRows
//
// Arguments: [hChapter] -- Chapter
//
// History: 22 Sep 98 VikasMan Created.
//
//----------------------------------------------------------------------------
STDMETHODIMP CSequentialSorted::RestartPosition( HCHAPTER hChapter )
{
for ( unsigned i = 0; i < _cChild; i++ )
{
_apCursor[i]->FlushCache();
}
_heap.ReInit( 0 );
SCODE sc = CDistributedRowset::RestartPosition( hChapter );
for ( i = 0; i < _cChild; i++ )
{
_apCursor[i]->Next();
}
_heap.ReInit( _cChild );
return sc;
}