windows-nt/Source/XPSP1/NT/admin/wmi/wbem/adapters/oledb/instrowfetch.cpp

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2020-09-26 03:20:57 -05:00
///////////////////////////////////////////////////////////////////////////////////
//
// Microsoft WMIOLE DB Provider
// (C) Copyright 1999 Microsoft Corporation. All Rights Reserved.
//
// CInstanceRowFetchObj object implementation
//
//
///////////////////////////////////////////////////////////////////////////////////
#include "headers.h"
#include "WmiOleDBMap.h"
///////////////////////////////////////////////////////////////////////////////////////
// Function which fetches required number of rows
///////////////////////////////////////////////////////////////////////////////////////
HRESULT CInstanceRowFetchObj::FetchRows(CRowset * pRowset,
HCHAPTER hChapter, // IN The Chapter handle.
DBROWOFFSET lRowOffset, // IN Rows to skip before reading
DBROWCOUNT cRows, // IN Number of rows to fetch
DBCOUNTITEM* pcRowsObtained, // OUT Number of rows obtained
HROW ** prghRows) // OUT Array of Hrows obtained)
{
DBCOUNTITEM cRowsTmp = 0;
HROW irow(0), ih(0);
PROWBUFF prowbuff = NULL;
HRESULT hr = S_OK;
HROW *prghRowsTemp = NULL;
HROW hRowCurrent = 0;
HSLOT hSlot = -1;
BOOL bAlreadyDataRetrieved = FALSE;
BOOL bAlreadyFetched = FALSE;
CVARIANT varKey;
BOOL bFetchBack = FALSE;
HROW hRowTemp = 0;
CBSTR strKey;
LONG_PTR lFetchPos = 0;
DBROWCOUNT ulMax = 0;
BOOL bMaxRowsExceed = FALSE;
DBSTATUS dwStat = DBSTATUS_S_OK;
BOOL bHRowsAllocated = FALSE;
CWbemClassWrapper *pInst = NULL;
if(cRows != 0)
{
{
VARIANT varTemp;
VariantInit(&varTemp);
pRowset->GetRowsetProperty(DBPROP_MAXOPENROWS,varTemp);
ulMax = varTemp.lVal;
VariantClear(&varTemp);
}
//=======================================================
// If already maximum rows are opened then return
//=======================================================
if( pRowset->m_ulRowRefCount >= (DBROWCOUNT)ulMax)
{
hr = DB_S_ROWLIMITEXCEEDED;
}
else
{
//========================
// Fetch Data
//========================
if (lRowOffset)
{
//===================================
// Calculate the new position
//===================================
hr = pRowset->ResetRowsetToNewPosition(lRowOffset,pInst);
if( FAILED(hr))
{
pRowset->SetStatus(hChapter , STAT_ENDOFCURSOR);
hr = DB_S_ENDOFROWSET ;
}
}
// 07/11/00
//141938
if(hr == S_OK)
{
if(0 >( lFetchPos = GetFirstFetchPos(pRowset,cRows,lRowOffset)))
{
hr = DB_E_BADSTARTPOSITION;
}
else
{
cRowsTmp = cRows >= 0 ? cRows : cRows * (-1);
ulMax = ulMax - pRowset->m_ulRowRefCount;
if(ulMax < (DBROWCOUNT)cRowsTmp)
{
bMaxRowsExceed = TRUE;
}
else
{
ulMax = cRowsTmp;
}
cRowsTmp = 0;
//=======================================================================
// If any rows is to be retrieved then allocate memory for the HROWS
//=======================================================================
if (ulMax )
{
try
{
prghRowsTemp = (HROW *) g_pIMalloc->Alloc( ulMax * sizeof( HROW ));
}
catch(...)
{
if(prghRowsTemp != NULL)
{
g_pIMalloc->Free(prghRowsTemp);
}
throw;
}
}
if(prghRowsTemp == NULL)
{
hr = E_OUTOFMEMORY;
}
else
{
memset(prghRowsTemp,0,ulMax * sizeof(HROW));
pRowset->m_FetchDir = (LONG_PTR)cRows < 0 ? FETCHDIRBACKWARD : FETCHDIRFORWARD;
bFetchBack = (LONG_PTR)cRows < 0 ? TRUE : FALSE;
hRowTemp = pRowset->m_hRowLastFetched;
for (irow =1; irow <= (ULONG)ulMax; irow++)
{
bAlreadyFetched = FALSE;
bAlreadyDataRetrieved = FALSE;
dwStat = DBSTATUS_S_OK;
//============================================================
// Get the pointer to the next instance
//============================================================
if (S_OK != ( hr = pRowset->GetNextInstance(pInst,strKey,bFetchBack)))
{
pRowset->SetStatus(hChapter , STAT_ENDOFCURSOR);
hr = DB_S_ENDOFROWSET;
break;
}
//==========================================================================
// If the instance is a deleted instance and deleted instance is to be
// removed then continue to the next instance
// If the rowset is opened in dyanamic cursor mode then skipping of
// deleted row doesn't depend on REMOVEDELETED
//==========================================================================
if(pRowset->IsInstanceDeleted(pInst) &&
(pRowset->m_ulProps & OTHERINSERT) ||
( pRowset->m_ulProps & REMOVEDELETED) )
{
irow--;
continue;
}
//=================================================================
// Check if instance already exist
//=================================================================
bAlreadyFetched = pRowset->m_InstMgr->IsInstanceExist(strKey);
//==========================================================================
// If not able to find the instance by key ( key might change sometime
// in some cases if all the properties are keys) So check if the instance
// is already fetched by the instance pointers
//==========================================================================
if(bAlreadyFetched == FALSE)
{
bAlreadyFetched = pRowset->m_InstMgr->IsInstanceExist(pInst );
//==========================================================================
// if found the instance has to be refreshed
//==========================================================================
if(bAlreadyFetched == TRUE)
{
pRowset->RefreshInstance(pInst);
}
}
//==================================================================
// if already exists get the HROW and slot number for the instance
//==================================================================
if(bAlreadyFetched == TRUE)
{
hRowCurrent = pRowset->m_InstMgr->GetHRow(strKey);
if((pRowset->GetRowStatus(hRowCurrent) & DBROWSTATUS_E_DELETED) && ( pRowset->m_ulProps & REMOVEDELETED))
{
continue;
}
//=================================================================
// if the slot number for the instance exist this means thet
// data is already retrieved for the row
//=================================================================
if((hSlot = pRowset->m_InstMgr->GetSlot(hRowCurrent)) != -1)
{
bAlreadyDataRetrieved = TRUE;
}
}
else
{
hRowCurrent = pRowset->GetNextHRow();
}
//=====================================================
// Get the data if data is already not fetched
//=====================================================
if(bAlreadyDataRetrieved == FALSE)
{
hSlot = -1;
//============================================
// Get the next slot for retrieving data and
// bind it to the column mem manager
//============================================
if (FAILED( hr = GetNextSlots( pRowset->m_pIBuffer, 1, &hSlot )))
{
break;
}
if (FAILED( pRowset->Rebind((BYTE *) pRowset->GetRowBuffFromSlot( hSlot, TRUE ))))
{
hr = E_FAIL;
break;
}
hRowCurrent = hSlot;
//=========================================================
// fill the bookmark with keyvalue of the instance
//=========================================================
varKey.SetStr(strKey);
//=================================================================================================
// if the other updates visible property is set to false ,then get the data to the local buffer
//=================================================================================================
if(!( pRowset->m_ulProps & OTHERUPDATEDELETE))
{
if(FAILED(hr = pRowset->GetInstanceDataToLocalBuffer(pInst,hSlot)))
{
break;
}
//===========================================================================
// if there is atleast one row retrieved and there are neseted columns
// then allocate rows for the child recordsets
//===========================================================================
if(pRowset->m_cNestedCols > 0 )
{
if(pRowset->m_ppChildRowsets == NULL)
{
pRowset->AllocateAndInitializeChildRowsets();
}
//=====================================================================
// Fill the HCHAPTERS for the column
//=====================================================================
if(FAILED(hr = pRowset->FillHChaptersForRow(pInst,strKey)))
{
break;
}
}
}
//=================================================
// add instance pointer to instance manager
//=================================================
if(FAILED(hr = pRowset->m_InstMgr->AddInstanceToList(hRowCurrent,pInst,strKey,hSlot)))
{
break;
}
//=====================================================
// if the row is deleted then set the row status
//=====================================================
if(pRowset->IsInstanceDeleted(pInst) && SUCCEEDED(hr))
{
pRowset->SetRowStatus(hRowCurrent,DBROWSTATUS_E_DELETED);
}
varKey.Clear();
}
prghRowsTemp[irow-1] = hSlot;
strKey.Clear();
strKey.Unbind();
}
if(SUCCEEDED(hr))
{
cRowsTmp = irow - 1; //Irow will be +1 because of For Loop
//=====================================================================
// Through fetching many rows of data
//
// Allocate row handles for client. Note that we need to use IMalloc
// for this. Should only malloc cRowsTmp, instead of cRows.
// Should malloc cRows, since client will assume it's that big.
//=====================================================================
if ( *prghRows == NULL && cRowsTmp )
{
try
{
*prghRows = (HROW *) g_pIMalloc->Alloc( cRowsTmp * sizeof( HROW ));
}
catch(...)
{
if(*prghRows)
{
g_pIMalloc->Free(*prghRows);
}
throw;
}
bHRowsAllocated = TRUE;
}
if ( *prghRows == NULL && cRowsTmp )
{
hr = E_OUTOFMEMORY ;
}
else
{
memset(*prghRows,0,cRowsTmp * sizeof( HROW ));
//=====================================================================
// Fill in the status information: Length, IsNull. May be able to wait
// until first call to GetData, but have to do it sometime.
//
// Suggest keeping an array of structs of accessor info. One element is
// whether accessor requires any status info or length info.
//
// Then we could skip this whole section.
//
// Added check for cRowsTmp to MarkRows call. Don't want to call if
// cRowsTmp==0.
// (Range passed to MarkRows is inclusive, so can't specify marking 0 rows.)
//
// Note that SetSlots is a CBitArray member function -- not an IBuffer function.
//
// Bits are [0...n-1], row handles are [1...n].
//
// Cleanup. Row handles, bits, indices are the same [m....(m+n)], where
// m is some # >0,
//
// Added row-wise reference counts and cursor-wise reference counts.
//
// Set row handles, fix data length field and compute data status field.
//=======================================================================
pRowset->m_cRows = cRowsTmp;
for (ih =0; ih < (ULONG) pRowset->m_cRows; ih++)
{
//=============================================================================
// Increment the rows-read count,
// then store it as the bookmark in the very first DWORD of the row.
//=============================================================================
prowbuff = pRowset->GetRowBuff( prghRowsTemp[ih], TRUE );
//=======================================================================================
// Insert the bookmark and its row number (from 1...n) into a hash table.
// This allows us to quickly determine the presence of a row in mem, given the bookmark.
// The bookmark is contained in the row buffer, at the very beginning.
// Bookmark is the row number within the entire result set [1...num_rows_read].
// This was a new Bookmark, not in memory,
// so return to user (in *prghRows) the hRow we stored.
//=======================================================================================
prowbuff->ulRefCount++;
pRowset->m_ulRowRefCount++;
(*prghRows)[ih] = prghRowsTemp[ih]; // (HROW) ( irow );
pRowset->m_hRowLastFetched = prghRowsTemp[ih];
if(pRowset->m_ulProps & BOOKMARKPROP)
{
if(ih != 0)
{
lFetchPos = (pRowset->m_FetchDir == FETCHDIRFORWARD ) ? lFetchPos + 1 : lFetchPos -1;
}
prowbuff->dwBmk = lFetchPos;
prowbuff->cbBmk = BOOKMARKSIZE;
pRowset->m_lLastFetchPos = lFetchPos;
// Add bookmark to the hashtable
pRowset->m_pHashTblBkmark->InsertFindBmk(FALSE,prghRowsTemp[ih],prowbuff->cbBmk,(BYTE *)&(prowbuff->dwBmk),(ULONG_PTR*)&hSlot);
}
}
} // If proper allocation of *prghRows if required
} // If succeeded(hr) after the loop
if(SUCCEEDED(hr))
{
*pcRowsObtained = cRowsTmp;
}
//=====================================================
// if the number of rows asked is more than
// the max number of open rows and if there
// is no error then set the error number
//=====================================================
if( hr == S_OK && bMaxRowsExceed == TRUE)
{
hr = DB_S_ROWLIMITEXCEEDED;
}
} // Else for check for proper allocation prghRowsTemp
} // Else for check for DB_E_BADSTARTPOSITION
}
}
} // if cRow > 0
// IF failed clean up
if( FAILED(hr))
{
for (ih =0; ih < (ULONG) cRowsTmp; ih++)
{
if(prghRowsTemp[ih] != 0)
{
pRowset->m_InstMgr->DeleteInstanceFromList(prghRowsTemp[ih]);
}
}
if(pcRowsObtained)
{
*pcRowsObtained = 0;
}
if(prghRows && bHRowsAllocated == TRUE)
{
g_pIMalloc->Free(prghRows);
prghRows = NULL;
}
else
if(prghRows)
{
*prghRows = NULL;
}
if(pcRowsObtained)
{
*pcRowsObtained = 0;
}
}
//==============================================
// free the temporary memory allocated
//==============================================
if(prghRowsTemp)
{
g_pIMalloc->Free(prghRowsTemp);
prghRowsTemp = NULL;
}
// reset the starting position to the original position
if(lRowOffset && (FAILED(hr) || (hr != S_OK && cRowsTmp == 0)))
{
pRowset->ResetRowsetToNewPosition(lRowOffset * (-1),pInst);
}
return hr;
}