Source code of Windows XP (NT5)
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//+-------------------------------------------------------------------------
//
// Microsoft Windows
// Copyright (C) Microsoft Corporation, 1994 - 1994.
//
// File: tablecur.cxx
//
// Contents: Large table row cursor
//
// Classes: CTableCursor - basic row cursor
// CTableCursorSet - set of row cursors
//
// Functions:
//
// History: 16 Jun 1994 AlanW Created
//
//--------------------------------------------------------------------------
#include "pch.cxx"
#pragma hdrstop
#include <query.hxx> // SBindSizes
#include <tblvarnt.hxx>
#include "tblrowal.hxx"
#include "tabledbg.hxx"
//
// Generate the implementation of the cursor set base class
//
IMPL_DYNARRAY( CTableCursorArray, CTableCursor )
//+-------------------------------------------------------------------------
//
// Member: CTableCursor::CTableCursor, public
//
// Synopsis: Constructor for a table cursor
//
// Notes:
//
//--------------------------------------------------------------------------
CTableCursor::CTableCursor( void ) :
_hUnique( 0 ),
_cbRowWidth( 0 ),
_BoundColumns( 0 )
{
}
//+-------------------------------------------------------------------------
//
// Member: CTableCursor::~CTableCursor, public
//
// Synopsis: Destructor for a table cursor
//
// Notes:
//
//--------------------------------------------------------------------------
CTableCursor::~CTableCursor( void )
{
}
//+---------------------------------------------------------------------------
//
// Member: CTableCursor::SetBindings, public
//
// Synopsis: Set new column bindings on the cursor
//
// Arguments: [cbRowLength] - width of output rows
// [NewColumns] - CTableColumnSet giving new bindings
//
// Returns: SCODE - S_OK if succeeded, E_FAIL if cbRowLength exceeds
// length we're willing to transfer, otherwise according
// to spec.
//
// Notes:
//
//----------------------------------------------------------------------------
SCODE
CTableCursor::SetBindings(
ULONG cbRowLength,
XPtr<CTableColumnSet> & NewColumns
) {
//
// Do some simple checks first
//
if (0 == cbRowLength || cbRowLength > TBL_MAX_OUTROWLENGTH)
return E_INVALIDARG; // provider-specific error
//
// Check bindings in case they have been hacked. Ordinarily, it would
// be a bug if they were wrong.
// Check that each column is valid and doesn't overlap some other
// column.
//
{
CTableRowAlloc RowMap(cbRowLength);
SCODE scResult = _CheckBindings(NewColumns.GetReference(),
RowMap,
(USHORT) cbRowLength);
if (FAILED(scResult))
return scResult;
}
//
// All the proposed bindings check out. Set them as the
// currently bound columns, and delete any old bindings.
//
unsigned iNewCol = 0;
CTableColumnSet * pOldCols = _BoundColumns.Acquire();
_BoundColumns.Set( NewColumns.Acquire() );
delete pOldCols;
_cbRowWidth = (USHORT) cbRowLength;
return S_OK;
}
//+-------------------------------------------------------------------------
//
// Member: CTableCursor::_CheckBinding, public
// CTableCursor::_CheckBindings, public
//
// Synopsis: Check that a column binding is legal. _CheckBindings does
// the same for an entire set of column bindings.
//
// Arguments: [rCol] - A reference to the column binding to be checked
// [rRowAlloc] - a reference to a row allocation map
// [maxRow] - maximum allowed size of a row
//
// Returns: SCODE - S_OK if no problems, otherwise the appropriate
// error code for the failure.
//
// Notes:
//
//--------------------------------------------------------------------------
SCODE CTableCursor::_CheckBinding(
CTableColumn const & rCol,
CTableRowAlloc& rRowAlloc,
USHORT maxRow
) {
//
// Check some static things about the binding structure
//
if (0 == rCol.IsValueStored() &&
0 == rCol.IsStatusStored() &&
0 == rCol.IsLengthStored() )
{
tbDebugOut((DEB_IWARN,
"CTableCursor::_CheckBinding - no value, length or status stored\n"));
return DB_E_BADBINDINFO;
}
ULONG cbData = rCol.GetValueSize();
USHORT cbWidth, cbAlign, gfFlags;
//
// Look up required width of field.
//
CTableVariant::VartypeInfo(rCol.GetStoredType(), cbWidth, cbAlign, gfFlags);
if (cbData != cbWidth && !(gfFlags & CTableVariant::MultiSize))
{
tbDebugOut((DEB_IWARN, "CTableCursor::_CheckBinding - incorrect field width\n"));
return DB_E_BADBINDINFO;
}
if ( rCol.GetStoredType() & VT_VECTOR )
{
tbDebugOut((DEB_IWARN, "CTableCursor::_CheckBinding - direct vector\n"));
return DB_E_BADBINDINFO;
}
if (rCol.GetValueOffset() + cbData > maxRow)
{
tbDebugOut((DEB_IWARN, "CTableCursor::_CheckBinding - bad data offset\n"));
return DB_E_BADBINDINFO;
}
if (rCol.IsStatusStored() &&
rCol.GetStatusOffset() + rCol.GetStatusSize() > maxRow)
{
tbDebugOut((DEB_IWARN, "CTableCursor::_CheckBinding - bad status offset\n"));
return DB_E_BADBINDINFO;
}
if (rCol.IsLengthStored() &&
rCol.GetLengthOffset() + rCol.GetLengthSize() > maxRow)
{
tbDebugOut((DEB_IWARN, "CTableCursor::_CheckBinding - bad length offset\n"));
return DB_E_BADBINDINFO;
}
//
// Check to see if any fields overlap with previously allocated ones
//
if (rCol.IsValueStored() &&
! rRowAlloc.ReserveRowSpace( rCol.GetValueOffset(), cbData ))
{
tbDebugOut((DEB_IWARN, "CTableCursor::_CheckBinding - value data overlap\n"));
return DB_E_BADBINDINFO;
}
if (rCol.IsStatusStored() &&
! rRowAlloc.ReserveRowSpace( rCol.GetStatusOffset(), rCol.GetStatusSize() ))
{
tbDebugOut((DEB_IWARN, "CTableCursor::_CheckBinding - status data overlap\n"));
return DB_E_BADBINDINFO;
}
if (rCol.IsLengthStored() &&
! rRowAlloc.ReserveRowSpace( rCol.GetLengthOffset(), rCol.GetLengthSize() ))
{
tbDebugOut((DEB_IWARN, "CTableCursor::_CheckBinding - length data overlap\n"));
return DB_E_BADBINDINFO;
}
return S_OK;
}
SCODE CTableCursor::_CheckBindings(
CTableColumnSet const & rCols,
CTableRowAlloc& rRowAlloc,
USHORT maxRow
) {
Win4Assert(maxRow > 0);
for (unsigned i = 0; i < rCols.Count(); i++)
{
SCODE sc = _CheckBinding(*rCols.Get(i), rRowAlloc, maxRow);
if (FAILED(sc))
return sc;
}
return S_OK;
}
//+-------------------------------------------------------------------------
//
// Member: CTableCursorSet::~CTableCursorSet, public
//
// Synopsis: Destroy a table cursor set
//
// Arguments: [hCursor] -- The handle of the cursor to be looked up
//
// Returns: - nothing -
//
// Notes:
//
//--------------------------------------------------------------------------
CTableCursorSet::~CTableCursorSet( )
{
#if CIDBG
for (unsigned i = 0; i < Size(); i++) {
if (Get(i) && Get(i)->_hUnique != 0) {
tbDebugOut((DEB_WARN, "Unreleased table cursor\n"));
}
}
#endif // CIDBG
}
//+-------------------------------------------------------------------------
//
// Member: CTableCursorSet::Lookup, public
//
// Synopsis: Find a table cursor given its handle
//
// Arguments: [hCursor] -- The handle of the cursor to be looked up
//
// Returns: CTableCursor& - reference to cursor
//
// Signals: Throws E_FAIL if error.
//
// Notes:
//
//--------------------------------------------------------------------------
CTableCursor&
CTableCursorSet::Lookup( ULONG hCursor )
{
USHORT iCursor = (USHORT) (hCursor & 0xFFFF);
USHORT hUnique = (USHORT) (hCursor >> 16);
Win4Assert(hUnique > 0 && iCursor < Size());
if (hUnique == 0 || iCursor >= Size()) {
THROW(CException(E_FAIL));
}
if (Get(iCursor) == 0 || Get(iCursor)->_hUnique != hUnique)
THROW(CException(E_FAIL));
return *Get(iCursor);
}
//+-------------------------------------------------------------------------
//
// Member: CTableCursorSet::Add, public
//
// Synopsis: Add a table cursor to a table cursor set.
//
// Arguments: [pCursorIn] -- A pointer to the cursor description to be
// added.
// [rhCursor] -- on return, the handle value assigned to the
// cursor.
//
// Returns: -Nothing-
//
// Notes:
//
//--------------------------------------------------------------------------
void
CTableCursorSet::Add( CTableCursor * const pCursorIn, ULONG &rhCursor )
{
//
// Find an unused handle uniquifier. The for loop may be
// overkill since we also use the array index in the real handle.
//
USHORT hUnique;
do {
hUnique = ++_hKeyGenerator;
if (hUnique == 0)
continue;
for (unsigned j = 0; j < Size(); j++) {
if (Get(j) && hUnique == Get(j)->_hUnique) {
hUnique = 0;
break; // break for, continue do-while
}
}
} while (hUnique == 0);
unsigned i;
for (i = 0; i < Size(); i++) {
if ( Get(i) == 0 )
break;
}
//
// Add the new entry to the set.
//
pCursorIn->_hUnique = hUnique;
CTableCursorArray::Add(pCursorIn, i);
Win4Assert( i < 0x10000 );
rhCursor = (hUnique << 16) | i;
return;
}
//+-------------------------------------------------------------------------
//
// Member: CTableCursorSet::Release, public
//
// Synopsis: Free an allocated table cursor
//
// Arguments: [hCursor] -- The handle of the cursor to be released
//
// Returns: SCODE - S_OK if lookup succeeded, E_FAIL if problems.
//
// Notes:
//
//--------------------------------------------------------------------------
SCODE
CTableCursorSet::Release(ULONG hCursor)
{
USHORT iCursor = (USHORT) (hCursor & 0xFFFF);
USHORT hUnique = (USHORT) (hCursor >> 16);
Win4Assert(hUnique > 0 && iCursor < Size());
if (hUnique == 0 || iCursor >= Size() || Get(iCursor) == 0) {
return E_FAIL;
}
CTableCursor * pCursor = Get(iCursor);
if (pCursor->_hUnique != hUnique)
return E_FAIL;
//
// Found the cursor, now free it and its location in the array.
//
pCursor = CTableCursorArray::Acquire( iCursor );
delete pCursor;
return S_OK;
}
//+-------------------------------------------------------------------------
//
// Member: CTableCursorSet::Count, public
//
// Synopsis: Counts the number of cursors in the set
//
// Returns: # of cursors in the set
//
//--------------------------------------------------------------------------
unsigned CTableCursorSet::Count()
{
unsigned cCursors = 0;
for ( unsigned i = 0; i < Size(); i++)
{
if ( 0 != Get(i) )
cCursors++;
}
return cCursors;
}