Source code of Windows XP (NT5)
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

137 lines
4.1 KiB

//+-------------------------------------------------------------------------
//
// Microsoft Windows
// Copyright (C) Microsoft Corporation, 1997 - 1999.
//
// File: accbase.hxx
//
// Class: CAccessorBase
//
// Purpose: Base class for CAccessor and CDistributedAccessor. Handles
// accessor refcount, type, and tracks # of current rowsets
// have an inherited copy of the accessor.
//
// History: 22 Apr 1997 emilyb created
//
//--------------------------------------------------------------------------
#pragma once
#include <tbag.hxx>
class CAccessorBase
{
public:
enum EAccessorType {
eInvalidAccessor,
eRowDataAccessor,
eParamsDataAccessor,
};
CAccessorBase (void * pCreator, EAccessorType eType) :
_pCreator(pCreator), _hAccessorParent(0),
_type(eType), _cRef(1),
_cInheritors(0) {}
virtual ~CAccessorBase() {}
void * GetCreator() {return _pCreator;}
virtual ULONG AddRef()
{
return InterlockedIncrement( (LONG *) &_cRef );
}
virtual ULONG Release()
{
// CAccessorBag does the destroy
return InterlockedDecrement( (LONG *) &_cRef );
}
ULONG GetRefcount() { return _cRef; }
BOOL IsValidType() const { return _type == eRowDataAccessor ||
_type == eParamsDataAccessor; }
void SetInvalid( void ) { _type = eInvalidAccessor; };
EAccessorType GetAccessorType() const { return _type; }
BOOL IsRowDataAccessor() const { return eRowDataAccessor == _type; }
CAccessorBase * GetParent() {return _hAccessorParent;}
void SetParent(CAccessorBase * hParent) { _hAccessorParent = hParent;}
ULONG IncInheritors() { return ++_cInheritors; }
ULONG DecInheritors() { return --_cInheritors; }
ULONG GetInheritorCount() { return _cInheritors; }
virtual SCODE GetBindings( DBACCESSORFLAGS * pBindIo,
DBCOUNTITEM * pcBindings,
DBBINDING ** ppBindings) = 0 ;
protected:
ULONG _cRef;
private:
void *_pCreator; // this pointer of comamnd or rowset that
// called CreateAccessor to create this accessor
CAccessorBase * _hAccessorParent; // if this accessor was inherited from a command,
// then the HACCESSOR of the original accessor
ULONG _cInheritors; // count of current rowsets
// which inherited this accessor
EAccessorType _type;
};
//+-------------------------------------------------------------------------
//
// Class: CAccessorBag
//
// Purpose: Holds a number of accessors
//
// History: 12 Jan 1995 dlee Created
//
//--------------------------------------------------------------------------
class CAccessorBag : public TBag<CAccessorBase *>
{
public:
CAccessorBag(void * pOwner): _pOwner(pOwner) { }
CAccessorBase * Convert(HACCESSOR hAccessor)
{
Win4Assert( 0 == DB_INVALID_HACCESSOR );
if ( DB_INVALID_HACCESSOR == hAccessor )
THROW( CException( DB_E_BADACCESSORHANDLE) );
CAccessorBase * pAccBase = (CAccessorBase *) hAccessor;
if (_pOwner != pAccBase->GetCreator())
{ // see if we inherited
pAccBase = First();
while (pAccBase && (pAccBase->GetParent() != (CAccessorBase *)hAccessor ))
pAccBase = Next();
if (!pAccBase)
THROW( CException( DB_E_BADACCESSORHANDLE ) );
}
if( !pAccBase->IsValidType() || pAccBase->GetRefcount() <= 0 )
THROW( CException( DB_E_BADACCESSORHANDLE ) );
return pAccBase;
}
~CAccessorBag();
void AddRef( HACCESSOR hAccessor,
ULONG *pcRef );
void Release( HACCESSOR hAccessor,
ULONG *pcRef );
private:
void Destroy( CAccessorBase * pAccessor );
// This is the pointer of the rowset or command to which this bag belongs
void * _pOwner;
}; //CAccessorBag