138 lines
2.7 KiB
C++
138 lines
2.7 KiB
C++
///////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// Copyright (c) 1998, Microsoft Corp. All rights reserved.
|
|
//
|
|
// FILE
|
|
//
|
|
// dsenum.cpp
|
|
//
|
|
// SYNOPSIS
|
|
//
|
|
// This file defines the class DBEnumerator.
|
|
//
|
|
// MODIFICATION HISTORY
|
|
//
|
|
// 02/20/1998 Original version.
|
|
// 04/15/1998 Initialize refCount to zero in constructor.
|
|
//
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
|
|
#include <ias.h>
|
|
#include <iasutil.h>
|
|
#include <dsenum.h>
|
|
|
|
DBEnumerator::DBEnumerator(DBObject* container, IRowset* members)
|
|
: refCount(0),
|
|
parent(container),
|
|
items(members),
|
|
readAccess(createReadAccessor(members))
|
|
{ }
|
|
|
|
STDMETHODIMP_(ULONG) DBEnumerator::AddRef()
|
|
{
|
|
return InterlockedIncrement(&refCount);
|
|
}
|
|
|
|
STDMETHODIMP_(ULONG) DBEnumerator::Release()
|
|
{
|
|
LONG l = InterlockedDecrement(&refCount);
|
|
|
|
if (l == 0) { delete this; }
|
|
|
|
return l;
|
|
}
|
|
|
|
STDMETHODIMP DBEnumerator::QueryInterface(const IID& iid, void** ppv)
|
|
{
|
|
if (iid == __uuidof(IUnknown))
|
|
{
|
|
*ppv = static_cast<IUnknown*>(this);
|
|
}
|
|
else if (iid == __uuidof(IEnumVARIANT))
|
|
{
|
|
*ppv = static_cast<IEnumVARIANT*>(this);
|
|
}
|
|
else
|
|
{
|
|
return E_NOINTERFACE;
|
|
}
|
|
|
|
InterlockedIncrement(&refCount);
|
|
|
|
return S_OK;
|
|
}
|
|
|
|
STDMETHODIMP DBEnumerator::Next(ULONG celt,
|
|
VARIANT* rgVar,
|
|
ULONG* pCeltFetched)
|
|
{
|
|
|
|
if (rgVar == NULL) { return E_INVALIDARG; }
|
|
|
|
//////////
|
|
// Initialize the out parameters.
|
|
//////////
|
|
|
|
if (pCeltFetched != NULL) { *pCeltFetched = celt; }
|
|
|
|
for (ULONG i=0; i<celt; ++i) { VariantInit(rgVar + i); }
|
|
|
|
try
|
|
{
|
|
//////////
|
|
// Move through the items at most 'celt' times.
|
|
//////////
|
|
|
|
while (celt && items.moveNext())
|
|
{
|
|
// Get the row data.
|
|
items.getData(readAccess, this);
|
|
|
|
// Never return the root from an enumerator.
|
|
if (identity == 1) { continue; }
|
|
|
|
// Create an object.
|
|
V_DISPATCH(rgVar) = parent->spawn(identity, name);
|
|
V_VT(rgVar) = VT_DISPATCH;
|
|
|
|
// Update the state.
|
|
--celt;
|
|
++rgVar;
|
|
}
|
|
}
|
|
catch (...)
|
|
{ }
|
|
|
|
// Subtract off any elements that weren't fetched.
|
|
if (pCeltFetched) { *pCeltFetched -= celt; }
|
|
|
|
return celt ? S_FALSE : S_OK;
|
|
}
|
|
|
|
STDMETHODIMP DBEnumerator::Skip(ULONG celt)
|
|
{
|
|
try
|
|
{
|
|
while (celt && items.moveNext()) { --celt; }
|
|
}
|
|
CATCH_AND_RETURN()
|
|
|
|
return celt ? S_FALSE : S_OK;
|
|
}
|
|
|
|
STDMETHODIMP DBEnumerator::Reset()
|
|
{
|
|
try
|
|
{
|
|
items.reset();
|
|
}
|
|
CATCH_AND_RETURN()
|
|
|
|
return S_OK;
|
|
}
|
|
|
|
STDMETHODIMP DBEnumerator::Clone(IEnumVARIANT** ppEnum)
|
|
{
|
|
return E_NOTIMPL;
|
|
}
|