Сущность технологии СОМ. Библиотека программиста
Шрифт:
}
AUnlock;
}
// send the OnNewUser event to all listeners
void
ChatSession::Fire_OnNewUser(const OLECHAR *pwszUser)
{
ALock;
for (LISTENER *pNode = m_pHeadListeners;
pNode != 0; pNode = pNode->pNext)
{
if (pNode->pItf)
pNode->pItf->OnNewUser(pwszUser);
}
AUnlock;
}
// send the OnUserLeft event to all listeners
void
ChatSession::Fire_OnUserLeft(const OLECHAR *pwszUser)
{
ALock;
for (LISTENER *pNode = m_pHeadListeners;
pNode != 0; pNode = pNode->pNext)
{
if (pNode->pItf)
pNode->pItf->OnUserLeft(pwszUser);
}
AUnlock;
}
// lock wrappers
void ChatSession::SLock(void)
{
EnterCriticalSection(&m_csStatementLock);
}
void ChatSession::SUnlock(void)
{
LeaveCriticalSection(&m_csStatementLock);
}
void ChatSession::ALock(void)
{
EnterCriticalSection(&m_csAdviseLock);
}
void ChatSession::AUnlock(void)
{
LeaveCriticalSection(&m_csAdviseLock);
}
// helper method to check access to Say method
bool
ChatSession::CheckAccess(const OLECHAR *pwszUser)
{
if (wcscmp(pwszUser, L"anonymous") == 0)
return m_bAllowAnonymousAccess;
// form trustee from caller and use Access Control
// object hardwired to COMChat Users group
TRUSTEEW trustee = {
0, NO_MULTIPLE_TRUSTEE, TRUSTEE_IS_NAME,
TRUSTEE_IS_USER,
const_cast<OLECHAR*>(pwszUser)
};
BOOL bIsAllowed;
HRESULT hr = g_pacUsers->IsAccessAllowed(&trustee,0,
COM_RIGHTS_EXECUTE,
&bIsAllowed);
return SUCCEEDED(hr) && bIsAllowed != FALSE;
}
// IUnknown methods
STDMETHODIMP
ChatSession::QueryInterface(REFIID riid, void **ppv)
{
if (riid == IID_IUnknown)
*ppv = static_cast<IChatSession*>(this);
else if (riid == IID_IChatSession)
*ppv = static_cast<IChatSession*>(this);
else
return (*ppv = 0), E_NOINTERFACE;
reinterpret_cast<IUnknown*>(*ppv)->AddRef;
return S_OK;
}
STDMETHODIMP_(ULONG)
ChatSession::AddRef(void)
{
ModuleLock;
return InterlockedIncrement(&m_cRef);
}
STDMETHODIMP_(ULONG)
ChatSession::Release(void)
{
LONG res = InterlockedDecrement(&m_cRef);
if (res == 0)
delete this;
ModuleUnlock;
return res;
}
// IChatSession methods
STDMETHODIMP
ChatSession::get_SessionName(OLECHAR **ppwsz)
{
if (!ppwsz)
return E_INVALIDARG;
else if ((*ppwsz = OLESTRDUP(m_wszSessionName)) == 0)
return E_OUTOFMEMORY;
return S_OK;
}
STDMETHODIMP
ChatSession::Say(const OLECHAR *pwszStatement)
{
HRESULT hr = S_OK;
// protect access to method
OLECHAR *pwszUser = GetCaller;
if (pwszUser && CheckAccess(pwszUser))
{
SLock;
try
{
wstring s = pwszUser;
s += L":";
s += pwszStatement;
m_statements.push_back(s);
}
catch(...)
{
hr = E_OUTOFMEMORY;
}
SUnlock;
if (SUCCEEDED(hr))
Fire_OnNewStatement(pwszUser, pwszStatement);
}
else
hr = E_ACCESSDENIED;
CoTaskMemFree(pwszUser);
return hr;
}
STDMETHODIMP
ChatSession::GetStatements(IEnumString **ppes)
{
if (ppes == 0)
return E_INVALIDARG;
*ppes = new StatementEnumerator(this);
if (*ppes == 0)
return E_OUTOFMEMORY;
(*ppes)->AddRef;
return S_OK;
}
STDMETHODIMP
ChatSession::Advise(IChatSessionEvents *pEventSink,
DWORD *pdwReg)
{
HRESULT hr = S_OK;
if (pEventSink == 0 || pdwReg == 0)
return E_INVALIDARG;
LISTENER *pNew = new LISTENER;
if (pNew == 0)
return E_OUTOFMEMORY;
OLECHAR *pwszUser = GetCaller;
if (pwszUser)
{
Fire_OnNewUser(pwszUser);
ALock;
pNew->pwszUser = pwszUser;
if (pNew->pItf = pEventSink)
pEventSink->AddRef;
pNew->pNext = m_pHeadListeners;
if (m_pHeadListeners)
m_pHeadListeners->pPrev = pNew;
pNew->pPrev = 0;
m_pHeadListeners = pNew;
AUnlock;
}
else
{
delete pNew;
return E_OUTOFMEMORY;
}
*pdwReg = reinterpret_cast<DWORD>(pNew);
return hr;
}
STDMETHODIMP
ChatSession::Unadvise(DWORD dwReg)
{
if (dwReg == 0)
return E_INVALIDARG;
HRESULT hr = S_OK;
LISTENER *pThisNode = reinterpret_cast<LISTENER *>(dwReg);
ALock;
if (pThisNode->pPrev)
pThisNode->pPrev->pNext = pThisNode->pNext;
else
m_pHeadListeners = pThisNode->pNext;
if (pThisNode->pNext)
pThisNode->pNext->pPrev = pThisNode->pPrev;
if (pThisNode->pItf)
pThisNode->pItf->Release;
OLECHAR *pwszUser = pThisNode->pwszUser;
delete pThisNode;
AUnlock;
Fire_OnUserLeft(pwszUser);
CoTaskMemFree(pwszUser);
return hr;
}
// class StatementEnumerator ///////////////////
StatementEnumerator::StatementEnumerator(ChatSession *pThis)
: m_cRef(0),
m_pThis(pThis),
m_cursor(pThis->m_statements.begin)
{
m_pThis->AddRef;
InitializeCriticalSection(&m_csLock);
}
StatementEnumerator::~StatementEnumerator(void)