Сущность технологии СОМ. Библиотека программиста
Шрифт:
// IEnumString methods
STDMETHODIMP Next(ULONG cElems, OLECHAR **rgElems,
ULONG *pcFetched);
STDMETHODIMP Skip(ULONG cElems);
STDMETHODIMP Reset(void);
STDMETHODIMP Clone(IEnumString **ppes);
};
#endif
/////////////////////////////////////////////////////
//
// ChatSession.cpp
//
// Copyright 1997, Don Box/Addison Wesley
//
// This code accompanies the book "The Component
// Object Model" from Addison Wesley. Blah blah blah
//
//
#include
#include <iaccess.h>
// these routines are defined in svc.cpp to
// control server lifetime
extern void ModuleLock(void);
extern void ModuleUnlock(void);
// these access control objects are created
// in svc.cpp to control various privileged
// operations. Most operations in this class
// are non-privileged, so anyone can get in.
extern IAccessControl *g_pacUsers;
extern IAccessControl *g_pacAdmins;
// utility functions /////////////////////////
// duplicate an OLECHAR * using CoTaskMemAlloc
OLECHAR *OLESTRDUP(const OLECHAR *pwsz)
{
DWORD cb = sizeof(OLECHAR)*(wcslen(pwsz) + 1);
OLECHAR *pwszResult = (OLECHAR*)CoTaskMemAlloc(cb);
if (pwszResult)
wcscpy(pwszResult, pwsz);
return pwszResult;
}
// get the caller's username (or «anonymous» if
// no authentication was specified by the caller).
OLECHAR *GetCaller(void)
{
OLECHAR *pwsz = 0;
HRESULT hr = CoQueryClientBlanket(0,0,0,0,0,(void**)&pwsz,0);
if (SUCCEEDED(hr))
return OLESTRDUP(pwsz);
else
return OLESTRDUP(OLESTR(«anonymous»));
}
// class ChatSession ///////////////////////////////
ChatSession::ChatSession(const OLECHAR *pwszSessionName,
bool bAllowAnonymousAccess)
: m_cRef(0),
m_bAllowAnonymousAccess(bAllowAnonymousAccess),
m_pHeadListeners(0)
{
wcscpy(m_wszSessionName, pwszSessionName);
InitializeCriticalSection(&m_csStatementLock);
InitializeCriticalSection(&m_csAdviseLock);
}
ChatSession::~ChatSession(void)
{
DeleteCriticalSection(&m_csStatementLock);
DeleteCriticalSection(&m_csAdviseLock);
// tear down connected listeners
while (m_pHeadListeners)
{
LISTENER *pThisNode = m_pHeadListeners;
if (pThisNode->pItf)
pThisNode->pItf->Release;
if (pThisNode->pwszUser)
CoTaskMemFree(pThisNode->pwszUser);
m_pHeadListeners = pThisNode->pNext;
delete pThisNode;
}
}
// helper methods ///////////
void ChatSession::Disconnect(void)
{
CoDisconnectObject(this, 0);
// tear down connected listeners
ALock;
while (m_pHeadListeners)
{
LISTENER *pThisNode = m_pHeadListeners;
if (pThisNode->pItf)
pThisNode->pItf->Release;
if (pThisNode->pwszUser)
CoTaskMemFree(pThisNode->pwszUser);
m_pHeadListeners = pThisNode->pNext;
delete pThisNode;
}
AUnlock;
}
// send the OnNewStatement event to all listeners
void
ChatSession::Fire_OnNewStatement(const OLECHAR *pwszUser,
const OLECHAR *pwszStatement)
{
ALock;
for (LISTENER *pNode = m_pHeadListeners;
pNode != 0; pNode = pNode->pNext)
{
if (pNode->pItf)
pNode->pItf->OnNewStatement(pwszUser, pwszStatement);
}
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,