MSGFILT.CPP

/* 
 * MSGFILT.CPP 
 * Koala Object for EXE Servers, Chapter 6 
 * 
 * Implementation of a message filter object to block or delay 
 * calls. 
 * 
 * Copyright (c)1993-1995 Microsoft Corporation, All Rights Reserved 
 * 
 * Kraig Brockschmidt, Microsoft 
 * Internet  :  kraigb@microsoft.com 
 * Compuserve:  >INTERNET:kraigb@microsoft.com 
 */ 
 
 
#include "ekoala3.h" 
 
 
/* 
 * CMessageFilter::CMessageFilter 
 * CMessageFilter::~CMessageFilter 
 * 
 * Parameters (Constructor): 
 *  pApp            PAPP of the application we're in 
 */ 
 
CMessageFilter::CMessageFilter(PAPP pApp) 
    { 
    m_cRef=0; 
    m_pApp=pApp; 
    return; 
    } 
 
CMessageFilter::~CMessageFilter(void) 
    { 
    return; 
    } 
 
 
 
/* 
 * CMessageFilter::QueryInterface 
 * CMessageFilter::AddRef 
 * CMessageFilter::Release 
 * 
 * Purpose: 
 *  Delegating IUnknown members for CMessageFilter. 
 */ 
 
STDMETHODIMP CMessageFilter::QueryInterface(REFIID riid 
    , LPVOID *ppv) 
    { 
    *ppv=NULL; 
 
    if (IID_IUnknown==riid || IID_IMessageFilter==riid) 
        *ppv=this; 
 
    if (NULL!=*ppv) 
        { 
        ((LPUNKNOWN)*ppv)->AddRef(); 
        return NOERROR; 
        } 
 
    return ResultFromScode(E_NOINTERFACE); 
    } 
 
STDMETHODIMP_(ULONG) CMessageFilter::AddRef(void) 
    { 
    return ++m_cRef; 
    } 
 
STDMETHODIMP_(ULONG) CMessageFilter::Release(void) 
    { 
    if (0!=--m_cRef) 
        return m_cRef; 
 
    delete this; 
    return 0; 
    } 
 
 
 
 
 
 
/* 
 * CMessageFilter::HandleInComingCall 
 * 
 * Purpose: 
 *  Requests that the container call OleSave for the object that 
 *  lives here.  Typically this happens on server shutdown. 
 * 
 * Parameters: 
 *  dwCallType      DWORD indicating the type of call received, from 
 *                  the CALLTYPE enumeration 
 *  hTaskCaller     HTASK of the caller 
 *  dwTickCount     DWORD elapsed tick count since the outgoing call 
 *                  was made if dwCallType is not CALLTYPE_TOPLEVEL. 
 *                  Ignored for other call types. 
 *  pInterfaceInfo  LPINTERFACEINFO providing information about the 
 *                  call.  Can be NULL. 
 * 
 * Return Value: 
 *  DWORD           One of SERVERCALL_ISHANDLED (if the call might 
 *                  be handled), SERVERCALL_REJECTED (call cannot 
 *                  be handled), or SERVERCALL_RETRYLATER (try 
 *                  again sometime). 
 */ 
 
STDMETHODIMP_(DWORD) CMessageFilter::HandleInComingCall 
    (DWORD dwCallType, HTASK htaskCaller, DWORD dwTickCount 
#ifdef WIN32 
    , LPINTERFACEINFO pInterfaceInfo) 
#else 
    , DWORD dwReserved) 
#endif 
    { 
    if (m_pApp->m_fBlock) 
        return SERVERCALL_REJECTED; 
 
    if (m_pApp->m_fDelay) 
        return SERVERCALL_RETRYLATER; 
 
    return SERVERCALL_ISHANDLED; 
    } 
 
 
 
 
 
/* 
 * CMessageFilter::RetryRejectedCall 
 * CMessageFilter::MessagePending 
 * 
 * Not implemented:  no outgoing calls from this process. 
 */ 
 
STDMETHODIMP_(DWORD) CMessageFilter::RetryRejectedCall 
    (HTASK htaskCallee, DWORD dwTickCount, DWORD dwRejectType) 
    { 
    return 0; 
    } 
 
STDMETHODIMP_(DWORD) CMessageFilter::MessagePending 
    (HTASK htaskCallee, DWORD dwTickCount, DWORD dwPendingType) 
    { 
    return PENDINGMSG_WAITDEFPROCESS; 
    }