windows-server-2003/admin/wmi/wbem/common/wmiutils/helpers.h

/*++



// Copyright (c) 1999-2001 Microsoft Corporation, All Rights Reserved 

Module Name:

    helpers.h

Abstract:

    Generic helper code

History:

--*/

#ifndef _HELPERS_H_

#include <genutils.h>

#define LENGTH_OF(a) (sizeof(a)/sizeof(a[0]))

#ifndef _DBG_ASSERT
  #ifdef DBG
    #define _DBG_ASSERT(X) { if (!(X)) { DebugBreak(); } }
  #else
    #define _DBG_ASSERT(X)
  #endif
#endif


inline wchar_t *Macro_CloneLPWSTR(LPCWSTR src)
{
    if (NULL == src) return 0;
    size_t cchTmp = wcslen(src) + 1;
    wchar_t *dest = new wchar_t[cchTmp];
    if (dest) memcpy(dest,src,cchTmp * sizeof(WCHAR));
    return dest;
}

template<class T>
class CDeleteMe
{
protected:
    T* m_p;

public:
    CDeleteMe(T* p) : m_p(p){}
    ~CDeleteMe() {delete m_p;}
};

class CSysFreeMe
{
protected:
    BSTR m_str;

public:
    CSysFreeMe(BSTR str) : m_str(str){}
    ~CSysFreeMe() {SysFreeString(m_str);}
};


typedef LPVOID * PPVOID;

template<class TObj>
class CGenFactory : public IClassFactory
    {
    protected:
        long           m_cRef;
    public:
        CGenFactory(void)
        {
            m_cRef=0L;
            return;
        };

        ~CGenFactory(void)
        {
            return;
        }

        //IUnknown members
        STDMETHODIMP         QueryInterface(REFIID riid, PPVOID ppv)
        {
            *ppv=NULL;

            if (IID_IUnknown==riid || IID_IClassFactory==riid)
                *ppv=this;

            if (NULL!=*ppv)
            {
                ((LPUNKNOWN)*ppv)->AddRef();
                return NOERROR;
            }

            return ResultFromScode(E_NOINTERFACE);
        };

        STDMETHODIMP_(ULONG) AddRef(void)
        {
            return InterlockedIncrement(&m_cRef);
        };
        STDMETHODIMP_(ULONG) Release(void)
        {
            long lRet = InterlockedDecrement(&m_cRef);
            if (0 ==lRet)
                delete this;
            return lRet;
        };

        //IClassFactory members
        STDMETHODIMP         CreateInstance(IN LPUNKNOWN pUnkOuter, IN REFIID riid, OUT PPVOID ppvObj)
        {
            HRESULT    hr;

            *ppvObj=NULL;
            hr=E_OUTOFMEMORY;

            // This object doesnt support aggregation.

            if (NULL!=pUnkOuter)
                return ResultFromScode(CLASS_E_NOAGGREGATION);

            //Create the object passing function to notify on destruction.

            TObj * pObj = new TObj();

            if (NULL==pObj)
                return hr;

            // Setup the class all empty, etc.

            pObj->InitEmpty();
            hr=pObj->QueryInterface(riid, ppvObj);
            pObj->Release();
            return hr;
            
        };
        STDMETHODIMP         LockServer(BOOL fLock)
        {
            if (fLock)
                InterlockedIncrement((long *)&g_cLock);
            else
                InterlockedDecrement((long *)&g_cLock);
            return NOERROR;
        };
    };
class CReleaseMe
{
protected:
    IUnknown* m_pUnk;

public:
    CReleaseMe(IUnknown* pUnk) : m_pUnk(pUnk){}
    ~CReleaseMe() { release();}
    void release() { if(m_pUnk) m_pUnk->Release(); m_pUnk=0;}
};

#endif