🚀 go-pugleaf

Thank you very much for your help. I really appreciate it.

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"Remy Lebeau (TeamB)" <no.spam@no.spam.com> wrote in message 
news:41d4b51d$1@newsgroups.borland.com...
>
> "Jonathan Benedicto" <incorrect@no.server> wrote in message
> news:41d4a5cc$1@newsgroups.borland.com...
>
>> I have to override the function AllocateDataUnit in the
>> IWMWriterSink interface to provide a pointer to a allocated
>> INSSBuffer. How do I allocate a INSSBuffer interface
>
> You need to write your own INSSBuffer-derived class.  Then you can
> instantiate a new instance of that class when needed, just like you would 
> do
> for any other C++ class - via the 'new' operator.  For example:
>
>    class TMyNSSBuffer : public INSSBuffer
>    {
>    private:
>        ULONG fRefCount;
>        BYTE* fBuffer;
>        DWORD fAllocatedSize;
>        DWORD fLength;
>    public:
>        TMyNSSBuffer(DWORD dwMaxSize);
>        ~TMyNSSBuffer();
>
>        ULONG __stdcall AddRef();
>        ULONG __stdcall Release();
>        HRESULT __stdcall QueryInterface(REFIID riid, LPVOID* ppv);
>
>        HRESULT __stdcall GetBuffer(BYTE** ppdwBuffer);
>        HRESULT __stdcall GetBufferAndLength(BYTE** ppdwBuffer, DWORD*
> pdwLength);
>        HRESULT __stdcall GetLength(DWORD* pdwLength);
>        HRESULT __stdcall GetMaxLength(DWORD* pdwLength);
>        HRESULT __stdcall SetLength(DWORD dwLength);
>    };
>
>
>    TMyNSSBuffer::TMyNSSBuffer(DWORD dwMaxSize)
>        : fRefCount(1), fAllocatedSize(dwMaxSize), fLength(0)
>    {
>        fBuffer = new BYTE[dwMaxSize];
>    }
>
>    TMyNSSBuffer::~TMyNSSBuffer()
>    {
>        delete[] fBuffer;
>    }
>
>    ULONG __stdcall TMyNSSBuffer::AddRef()
>    {
>        return ++fRefCount;
>    }
>
>    ULONG __stdcall TMyNSSBuffer::Release()
>    {
>        if( --fRefCount == 0 )
>        {
>            delete this;
>            return 0;
>        }
>        return fRefCount;
>    }
>
>    HRESULT __stdcall TMyNSSBuffer::QueryInterface(REFIID riid, LPVOID* 
> ppv)
>    {
>        if( ppv == NULL )
>            return E_POINTER;
>
>        *ppv = NULL;
>
>        if( IsEqualIID(riid, IID_IUnknown) )
>            *ppv = (IUnknown*) this;
>        else if( IsEqualIID(riid, IID_INSSBuffer) )
>            *ppv = (INNSBuffer*) this;
>
>        if( *ppv != NULL )
>        {
>            AddRef();
>            return S_OK;
>        }
>
>        return E_NOINTERFACE;
>    }
>
>    HRESULT __stdcall TMyNSSBuffer::GetBuffer(BYTE** ppdwBuffer)
>    {
>        if( ppdwBuffer == NULL )
>            return E_POINTER;
>        *ppdwBuffer = fBuffer;
>        return S_OK;
>    }
>
>    HRESULT __stdcall TMyNSSBuffer::GetBufferAndLength(BYTE** ppdwBuffer,
> DWORD* pdwLength)
>    {
>        if( (ppdwBuffer == NULL) || (pdwLength == NULL) )
>            return E_POINTER;
>        *ppdwBuffer = fBuffer;
>        *pdwLength = fLength;
>        return S_OK;
>    }
>
>    HRESULT __stdcall TMyNSSBuffer::GetLength(DWORD* pdwLength)
>    {
>        if( pdwLength == NULL )
>            return E_POINTER;
>        *pdwLength = fLength;
>        return S_OK;
>    }
>
>    HRESULT __stdcall TMyNSSBuffer::GetMaxLength(DWORD* pdwLength)
>    {
>        if( pdwLength == NULL )
>            return E_POINTER;
>        *pdwLength = fAllocatedSize;
>        return S_OK;
>    }
>
>    HRESULT __stdcall TMyNSSBuffer::SetLength(DWORD dwLength)
>    {
>        if( dwLength > fAllocatedSize )
>            return E_INVALIDARG;
>        fLength = dwLength;
>        return S_OK;
>    }
>
>
> Then your IWMWriterSink can do the following:
>
>    class TMyWMWriterSink : public IWMWriterSink
>    {
>    public:
>        HRESULT __stdcall AllocateDataUnit(DWORD cbDataUnit, INSSBuffer**
> ppDataUnit);
>        //...
>    };
>
>    HRESULT __stdcall TMyWMWriterSink::AllocateDataUnit(DWORD cbDataUnit,
> INSSBuffer** ppDataUnit)
>    {
>        if ( *ppDataUnit == NULL )
>            return E_POINTER;
>
>        try
>        {
>            *ppDataUnit = new TMyNSSBuffer(cbDataUnit);
>            return S_OK;
>        }
>        catch(...) {
>            return E_FAIL;
>        }
>    }
>
>> I've tried IWMWriter's AllocateSample method, but it the app just hangs.
>
> You are deadlocking your code with an endless recursion loop.
> IWMWriter::AllocateSample() calls IWMWriterSink::AllocateDataUnit()
> internally.  So by having your IWMWriterSink interface call
> AllocateSample(), you are calling back into IWMWriterSink over and over
> endlessly.
>
>
> Gambit
>
>