chxfgbuf.cpp

著名的 helix realplayer 基于手机 symbian 系统的 播放器全套源代码

	ulLength = ulLengthFrom;
    }

    HX_RELEASE(phxbufBuffy);

    return HXR_OK;
}

void 
CHXFragmentedBuffer::_RecursiveBufferCopy
(
    UCHAR* pucDestBuffer,
    IHXBuffer* pbufSource,
    UINT32 ulStartIndex,
    UINT32 ulSize
)
{
    IHXFragmentedBuffer* pfgbufCurrent = NULL;

    /* Optimized by directly enumerating nested 
     * fragmented buffers.
     * (instead of "pfrgCurrent->GetData()->GetBuffer()")
     */
    if (!(pbufSource->QueryInterface(IID_IHXFragmentedBuffer, (void**)&pfgbufCurrent)) || pfgbufCurrent)
    {
	IHXEnumFragmentedBuffer* pefbCurrent = NULL;
	IHXBuffer* pbufCurrent = NULL;
	UINT32 ulSizeCurrent=0;
	UINT32 ulCopied=0;
	UINT32 ulTotal=0;

	pfgbufCurrent->GetEnumerator(&pefbCurrent);

	pefbCurrent->Reset();
	
	while(!(pefbCurrent->Next(1, &pbufCurrent, NULL)) && ulSize>0)
	{
	    ulSizeCurrent =  pbufCurrent->GetSize();
	    
	    if ((ulTotal+ulSizeCurrent) < ulStartIndex)
	    {
		ulTotal += ulSizeCurrent;
	    }
	    else
	    {
		_RecursiveBufferCopy
		(
		    pucDestBuffer+ulCopied,
		    pbufCurrent,
		    ulStartIndex-ulTotal,
		    min(ulSize, ulSizeCurrent)
		);

		ulSize -= ulSizeCurrent;
		ulCopied += ulSizeCurrent;
		ulStartIndex = 0;
		ulTotal=0;
	    }

	    HX_RELEASE(pbufCurrent);
	}
	
	HX_RELEASE(pefbCurrent);
	HX_RELEASE(pfgbufCurrent);
    }
    else
    {
	memcpy /* Flawfinder: ignore */
	(
	    pucDestBuffer, 
	    pbufSource->GetBuffer()+ulStartIndex, 
	    HX_SAFESIZE_T(ulSize-ulStartIndex)
	);
    }
}

STDMETHODIMP_(UCHAR*) 
CHXFragmentedBuffer::GetBuffer(UINT32 ulStartFrom, UINT32 ulLengthFrom)
{
    UCHAR* pData;
    UINT32 ulLength;

    /* Gather from start to start+length
     */
    Get(ulStartFrom, ulLengthFrom, pData, ulLength);

    return pData;
}


/* IHXBuffer Methods
 */ 

/* XXX I am not doing memcopies into existing space as I cannot guarantee write access.
 * An acceptable Optimization is to try to memcopy, and fragment only if that fails.
 */
STDMETHODIMP 
CHXFragmentedBuffer::Set(const UCHAR* pData, ULONG32 ulLength)
{
    /* Need to make an empty Buffer sizeof ulLength
     */
    IHXBuffer* phxbufTemp = (IHXBuffer*)(new CHXBuffer());

    phxbufTemp->AddRef();
    phxbufTemp->SetSize(ulLength);
    phxbufTemp->Set(pData, ulLength);
    
    Replace(phxbufTemp, 0, ulLength, 0);

    HX_RELEASE(phxbufTemp);

    return HXR_OK;
}

STDMETHODIMP 
CHXFragmentedBuffer::Get(REF(UCHAR*) pData, REF(ULONG32) ulLength)
{
    return Get(0,UINT32(-1), pData, ulLength);
}

/* adds/removes fragment(s) to the end to set the size to the requested length
 */
STDMETHODIMP 
CHXFragmentedBuffer::SetSize(ULONG32 ulLength)
{
    UINT32 ulSize;

    ulSize = GetSize();
    
    if (ulLength > ulSize)
    {
	/* The existing buffers are not big enough
	 * Need to make an empty Buffer sizeof ulLength-GetSize()
	 */
	IHXBuffer* phxbufTemp = (IHXBuffer*)(new CHXBuffer());
	_CFragment* pfrgNew;

	phxbufTemp->AddRef();
	phxbufTemp->SetSize(ulLength-ulSize);
	
	pfrgNew = new _CFragment();
	pfrgNew->SetData(phxbufTemp);
	
	m_frglstThis.Append(pfrgNew);

	HX_RELEASE(phxbufTemp);
    }
    else if (ulLength < ulSize)
    {
	_CFragment* pfrgFirst;
	_CFragment* pfrgCurrent;
	_CFragment* pfrgTmp;
	UINT32 ulTotalFirst=0, ulSizeFirst=0;

	/* Find First affected fragment
	 */
	_FindFragment(ulLength, pfrgFirst, ulSizeFirst, ulTotalFirst);

	if(pfrgFirst)
	{
	    IHXBuffer* phxbufBuffy;

	    pfrgCurrent = pfrgFirst->Next();

	    phxbufBuffy = pfrgFirst->GetData();
	    phxbufBuffy->AddRef();

	    if(ulLength-ulTotalFirst > 0)
	    {
		/* Reset existing fragment to contain first part of phxbufBuffy
		 */
		pfrgFirst->SetData(phxbufBuffy, 0, ulLength-ulTotalFirst);
	    }
	    else
	    {
		m_frglstThis.Remove(pfrgFirst);
	    }

	    HX_RELEASE(phxbufBuffy);

	    /* Remove the truncated items.
	     */
	    while(pfrgCurrent)
	    {
		pfrgTmp = pfrgCurrent;
		pfrgCurrent = pfrgCurrent->Next();
		m_frglstThis.Remove(pfrgTmp);
	    }
	}
    }

    return HXR_OK;
}

/* returns the sum of all the fragments sizes
 */
STDMETHODIMP_(ULONG32) 
CHXFragmentedBuffer::GetSize()
{
    _CFragment* pfrgCurrent;
    UINT32 ulTotal = 0;

    pfrgCurrent = m_frglstThis.First();

    while (pfrgCurrent)
    {
	ulTotal += pfrgCurrent->GetData()->GetSize();

	pfrgCurrent = pfrgCurrent->Next();
    }

    return ulTotal;
}

STDMETHODIMP_(UCHAR*) 
CHXFragmentedBuffer::GetBuffer()
{
    return GetBuffer(0,UINT32(-1));
}

CHXFragmentedBuffer::_CFragment* 
CHXFragmentedBuffer::_CFragment::SetData(IHXBuffer* pData)
{
    HX_RELEASE(m_pData); 
    m_pData=pData; 
    m_pData->AddRef(); 
    return this;
}

CHXFragmentedBuffer::_CFragment* 
CHXFragmentedBuffer::_CFragment::SetData(IHXBuffer* pData, UINT32 ulStartFrom, UINT32 ulLengthFrom)
{
    HX_RELEASE(m_pData); 
    
    if(!ulStartFrom && ulLengthFrom >= pData->GetSize())
    {
	/* Use whole Buffer
	 */
	m_pData=pData;
        m_pData->AddRef();
    }
    else
    {
	/* Use Part of Buffer
	 */
	(
	    _CBufferFragment::CreateObject()
	)
	->_SetBuffer
	(
	    pData, 
	    ulStartFrom, 
	    ulLengthFrom
	)
	->QueryInterface
	(
	    IID_IHXBuffer,
	    (void**)&m_pData
	);
    }

    return this;
}

CHXFragmentedBuffer::_CFragment* 
CHXFragmentedBuffer::_CFragment::Insert(_CFragment* pNewPrev)
{
    if(pNewPrev == m_pPrev)
    {
	return this;
    }

    if(m_pPrev)
    {
	m_pPrev->_SetNext(pNewPrev);
    }

    if(pNewPrev)
    {
	pNewPrev->_SetNext(this);
	pNewPrev->_SetPrev(m_pPrev);
    }

    _SetPrev(pNewPrev);

    return pNewPrev;
}

CHXFragmentedBuffer::_CFragment* 
CHXFragmentedBuffer::_CFragment::Append(_CFragment* pNewNext)
{
    if(pNewNext == m_pNext)
    {
	return this;
    }

    if(m_pNext)
    {
	m_pNext->_SetPrev(pNewNext);
    }

    if(pNewNext)
    {
	pNewNext->_SetPrev(this);
	pNewNext->_SetNext(m_pNext);
    }

    _SetNext(pNewNext);
    
    return pNewNext;
}

CHXFragmentedBuffer::_CFragment* 
CHXFragmentedBuffer::_CFragment::Remove()
{
    _CFragment* pfrgRet;
    
    if(m_pNext)
    {
	pfrgRet = m_pNext;
    }
    else 
    {
	pfrgRet = m_pPrev;
    }
    
    delete this;

    return pfrgRet;
}

void 
CHXFragmentedBuffer::_CFragmentList::Remove(_CFragment* pfrgObsolete)
{
    if(pfrgObsolete)
    {
	if (pfrgObsolete == m_pfrgListEnd)
	{
	    m_pfrgListEnd = pfrgObsolete->Prev();
	}
	if (pfrgObsolete == m_pfrgListStart)
	{
	    m_pfrgListStart = pfrgObsolete->Next();
	}

	pfrgObsolete->Remove();
        --m_ulTotal;
    }
}

void 
CHXFragmentedBuffer::_CFragmentList::Insert(_CFragment* pfrgNew, _CFragment* pfrgRelative)
{
    if (!pfrgNew)
    {
	return;
    }

    if(pfrgRelative)
    {
	pfrgRelative->Insert(pfrgNew);

	if (pfrgRelative == m_pfrgListStart)
	{
	    m_pfrgListStart = pfrgNew;
	}
    }
    else if (m_pfrgListStart)
    {
	m_pfrgListStart->Insert(pfrgNew);
	m_pfrgListStart = pfrgNew;
    }
    else
    {
	m_pfrgListStart = m_pfrgListEnd = pfrgNew;
    }

    ++m_ulTotal;
}

void 
CHXFragmentedBuffer::_CFragmentList::Append(_CFragment* pfrgNew, _CFragment* pfrgRelative)
{
    if (!pfrgNew)
    {
	return;
    }

    if(pfrgRelative)
    {
	pfrgRelative->Append(pfrgNew);

	if (pfrgRelative == m_pfrgListEnd)
	{
	    m_pfrgListEnd = pfrgNew;
	}
    }
    else if (m_pfrgListEnd)
    {
	m_pfrgListEnd->Append(pfrgNew);
	m_pfrgListEnd = pfrgNew;
    }
    else
    {
	m_pfrgListStart = m_pfrgListEnd = pfrgNew;
    }

    ++m_ulTotal;
}

_CBufferFragment* 
_CBufferFragment::_SetBuffer(IHXBuffer* pData, UINT32 ulStart, UINT32 ulLength)
{
    HX_RELEASE(m_pData); 

    m_pData = pData; 
    
    if(m_pData)
    {
	m_pData->AddRef();

	m_ulStart=ulStart;

	if(m_pData->GetSize()-ulStart < ulLength)
	{
	    m_ulLength=m_pData->GetSize()-ulStart;
	}
	else
	{
	    m_ulLength=ulLength;
	}
    }
    else
    {
	m_ulStart=0;
	m_ulLength=0;
    }

    return this;
}

STDMETHODIMP 
_CBufferFragment::Set(const UCHAR* pData, UINT32 ulLength)
{
    if(!m_pData)
    {
	return HXR_UNEXPECTED;
    }

    return m_pData->Set(pData+m_ulStart, ulLength);
}

STDMETHODIMP
_CBufferFragment::Get(REF(UCHAR*) pData, REF(UINT32) ulLength)
{
    if(!m_pData)
    {
	return HXR_UNEXPECTED;
    }

    if(ulLength > m_ulLength)
    {
	return HXR_INVALID_PARAMETER;
    }

    pData = GetBuffer();
    ulLength = GetSize();
    
    return HXR_OK;
}

STDMETHODIMP
_CBufferFragment::SetSize(UINT32 ulLength)
{
    HX_RESULT hxrRet = HXR_FAIL;

    if(!m_pData)
    {
	/* Make New Buffer
	 */
	m_pData = (IHXBuffer*)(new CHXBuffer());
	m_pData->AddRef();
	m_ulStart = 0;
    }
    
    hxrRet = m_pData->SetSize(ulLength+m_ulStart);
    m_ulLength = ulLength;
    
    return hxrRet;
}

STDMETHODIMP_(UINT32)
_CBufferFragment::GetSize()
{
    if(!m_pData)
    {
	return 0;
    }

    return min(m_pData->GetSize()-m_ulStart, m_ulLength);
}

STDMETHODIMP_(UCHAR*)
_CBufferFragment::GetBuffer()
{
    if(!m_pData)
    {
	return NULL;
    }

    return m_pData->GetBuffer()?m_pData->GetBuffer()+m_ulStart:NULL;
}