smlpkt.cpp

来自「linux下的一款播放器」· C++ 代码 · 共 728 行 · 第 1/2 页

CSmilPacketParser::~CSmilPacketParser()
{
    deleteNode(m_pRootNode);
}

CSmilPacketParser::SMILPacketParseResult
CSmilPacketParser::getAtom(const char*& pBuf, UINT32 len, 
                           CSmilPacketTag*& pTag)
{
    CSmilPacketParser::SMILPacketParseResult retCode = SMILUnknown;
    const char* pEnd;
    const char* pCur;

    pTag = 0;
    pEnd = pBuf + len;
    pCur = pBuf;

    if(*pCur == '(')
    {
        pCur++;
        pBuf = pCur;
        retCode = SMILOpenList;
    }
    else if(*pCur == ')')
    {
        pCur++;
        pBuf = pCur;
        retCode = SMILCloseList;
    }
    else
    {
        // skip whitespace
        while(isspace(*pCur) && (pCur < pEnd))
        {
            pCur++;
        }
        if(pCur >= pEnd)
        {
            pBuf = pCur;
            retCode = SMILNoValue;
        }
        else if(*pCur == ')')
        {
            pCur++;
            pBuf = pCur;
            retCode = SMILCloseList;
        }
        else if(*pCur == '(')
        {
            pCur++;
            pBuf = pCur;
            retCode = SMILOpenList;
        }
        else
        {
            char* tmpBuf = new char [MAX_STRING_LEN + 2]; /* Flawfinder: ignore */ // one for null, one for luck
            char* pTmpBuf = tmpBuf;
            if(*pCur == '"')
            {
                pCur++;
                int iLen = 0;  
                while((*pCur != '"') && (pCur < pEnd) && (++iLen < MAX_STRING_LEN))
                {
                    if(*pCur == '\\')
                    {
                        pCur++;
                        *pTmpBuf++ = *pCur++;
                    }
                    else
                    {
                        *pTmpBuf++ = *pCur++;
                    }
                }
                if(*pCur != '"')
                {
                    pBuf = pCur;
                    retCode = SMILMissingQuote;
                }
                else
                {
                    *pTmpBuf = 0;
                    pCur++;
                }
            }
            else
            {
                while((pCur<pEnd) && !isspace(*pCur) && (*pCur != ')') && 
                      (*pCur != '(') )
                {
                    if(*pCur == '\\')
                    {
                        pCur++;
                        *pTmpBuf++ = *pCur++;
                    }
                    else
                    {
                        *pTmpBuf++ = *pCur++;
                    }
                }
                *pTmpBuf = 0;
            }
            if( retCode != SMILMissingQuote )
            {
                pTag = new CSmilPacketTag;
                pTag->m_name = tmpBuf;
                pBuf = pCur;
                retCode = SMILString;
            }
            HX_VECTOR_DELETE(tmpBuf);
        }
    }
    return retCode;
}

CSmilPacket*
CSmilPacketParser::parse(IHXBuffer* pBuffer,
                         REF(CSmilPacketParser::SMILPacketParseResult) pktPrsRslt)
{
    BOOL bErrorOccurred = FALSE;

    CSmilPacketTag* pTag = 0;

    HX_RESULT pnr = HXR_OK;

    if(m_pRootNode)
    {
        deleteNode(m_pRootNode);
    }
    m_pRootNode = new Node;
    Node* pCurNode = m_pRootNode;
    Node* pCurList = m_pRootNode;

    CHXStack* pStack = new CHXStack;

    CBigByteQueue* pQueue = new CBigByteQueue(pBuffer->GetSize());
    pQueue->EnQueue((void*)pBuffer->GetBuffer(), pBuffer->GetSize());

    BOOL bFirst = TRUE;
    for(;;)
    {
        UINT32 bytesUsed;
        UINT32 bytesAvail = pQueue->GetQueuedItemCount();
        if(bytesAvail <= 0)
        {
            break;
        }

        BYTE* pBuf = new BYTE[bytesAvail];
        BYTE* p = pBuf;
        pQueue->DeQueue(pBuf, bytesAvail);
        bytesUsed = bytesAvail;

        if(pTag)
        {
            delete pTag;
            pTag = 0;
        }

        SMILPacketParseResult rc = getAtom((const char*&)p, bytesAvail, pTag);
        // /Fixes PR 32297 (release-build-only crash):
        // In case rc is SMILMissingQuote, quit and return an error,
        // otherwise a 0-sized buffer gets created later on that is the
        // subject of an access violation:
        INT32 lSizeToEnqueue = bytesAvail - (p - pBuf);
        HX_ASSERT(lSizeToEnqueue >= 0); // /If < 0, something is messed up.
        if (0 == lSizeToEnqueue  &&  SMILMissingQuote == rc)
        {
            pktPrsRslt = rc;
            bErrorOccurred = TRUE;
            goto cleanup;
        }
        pQueue->EnQueue(p, (UINT32)(bytesAvail - (p - pBuf)));
        switch(rc)
        {
           case SMILOpenList:
           {
               Node* pNode = new Node;
               if(pCurNode == m_pRootNode)
               {
                   pCurNode->car = pNode;
               }
               else
               {
                   pCurNode->cdr = pNode;
               }
               pStack->Push(pNode);
               pCurNode = pNode;
           }
           break;

           case SMILString:
           {
               if(bFirst)
               {
                   bFirst = FALSE;
               }
               else
               {
                   Node* pNode = new Node;
                   if(!pCurNode->m_bIsSymbol)
                   {
                       if(!pCurNode->car)
                           pCurNode->car = pNode;
                       else
                           pCurNode->cdr = pNode;
                   }
                   else
                   {
                       pCurNode->cdr = pNode;
                   }
                   pCurNode = pNode;
               }
               pCurNode->m_name = pTag->m_name;
               pCurNode->m_bIsSymbol = TRUE;
           }
           break;

           case SMILCloseList:
           {
               pCurNode = (Node*)pStack->Pop();
           }
           break;

           default:
               break;
        }
        HX_VECTOR_DELETE(pBuf);
    }

  cleanup:
    if(pTag)
    {
        delete pTag;
    }

    delete pQueue;
    delete pStack;

    if (bErrorOccurred)
    {
        return NULL;
    }
    return evalNode(getRoot());
}

void
CSmilPacketParser::deleteNode(Node* pNode)
{
    if(!pNode)
    {
        return;
    }
    deleteNode(pNode->car);
    deleteNode(pNode->cdr);
    delete pNode;
}

void
CSmilPacketParser::eval(Node* pNode, CSmilPacket* pPacket)
{
    if(!pNode)
        return;

    BOOL bFirst = TRUE;
    const char* pName = 0;
    const char* pValue[MAX_ARGS] = {0};
    int i = 0;
    while(pNode && i < MAX_ARGS)
    {
        if(pNode->m_bIsSymbol)
        {
            if(bFirst)
            {
                pName = (const char*)pNode->m_name;
                bFirst = FALSE;
                i = 0;
            }
            else
            {
                pValue[i] = (const char*)pNode->m_name;
                i++;
            }
        }
        else
        {
            eval(pNode->car, pPacket);
        }
        pNode = pNode->cdr;
    }
    if(pName)
    {
        pPacket->assign(pName, pValue, i);
    }
}

CSmilPacket*
CSmilPacketParser::evalNode(Node* pNode)
{
    if(!pNode || !pNode->m_bIsSymbol)
    {
        return 0;
    }

    CSmilPacket* pPacket = 0;
    // const char* pID = 0;
    const char* pName = 0;

    pName = (const char*)pNode->m_name;
    pNode = pNode->cdr;
    if(pNode)
    {
//      if(pNode->m_bIsSymbol)
//      {
//          pID = (const char*)pNode->m_name;
//          pNode = pNode->cdr;
//      }
//      else
//      {
//          pID = "<anonymous>";
//      }

        if(strcmp(pName, "smil-document") == 0)
        {
            pPacket = new CSmilDocumentPacket;
        }
        else if(strcmp(pName, "add-channel") == 0)
        {
            pPacket = new CSmilAddChannelPacket;
        }
        else if(strcmp(pName, "add-group") == 0)
        {
            pPacket = new CSmilAddGroupPacket;
        }
        else if(strcmp(pName, "play-group") == 0)
        {
            pPacket = new CSmilPlayGroupPacket;
        }
        else if(strcmp(pName, "add-source") == 0)
        {
            pPacket = new CSmilAddSourcePacket;
        }
        else if(strcmp(pName, "source-added") == 0)
        {
            pPacket = new CSmilSourceAddedPacket;
        }
        else if(strcmp(pName, "end-layout") == 0)
        {
            pPacket = new CSmilEndLayoutPacket;
        }
        else if(strcmp(pName, "meta") == 0)
        {
            pPacket = new CSmilMetaValuesPacket;
        }

        if(pPacket)
        {
            eval(pNode, pPacket);
        }
        return pPacket;
    }
    return 0;
}