C++ 字節流 CByteBuffer

CByteBuffer使用

static void Main()
{
    BYTE a;
    short b;
    int c;
    CByteBuffer buffer;
    buffer<<a<<b<<c;
}

 

class CByteBuffer
{
public:
    BYTE* m_lpBuf;
    int nCurrentIndex;
    int nCapacity;
    int nLen;
    CByteBuffer()
    {
        Init(128);
    }

    CByteBuffer(int nCapacityIn)
    {
        Init(nCapacityIn);
    }

    ~CByteBuffer()
    {
        delete [] m_lpBuf;
        m_lpBuf=NULL;
    }

    void GetMoreCapacity()
    {
        BYTE *pBytesMore=new BYTE[nCapacity*2]; //兩倍
        memcpy(pBytesMore,m_lpBuf,nCapacity*sizeof(BYTE));
        memset(pBytesMore+nCapacity,0x00,nCapacity*sizeof(BYTE));
        delete [] m_lpBuf;
        m_lpBuf=pBytesMore;
        nCapacity*=2;
    }
    
    template<typename T>
    CByteBuffer& operator <<(T dw)
    {
        int nSizeNew=nCurrentIndex + sizeof(T);
        while(nSizeNew>nCapacity)
        {
            GetMoreCapacity(); //緩衝區空間不夠
        }
        *(T*)(&m_lpBuf[nCurrentIndex])=dw; //添入緩衝區
        nCurrentIndex += sizeof(T);     //移動當前索引
        nLen+=sizeof(T);
        return *this;
    }

private:
    void Init(int nCapatityIn)
    {
        nCapacity=nCapatityIn;
        m_lpBuf=new BYTE[nCapatityIn];
        memset(m_lpBuf,0x00,nCapacity);
        nCurrentIndex=0;
        nLen=0;
    }
};