Read Unknown Size Data For File

ReadUnknownSizeForFile.cpp

// Example for pfnRead
int ReadThunk(int* pData, FILE* pFile)
{
    fread(pData, sizeof(*pData), 1, pFile);
    // EOF ?
    if (*pData == 0)
    {
        return 0;
    }
}

template<typename T>
int ReadUnknownSizeForFile<T>(
    T*& pDatas, int& count, 
    int(*pfnRead)(T*, FILE*), FILE* pFile, 
    unsigned int maxCount = -1, unsigned int segSize = 256
)
{
    int ret = 0;
    int segCount = 0;
    pDatas = new T[segSize];
    count = 0;
    while (count >= segSize * segCount++)
    {
        for (; count < segSize * segCount; count++)
        {
            if (count > maxCount)
            {
                // -1: Count Over Range
                return -1;
            }
            ret = pfnRead(&pDatas[count], pFile);
            if (ret != 1) // 1: pfnRead OK
            {
                // Exception Occurred
                return ret;
            }
        }
        T* pBuf = pDatas;
        pDatas = new T[segSize * segCount];
        memcpy(pDatas, pBuf, sizeof(T) * segSize * (segCount - 1));
        delete[] pBuf;
    }
    // 0: OK
    return 0;
}