{

// Since this is the constructor, this should not be deleting anything

// Otherwise, we might would need py::gil_scoped_acquire gil

this->data.array.reset(new py::array_t<uint16_t>(std::move(pyarray)));

Dimensions2D scanDimensions, uint32_t blockSize,

uint32_t totalImageNum)

: m_pydataset(pyDataSet), m_scanDimensions(scanDimensions),

m_imageNumbers(imageNumbers), m_imageNumInBlock(blockSize),

m_totalImageNum(totalImageNum)

{

{

// Acquire GIL before calling Python code

py::gil_scoped_acquire acquire;

// get to the end of the file, return empty Block

if (m_currIndex >= m_totalImageNum) {

return PyBlock();

}

// get the data pointer from the py object

auto getItems = m_pydataset.attr("__getitem__");

uint32_t upperBound = m_currIndex + m_imageNumInBlock;

if (upperBound > m_totalImageNum) {

upperBound = m_totalImageNum;

}

auto sliceIndex = py::slice(m_currIndex, upperBound, 1);

py::array_t<uint16_t> pyarray = getItems(sliceIndex);

PyBlock b(pyarray);

Dimensions2D frameDimensions = { pyarray.shape()[2], pyarray.shape()[1] };

// get the image numbers for current header

std::vector<uint32_t> imageNumberForBlock;

for (auto i = m_currIndex; i < upperBound; i++) {

imageNumberForBlock.push_back(m_imageNumbers[i]);

}

b.header = Header(frameDimensions, imageNumberForBlock.size(), m_scanDimensions,

imageNumberForBlock);

b.header.version = 3;

m_currIndex = upperBound;

return b;

{

// read data at first time

return iterator(this);