Not able to set flag for track order while creating a group.

In Situ Support
1

Hi, I am trying to create VTKHDF group with track order flag(like we do in python).
I am creating a C++ API, so trying to add the flags while creating a group.
I tried to use both C++ based and C based functions from HDF5 Api. But the group is still showing
“Creation Order NOT Tracked”.
This is important because, as far as I know, we need the VTKHDF and Assembly group to be tracked for reading MultiblockDataset. That is why I am not able read in Paraview.

bool createGroup(const std::string grpNm )
{
    if (grpNm.empty()) {
        return false;
    }

    try {
        // Create a property list for the creation of the group
        hid_t gcpl = H5Pcreate(H5P_GROUP_CREATE);

        // Set the link creation order
        herr_t status = H5Pset_link_creation_order(gcpl, H5P_CRT_ORDER_TRACKED | H5P_CRT_ORDER_INDEXED);
        std::cout<<status;
        // Create the group with the property list
        hid_t group = H5Gcreate(H5F_OBJ_FILE, grpNm.c_str(), H5P_DEFAULT, gcpl, H5P_DEFAULT);
        std::cout<<group;
        // Close the group and property list
        H5Gclose(group);
        H5Pclose(gcpl);
    } catch(...) {
        return false;
    }
    return true;
}

Am I missing something?

2

@Lucas_Givord

3

Hello @mrx

indeed you need that for the MultiBlock or PartitionedDataSetCollection vtkhdf file. However your method looks ok, you can also look at this method https://gitlab.kitware.com/vtk/vtk/-/blob/master/IO/HDF/vtkHDFWriterImplementation.cxx#L250-L260 and how we call it

4

Yes I did see it. I tried mimicking your function, but still it isn’t working.

5

the only thing that I see here is that you use directly the H5F_OBJ_FILE, in the writer we pass the hid_t of the file directly.

Also maybe the issue come from another part of your code and not from this snippet?

6

Rest all is actually working fine, and this is more or less standalone code. The other function which I am just using to create groups is working fine.
Okay I will check the id thing. Thanks!