H5Dchunk_iter offset is not scaled by chunk dimensions

[wenjuno]

I'm not very sure if this is intentional but I find it inconsistent with offset in H5Dget_chunk_info.
I think the relevant code for H5Dchunk_iter is this:

hdf5/src/H5Dchunk.c

Lines 7519 to 7520 in 1d59818

	if ((ret_value = (data->op)(chunk_rec->scaled, chunk_rec->filter_mask, chunk_rec->chunk_addr,
	chunk_rec->nbytes, data->op_data)) < 0)

Comparing to how the offset in H5Dget_chunk_info is calculated below, there are missing multipliers of dset->shared->layout.u.chunk.dim[ii]:

hdf5/src/H5Dchunk.c

Lines 7347 to 7349 in 1d59818

	if (offset)
	for (ii = 0; ii < udata.ndims; ii++)
	offset[ii] = udata.scaled[ii] * dset->shared->layout.u.chunk.dim[ii];

In order to use H5Dchunk_iter I will need to apply the chunk dimensions multipliers myself. Is this a bug or a conscious design choice? Thanks.

[mkitti]

This is an important inconsistency. @gauteh was this intended?

[gauteh]

Hm, that was probably not intended: I can see in my library code that I scale it when this function is available, and that I don't scale when I use chunk_info directly.

I also noticed that in

hdf5/src/H5Dchunk.c

Line 7487 in 1d59818

*size = udata.nbytes;

the *offset seems to not be written to, that also seems like a bug?

Neither it seems that the offset is set here:

hdf5/src/H5Dchunk.c

Line 7391 in 1d59818

if (!different) {

[mkitti]

the *offset seems to not be written to, that also seems like a bug?

You're looking at H5Dget_chunk_info_by_coord which takes offset as an input parameter.

https://docs.hdfgroup.org/hdf5/develop/group___h5_d.html#ga408a49c6ec59c5b65ce4c791f8d26cb0

[gauteh]

Doh, of course.

[mkitti]

I'll tackle if this unless someone else has started already.