I am trying the VDS feature with Hdf5 1.10. If the virtual dataset references elements that don't exist in the source datasets, tools to dump the dataset hang. If a source file is missing, then it works and I get the fill value.
For instance, If I create 3 src files with 1D datasets of 6 elements, say I have
fileA/dsetA: 0,1,2,3,4,5
fileB/dsetB: 10,11,12,13,14,15
fileC/dsetC: 20,21,22,23,24,25
and then make a 1D vds in a new file which has a size of 4*6=24 elements mapped as follows
fileA/dsetA -> start 0, stride 4, count 1, block 1
fileB/dsetB -> start 1, stride 4, count 1, block 1
fileC/dsetC -> start 2, stride 4, count 1, block 1
fileD/dsetD -> start 3, stride 4, count 1, block 1
where fileD doesn't exist, then h5ls -d shows what I'd expect, where the fill value for the vds is -1
0, 10, 20, -1,
1, 11, 21, -1,
2, 12, 22, -1,
3, 13, 23, -1,
4, 14, 24, -1,
5, 15, 25, -1
but if I change the size of the vds to be 4*10=40 elements, without altering the source files, than h5ls -d hangs. I was expecting to see 16 more -1's following the 24 elements printed above.
If it sounds like a bug I can prepare an example to re-produce, but maybe this is how the VDS works?
best,
David Schneider
SLAC/LCLS