H5D_GET_OFFSET and H5D_GET_CHUNK_INFO_BY_COORD

[mburkat]

Hi HDF5 community,

I’m trying to get the offset of a COMPACT dataset and seeing a return value of -1, is it possible to get the offset of that compact dataset data field?

For H5D_GET_CHUNK_INFO_BY_COORD is it possible to get all the address/size/filter for all my chunks in a dataset with one function call?
Context is that I’m trying to use the ROS3 plugin and I believe there are multiple or maybe even one S3 request from the plugin per H5D_GET_CHUNK_INFO_BY_COORD call. Some datasets I’m looking at have 16,000 chunks so there is potentially up to 16k s3 requests?

Thanks,
Mike

[gheber]

I’m trying to get the offset of a COMPACT dataset and seeing a return value of -1, is it possible to get the offset of that compact dataset data field?

Use H5Oget_info or H5Oget_native_info depending on which version of HDF5 you are using to get the object header address. The data of a dataset with compact layout is stored in the object header. You’ll have to parse that.

For H5D_GET_CHUNK_INFO_BY_COORD is it possible to get all the address/size/filter for all my chunks in a dataset with one function call?

No, not at the moment.

I think it’s important to keep in mind that ROS3 is a compatibility approach and has several limitations. If you want something “could-native”, have a look at HSDS and see it in action at Kita Lab.

G.