osobhandClaude Opus 5.5
7c1968a34a
dataset_fill_value treated a shared Fill Value message as "no fill value", so unwritten storage of a dataset whose fill value lives in the file's shared-message (SOHM) heap read as zeros rather than its fill value. libhdf5 shares fill values whenever the file has a SOHM index for them. - fill_value::dataset_fill_value_in follows the reference (another object header, or the SOHM heap); read_full_with_fill and the facade's selection read use it. - dataset_fill_value, which has no file to follow a reference into, now returns UnresolvedSharedMessage for a shared message instead of None. - shared_message::load_sohm_table / message_data_with_sohm load the SOHM table from the superblock extension on demand. - parse_sohm_table skipped each index's leading version byte, reading every field one byte off; SOHM references could never resolve. Fixture shared_fill_value.h5 (HDF5 2.0, gen_shared_fill.py): sohm_b read [0,1,2,3,0,0,0,0] and now reads [0,1,2,3,-7,-7,-7,-7], as h5py does. Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>
clawhdf5-format
Pure-Rust HDF5 binary format parsing and writing — no C dependencies.
Features
- Zero-copy superblock, object header, and B-tree parsing
- Chunked dataset read/write with filter pipelines
no_stdsupport (disablestdfeature)- Optional parallel reads via Rayon
- SHA-256 provenance tracking
Usage
use clawhdf5_format::Superblock;
let data = std::fs::read("data.h5").unwrap();
let sb = Superblock::from_bytes(&data).unwrap();
println!("HDF5 version {}.{}", sb.version_major(), sb.version_minor());
License
MIT