osobhandClaude Opus 5.5
afae86f3ea
libhdf5 encodes a version-4 layout's chunk dimensions in (log2(max) + 8) / 8 bytes, and HDF5 2.0.0 (h5py 3.16) refuses any other width: "stored chunk dimension encoding length does not match value calculated from chunk dimensions". The writer rounded 3 bytes up to 4, so h5py could not open a dataset we wrote with a chunk dimension from 65 536 to 16 777 215, for every chunk index (single chunk, fixed and extensible array, v2 B-tree). The three encoders now share push_v4_chunk_dims, which writes the exact width. 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