osobhandClaude Opus 5.5
02e89c1d2d
Finding one link or attribute by name read every entry: Group::dataset and Group::group (File, MmapFile, LazyFile) listed the whole group per call, and path resolution scanned each group's links. Opening every child of a 35 001-link group by name decoded ~1.2e9 links. Now a dense group's v2 B-tree name index (type 5, lookup3 hash of the name) is descended to the records with the name's hash (btree_v2::find_btree_v2_records reads only the nodes whose key interval overlaps), and only those links are read and compared; all hash-equal records are compared, so libhdf5's tie order does not matter. Dense attributes the same through their type 8 index (attribute::find_attribute_in_file, facade attr(name)); huge heap objects through their ID-ordered index. group_v2::resolve_child returns what the listing has under a name (soft links followed, dangling/external ones not found). Group::entries and File::group_at hand out a listing's addresses. The lookup-stats feature counts heap objects read. Tests: one lookup in an h5py-written 35 001-link group with colliding hashes reads at most two links (before: 35 001, failing), attribute lookups likewise (before: 3 000, failing), every child opens through all three readers and matches h5py, every link kind resolves as h5py resolves it in dense and compact groups, 300 huge attributes are found, and a range search matches a full scan at every tree depth. 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