osobhandClaude Fable 5.1
0addf328bc
Same-moment A/B on a 64 MB f64 dataset: chunked+deflate 110 -> 69 ms, chunked 72 -> 60 ms, contiguous 56 -> 30 ms. - read_chunked_data_cached — the path the facade uses — decompressed chunks one at a time; only the uncached reader was parallel. Cache misses are now decoded in bounded batches (128), in parallel with the `parallel` feature. - Every chunk was pushed into the 16 MiB chunk cache, which a larger dataset just churns (insert, evict moments later). Chunks are cached only when the whole dataset fits (new ChunkCache::max_bytes). - Unfiltered chunks went file -> Vec -> aligned cache buffer -> output. They are copied straight from the file bytes. - The facade's typed reads convert a contiguous dataset straight from the borrowed file bytes instead of copying it into a Vec first. - The native little-endian fast paths allocated vec![0; n] and then overwrote it; they now fill an uninitialised buffer in one copy (native_le_to_vec). alloc_output requests zeroed memory from the allocator instead of reserving and filling. The unit test that expected unfiltered chunks to land in the decompressed cache now asserts the new design (index reused, cache not involved). Co-Authored-By: Claude Fable 5.1 <[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