osobhandClaude Opus 5.5
a6e90f3ee3
A file may start with a user block (h5py userblock_size, h5jam), putting the superblock at 512, 1024, ...; every address in the file is then relative to the superblock. The signature search found it, but every reader passed the whole file to the parsers, so addresses landed userblock bytes early and the root group failed with InvalidObjectHeaderVersion (twithub.h5, twithub513.h5, h5clear_fsm_persist_user_*.h5). Readers now view the file from the superblock on, taking the signature's position as the base address as libhdf5 does: File (mmap, buffered, from_bytes), MmapFile, LazyFile, AsyncHDF5File, the VOL and MPI VOL readers, the HNSW loader and external VDS source files. File, MmapFile and LazyFile gain user_block_size(). The new signature::split_user_block returns the two parts, and Superblock::parse refuses a non-zero offset (UserBlockNotStripped) so a format-level caller cannot silently apply superblock-relative addresses to the whole file. 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