Implements Pcodec (filter ID 32023) via the `pco` 1.0.x crate as a new
optional compression codec. Pcodec achieves 30–94% better compression
ratio than Zstd for f32/f64 columnar data at 1–5 GiB/s decompression
speed, making it ideal for write-once/read-many embedding archives.
Write throughput at 512×512: 591 MiB/s (parity with Zstd-3 at 610 MiB/s).
For smaller chunks Zstd-3 remains faster due to Pcodec's fixed per-chunk
distributional analysis overhead.
- Add FILTER_PCODEC = 32023 constant to filter_pipeline.rs
- Add pcodec_compress/pcodec_decompress using pco::standalone API
- Wire into compress_chunk/decompress_chunk dispatch
- Add ChunkOptions.pcodec field and DatasetBuilder.with_pcodec() method
- Enable pcodec as highest-priority codec in build_pipeline()
- Add pco dep (optional, feature = "pcodec") to clawhdf5-format/clawhdf5
- Add write_2d_chunked_pcodec benchmark comparing pcodec vs zstd-3
- Document results in BENCHMARKS.md
Co-Authored-By: Claude Sonnet 4.6 <[email protected]>
Add features = ["zstd"] to clawhdf5-bench dev-dependency so the
write_2d_chunked_zstd benchmark no longer panics with UnsupportedFilter(32015).
Update BENCHMARKS.md and README.md with measured results from the full
h5bench write suite (2026-06-30, post write-performance improvements):
- Zstd-3 hits 593 MiB/s at 512×512 vs deflate-6's 280 MiB/s (2.12×)
- Zstd-3 hits 330 MiB/s at 128×128 vs deflate-6's 132 MiB/s (2.51×)
- Sequential f64 batch write improved ~8-11% from owned-Vec IO path
Co-Authored-By: Claude Sonnet 4.6 <[email protected]>
Adds three Criterion benchmark suites mirroring the h5bench HPC I/O
benchmark workloads in pure Rust — no C libhdf5 required for the default
path, with an optional `libhdf5-compare` feature for side-by-side numbers.
- benches/h5bench_write.rs: write_1d_contiguous, write_2d_chunked,
write_f64_batch, write_multi_dataset, write_with_attrs
- benches/h5bench_read.rs: read_sequential, read_f64_sequential,
read_chunked_2d, read_from_disk, read_hyperslab
- benches/h5bench_meta.rs: metadata_attrs_write, metadata_attrs_read,
metadata_groups_create, metadata_groups_traverse, metadata_string_attrs
All benchmarks pass `cargo bench --bench <name> -- --test` and clippy
reports zero warnings. Run with `cargo bench -p clawhdf5-bench`.
Co-Authored-By: Claude Sonnet 4.6 <[email protected]>
Bumps [workspace.package] and all 17 crate package versions (and internal
path-dependency requirements) from 2.0.0 to 2.1.0 for a coordinated release.
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
