oxistore-compress — Pure-Rust OxiARC compression bridge for OxiStore

oxistore-compress is the compression layer of the OxiStore stack. It provides a single DEFLATE codec — [OxiArcCodec] — backed exclusively by oxiarc-deflate (Pure-Rust DEFLATE, RFC 1951) from the COOLJAPAN OxiARC stack, plus a [parquet::compression::Codec] shim so that Parquet pages can be compressed and decompressed through the same Pure-Rust path.

In line with the COOLJAPAN Pure-Rust compression policy, this crate never depends on flate2, zstd, brotli, snap, or miniz_oxide. The only codec backend is OxiARC. The CompressError error type integrates with the wider stack via a From<CompressError> conversion into oxistore_core::StoreError.

Installation

[dependencies]
# Codec + Parquet shim require the `compress` feature.
oxistore-compress = { version = "0.1.0", features = ["compress"] }

Without the compress feature only the CompressError type is compiled; the codec and Parquet shim are feature-gated.

Quick Start

# #[cfg(feature = "compress")]
# {
use oxistore_compress::OxiArcCodec;

let codec = OxiArcCodec::new();                 // level 6 (balanced)
let data = b"hello, world! ".repeat(1000);

let compressed = codec.compress(&data)?;
let decompressed = codec.decompress(&compressed)?;
assert_eq!(decompressed, data);
# }
# Ok::<(), oxistore_compress::CompressError>(())

Choosing a level

# #[cfg(feature = "compress")]
# {
use oxistore_compress::OxiArcCodec;

let fast = OxiArcCodec::with_level(1);          // clamps values > 9 to 9
let best = OxiArcCodec::new_with_level(9)?;     // errors on level > 9
assert_eq!(best.algorithm_name(), "DEFLATE");
assert_eq!(best.compression_level(), Some(9));
# }
# Ok::<(), oxistore_compress::CompressError>(())

Parquet page compression

With the compress feature, OxiArcCodec implements parquet::compression::Codec, so it can be slotted directly into a Parquet writer/reader pipeline to compress pages with OxiARC DEFLATE instead of any C-backed codec.

API Overview

`OxiArcCodec` (feature `compress`)

A stateless, Copy DEFLATE codec. Carries only a compression level (0 = store, 9 = best).

Method	Description
`OxiArcCodec::new()`	`const` constructor at the default level (6, balanced)
`OxiArcCodec::with_level(level: u8)`	`const` constructor; values above 9 are clamped to 9
`OxiArcCodec::new_with_level(level: u32)`	Fallible constructor; returns `CompressError::InvalidLevel` for `level > 9`
`compress(&self, data)`	Compress with DEFLATE → `Vec<u8>`
`decompress(&self, data)`	Decompress a DEFLATE stream → `Vec<u8>`
`OxiArcCodec::decompress_into(data, &mut out)`	Decompress, appending to an existing buffer (associated fn)
`compress_with_hint(&self, data, size_hint)`	Compress with an advisory size hint (currently delegates to `compress`)
`algorithm_name(&self)`	`const` — always `"DEFLATE"`
`compression_level(&self)`	`const` — `Some(level)`, level in 0–9

`parquet::compression::Codec` impl (feature `compress`)

OxiArcCodec implements the Parquet Codec trait (compress / decompress) via the parquet_shim module, bridging Parquet page compression to OxiARC DEFLATE.

Feature Flags

Feature	Default	Description
`compress`	off	Enables `OxiArcCodec` and the Parquet `Codec` shim. Pulls in `oxiarc-deflate`, `oxiarc-core`, and `parquet`. Never pulls in flate2, zstd, brotli, snap, or miniz_oxide

Error variants

CompressError is #[non_exhaustive] and implements std::error::Error + Display. It converts into oxistore_core::StoreError (via StoreError::Other), and (under the compress feature) From<oxiarc_core::error::OxiArcError> maps OxiARC errors into it.

Variant	Description
`Compress(String)`	Compression failure (wraps the underlying error message)
`Decompress(String)`	Decompression failure (wraps the underlying error message)
`InvalidLevel(u32)`	Requested compression level is outside the valid range 0–9

OxiARC compression backend

The sole backend is oxiarc-deflate — a Pure-Rust RFC 1951 DEFLATE implementation from the COOLJAPAN OxiARC stack. compress calls oxiarc_deflate::deflate(data, level); decompress calls oxiarc_deflate::inflate(data). No C, C++, or Fortran code is linked at any point.

Cross-references

oxistore — the storage facade; enable the compress feature to re-export this crate (it forwards oxistore-compress/compress).
oxistore-core — provides StoreError, the target of the From<CompressError> conversion.
oxistore-columnar — uses the same OxiARC DEFLATE backend for optional payload-level Parquet compression.

License

Apache-2.0 — COOLJAPAN OU (Team Kitasan)

oxistore-compress 0.1.2