riegeli-rs

A pure-Rust implementation of Google's Riegeli/records file format. Riegeli is a seekable, compressed record store designed for high-throughput sequential reads and writes, commonly used in machine learning pipelines and large-scale data processing. This crate is byte-level compatible with the C++ reference implementation.

The repository contains two crates: riegeli, the published library, and riegeli-ffi, an internal test harness that builds the C++ reference implementation for differential testing — it is never published and is not for external use.

Quick start

[dependencies]
riegeli = "0.2"

use std::io::Cursor;
use riegeli::{RecordWriter, RecordReader, WriterOptions, ReaderOptions, CompressionType};

// Write
let mut buf = Vec::new();
let opts = WriterOptions::new().compression(CompressionType::Zstd);
let mut writer = RecordWriter::new(Cursor::new(&mut buf), opts).unwrap();
writer.write_record(b"alpha").unwrap();
writer.write_record(b"bravo").unwrap();
writer.write_record(b"charlie").unwrap();
writer.close().unwrap();

// Read
let mut reader = RecordReader::new(Cursor::new(&buf), ReaderOptions::new()).unwrap();
while let Some(record) = reader.read_record().unwrap() {
    println!("{}", std::str::from_utf8(&record).unwrap());
}

Benchmarks

See riegeli/benches/README.md for the full head-to-head Rust vs. C++ benchmark matrix. Representative results on Linux x86-64 (10 000 records, large payload):

C++ read throughput is measured through the FFI bridge and includes a per-record copy across the boundary, making it lower than native C++ performance.

License

Apache-2.0