congee dependency status codecov Documentation

A Rust implementation of ART-OLC concurrent adaptive radix tree. It implements the optimistic lock coupling with proper SIMD support.

It only supports (and is optimized for) 8 byte key; due to this specialization, congee has great performance – basic operations are faster than most hash tables, range scan is an order of magnitude faster.

The code is extensively tested with [{address leak} sanitizer]( as well as libfuzzer.

Why Congee?

Why not Congee?


use congee::Art;
let art = Art::new();
let guard =; // enter an epoch

art.insert(0, 42, &guard); // insert a value
let val = art.get(&0, &guard).unwrap(); // read the value
assert_eq!(val, 42);

let mut scan_buffer = vec![(0, 0); 8];
let scan_result = art.range(&0, &10, &mut scan_buffer, &guard); // scan values
assert_eq!(scan_result, 1);
assert_eq!(scan_buffer[0], (0, 42));


Congee was originally developed in the Alchemy project to fullfil its need for a concurrent, scalable, and low memory footprint range index.