Crate maglev

Maglev hashing - A consistent hashing algorithm from Google

[Maglev: A Fast and Reliable Software Network Load Balancer] (https://static.googleusercontent.com/media/research.google.com/zh-CN//pubs/archive/44824.pdf)

Example

use maglev::*;

let m = Maglev::new(vec!["Monday",
                         "Tuesday",
                         "Wednesday",
                         "Thursday",
                         "Friday",
                         "Saturday",
                         "Sunday"]);

assert_eq!(m["alice"], "Friday");
assert_eq!(m["bob"], "Wednesday");

// When the node list changed, ensure to use same `capacity` to rebuild the lookup table.

let m = Maglev::with_capacity(vec!["Monday",
                                // "Tuesday",
                                   "Wednesday",
                                // "Thursday",
                                   "Friday",
                                   "Saturday",
                                   "Sunday"],
                              m.capacity());

assert_eq!(m["alice"], "Friday");
assert_eq!(m["bob"], "Wednesday");

Maglev use std::collections::hash_map::DefaultHasher by default, we could use the given hash builder to hash keys.

extern crate fasthash;
extern crate maglev;

use fasthash::spooky::Hash128;

use maglev::*;

fn main() {
    let m = Maglev::with_hasher(vec!["Monday",
                                     "Tuesday",
                                     "Wednesday",
                                     "Thursday",
                                     "Friday",
                                     "Saturday",
                                     "Sunday"],
                                Hash128 {});

    assert_eq!(m["alice"], "Monday");
    assert_eq!(m["bob"], "Wednesday");
}

Structs

Maglev

Maglev lookup table

Traits

ConsistentHasher

Consistent hasher is a special kind of hashing such that when a hash table is resized, only K/n keys need to be remapped on average, where K is the number of keys, and n is the number of slots.