跳转一致散列

实现跳转一致散列算法，如[A Fast, Minimal Memory, Consistent Hash Algorithim] (https://arxiv.org/pdf/1406.2294v1.pdf)中所述。

示例

extern crate jmphash;

use jmphash::jump_hash;

fn really_complicated_hash_function() -> u64 {
  42
}

fn main() {
    let num_buckets = 100;

    // first use a hash function of your choice to create a u64 key
    let key = really_complicated_hash_function();

    // then one can use `jump_hash` to map the key to a bucket
    let bucket = jump_hash(key, num_buckets);
}