Lib.rs

一个包装器，用于存储哈希结果，以避免在值未更改的情况下多次运行昂贵的哈希函数

由于Rust对哈希系统的抽象，目前只能将其实现为使用另一个内部Hasher的哈希

示例

use hash_on_write::How;
use std::collections::HashSet;

let mut x = How::new_default("foo".to_owned());

assert!(! How::is_hashed(&x));
HashSet::new().insert(&x);
assert!(How::is_hashed(&x));

How::make_mut(&mut x).push('!');
assert!(! How::is_hashed(&x));
assert_eq!(*x, "foo!");

bench

Warning: Unable to complete 100 samples in 5.0s. You may wish to increase target time to 8.2s, or reduce sample count to 60.
no cache                time:   [81.408 ms 81.529 ms 81.673 ms]
                        change: [-0.7393% -0.4157% -0.1121%] (p = 0.01 < 0.05)
                        Change within noise threshold.
Found 5 outliers among 100 measurements (5.00%)
  2 (2.00%) low mild
  2 (2.00%) high mild
  1 (1.00%) high severe

Benchmarking cache key: Warming up for 3.0000 s
Warning: Unable to complete 100 samples in 5.0s. You may wish to increase target time to 5.3s, or reduce sample count to 90.
cache key               time:   [53.380 ms 53.608 ms 53.855 ms]
                        change: [-0.6099% +0.0048% +0.5883%] (p = 0.99 > 0.05)
                        No change in performance detected.
Found 5 outliers among 100 measurements (5.00%)
  4 (4.00%) high mild
  1 (1.00%) high severe