improve performances by not shuffling vectors

in ./bins/inbreeding/, this MR does

• refactor the "list item drawing" from environment.rs and strategy.rs into the draw_unique_elements function of new random.rs module
• use a HashSet to draw unique indices in the slice of "things" to draw from and then extracts the items corresponding to these indices

results

use ./bins/inbreeding
use std bench

const PRNG_SEED = 0
const OPTS = {
    nb_bytes: (10 * 1_024),
    k: 10,
    n: 20,
    nb_measurements: 100,
    nb_scenarii: 10,
    measurement_schedule: 1,
    measurement_schedule_start: 2_000,
    max_t: 2_000,
    strategies: [ "single:5" ],
    environment: null,
}

def run [rev: string] {
    git co $rev

    inbreeding build

    let a = bench --rounds 5 {
        inbreeding run --options ($OPTS | update environment "fixed:0") --prng-seed $PRNG_SEED
    }
    let b = bench --rounds 5 {
        inbreeding run --options ($OPTS | update environment "fixed:1") --prng-seed $PRNG_SEED
    }

    {
        0: $a,
        1: $b,
    }
}

let main = run a29b511
let mr = run fix-shuffle

let table = [
    [env, main, mr, improvement];

    ["fixed:0", $main."0".mean, $mr."0".mean, (($main."0".mean - $mr."0".mean) / $main."0".mean * 100)],
    ["fixed:1", $main."1".mean, $mr."1".mean, (($main."1".mean - $mr."1".mean) / $main."1".mean * 100)],
]

$table | to md --pretty

env	main	mr	improvement
fixed:0	8sec 504ms 794µs 784ns	6sec 353ms 206µs 645ns	25.298530930431912
fixed:1	727ms 648µs 292ns	639ms 443µs 782ns	12.12186037811795

the improvement is quite nice, even though not huge, but the code is cleaner anyways

merged

mentioned in commit 47ba0de8

mentioned in merge request !127 (merged)

mentioned in commit e5311d6c