1 use crate::cli::TestOpts;
2 use crate::types::{TestDescAndFn, TestId, TestName};
3 use std::collections::hash_map::DefaultHasher;
5 use std::time::{SystemTime, UNIX_EPOCH};
7 pub fn get_shuffle_seed(opts: &TestOpts) -> Option<u64> {
8 opts.shuffle_seed.or_else(|| {
12 .duration_since(UNIX_EPOCH)
13 .expect("Failed to get system time")
22 pub fn shuffle_tests(shuffle_seed: u64, tests: &mut [(TestId, TestDescAndFn)]) {
23 let test_names: Vec<&TestName> = tests.iter().map(|test| &test.1.desc.name).collect();
24 let test_names_hash = calculate_hash(&test_names);
25 let mut rng = Rng::new(shuffle_seed, test_names_hash);
26 shuffle(&mut rng, tests);
29 // `shuffle` is from `rust-analyzer/src/cli/analysis_stats.rs`.
30 fn shuffle<T>(rng: &mut Rng, slice: &mut [T]) {
31 for i in 0..slice.len() {
32 randomize_first(rng, &mut slice[i..]);
35 fn randomize_first<T>(rng: &mut Rng, slice: &mut [T]) {
36 assert!(!slice.is_empty());
37 let idx = rng.rand_range(0..slice.len() as u64) as usize;
48 fn new(seed: u64, extra: u64) -> Self {
49 Self { state: seed, extra }
52 fn rand_range(&mut self, range: core::ops::Range<u64>) -> u64 {
53 self.rand_u64() % (range.end - range.start) + range.start
56 fn rand_u64(&mut self) -> u64 {
57 self.state = calculate_hash(&(self.state, self.extra));
62 // `calculate_hash` is from `core/src/hash/mod.rs`.
63 fn calculate_hash<T: core::hash::Hash>(t: &T) -> u64 {
64 let mut s = DefaultHasher::new();