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sloop/
clock.rs

1use std::future::Future;
2use std::path::PathBuf;
3use std::pin::Pin;
4use std::time::{Duration, SystemTime, UNIX_EPOCH};
5
6use time::OffsetDateTime;
7use time::format_description::well_known::Rfc3339;
8
9pub trait Clock: Send + Sync {
10    fn now_ms(&self) -> i64;
11    fn local_minute(&self, timestamp_ms: i64) -> u16;
12    fn sleep_until(&self, deadline_ms: i64) -> Pin<Box<dyn Future<Output = ()> + Send + '_>>;
13}
14
15#[derive(Debug, Default)]
16pub struct SystemClock;
17
18impl Clock for SystemClock {
19    fn now_ms(&self) -> i64 {
20        SystemTime::now()
21            .duration_since(UNIX_EPOCH)
22            .map(|elapsed| elapsed.as_millis() as i64)
23            .unwrap_or(0)
24    }
25
26    fn local_minute(&self, timestamp_ms: i64) -> u16 {
27        local_minute(timestamp_ms)
28    }
29
30    fn sleep_until(&self, deadline_ms: i64) -> Pin<Box<dyn Future<Output = ()> + Send + '_>> {
31        Box::pin(async move {
32            loop {
33                let delay_ms = deadline_ms.saturating_sub(self.now_ms());
34                if delay_ms <= 0 {
35                    return;
36                }
37                // Recheck wall time so suspend and clock corrections cannot
38                // leave a long monotonic sleep armed past the local opening.
39                tokio::time::sleep(Duration::from_millis(delay_ms.min(30_000) as u64)).await;
40            }
41        })
42    }
43}
44
45/// File-backed clock used by integration tests that run the daemon as a child
46/// process. Advancing the integer timestamp in the file wakes pending timers.
47#[derive(Debug)]
48pub struct FileClock {
49    path: PathBuf,
50}
51
52impl FileClock {
53    pub fn new(path: PathBuf) -> Self {
54        Self { path }
55    }
56
57    fn read_now_ms(&self) -> i64 {
58        std::fs::read_to_string(&self.path)
59            .ok()
60            .and_then(|value| value.trim().parse().ok())
61            .unwrap_or(0)
62    }
63}
64
65impl Clock for FileClock {
66    fn now_ms(&self) -> i64 {
67        self.read_now_ms()
68    }
69
70    fn local_minute(&self, timestamp_ms: i64) -> u16 {
71        local_minute(timestamp_ms)
72    }
73
74    fn sleep_until(&self, deadline_ms: i64) -> Pin<Box<dyn Future<Output = ()> + Send + '_>> {
75        Box::pin(async move {
76            while self.now_ms() < deadline_ms {
77                tokio::time::sleep(Duration::from_millis(10)).await;
78            }
79        })
80    }
81}
82
83pub fn format_timestamp(timestamp_ms: i64) -> Option<String> {
84    OffsetDateTime::from_unix_timestamp_nanos(i128::from(timestamp_ms) * 1_000_000)
85        .ok()?
86        .format(&Rfc3339)
87        .ok()
88}
89
90/// Finds the next real instant whose local wall clock matches `minute`.
91/// Starting at the next whole minute makes the current minute mean its next
92/// occurrence, while scanning real instants handles DST transitions.
93pub fn next_local_minute_ms(clock: &dyn Clock, now_ms: i64, minute: u16) -> Option<i64> {
94    let mut candidate = now_ms
95        .div_euclid(60_000)
96        .checked_add(1)?
97        .checked_mul(60_000)?;
98    for _ in 0..=(49 * 60) {
99        if clock.local_minute(candidate) == minute {
100            return Some(candidate);
101        }
102        candidate = candidate.checked_add(60_000)?;
103    }
104    None
105}
106
107fn local_minute(timestamp_ms: i64) -> u16 {
108    let seconds = timestamp_ms.div_euclid(1_000) as libc::time_t;
109    let mut local = unsafe { std::mem::zeroed::<libc::tm>() };
110    let result = unsafe { libc::localtime_r(&seconds, &mut local) };
111    if result.is_null() {
112        return 0;
113    }
114    (local.tm_hour as u16) * 60 + local.tm_min as u16
115}