diesel/pg/types/date_and_time/
std_time.rs

1use std::time::{Duration, SystemTime, UNIX_EPOCH};
2
3use crate::deserialize::{self, FromSql};
4use crate::pg::{Pg, PgValue};
5use crate::serialize::{self, Output, ToSql};
6use crate::sql_types;
7
8fn pg_epoch() -> SystemTime {
9    let thirty_years = Duration::from_secs(946_684_800);
10    UNIX_EPOCH + thirty_years
11}
12
13#[cfg(feature = "postgres_backend")]
14impl ToSql<sql_types::Timestamp, Pg> for SystemTime {
15    fn to_sql<'b>(&'b self, out: &mut Output<'b, '_, Pg>) -> serialize::Result {
16        let (before_epoch, duration) = match self.duration_since(pg_epoch()) {
17            Ok(duration) => (false, duration),
18            Err(time_err) => (true, time_err.duration()),
19        };
20        let time_since_epoch = if before_epoch {
21            -(i64::try_from(duration_to_usecs(duration))?)
22        } else {
23            duration_to_usecs(duration).try_into()?
24        };
25        ToSql::<sql_types::BigInt, Pg>::to_sql(&time_since_epoch, &mut out.reborrow())
26    }
27}
28
29#[cfg(feature = "postgres_backend")]
30impl FromSql<sql_types::Timestamp, Pg> for SystemTime {
31    fn from_sql(bytes: PgValue<'_>) -> deserialize::Result<Self> {
32        let usecs_passed = <i64 as FromSql<sql_types::BigInt, Pg>>::from_sql(bytes)?;
33        let before_epoch = usecs_passed < 0;
34        let time_passed = usecs_to_duration(usecs_passed.unsigned_abs());
35
36        if before_epoch {
37            Ok(pg_epoch() - time_passed)
38        } else {
39            Ok(pg_epoch() + time_passed)
40        }
41    }
42}
43
44const USEC_PER_SEC: u64 = 1_000_000;
45const NANO_PER_USEC: u32 = 1_000;
46
47fn usecs_to_duration(usecs_passed: u64) -> Duration {
48    let seconds = usecs_passed / USEC_PER_SEC;
49    let subsecond_usecs = usecs_passed % USEC_PER_SEC;
50    let subseconds = subsecond_usecs as u32 * NANO_PER_USEC;
51    Duration::new(seconds, subseconds)
52}
53
54fn duration_to_usecs(duration: Duration) -> u64 {
55    let seconds = duration.as_secs() * USEC_PER_SEC;
56    let subseconds = duration.subsec_micros();
57    seconds + u64::from(subseconds)
58}
59
60#[cfg(test)]
61mod tests {
62    extern crate dotenvy;
63
64    use std::time::{Duration, SystemTime, UNIX_EPOCH};
65
66    use crate::dsl::{now, sql};
67    use crate::prelude::*;
68    use crate::select;
69    use crate::sql_types::Timestamp;
70    use crate::test_helpers::pg_connection;
71
72    #[diesel_test_helper::test]
73    fn unix_epoch_encodes_correctly() {
74        let connection = &mut pg_connection();
75        let query = select(sql::<Timestamp>("'1970-01-01'").eq(UNIX_EPOCH));
76        assert!(query.get_result::<bool>(connection).unwrap());
77    }
78
79    #[diesel_test_helper::test]
80    fn unix_epoch_decodes_correctly() {
81        let connection = &mut pg_connection();
82        let epoch_from_sql = select(sql::<Timestamp>("'1970-01-01'::timestamp"))
83            .get_result::<SystemTime>(connection);
84        assert_eq!(Ok(UNIX_EPOCH), epoch_from_sql);
85    }
86
87    #[diesel_test_helper::test]
88    fn times_relative_to_now_encode_correctly() {
89        let connection = &mut pg_connection();
90        let time = SystemTime::now() + Duration::from_secs(60);
91        let query = select(now.at_time_zone("utc").lt(time));
92        assert!(query.get_result::<bool>(connection).unwrap());
93
94        let time = SystemTime::now() - Duration::from_secs(60);
95        let query = select(now.at_time_zone("utc").gt(time));
96        assert!(query.get_result::<bool>(connection).unwrap());
97    }
98}
diesel/pg/types/date_and_time/std_time.rs

diesel/pg/types/date_and_time/
std_time.rs
