diesel/pg/types/date_and_time/
std_time.rs

1use core::time::Duration;
2use std::time::{SystemTime, UNIX_EPOCH};
3
4use crate::deserialize::{self, FromSql};
5use crate::pg::{Pg, PgValue};
6use crate::serialize::{self, Output, ToSql};
7use crate::sql_types;
8
9fn pg_epoch() -> SystemTime {
10    let thirty_years = Duration::from_secs(946_684_800);
11    UNIX_EPOCH + thirty_years
12}
13
14#[cfg(feature = "postgres_backend")]
15impl ToSql<sql_types::Timestamp, Pg> for SystemTime {
16    fn to_sql<'b>(&'b self, out: &mut Output<'b, '_, Pg>) -> serialize::Result {
17        let (before_epoch, duration) = match self.duration_since(pg_epoch()) {
18            Ok(duration) => (false, duration),
19            Err(time_err) => (true, time_err.duration()),
20        };
21        let time_since_epoch = if before_epoch {
22            -(i64::try_from(duration_to_usecs(duration))?)
23        } else {
24            duration_to_usecs(duration).try_into()?
25        };
26        ToSql::<sql_types::BigInt, Pg>::to_sql(&time_since_epoch, &mut out.reborrow())
27    }
28}
29
30#[cfg(feature = "postgres_backend")]
31impl FromSql<sql_types::Timestamp, Pg> for SystemTime {
32    fn from_sql(bytes: PgValue<'_>) -> deserialize::Result<Self> {
33        let usecs_passed = <i64 as FromSql<sql_types::BigInt, Pg>>::from_sql(bytes)?;
34        let before_epoch = usecs_passed < 0;
35        let time_passed = usecs_to_duration(usecs_passed.unsigned_abs());
36
37        if before_epoch {
38            Ok(pg_epoch() - time_passed)
39        } else {
40            Ok(pg_epoch() + time_passed)
41        }
42    }
43}
44
45const USEC_PER_SEC: u64 = 1_000_000;
46const NANO_PER_USEC: u32 = 1_000;
47
48fn usecs_to_duration(usecs_passed: u64) -> Duration {
49    let seconds = usecs_passed / USEC_PER_SEC;
50    let subsecond_usecs = usecs_passed % USEC_PER_SEC;
51    let subseconds = subsecond_usecs as u32 * NANO_PER_USEC;
52    Duration::new(seconds, subseconds)
53}
54
55fn duration_to_usecs(duration: Duration) -> u64 {
56    let seconds = duration.as_secs() * USEC_PER_SEC;
57    let subseconds = duration.subsec_micros();
58    seconds + u64::from(subseconds)
59}
60
61#[cfg(test)]
62mod tests {
63    extern crate dotenvy;
64
65    use std::time::{Duration, SystemTime, UNIX_EPOCH};
66
67    use crate::dsl::{now, sql};
68    use crate::prelude::*;
69    use crate::select;
70    use crate::sql_types::Timestamp;
71    use crate::test_helpers::pg_connection;
72
73    #[diesel_test_helper::test]
74    fn unix_epoch_encodes_correctly() {
75        let connection = &mut pg_connection();
76        let query = select(sql::<Timestamp>("'1970-01-01'").eq(UNIX_EPOCH));
77        assert!(query.get_result::<bool>(connection).unwrap());
78    }
79
80    #[diesel_test_helper::test]
81    fn unix_epoch_decodes_correctly() {
82        let connection = &mut pg_connection();
83        let epoch_from_sql = select(sql::<Timestamp>("'1970-01-01'::timestamp"))
84            .get_result::<SystemTime>(connection);
85        assert_eq!(Ok(UNIX_EPOCH), epoch_from_sql);
86    }
87
88    #[diesel_test_helper::test]
89    fn times_relative_to_now_encode_correctly() {
90        let connection = &mut pg_connection();
91        let time = SystemTime::now() + Duration::from_secs(60);
92        let query = select(now.at_time_zone("utc").lt(time));
93        assert!(query.get_result::<bool>(connection).unwrap());
94
95        let time = SystemTime::now() - Duration::from_secs(60);
96        let query = select(now.at_time_zone("utc").gt(time));
97        assert!(query.get_result::<bool>(connection).unwrap());
98    }
99}
diesel/pg/types/date_and_time/std_time.rs

diesel/pg/types/date_and_time/
std_time.rs
