env_logger/fmt/
humantime.rs

1use std::fmt;
2use std::time::SystemTime;
3
4use crate::fmt::{Formatter, TimestampPrecision};
5
6impl Formatter {
7    /// Get a [`Timestamp`] for the current date and time in UTC.
8    ///
9    /// # Examples
10    ///
11    /// Include the current timestamp with the log record:
12    ///
13    /// ```
14    /// use std::io::Write;
15    ///
16    /// let mut builder = env_logger::Builder::new();
17    ///
18    /// builder.format(|buf, record| {
19    ///     let ts = buf.timestamp();
20    ///
21    ///     writeln!(buf, "{}: {}: {}", ts, record.level(), record.args())
22    /// });
23    /// ```
24    pub fn timestamp(&self) -> Timestamp {
25        Timestamp {
26            time: SystemTime::now(),
27            precision: TimestampPrecision::Seconds,
28        }
29    }
30
31    /// Get a [`Timestamp`] for the current date and time in UTC with full
32    /// second precision.
33    pub fn timestamp_seconds(&self) -> Timestamp {
34        Timestamp {
35            time: SystemTime::now(),
36            precision: TimestampPrecision::Seconds,
37        }
38    }
39
40    /// Get a [`Timestamp`] for the current date and time in UTC with
41    /// millisecond precision.
42    pub fn timestamp_millis(&self) -> Timestamp {
43        Timestamp {
44            time: SystemTime::now(),
45            precision: TimestampPrecision::Millis,
46        }
47    }
48
49    /// Get a [`Timestamp`] for the current date and time in UTC with
50    /// microsecond precision.
51    pub fn timestamp_micros(&self) -> Timestamp {
52        Timestamp {
53            time: SystemTime::now(),
54            precision: TimestampPrecision::Micros,
55        }
56    }
57
58    /// Get a [`Timestamp`] for the current date and time in UTC with
59    /// nanosecond precision.
60    pub fn timestamp_nanos(&self) -> Timestamp {
61        Timestamp {
62            time: SystemTime::now(),
63            precision: TimestampPrecision::Nanos,
64        }
65    }
66}
67
68/// An [RFC3339] formatted timestamp.
69///
70/// The timestamp implements [`Display`] and can be written to a [`Formatter`].
71///
72/// [RFC3339]: https://www.ietf.org/rfc/rfc3339.txt
73/// [`Display`]: std::fmt::Display
74pub struct Timestamp {
75    time: SystemTime,
76    precision: TimestampPrecision,
77}
78
79impl fmt::Debug for Timestamp {
80    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
81        /// A `Debug` wrapper for `Timestamp` that uses the `Display` implementation.
82        struct TimestampValue<'a>(&'a Timestamp);
83
84        impl fmt::Debug for TimestampValue<'_> {
85            fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
86                fmt::Display::fmt(&self.0, f)
87            }
88        }
89
90        f.debug_tuple("Timestamp")
91            .field(&TimestampValue(self))
92            .finish()
93    }
94}
95
96impl fmt::Display for Timestamp {
97    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
98        let Ok(ts) = jiff::Timestamp::try_from(self.time) else {
99            return Err(fmt::Error);
100        };
101
102        match self.precision {
103            TimestampPrecision::Seconds => write!(f, "{ts:.0}"),
104            TimestampPrecision::Millis => write!(f, "{ts:.3}"),
105            TimestampPrecision::Micros => write!(f, "{ts:.6}"),
106            TimestampPrecision::Nanos => write!(f, "{ts:.9}"),
107        }
108    }
109}
110
111#[cfg(test)]
112mod tests {
113    use super::Timestamp;
114    use crate::TimestampPrecision;
115
116    #[test]
117    fn test_display_timestamp() {
118        let mut ts = Timestamp {
119            time: std::time::SystemTime::UNIX_EPOCH,
120            precision: TimestampPrecision::Nanos,
121        };
122
123        assert_eq!("1970-01-01T00:00:00.000000000Z", format!("{ts}"));
124
125        ts.precision = TimestampPrecision::Micros;
126        assert_eq!("1970-01-01T00:00:00.000000Z", format!("{ts}"));
127
128        ts.precision = TimestampPrecision::Millis;
129        assert_eq!("1970-01-01T00:00:00.000Z", format!("{ts}"));
130
131        ts.precision = TimestampPrecision::Seconds;
132        assert_eq!("1970-01-01T00:00:00Z", format!("{ts}"));
133    }
134}
env_logger/fmt/humantime.rs

env_logger/fmt/
humantime.rs
