1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158

//! golang style duration format wrapper
use std::cmp;
use std::fmt;
use std::time::Duration;

pub struct DurationFmt(pub Duration);

impl DurationFmt {
    pub fn from_nanos(nanos: u64) -> DurationFmt {
        DurationFmt(Duration::from_nanos(nanos))
    }

    #[inline(always)]
    fn duration(&self) -> Duration {
        self.0
    }

    #[inline(always)]
    fn pure_nanos(&self) -> u128 {
        self.0.as_nanos() % Duration::from_micros(1).as_nanos()
    }

    #[inline(always)]
    fn pure_micros(&self) -> u128 {
        (self.0.as_nanos() % Duration::from_millis(1).as_nanos())
            / Duration::from_micros(1).as_nanos()
    }

    #[inline(always)]
    fn pure_millis(&self) -> u128 {
        (self.0.as_nanos() % Duration::from_secs(1).as_nanos())
            / Duration::from_millis(1).as_nanos()
    }

    #[inline(always)]
    fn pure_secs_as_f64(&self) -> f64 {
        ((self.0.as_nanos() % Duration::from_secs(60).as_nanos()) as f64)
            / (Duration::from_secs(1).as_nanos() as f64)
    }

    #[inline(always)]
    fn pure_mins(&self) -> u128 {
        (self.0.as_nanos() % Duration::from_secs(60 * 60).as_nanos())
            / Duration::from_secs(60).as_nanos()
    }

    #[inline(always)]
    fn pure_hours(&self) -> u128 {
        self.0.as_nanos() / Duration::from_secs(60 * 60).as_nanos()
    }
}

impl cmp::PartialEq for DurationFmt {
    fn eq(&self, other: &Self) -> bool {
        self.duration() == other.duration()
    }
}

impl From<Duration> for DurationFmt {
    #[inline(always)]
    fn from(d: Duration) -> Self {
        DurationFmt(d)
    }
}

impl fmt::Display for DurationFmt {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self.duration() {
            d if d <= Duration::from_micros(1) => write!(f, "{}ns", self.pure_nanos()),
            d if d <= Duration::from_millis(1) => {
                let ns = self.pure_nanos();
                let mcs = self.pure_micros();

                match ns {
                    0 => write!(f, "{}us", mcs),
                    _ => write!(f, "{}us{}ns", mcs, ns),
                }
            }
            d if d <= (Duration::from_secs(1) / 10) => {
                let mcs = self.pure_micros();
                let ms = self.pure_millis();

                match mcs {
                    0 => write!(f, "{}ms", ms),
                    _ => write!(f, "{}ms{}us", ms, mcs),
                }
            }
            _ => {
                let h = self.pure_hours();
                let m = self.pure_mins();
                let s = self.pure_secs_as_f64();

                if h != 0 {
                    write!(f, "{}h", h)?;
                }

                if m != 0 {
                    write!(f, "{}m", m)?;
                }

                if s != 0.0 {
                    write!(f, "{:.2}s", s)
                } else {
                    Ok(())
                }
            }
        }
    }
}

impl fmt::Debug for DurationFmt {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}", self)
    }
}

#[cfg(test)]
mod tests {
    use super::DurationFmt;

    use std::time::Duration;

    #[test]
    fn fmt_ns() {
        assert_eq!(format!("{}", DurationFmt::from_nanos(1)), "1ns");
    }

    #[test]
    fn fmt_h_m_s() {
        assert_eq!(
            format!(
                "{}",
                DurationFmt::from(
                    Duration::from_secs(10*3600) + // 10h
                    Duration::from_secs(30*60) + // 30m
                    Duration::from_secs(15) + // 15s
                    Duration::from_millis(100) // 0.1s
                )
            ),
            "10h30m15.10s"
        );
    }

    #[test]
    fn fmt_ms_us() {
        assert_eq!(
            format!(
                "{}",
                DurationFmt::from(
                    Duration::from_millis(23) + // 23ms
                    Duration::from_micros(17) + // 17us
                    Duration::from_nanos(40) // 40ns
                )
            ),
            "23ms17us"
        );
    }
}