dstats/
bytes.rs

1#![allow(clippy::cast_precision_loss)]
2
3use std::fmt::Display;
4
5pub fn humanize(bytes: u64) -> String {
6    Unit::from(bytes).to_string()
7}
8
9const BASE: u64 = 1_000;
10
11enum Unit {
12    B(u64),
13    KB(f64),
14    MB(f64),
15    GB(f64),
16    TB(f64),
17    PB(f64),
18}
19
20impl Display for Unit {
21    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
22        match self {
23            Unit::B(v) => write!(f, "{v} B"),
24            Unit::KB(v) => write!(f, "{v:.0} KB"),
25            Unit::MB(v) => write!(f, "{v:.1} MB"),
26            Unit::GB(v) => write!(f, "{v:.2} GB"),
27            Unit::TB(v) => write!(f, "{v:.2} TB"),
28            Unit::PB(v) => write!(f, "{v:.2} PB"),
29        }
30    }
31}
32
33impl From<u64> for Unit {
34    fn from(value: u64) -> Self {
35        if value < BASE {
36            return Unit::B(value);
37        }
38        let exponent = value.ilog10() / BASE.ilog10();
39        let value = value as f64 / BASE.pow(exponent) as f64;
40        match exponent {
41            1 => Unit::KB(value),
42            2 => Unit::MB(value),
43            3 => Unit::GB(value),
44            4 => Unit::TB(value),
45            _ => Unit::PB(value),
46        }
47    }
48}
49
50#[cfg(test)]
51mod test {
52    use super::humanize;
53
54    #[test]
55    fn humanize_returns_bytes_in_a_human_readable_format() {
56        assert_eq!(humanize(0), "0 B");
57        assert_eq!(humanize(256), "256 B");
58        assert_eq!(humanize(512), "512 B");
59        assert_eq!(humanize(1_000), "1 KB");
60        assert_eq!(humanize(2_650), "3 KB");
61        assert_eq!(humanize(737_525), "738 KB");
62        assert_eq!(humanize(1_000_000), "1.0 MB");
63        assert_eq!(humanize(1_240_000), "1.2 MB");
64        assert_eq!(humanize(1_250_000), "1.2 MB");
65        assert_eq!(humanize(1_260_000), "1.3 MB");
66        assert_eq!(humanize(10_525_000), "10.5 MB");
67        assert_eq!(humanize(2_886_000_000), "2.89 GB");
68        assert_eq!(humanize(200_500_150_001), "200.50 GB");
69        assert_eq!(humanize(50_000_000_000_000), "50.00 TB");
70        assert_eq!(humanize(1_421_000_000_000_000), "1.42 PB");
71    }
72}
dstats/bytes.rs

dstats/
bytes.rs
