use core::str::FromStr;
#[derive(Debug, Clone, Copy, Default, PartialEq)]
pub enum Units {
#[default]
Si, Binary, Bytes, }
impl FromStr for Units {
type Err = String;
fn from_str(value: &str) -> Result<Self, String> {
match value.to_lowercase().as_ref() {
"si" => Ok(Self::Si),
"binary" => Ok(Self::Binary),
"bytes" => Ok(Self::Bytes),
_ => Err(format!(
"Illegal value: {:?} - valid values are 'SI', 'binary', and 'bytes'",
value
)),
}
}
}
static PREFIXES: &[char] = &['K', 'M', 'G', 'T', 'P'];
impl Units {
pub fn fmt(
self,
size: u64,
) -> String {
match self {
Self::Si => file_size::fit_4(size),
Self::Binary => {
if size < 10_000 {
size.to_string()
} else {
let i = size.ilog2() / 10u32;
let idx = i as usize - 1;
let size = size as f64;
if idx >= PREFIXES.len() {
"huge".to_string()
} else {
let v = size / (1024u64.pow(i) as f64);
if v >= 10f64 {
format!("{:.0}{}i", v.round(), PREFIXES[idx])
} else {
format!("{:.1}{}i", v, PREFIXES[idx])
}
}
}
}
Self::Bytes => {
let mut rev: Vec<char> = Vec::new();
for (i, c) in size.to_string().chars().rev().enumerate() {
if i > 0 && i % 3 == 0 {
rev.push(',');
}
rev.push(c);
}
rev.drain(..).rev().collect()
}
}
}
}
#[test]
fn test_fmt_binary() {
fn check(
v: u64,
s: &str,
) {
assert_eq!(&Units::Binary.fmt(v), s);
}
check(0, "0");
check(1, "1");
check(456, "456");
check(1456, "1456");
check(9_999, "9999");
check(10_000, "9.8Ki");
check(12_345, "12Ki");
check(123_456, "121Ki");
check(1_000_000_000, "954Mi");
check(1_073_741_824, "1.0Gi");
check(1_234_567_890, "1.1Gi");
}
#[test]
fn test_fmt_bytes() {
fn check(
v: u64,
s: &str,
) {
assert_eq!(&Units::Bytes.fmt(v), s);
}
check(0, "0");
check(1, "1");
check(456, "456");
check(1456, "1,456");
check(9_999, "9,999");
check(10_000, "10,000");
check(12_345, "12,345");
check(123_456, "123,456");
check(1_234_567, "1,234,567");
check(1_000_000_000, "1,000,000,000");
check(1_234_567_890, "1,234,567,890");
}