Lines
66.67 %
Functions
30 %
Branches
40 %
use std::fmt;
/// Formats bytes into human-readable format using decimal units (GB, MB, KB, bytes)
///
/// Note: This uses decimal units (1 KB = 1000 bytes) rather than binary units (1 KiB = 1024 bytes).
pub struct BytesFormatter(pub usize);
impl fmt::Display for BytesFormatter {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
const KB: usize = 1_000;
const MB: usize = 1_000_000;
const GB: usize = 1_000_000_000;
// Choose appropriate unit based on size for best readability
if self.0 >= GB {
write!(f, "{:.2} GB", self.0 as f64 / GB as f64)
} else if self.0 >= MB {
write!(f, "{:.2} MB", self.0 as f64 / MB as f64)
} else if self.0 >= KB {
write!(f, "{:.2} KB", self.0 as f64 / KB as f64)
} else {
write!(f, "{} bytes", self.0)
}
pub struct LargeFormatter<T: ToString>(pub T);
impl<T: ToString> fmt::Display for LargeFormatter<T> {
let num_str = self.0.to_string();
// Add spaces every three digits from the right
let len = num_str.len();
for (i, ch) in num_str.chars().enumerate() {
if i > 0 && (len - i).is_multiple_of(3) {
write!(f, ",")?;
write!(f, "{}", ch)?;
Ok(())
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_large_formatter_small_numbers() {
assert_eq!(format!("{}", LargeFormatter(0)), "0");
assert_eq!(format!("{}", LargeFormatter(123)), "123");
fn test_large_formatter_millions() {
assert_eq!(format!("{}", LargeFormatter(1234567)), "1,234,567");
assert_eq!(format!("{}", LargeFormatter(12345678)), "12,345,678");