ids.rs 100.0%

38 of 38 lines run, 13 of 13 functions · run #19 on main · run missed

//! Identifiers (spec §9.4): ULIDs, 26 characters of Crockford base32, time
//! ordered and globally unique, so an id made on one machine merges into a
//! hub without renaming.

use rand::RngCore;

const CROCKFORD: &[u8; 32] = b"0123456789ABCDEFGHJKMNPQRSTVWXYZ";

/// A new ULID for the current time.
pub fn ulid() -> String {
    let mut r = [0u8; 16];
    rand::rngs::OsRng.fill_bytes(&mut r);
    ulid_from(now_ms(), u128::from_be_bytes(r))
}

/// A ULID from a millisecond time and 80 bits taken from `random`.
pub fn ulid_from(ms: u64, random: u128) -> String {
    let v: u128 = ((ms as u128 & ((1 << 48) - 1)) << 80) | (random & ((1u128 << 80) - 1));
    (0..26).map(|i| CROCKFORD[((v >> (125 - 5 * i)) & 31) as usize] as char).collect()
}

/// Milliseconds since the Unix epoch.
pub fn now_ms() -> u64 {
    std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH).map(|d| d.as_millis() as u64).unwrap_or(0)
}

/// A time as people and models read it: `2026-11-02 21:43Z`, UTC.
pub fn format_time(ms: u64) -> String {
    let secs = (ms / 1000) as i64;
    let days = secs.div_euclid(86_400);
    let rem = secs.rem_euclid(86_400);
    // Civil from days (Howard Hinnant), as oxy's `format::when`.
    let z = days + 719_468;
    let era = z.div_euclid(146_097);
    let doe = z - era * 146_097;
    let yoe = (doe - doe / 1460 + doe / 36_524 - doe / 146_096) / 365;
    let doy = doe - (365 * yoe + yoe / 4 - yoe / 100);
    let mp = (5 * doy + 2) / 153;
    let d = doy - (153 * mp + 2) / 5 + 1;
    let m = if mp < 10 { mp + 3 } else { mp - 9 };
    let y = yoe + era * 400 + if m <= 2 { 1 } else { 0 };
    format!("{y:04}-{m:02}-{d:02} {:02}:{:02}Z", rem / 3600, (rem % 3600) / 60)
}

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

    #[test]
    fn ulids_are_26_chars_and_sort_by_time() {
        let a = ulid_from(1_000, 5);
        let b = ulid_from(2_000, 0);
        assert_eq!(a.len(), 26);
        assert!(a < b);
        assert_eq!(ulid_from(0, 0), "00000000000000000000000000");
        assert_ne!(ulid(), ulid());
        assert_eq!(format_time(1_793_655_780_000), "2026-11-02 21:43Z");
    }
}

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1		//! Identifiers (spec §9.4): ULIDs, 26 characters of Crockford base32, time
2		//! ordered and globally unique, so an id made on one machine merges into a
3		//! hub without renaming.
4
5		use rand::RngCore;
6
7		const CROCKFORD: &[u8; 32] = b"0123456789ABCDEFGHJKMNPQRSTVWXYZ";
8
9		/// A new ULID for the current time.
10	12345×	pub fn ulid() -> String {
11	12345×	let mut r = [0u8; 16];
12	12345×	rand::rngs::OsRng.fill_bytes(&mut r);
13	12345×	ulid_from(now_ms(), u128::from_be_bytes(r))
14	12345×	}
15
16		/// A ULID from a millisecond time and 80 bits taken from `random`.
17	12348×	pub fn ulid_from(ms: u64, random: u128) -> String {
18	12348×	let v: u128 = ((ms as u128 & ((1 << 48) - 1)) << 80) \| (random & ((1u128 << 80) - 1));
19	321048×	(0..26).map(\|i\| CROCKFORD[((v >> (125 - 5 * i)) & 31) as usize] as char).collect()
20	12348×	}
21
22		/// Milliseconds since the Unix epoch.
23	27528×	pub fn now_ms() -> u64 {
24	27528×	std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH).map(\|d\| d.as_millis() as u64).unwrap_or(0)
25	27528×	}
26
27		/// A time as people and models read it: `2026-11-02 21:43Z`, UTC.
28	56×	pub fn format_time(ms: u64) -> String {
29	56×	let secs = (ms / 1000) as i64;
30	56×	let days = secs.div_euclid(86_400);
31	56×	let rem = secs.rem_euclid(86_400);
32		// Civil from days (Howard Hinnant), as oxy's `format::when`.
33	56×	let z = days + 719_468;
34	56×	let era = z.div_euclid(146_097);
35	56×	let doe = z - era * 146_097;
36	56×	let yoe = (doe - doe / 1460 + doe / 36_524 - doe / 146_096) / 365;
37	56×	let doy = doe - (365 * yoe + yoe / 4 - yoe / 100);
38	56×	let mp = (5 * doy + 2) / 153;
39	56×	let d = doy - (153 * mp + 2) / 5 + 1;
40	56×	let m = if mp < 10 { mp + 3 } else { mp - 9 };
41	56×	let y = yoe + era * 400 + if m <= 2 { 1 } else { 0 };
42	56×	format!("{y:04}-{m:02}-{d:02} {:02}:{:02}Z", rem / 3600, (rem % 3600) / 60)
43	56×	}
44
45		#[cfg(test)]
46		mod tests {
47		use super::*;
48
49		#[test]
50	1×	fn ulids_are_26_chars_and_sort_by_time() {
51	1×	let a = ulid_from(1_000, 5);
52	1×	let b = ulid_from(2_000, 0);
53	1×	assert_eq!(a.len(), 26);
54	1×	assert!(a < b);
55	1×	assert_eq!(ulid_from(0, 0), "00000000000000000000000000");
56	1×	assert_ne!(ulid(), ulid());
57	1×	assert_eq!(format_time(1_793_655_780_000), "2026-11-02 21:43Z");
58	1×	}
59		}

Coverage / crates/spectra-core/src/ids.rs 100.0%

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