even betterer uuid stuff

This commit is contained in:
Joe Ardent 2025-06-25 23:20:28 -07:00
parent 66621bb8c7
commit 02b99ba010
4 changed files with 25 additions and 17 deletions

View file

@ -1,8 +1,8 @@
[package]
name = "julid-rs"
# 1.61803398874989484
#--------------^
version = "1.6.18033988749"
#---------------^
version = "1.6.180339887498"
authors = ["Joe Ardent <code@ardent.nebcorp.com>"]
edition = "2024"
keywords = ["ulid", "sqlite", "julid", "uuid", "guid"]
@ -41,7 +41,7 @@ uuid = { version = "1.17", default-features = false, optional = true }
[dev-dependencies]
divan = "0.1"
uuid = { version = "1", default-features = false, features = ["v7", "v4"] }
uuid = { version = "1", default-features = false, features = ["v4"] }
julid-rs = { path = ".", features = ["uuid"] }
[[bench]]

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@ -1 +1 @@
1.618033988749
1.6180339887498

View file

@ -65,7 +65,7 @@ impl fmt::Display for DecodeError {
DecodeError::InvalidLength(len) => format!("invalid length: {len}"),
DecodeError::InvalidChar(c) => format!("invalid character: {c}"),
};
write!(f, "{}", text)
write!(f, "{text}")
}
}

View file

@ -2,7 +2,7 @@ use std::fmt;
use uuid::{Uuid, Variant};
use crate::Julid;
use crate::{Julid, COUNTER_BITS};
impl Julid {
/// Convert to UUIDv7, possibly losing counter bits and altering the top
@ -40,7 +40,14 @@ impl Julid {
return Err(UuidError::UnsupportedVariant(var));
}
Ok(id.as_u64_pair().into())
let (hi, lo) = id.as_u64_pair();
// zero out the high bits of the counter, which are "7" (0b0111) from the uuid
let mask = (1 << 12) - 1;
let counter = hi & mask;
let ts = hi >> COUNTER_BITS;
let hi = (ts << COUNTER_BITS) | counter;
Ok((hi, lo).into())
}
}
@ -78,6 +85,8 @@ impl fmt::Display for UuidError {
#[cfg(test)]
mod test {
use uuid::Uuid;
use crate::{uuid::UuidError, Julid};
#[test]
@ -92,22 +101,21 @@ mod test {
#[test]
fn from_uuid() {
let j1 = Julid::new();
let u1 = j1.as_uuid();
let ju1 = Julid::from_uuid(u1).unwrap();
// casting a julid to a uuid alters the counter and entropy bits slightly, so
// the original julid and one derived from a uuid made from it won't be the
// same.
assert_ne!(j1, ju1);
let u1: Uuid = j1.into();
let ju1: Julid = u1.try_into().unwrap();
assert_eq!(j1.timestamp(), ju1.timestamp());
assert_eq!(j1.counter(), ju1.counter());
assert_eq!(j1.random() << 2, ju1.random() << 2);
// once we've converted to uuid and then back to julid, we've reached the fixed
// point
let u2 = ju1.as_uuid();
let ju2 = Julid::from_uuid(u2).unwrap();
// but once we've made that alteration, we've reached the fixed point
let ju2 = u2.try_into().unwrap();
assert_eq!(ju1, ju2);
assert_eq!(u1, u2);
}
#[test]
fn cant_even_from_uuid() {
fn cant_even_from_uuid_non_v7() {
let u = uuid::Uuid::new_v4();
let jr: Result<Julid, UuidError> = u.try_into();
assert_eq!(jr, Err(UuidError::UnsupportedVersion(4)));