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//! The implementation for Version 7 UUIDs.
//!
//! Note that you need to enable the `v7` Cargo feature
//! in order to use this module.
use crate::{std::convert::TryInto, rng, timestamp::Timestamp, Builder, Uuid};
impl Uuid {
/// Create a new version 7 UUID using the current time value and random bytes.
///
/// This method is a convenient alternative to [`Uuid::new_v7`] that uses the current system time
/// as the source timestamp.
#[cfg(feature = "std")]
pub fn now_v7() -> Self {
Self::new_v7(Timestamp::now(crate::NoContext))
}
/// Create a new version 7 UUID using a time value and random bytes.
///
/// When the `std` feature is enabled, you can also use [`Uuid::now_v7`].
///
/// Note that usage of this method requires the `v7` feature of this crate
/// to be enabled.
///
/// Also see [`Uuid::now_v7`] for a convenient way to generate version 7
/// UUIDs using the current system time.
///
/// # Examples
///
/// A v7 UUID can be created from a unix [`Timestamp`] plus a 128 bit
/// random number. When supplied as such, the data will be
///
/// ```rust
/// # use uuid::{Uuid, Timestamp, NoContext};
/// let ts = Timestamp::from_unix(NoContext, 1497624119, 1234);
///
/// let uuid = Uuid::new_v7(ts);
///
/// assert!(
/// uuid.hyphenated().to_string().starts_with("015cb15a-86d8-7")
/// );
/// ```
///
/// # References
///
/// * [Version 7 UUIDs in Draft RFC: New UUID Formats, Version 4](https://datatracker.ietf.org/doc/html/draft-peabody-dispatch-new-uuid-format-04#section-5.2)
pub fn new_v7(ts: Timestamp) -> Self {
let (secs, nanos) = ts.to_unix();
let millis = (secs * 1000).saturating_add(nanos as u64 / 1_000_000);
Builder::from_unix_timestamp_millis(millis, &rng::bytes()[..10].try_into().unwrap())
.into_uuid()
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::{std::string::ToString, NoContext, Variant, Version};
#[cfg(target_arch = "wasm32")]
use wasm_bindgen_test::*;
#[test]
#[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
fn test_new() {
let ts: u64 = 1645557742000;
let seconds = ts / 1000;
let nanos = ((ts % 1000) * 1_000_000) as u32;
let uuid = Uuid::new_v7(Timestamp::from_unix(NoContext, seconds, nanos));
let uustr = uuid.hyphenated().to_string();
assert_eq!(uuid.get_version(), Some(Version::SortRand));
assert_eq!(uuid.get_variant(), Variant::RFC4122);
assert!(uuid.hyphenated().to_string().starts_with("017f22e2-79b0-7"));
// Ensure parsing the same UUID produces the same timestamp
let parsed = Uuid::parse_str(uustr.as_str()).unwrap();
assert_eq!(uuid, parsed);
}
#[test]
#[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
#[cfg(feature = "std")]
fn test_now() {
let uuid = Uuid::now_v7();
assert_eq!(uuid.get_version(), Some(Version::SortRand));
assert_eq!(uuid.get_variant(), Variant::RFC4122);
}
#[test]
#[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
fn test_sorting() {
let time1: u64 = 1_496_854_535;
let time_fraction1: u32 = 812_000_000;
let time2 = time1 + 4000;
let time_fraction2 = time_fraction1;
let uuid1 = Uuid::new_v7(Timestamp::from_unix(NoContext, time1, time_fraction1));
let uuid2 = Uuid::new_v7(Timestamp::from_unix(NoContext, time2, time_fraction2));
assert!(uuid1.as_bytes() < uuid2.as_bytes());
assert!(uuid1.to_string() < uuid2.to_string());
}
#[test]
#[cfg_attr(target_arch = "wasm32", wasm_bindgen_test)]
fn test_new_timestamp_roundtrip() {
let time: u64 = 1_496_854_535;
let time_fraction: u32 = 812_000_000;
let ts = Timestamp::from_unix(NoContext, time, time_fraction);
let uuid = Uuid::new_v7(ts);
let decoded_ts = uuid.get_timestamp().unwrap();
assert_eq!(ts.to_unix(), decoded_ts.to_unix());
}
}
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