Struct Ulid 

pub struct Ulid;

Available on crate features ulid and thread-local only.

A thread-local ULID generator with monotonic and non-monotonic modes.

Provides fast, per-thread ULID generation using a shared monotonic clock and thread-local RNG. Monotonic overflows are handled with configurable Backoff strategies.

Implementations

impl Ulid

pub fn new_ulid() -> ULID

Available on crate features snowflake or ulid only.

Generates a non-monotonic ULID that is always random, even when generated within the same millisecond.

Example

use ferroid::Ulid;
let id = Ulid::new_ulid();

pub fn new_mono_ulid() -> ULID

Available on crate features snowflake or ulid only.

Generates a monotonic ULID using Backoff::Yield as the overflow strategy.

Example

use ferroid::Ulid;
let id = Ulid::new_mono_ulid();

pub fn with_mono_backoff(strategy: Backoff) -> ULID

Available on crate features snowflake or ulid only.

Generates a monotonic ULID using the given Backoff strategy to handle overflow.

If the generator exhausts available entropy within the same millisecond, the backoff strategy determines how it waits before retrying.

Example

use ferroid::{Ulid, Backoff};
let id = Ulid::with_mono_backoff(Backoff::Spin);

pub fn from_timestamp(timestamp: <ULID as Id>::Ty) -> ULID

Available on crate features snowflake or ulid only.

Creates a ULID from a given millisecond timestamp.

Random bits are generated using the thread-local RNG. The resulting ID is not guaranteed to be monotonic.

Example

use ferroid::Ulid;
let id = Ulid::from_timestamp(1_694_201_234_000);

pub fn from_timestamp_and_rand<R>(timestamp: <ULID as Id>::Ty, rng: &R) -> ULID

where R: RandSource<<ULID as Id>::Ty>,

Available on crate features snowflake or ulid only.

Creates a ULID from a given millisecond timestamp and a custom RNG.

Useful in deterministic or testable scenarios where a specific random source is preferred.

Example

 use ferroid::{Ulid, ThreadRandom};
 let id = Ulid::from_timestamp_and_rand(0, &ThreadRandom);

pub fn from_datetime(datetime: SystemTime) -> ULID

Available on crate features snowflake or ulid only.

Creates a ULID from a SystemTime.

This is a convenience wrapper over Ulid::from_timestamp that extracts the Unix timestamp in milliseconds.

Example

use ferroid::Ulid;
let id = Ulid::from_datetime(std::time::SystemTime::now());

pub fn from_datetime_and_rand<R>(datetime: SystemTime, rng: &R) -> ULID

where R: RandSource<<ULID as Id>::Ty>,

Available on crate features snowflake or ulid only.

Creates a ULID from a SystemTime and a custom RNG.

Example

use ferroid::{Ulid, ThreadRandom};
let now = std::time::SystemTime::now();
let id = Ulid::from_datetime_and_rand(now, &ThreadRandom);