#identifier #uuid #guid #ulid #ksuid

no-std scru128

SCRU128: Sortable, Clock and Random number-based Unique identifier

32 releases (19 stable)

3.0.2 Sep 18, 2023
3.0.1 Jul 29, 2023
3.0.0-rc.1 Jun 21, 2023
2.8.1 Jun 20, 2023
0.2.1 Nov 21, 2021

#169 in Algorithms

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Used in 2 crates

Apache-2.0

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SCRU128: Sortable, Clock and Random number-based Unique identifier

Crates.io License

SCRU128 ID is yet another attempt to supersede UUID for the users who need decentralized, globally unique time-ordered identifiers. SCRU128 is inspired by ULID and KSUID and has the following features:

  • 128-bit unsigned integer type
  • Sortable by generation time (as integer and as text)
  • 25-digit case-insensitive textual representation (Base36)
  • 48-bit millisecond Unix timestamp that ensures useful life until year 10889
  • Up to 281 trillion time-ordered but unpredictable unique IDs per millisecond
  • 80-bit three-layer randomness for global uniqueness
// generate a new identifier object
let x = scru128::new();
println!("{}", x); // e.g., "036z951mhjikzik2gsl81gr7l"
println!("{}", x.to_u128()); // as a 128-bit unsigned integer

// generate a textual representation directly
println!("{}", scru128::new_string()); // e.g., "036z951mhzx67t63mq9xe6q0j"

See SCRU128 Specification for details.

Crate features

Default features:

  • std configures Scru128Generator with the system clock. Without std, this crate provides basic SCRU128 primitives available under no_std environments.
  • rand enables a blanket implementation for rand::RngCore to use rand and any other conforming random number generators with Scru128Generator.
  • default_rng (implies std and rand) provides the default random number generator for Scru128Generator and enables the Scru128Generator::new() constructor.
  • global_gen (implies default_rng) provides the process-wide default SCRU128 generator and enables the new() and new_string() functions.

Optional features:

  • serde enables serialization/deserialization of Scru128Id via serde.

License

Licensed under the Apache License, Version 2.0.

See also

Dependencies

~35–420KB