Struct Uuid 

pub struct Uuid { /* private fields */ }

A universally unique identifier (UUID).

Support for UUID Version::Nil, Version::Max, Version::V4 (random) and Version::V7 (timestamp + counter + random).

Implementations

impl Uuid

pub const NIL: Uuid

The nil UUID (all zeros).

Example:

let uuid = Uuid::NIL;

assert_eq!(
    "00000000-0000-0000-0000-000000000000",
    uuid.to_string(),
);

pub const MAX: Uuid

The max UUID (all ones).

Example:

let uuid = Uuid::MAX;

assert_eq!(
    "ffffffff-ffff-ffff-ffff-ffffffffffff",
    uuid.to_string(),
);

pub fn from_random_bytes_v4(counter_random_bytes: [u8; 16]) -> Uuid

Create a UUID v4 from explicit random bytes.

This method assumes the bytes are already sufficiently random, it will only set the appropriate bits for the UUID version and variant.

Example

// Use the `ReducerContext::rng()` method to generate random bytes in reducers,
// or call `ReducerContext::new_uuid_v4`
let random_bytes = [0u8; 16];
let uuid = Uuid::from_random_bytes_v4(random_bytes);

assert_eq!(
    "00000000-0000-4000-8000-000000000000",
    uuid.to_string(),
);

pub fn from_counter_v7( counter: &Cell<u32>, now: Timestamp, random_bytes: &[u8; 4], ) -> Result<Uuid, Error>

Generate a UUID v7 using a monotonic counter from 0 to 2^31-1, a timestamp, and 4 random bytes.

The counter will wrap around on overflow.

The UUID v7 is structured as follows:

 ┌───────────────────────────────────────────────┬───────────────────┐
 | B0  | B1  | B2  | B3  | B4  | B5              |         B6        |
 ├───────────────────────────────────────────────┼───────────────────┤
 |                 unix_ts_ms                    |      version 7    |
 └───────────────────────────────────────────────┴───────────────────┘
 ┌──────────────┬─────────┬──────────────────┬───────────────────────┐
 | B7           | B8      | B9  | B10 | B11  | B12 | B13 | B14 | B15 |
 ├──────────────┼─────────┼──────────────────┼───────────────────────┤
 | counter_high | variant |    counter_low   |        random         |
 └──────────────┴─────────┴──────────────────┴───────────────────────┘

Panics

Panics if the counter value is negative, or the timestamp is before the Unix epoch.

Example

 use spacetimedb_sats::uuid::Uuid;
 use spacetimedb_sats::timestamp::Timestamp;

 let now = Timestamp::from_micros_since_unix_epoch(1_686_000_000_000);
 let counter = std::cell::Cell::new(1);
 // Use the `ReducerContext::rng()` | `ProcedureContext::rng()` to generate random bytes,
 // or call `ReducerContext::new_uuid_v7()` / `ProcedureContext::new_uuid_v7()`
 let random_bytes = [0u8; 4];
 let uuid = Uuid::from_counter_v7(&counter, now, &random_bytes).unwrap();

 assert_eq!(
     "0000647e-5180-7000-8000-000200000000",
     uuid.to_string(),
 );

pub fn parse_str(s: &str) -> Result<Uuid, Error>

Parse a UUID from a string representation.

Any of the formats generated by this module (simple, hyphenated, urn, Microsoft GUID) are supported by this parsing function.

Example

let s = "01888d6e-5c00-7000-8000-000000000000";
let uuid = Uuid::parse_str(s).unwrap();

assert_eq!(
    s,
    uuid.to_string(),
);

pub fn get_version(&self) -> Option<Version>

Returns the version of the UUID.

This represents the algorithm used to generate the value. If the version field doesn’t contain a recognized version then None is returned.

pub fn to_uuid(self) -> Uuid

Convert to the uuid crate’s Uuid type.

pub fn from_u128(u: u128) -> Uuid

pub fn as_u128(&self) -> u128

Trait Implementations

impl Clone for Uuid

fn clone(&self) -> Uuid

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Uuid

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Uuid

fn deserialize<D>( deserializer: D, ) -> Result<Uuid, <D as Deserializer<'de>>::Error>

where D: Deserializer<'de>,

Deserialize this value from the given deserializer.

impl Display for Uuid

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl From<Uuid> for AlgebraicValue

fn from(value: Uuid) -> AlgebraicValue

Converts to this type from the input type.

impl GroundSpacetimeType for Uuid

fn get_type() -> AlgebraicType

Returns the AlgebraicType representation of Self.

impl Hash for Uuid

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for Uuid

fn cmp(&self, other: &Uuid) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for Uuid

fn eq(&self, other: &Uuid) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for Uuid

fn partial_cmp(&self, other: &Uuid) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Serialize for Uuid

fn serialize<S>( &self, __serializer: S, ) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error>

where S: Serializer,

Serialize self in the data format of S using the provided serializer.

impl SpacetimeType for Uuid

fn make_type<S>(_ts: &mut S) -> AlgebraicType

where S: TypespaceBuilder,

Returns an AlgebraicType representing the type for Self in SATS and in the typing context in typespace. This is used by the automatic type registration system in Rust modules.

impl Copy for Uuid

impl Eq for Uuid

impl StructuralPartialEq for Uuid