Struct Tuid

#[repr(C, align(1))]
pub struct Tuid {
    pub(crate) time_nanos: [u8; 8],
    pub(crate) inc: [u8; 8],
}

TUID: Time-based Unique Identifier.

Time-ordered globally unique 128-bit identifiers.

The raw bytes of the Tuid sorts in time order as the Tuid itself, and the Tuid is byte-aligned so you can just transmute between Tuid and raw bytes.

Fields

time_nanos: [u8; 8]

Approximate nanoseconds since epoch.

A big-endian u64 encoded as bytes to keep the alignment of Tuid to 1.

We use big-endian so that the raw bytes of the Tuid sorts in time order.

inc: [u8; 8]

Initialized to something random on each thread, then incremented for each new Tuid being allocated.

Uses big-endian u64 encoded as bytes to keep the alignment of Tuid to 1.

We use big-endian so that the raw bytes of the Tuid sorts in creation order.

Implementations

impl Tuid

pub const ARROW_EXTENSION_NAME: &'static str = "rerun.datatypes.TUID"

We give an actual name to Tuid, and inject that name into the Arrow datatype extensions, as a hack so that we can compactly format them when printing Arrow data to the terminal. Check out re_format_arrow for context.

impl Tuid

pub const ZERO: Self = _

All zeroes.

pub const MAX: Self = _

All ones.

pub fn new() -> Self

Create a new unique Tuid based on the current time.

pub fn from_nanos_and_inc(time_nanos: u64, inc: u64) -> Self

Construct a Tuid from the upper and lower halves of a u128-bit. The first should be nano-seconds since epoch.

pub fn from_u128(id: u128) -> Self

pub fn as_u128(&self) -> u128

pub fn from_bytes(bytes: [u8; 16]) -> Self

pub fn as_bytes(&self) -> [u8; 16]

Returns most significant byte first (big endian).

pub fn nanos_since_epoch(&self) -> u64

Approximate nanoseconds since unix epoch.

The upper 64 bits of the Tuid.

pub fn inc(&self) -> u64

The increment part of the Tuid.

The lower 64 bits of the Tuid.

pub fn next(&self) -> Self

Returns the next logical Tuid.

Wraps the monotonically increasing back to zero on overflow.

Beware: wrong usage can easily lead to conflicts. Prefer Tuid::new when unsure.

pub fn incremented_by(&self, n: u64) -> Self

Returns the n-next logical Tuid.

This is equivalent to calling Tuid::next n times. Wraps the monotonically increasing back to zero on overflow.

Beware: wrong usage can easily lead to conflicts. Prefer Tuid::new when unsure.

pub fn short_string(&self) -> String

A shortened string representation of the Tuid.

Trait Implementations

impl Clone for Tuid

fn clone(&self) -> Tuid

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Tuid

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Tuid

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for Tuid

Formats the Tuid as a hex string.

The format uses upper case for the first 16 hex digits, and lower case for the last 16 hex digits. This is to make it easily distinguished from other hex strings.

Example: 182342300C5F8C327a7b4a6e5a379ac4

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

Formats the value using the given formatter.

impl<'a> From<&'a Tuid> for Cow<'a, Tuid>

fn from(value: &'a Tuid) -> Self

Converts to this type from the input type.

impl From<Tuid> for Cow<'_, Tuid>

fn from(value: Tuid) -> Self

Converts to this type from the input type.

impl FromStr for Tuid

type Err = ParseIntError

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl Hash for Tuid

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

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 Tuid

fn cmp(&self, other: &Tuid) -> 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 Tuid

fn eq(&self, other: &Tuid) -> 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 Tuid

fn partial_cmp(&self, other: &Tuid) -> 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 Tuid

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl SizeBytes for Tuid

fn heap_size_bytes(&self) -> u64

Returns how many bytes self uses on the heap.

fn total_size_bytes(&self) -> u64

Returns the total size of self in bytes, accounting for both stack and heap space.

fn stack_size_bytes(&self) -> u64

Returns the total size of self on the stack, in bytes.

fn is_pod() -> bool

Is Self just plain old data?

impl Zeroable for Tuid

fn zeroed() -> Self

Calls zeroed.

impl AnyBitPattern for Tuid

impl Copy for Tuid

impl Eq for Tuid

impl NoUninit for Tuid

impl StructuralPartialEq for Tuid