Struct Id

pub struct Id(/* private fields */);

An identifier for flows and async spans.

Implementations

impl Id

pub fn new() -> Id

Creates a new Id. Ids created by separate calls to new in the same process are guaranteed to be distinct.

WARNING: Id::new is likely to hit the UI bug where UIs group async durations with the same trace id but different process ids. Use Id::random instead. (Until https://fxbug.dev/42054669 is fixed.)

pub fn random() -> Id

Creates a new Id based on the current montonic time and a random u16 to, with high probability, avoid the bug where UIs group async durations with the same trace id but different process ids. Id::new is likely to hit the UI bug because it (per process) generates trace ids consecutively starting from 1. https://cs.opensource.google/fuchsia/fuchsia/+/main:zircon/system/ulib/trace-engine/nonce.cc;l=15-17;drc=b1c2f508a59e6c87c617852ed3e424693a392646 TODO(https://fxbug.dev/42054669) Delete this and migrate clients to Id::new when:

1. UIs stop grouping async durations with the same trace id but different process ids.
2. input events tracing cross components has uid for flow id.

Trait Implementations

impl Clone for Id

fn clone(&self) -> Id

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Id

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

Formats the value using the given formatter.

impl From<u64> for Id

fn from(u: u64) -> Id

Converts to this type from the input type.

impl Hash for Id

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 Id

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

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

fn partial_cmp(&self, other: &Id) -> 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 Copy for Id

impl Eq for Id

impl StructuralPartialEq for Id