🛈 Note: This is pre-release documentation for the upcoming tracing 0.2.0 ecosystem.

For the release documentation, please see docs.rs, instead.

Struct tracing_core::Event

source ·
pub struct Event<'a> { /* private fields */ }
Expand description

Events represent single points in time where something occurred during the execution of a program.

An Event can be compared to a log record in unstructured logging, but with two key differences:

  • Events exist within the context of a span. Unlike log lines, they may be located within the trace tree, allowing visibility into the temporal context in which the event occurred, as well as the source code location.
  • Like spans, Events have structured key-value data known as fields, which may include textual message. In general, a majority of the data associated with an event should be in the event’s fields rather than in the textual message, as the fields are more structured.

Implementations§

source§

impl<'a> Event<'a>

source

pub fn dispatch(metadata: &'static Metadata<'static>, fields: &'a ValueSet<'_>)

Constructs a new Event with the specified metadata and set of values, and observes it with the current collector.

source

pub fn new( metadata: &'static Metadata<'static>, fields: &'a ValueSet<'a> ) -> Self

Returns a new Event in the current span, with the specified metadata and set of values.

source

pub fn new_child_of( parent: impl Into<Option<Id>>, metadata: &'static Metadata<'static>, fields: &'a ValueSet<'a> ) -> Self

Returns a new Event as a child of the specified span, with the provided metadata and set of values.

source

pub fn child_of( parent: impl Into<Option<Id>>, metadata: &'static Metadata<'static>, fields: &'a ValueSet<'_> )

Constructs a new Event with the specified metadata and set of values, and observes it with the current collector and an explicit parent.

source

pub fn record(&self, visitor: &mut dyn Visit)

Visits all the fields on this Event with the specified visitor.

source

pub fn fields(&self) -> Iter

Returns an iterator over the set of values on this Event.

source

pub fn metadata(&self) -> &'static Metadata<'static>

Returns metadata describing this Event.

source

pub fn is_root(&self) -> bool

Returns true if the new event should be a root.

source

pub fn is_contextual(&self) -> bool

Returns true if the new event’s parent should be determined based on the current context.

If this is true and the current thread is currently inside a span, then that span should be the new event’s parent. Otherwise, if the current thread is not inside a span, then the new event will be the root of its own trace tree.

source

pub fn parent(&self) -> Option<&Id>

Returns the new event’s explicitly-specified parent, if there is one.

Otherwise (if the new event is a root or is a child of the current span), returns None.

Trait Implementations§

source§

impl<'a> Debug for Event<'a>

source§

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

Formats the value using the given formatter. Read more

Auto Trait Implementations§

§

impl<'a> Freeze for Event<'a>

§

impl<'a> !RefUnwindSafe for Event<'a>

§

impl<'a> !Send for Event<'a>

§

impl<'a> !Sync for Event<'a>

§

impl<'a> Unpin for Event<'a>

§

impl<'a> !UnwindSafe for Event<'a>

Blanket Implementations§

source§

impl<T> Any for T
where T: 'static + ?Sized,

source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
source§

impl<T> Borrow<T> for T
where T: ?Sized,

source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

impl<T> BorrowMut<T> for T
where T: ?Sized,

source§

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
source§

impl<T> From<T> for T

source§

fn from(t: T) -> T

Returns the argument unchanged.

source§

impl<T, U> Into<U> for T
where U: From<T>,

source§

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

source§

impl<T, U> TryFrom<U> for T
where U: Into<T>,

§

type Error = Infallible

The type returned in the event of a conversion error.
source§

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
source§

impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

§

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
source§

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.