[][src]Struct tracing::event::Event

pub struct Event<'a> { /* fields omitted */ }

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

impl<'a> Event<'a>[src]

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

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

pub fn new(
    metadata: &'static Metadata<'static>,
    fields: &'a ValueSet<'a>
) -> Event<'a>
[src]

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

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

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

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

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

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

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

pub fn fields(&self) -> Iter

Notable traits for Iter

impl Iterator for Iter type Item = Field;
[src]

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

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

Returns metadata describing this Event.

pub fn is_root(&self) -> bool[src]

Returns true if the new event should be a root.

pub fn is_contextual(&self) -> bool[src]

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.

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

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 false.

Trait Implementations

impl<'a> Debug for Event<'a>[src]

Auto Trait Implementations

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

impl<T> Any for T where
    T: 'static + ?Sized
[src]

impl<T> Borrow<T> for T where
    T: ?Sized
[src]

impl<T> BorrowMut<T> for T where
    T: ?Sized
[src]

impl<T> From<T> for T[src]

impl<T> Instrument for T[src]

impl<T, U> Into<U> for T where
    U: From<T>, 
[src]

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
[src]

type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

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

The type returned in the event of a conversion error.