Struct Subscriber

pub struct Subscriber<N = DefaultFields, E = Format<Full>, F = LevelFilter, W = fn() -> Stdout> { /* private fields */ }

Available on crate features fmt and std only.

A Subscriber that logs formatted representations of tracing events.

This consists of an inner Formatter wrapped in a layer that performs filtering.

Implementations

impl Subscriber

pub const DEFAULT_MAX_LEVEL: LevelFilter = LevelFilter::INFO

The maximum verbosity level that is enabled by a Subscriber by default.

This can be overridden with the SubscriberBuilder::with_max_level method.

pub fn builder() -> SubscriberBuilder

Returns a new SubscriberBuilder for configuring a format subscriber.

pub fn new() -> Self

Returns a new format subscriber with the default configuration.

Trait Implementations

impl<N: Debug, E: Debug, F: Debug, W: Debug> Debug for Subscriber<N, E, F, W>

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

Formats the value using the given formatter.

impl Default for Subscriber

fn default() -> Self

Returns the “default value” for a type.

impl<'a, N, E, F, W> LookupSpan<'a> for Subscriber<N, E, F, W>

where Layered<F, Formatter<N, E, W>>: LookupSpan<'a>,

type Data = <Layered<F, Layered<Layer<Registry, N, E, W>, Registry>> as LookupSpan<'a>>::Data

The type of span data stored in this registry.

fn span_data(&'a self, id: &Id) -> Option<Self::Data>

Returns the SpanData for a given Id, if it exists.

fn span(&'a self, id: &Id) -> Option<SpanRef<'_, Self>>

where Self: Sized,

Returns a SpanRef for the span with the given Id, if it exists.

fn register_filter(&mut self) -> FilterId

Available on crate feature registry only.

Registers a Filter for per-layer filtering with this Subscriber.

impl<N, E, F, W> Subscriber for Subscriber<N, E, F, W>

where N: for<'writer> FormatFields<'writer> + 'static, E: FormatEvent<Registry, N> + 'static, F: Layer<Formatter<N, E, W>> + 'static, W: for<'writer> MakeWriter<'writer> + 'static, Layered<F, Formatter<N, E, W>>: Subscriber, Layer<Registry, N, E, W>: Layer<Registry>,

fn register_callsite(&self, meta: &'static Metadata<'static>) -> Interest

Registers a new callsite with this subscriber, returning whether or not the subscriber is interested in being notified about the callsite.

fn enabled(&self, meta: &Metadata<'_>) -> bool

Returns true if a span or event with the specified metadata would be recorded.

fn new_span(&self, attrs: &Attributes<'_>) -> Id

Visit the construction of a new span, returning a new span ID for the span being constructed.

fn record(&self, span: &Id, values: &Record<'_>)

Record a set of values on a span.

fn record_follows_from(&self, span: &Id, follows: &Id)

Adds an indication that span follows from the span with the id follows.

fn event_enabled(&self, event: &Event<'_>) -> bool

Determine if an Event should be recorded.

fn event(&self, event: &Event<'_>)

Records that an Event has occurred.

fn enter(&self, id: &Id)

Records that a span has been entered.

fn exit(&self, id: &Id)

Records that a span has been exited.

fn current_span(&self) -> Current

Returns a type representing this subscriber’s view of the current span.

fn clone_span(&self, id: &Id) -> Id

Notifies the subscriber that a span ID has been cloned.

fn try_close(&self, id: Id) -> bool

Notifies the subscriber that a span ID has been dropped, and returns true if there are now 0 IDs that refer to that span.

fn max_level_hint(&self) -> Option<LevelFilter>

Returns the highest verbosity level that this Subscriber will enable, or None, if the subscriber does not implement level-based filtering or chooses not to implement this method.

unsafe fn downcast_raw(&self, id: TypeId) -> Option<*const ()>

If self is the same type as the provided TypeId, returns an untyped *const pointer to that type. Otherwise, returns None.

fn on_register_dispatch(&self, subscriber: &Dispatch)

Invoked when this subscriber becomes a Dispatch.

fn drop_span(&self, _id: Id)

👎Deprecated since 0.1.2: use Subscriber::try_close instead

This method is deprecated.

Layout

Note: Unable to compute type layout, possibly due to this type having generic parameters. Layout can only be computed for concrete, fully-instantiated types.