Struct NoSubscriber

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

A no-op Subscriber.

NoSubscriber implements the Subscriber trait by never being enabled, never being interested in any callsite, and dropping all spans and events.

Implementations

impl NoSubscriber

pub const fn new() -> Self

Returns a new NoSubscriber.

Trait Implementations

impl Clone for NoSubscriber

fn clone(&self) -> NoSubscriber

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for NoSubscriber

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

Formats the value using the given formatter.

impl Default for NoSubscriber

fn default() -> NoSubscriber

Returns the “default value” for a type.

impl Subscriber for NoSubscriber

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

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

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

Records that an Event has occurred.

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

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

fn enter(&self, _span: &Id)

Records that a span has been entered.

fn exit(&self, _span: &Id)

Records that a span has been exited.

fn on_register_dispatch(&self, subscriber: &Dispatch)

Invoked when this subscriber becomes a Dispatch.

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.

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

Determine if an Event should be recorded.

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

Notifies the subscriber that a span ID has been cloned.

fn drop_span(&self, _id: Id)

👎Deprecated since 0.1.2: use Subscriber::try_close instead

This method is deprecated.

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 current_span(&self) -> Current

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

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.

impl Copy for NoSubscriber

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 0 bytes