Struct Interest

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

Available on crate features dep_tracing and alloc only.

Indicates a Subscriber’s interest in a particular callsite.

Subscribers return an Interest from their register_callsite methods in order to determine whether that span should be enabled or disabled.

Implementations

impl Interest

pub fn never() -> Interest

Returns an Interest indicating that the subscriber is never interested in being notified about a callsite.

If all active subscribers are never() interested in a callsite, it will be completely disabled unless a new subscriber becomes active.

pub fn sometimes() -> Interest

Returns an Interest indicating the subscriber is sometimes interested in being notified about a callsite.

If all active subscribers are sometimes or never interested in a callsite, the currently active subscriber will be asked to filter that callsite every time it creates a span. This will be the case until a new subscriber expresses that it is always interested in the callsite.

pub fn always() -> Interest

Returns an Interest indicating the subscriber is always interested in being notified about a callsite.

If any subscriber expresses that it is always() interested in a given callsite, then the callsite will always be enabled.

pub fn is_never(&self) -> bool

Returns true if the subscriber is never interested in being notified about this callsite.

pub fn is_sometimes(&self) -> bool

Returns true if the subscriber is sometimes interested in being notified about this callsite.

pub fn is_always(&self) -> bool

Returns true if the subscriber is always interested in being notified about this callsite.

Trait Implementations

impl Clone for Interest

fn clone(&self) -> Interest

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Interest

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

Formats the value using the given formatter.