Struct ChancePredicate 

pub struct ChancePredicate<P: EnabledPredicate> { /* private fields */ }

Predicate wrapper that probabilistically denies root spans before they get to the inner predicate. Root spans (the ones whose Attributes carry tracing::span::Attributes::is_root() — typically tracing::span!(parent: None, …)) are gated by a runtime-tunable percentage; descendants and events pass straight through to the inner predicate.

Because the chance is read with a Relaxed load of an AtomicU64 holding f64::to_bits of the percentage, updates from a ChanceHandle are picked up by the next root-span roll without needing a wake — the inner subscriber’s existing rebuild_interest_cache invalidation isn’t required either, since the dice are rerolled per span instance via EnabledPredicate::new_span_enabled, not at callsite-registration time.

Implementations

impl<P: EnabledPredicate> ChancePredicate<P>

pub fn new(inner: P, chance_pct: f64) -> Self

Construct with an initial chance percentage [0.0, 100.0]. Out-of-range inputs are silently clamped. Use 100.0 for “always pass to inner”.

pub fn handle(&self) -> ChanceHandle

Cheap-to-clone handle for changing the chance percentage at runtime — typically held by an admin RPC.

Trait Implementations

impl<P: EnabledPredicate> EnabledPredicate for ChancePredicate<P>

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

fn callsite_enabled(&self, metadata: &'static Metadata<'static>) -> Interest

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

fn new_span_enabled(&self, span: &Attributes<'_>) -> bool