Struct TraceSamplingSubscription 

pub struct TraceSamplingSubscription { /* private fields */ }

Watches the latest accepted remote trace sampling configuration.

Create with new and read current before processing a batch of traces. This is a latest-state watch, not a queue: successive concrete configurations can coalesce before you read them.

Once accepted, a concrete configuration remains available across withdrawal, cache expiry, polling-worker restart, and rejected updates. An initially accepted empty assignment publishes RemoteSampling::Unassigned, for which the consumer uses local settings. Later withdrawals never replace an accepted concrete configuration with that marker.

The default subscription is inert: it receives no updates and contacts no service. Clones share a registration; dropping the last clone unsubscribes.

Implementations

impl TraceSamplingSubscription

pub fn new(client: &RemoteConfigurationClient) -> Result<Self, Error>

Subscribes to APM_SAMPLING on client.

Errors

Returns an error if client already has a live subscription to APM_SAMPLING.

pub fn current(&self) -> Option<Arc<RemoteSampling>>

Returns the current accepted snapshot immediately.

Returns None until the first accepted snapshot, not merely the first poll: polling may fail or reject an update. An initially accepted empty assignment publishes RemoteSampling::Unassigned.

Each newly accepted concrete configuration gets a new Arc, even if its values are unchanged. Later withdrawals and rejected updates preserve the current Arc; use Arc::ptr_eq to compare snapshot identity.

Trait Implementations

impl Clone for TraceSamplingSubscription

fn clone(&self) -> TraceSamplingSubscription

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TraceSamplingSubscription

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

Formats the value using the given formatter.

impl Default for TraceSamplingSubscription

fn default() -> Self

Returns the “default value” for a type.