Struct SamplingState 

pub struct SamplingState { /* private fields */ }

Runtime sampling state. Tracks counters and drives both the VU-threshold gate and Vitter’s Algorithm R reservoir gate.

Implementations

impl SamplingState

pub fn new(params: SamplingParams) -> Self

pub fn set_active_vus(&mut self, vus: usize)

Call on each coordinator tick when the active VU count may have changed.

When vus > vu_threshold (and vu_threshold != 0), caps the collection rate to threshold / vus. Otherwise rate is 1.0 (collect everything).

pub fn record_request(&mut self, success: bool)

Always call for every completed request. Updates the unsampled counters regardless of whether this result will be stored in the reservoir.

pub fn should_collect(&mut self) -> bool

VU-threshold gate: returns true if this result should proceed toward the reservoir. At sample_rate >= 1.0 always returns true.

pub fn reservoir_slot(&mut self, results_len: usize) -> ReservoirAction

Reservoir gate (Vitter’s Algorithm R). Call only when should_collect() returned true.

Increments the internal seen-counter and returns the storage instruction:

• Push — buffer not yet full; append.
• Replace(j) — buffer full; replace slot j (uniform random).
• Discard — buffer full; this result lost the lottery.

pub fn total_requests(&self) -> usize

pub fn total_failures(&self) -> usize

pub fn sample_rate(&self) -> f64

pub fn min_sample_rate(&self) -> f64