Struct SpecTelemetry 

pub struct SpecTelemetry {
    pub rounds: u64,
    pub drafted: u64,
    pub accepted: u64,
    pub pos_drafted: [u64; 8],
    pub pos_accepted: [u64; 8],
}

Always-on per-draft-position acceptance telemetry (lane/accept-telemetry, 2026-08-05 — the llama.cpp #26389 / vLLM spec-decode counter schema, upstream-sweeps 2026-08-05). Lives on the SpecSession and accumulates across bursts; the serve worker diffs a stashed copy per burst for its per-model /metrics aggregation and per-request usage. Same normalization as the [spec-stats] line: p-min-discarded chain tokens are counted in NEITHER drafted nor accepted.

Fields

rounds: u64

verify rounds completed (a round-stream burst counts each of its M rounds).

drafted: u64

tokens drafted / accepted across all rounds.

accepted: u64

pos_drafted: [u64; 8]

how often draft position j (0-based within a round’s chain) was offered / accepted. Positions >= SPEC_TELEM_POS are untracked (totals still count them). The opt-in round-stream arm (MEMRA_SPEC_STREAM=1) reads back only totals, so under it these arrays cover the standard-path rounds only and their sums may undercount the totals.

pos_accepted: [u64; 8]

Implementations

impl SpecTelemetry

pub fn delta_since(&self, prev: &SpecTelemetry) -> SpecTelemetry

Fieldwise self - prev — the worker’s per-burst delta off a copy stashed before the burst call. Saturating: a caller diffing against the wrong snapshot gets zeros, not a wrapped counter.

pub fn merge(&mut self, d: &SpecTelemetry)

Fieldwise self += d — the worker’s per-model aggregation.

pub fn tau(&self) -> f64

Mean accepted draft-prefix length per verify round (tau).

Trait Implementations

impl Clone for SpecTelemetry

fn clone(&self) -> SpecTelemetry

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for SpecTelemetry

impl Debug for SpecTelemetry

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

Formats the value using the given formatter.

impl Default for SpecTelemetry

fn default() -> SpecTelemetry

Returns the “default value” for a type.