Struct TurnBudgetMeter 

pub struct TurnBudgetMeter { /* private fields */ }

One turn’s running budget meter. NOT thread-shared: owned by the stream loop; the only cross-task input is the UsageCounters cell.

Implementations

impl TurnBudgetMeter

pub fn new(budget: TurnBudget) -> Self

pub fn budget(&self) -> &TurnBudget

pub fn begin_round(&mut self) -> Result<(), BudgetDimension>

Charge one provider round. Checked BEFORE the provider call: wall-clock first (a stale turn must not spend another request), then the exact round cap.

pub fn try_renew_rounds(&mut self) -> Option<u32>

Attempt a bounded graceful extension after the provider-round cap is hit. Resets the round counter and returns the number of renewals still remaining, or None when the renewal budget is exhausted. Wall-clock is deliberately untouched — Self::begin_round re-checks it, so a stale turn cannot extend past max_elapsed. Only meaningful right after begin_round returned BudgetDimension::ProviderRounds.

pub fn round_renewals_used(&self) -> u32

Number of graceful round renewals already consumed this turn.

pub fn elapsed(&self) -> Duration

Wall-clock consumed by this turn so far. Diagnostics only — the enforcement path uses Self::wall_clock_exceeded.

pub fn exhaustion_error(&self, dimension: BudgetDimension) -> TurnError

Metadata-only diagnostic; preserve the typed outcome for every frontend and autonomous driver. Exhaustion is a local stop, not provider fallback.

pub fn rounds_used(&self) -> u32

Provider rounds charged since the last renewal (reset by Self::try_renew_rounds). Diagnostics only.

pub fn tool_calls_used(&self) -> u32

Tool calls charged this turn. Diagnostics only.

pub fn tool_result_bytes_used(&self) -> usize

Accumulated tool-result bytes charged this turn. Diagnostics only.

pub fn remaining_tool_calls(&self) -> u32

Remaining tool-call allowance (for exact-cap batch splitting).

pub fn charge_tool_calls(&mut self, n: u32)

Charge n executed tool calls (the caller split the batch against Self::remaining_tool_calls, so this never over-charges).

pub fn charge_tool_result_bytes( &mut self, bytes: usize, ) -> Result<(), BudgetDimension>

Charge the bytes of one round’s tool results; exceeding the accumulated cap exhausts the ToolResultBytes dimension.

pub fn check_usage( &self, usage: &UsageCounters, model: &str, ) -> Result<(), BudgetDimension>

Optional dimensions, consulted after each provider round from the shared usage counters. model feeds the pricing table for the cost estimate; both checks are no-ops when unconfigured.

Trait Implementations

impl Debug for TurnBudgetMeter

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

Formats the value using the given formatter.