Struct BudgetTracker 

pub struct BudgetTracker { /* private fields */ }

Per-job cost.budget counters (ARCP v1.1 §9.6).

Tracks remaining authority for each declared currency. Reporting cost is the agent’s responsibility; the runtime decrements counters on each cost.* metric emitted via ToolContext::charge or BudgetTracker::charge. Once a counter falls below zero further charges return ARCPError::BudgetExhausted.

Implementations

impl BudgetTracker

pub fn new() -> Self

Construct an empty tracker (no budget declared).

pub fn from_budget(budget: &CostBudget) -> Self

Construct a tracker pre-seeded from a CostBudget lease capability.

pub fn is_disabled(&self) -> bool

True when no currencies are tracked (i.e. budgeting is disabled).

pub fn remaining(&self, currency: &str) -> Option<f64>

Remaining budget for currency, if tracked. None means the currency was not in the declared lease (i.e. unbudgeted, treated as unbounded for that currency).

pub fn snapshot_remaining(&self) -> HashMap<String, f64>

Snapshot of remaining-per-currency for all tracked currencies.

pub fn charge(&self, currency: &str, amount: f64) -> Result<f64, ARCPError>

Charge amount to currency. Returns Ok(remaining) after the decrement, or ARCPError::BudgetExhausted when the charge would push the counter below zero.

Negative amounts are rejected per §9.6.

Currencies not present in the declared lease are silently ignored (returns Ok(f64::INFINITY)), matching the §9.6 rule that “unreported / unbudgeted costs are not enforced”.

Examples

use arcp_core::messages::{CostBudget, CostBudgetAmount};
use arcp_runtime::runtime::context::BudgetTracker;

let tracker = BudgetTracker::from_budget(&CostBudget {
    amounts: vec![CostBudgetAmount { currency: "USD".into(), amount: 1.00 }],
});
assert!(tracker.charge("USD", 0.30).is_ok());
assert!(tracker.charge("USD", 5.00).is_err()); // overspend rejected
assert!((tracker.remaining("USD").unwrap() - 0.70).abs() < 1e-9);

Errors

• ARCPError::InvalidArgument for a negative or non-finite amount.
• ARCPError::BudgetExhausted when the charge would overspend the remaining budget. The charge is rejected and the counter is left unchanged so the agent sees the canonical signal on the first operation that would have overspent.

Trait Implementations

impl Clone for BudgetTracker

fn clone(&self) -> BudgetTracker

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BudgetTracker

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

Formats the value using the given formatter.

impl Default for BudgetTracker

fn default() -> BudgetTracker

Returns the “default value” for a type.