use rho_providers::model::{ModelMetadata, ModelUsage};
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
pub(super) enum CostSource {
#[default]
ProviderReported,
Estimated,
}
impl CostSource {
fn combine(self, other: Self) -> Self {
if self == Self::Estimated || other == Self::Estimated {
Self::Estimated
} else {
Self::ProviderReported
}
}
}
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
pub(super) struct UsageCostTracker {
cumulative: CostSource,
before_run: CostSource,
failed_attempts: CostSource,
current_snapshot: CostSource,
}
impl UsageCostTracker {
pub(super) fn reset(&mut self) {
*self = Self::default();
}
pub(super) fn run_started(&mut self) {
self.before_run = self.cumulative;
self.failed_attempts = CostSource::ProviderReported;
self.current_snapshot = CostSource::ProviderReported;
}
pub(super) fn step_started(&mut self) {
self.current_snapshot = CostSource::ProviderReported;
}
pub(super) fn attempt_restarted(&mut self) {
self.failed_attempts = self.failed_attempts.combine(self.current_snapshot);
self.current_snapshot = CostSource::ProviderReported;
}
pub(super) fn record_usage(&mut self, usage: &ModelUsage) -> CostSource {
let latest = if usage.cost_usd_micros.is_some() {
CostSource::ProviderReported
} else {
CostSource::Estimated
};
self.current_snapshot = latest;
let current_run = self.failed_attempts.combine(self.current_snapshot);
self.cumulative = self.before_run.combine(current_run);
current_run
}
pub(super) fn cumulative_source(self) -> CostSource {
self.cumulative
}
}
pub(super) fn estimated_cost_usd_micros(
usage: &ModelUsage,
metadata: Option<&ModelMetadata>,
) -> Option<u64> {
let metadata = metadata?;
let input = usage.input_tokens.unwrap_or_default();
let cache_read = usage.cache_read_tokens.unwrap_or_default();
let total_input = usage.total_input_tokens().unwrap_or_default();
let cost = metadata.cost_for_input_tokens(total_input)?;
let mut micros = 0u128;
micros += cost_component(input, cost.input_micros_per_m);
micros += cost_component(
usage.output_tokens.unwrap_or_default(),
cost.output_micros_per_m,
);
micros += cost_component(cache_read, cost.cache_read_micros_per_m);
micros += cost_component(
usage.cache_write_tokens.unwrap_or_default(),
cost.cache_write_micros_per_m,
);
(micros > 0).then_some(micros.min(u64::MAX as u128) as u64)
}
pub(super) fn format_usd(micros: u64) -> String {
let dollars = micros as f64 / 1_000_000.0;
if dollars >= 100.0 {
format!("${dollars:.0}")
} else if dollars >= 10.0 {
format!("${dollars:.2}")
} else {
format!("${dollars:.3}")
}
}
fn cost_component(tokens: u64, micros_per_million: Option<u64>) -> u128 {
tokens as u128 * micros_per_million.unwrap_or_default() as u128 / 1_000_000
}
#[cfg(test)]
#[path = "usage_cost_tests.rs"]
mod tests;