pub trait ReadStat: Send + Sync + Debug {
fn qps(&self, _event: MetricEvent) -> f64 { ... }
fn qps_previous(&self, _event: MetricEvent) -> f64 { ... }
fn sum(&self, _event: MetricEvent) -> u64 { ... }
fn min_rt(&self) -> f64 { ... }
fn avg_rt(&self) -> f64 { ... }
}