Method add_maintenance_cpu_secs

nodedb/src/control/metrics/database.rs:138–150

Add `secs` fractional CPU-seconds to the maintenance counter for `db_name`. Converts to integer microseconds (rounded) to avoid `AtomicF64` complexity. Negative or non-finite inputs are clamped to zero so accidental underflow in upstream timing arithmetic cannot subtract from the cumulative counter.

(&self, db_name: &str, secs: f64)

    /// Negative or non-finite inputs are clamped to zero so accidental underflow
    /// in upstream timing arithmetic cannot subtract from the cumulative counter.
    pub fn add_maintenance_cpu_secs(&self, db_name: &str, secs: f64) {
        let us = if secs.is_finite() && secs > 0.0 {
            (secs * 1_000_000.0).round() as u64
        } else {
            0
        };
        if us == 0 {
            return;
        }
        self.get_or_create(db_name)
            .maintenance_cpu_seconds_total
            .fetch_add(us, Ordering::Relaxed);
    }

    /// Render all registered databases as Prometheus text format 0.0.4.
    ///