Method parse

nodedb/src/control/promql/ast.rs:75–108

Parse a PromQL duration string (e.g., "5m", "1h30m", "300s").

(s: &str)

    /// Parse a PromQL duration string (e.g., "5m", "1h30m", "300s").
    pub fn parse(s: &str) -> Option<Self> {
        let mut total_ms: i64 = 0;
        let mut num_buf = String::new();

        for ch in s.chars() {
            if ch.is_ascii_digit() || ch == '.' {
                num_buf.push(ch);
            } else {
                let n: f64 = num_buf.parse().ok()?;
                num_buf.clear();
                let multiplier: i64 = match ch {
                    'y' => 365 * 24 * 3600 * 1000,
                    'w' => 7 * 24 * 3600 * 1000,
                    'd' => 24 * 3600 * 1000,
                    'h' => 3600 * 1000,
                    'm' => 60 * 1000,
                    's' => 1000,
                    _ => return None,
                };
                total_ms += (n * multiplier as f64) as i64;
            }
        }
        // Bare number without suffix = seconds.
        if !num_buf.is_empty() {
            let n: f64 = num_buf.parse().ok()?;
            total_ms += (n * 1000.0) as i64;
        }

        if total_ms > 0 {
            Some(Self(total_ms))
        } else {
            None
        }
    }
}

/// Binary operators.